@article { ISI:000228203100026, title = {Hydroformylation of 1-hexene using Rh/TPPTS complex exchanged on anion exchange resin: kinetic studies}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {232}, number = {1-2}, year = {2005}, month = {MAY}, pages = {179-186}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The exchange of the Rh/Triphenylphosphine trisulfonate sodium [TPPTS] complex on to an anion exchange resin results in a stable heterogenized catalyst for the hydroformylation of alkenes. The kinetics of hydroformylation of 1-hexene using Rh/TPPTS complex exchanged on anion exchange resin to Amberlite IRA-93 has been investigated for the first time. The rate of the reaction was found to be dependent on the partial pressure of hydrogen and 1-hexene concentrations with a first order. A maximum in the rate with increasing partial pressure of carbon monoxide was observed. A rate model has been proposed which predicts the observed rate data within reasonable error. The activation energy was found to be 84.37 kJ/mol. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {heterogenized catalyst, Hydroformylation, ion-exchange resin, kinetics, Rhodium}, issn = {1381-1169}, doi = {10.1016/j.molcata.2005.01.033}, author = {Diwakar, Makarand M. and Deshpande, R. M. and Chaudhari, Raghunath V.} } @article { ISI:000240521800008, title = {Adsorption of methanol on Si(100)/SiO(2)and mesoporous SBA-15}, journal = {Colloids and Surfaces A-Physicochemical and Engineering Aspects}, volume = {287}, number = {1-3}, year = {2006}, month = {SEP}, pages = {51-58}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Adsorption of methanol on SiO(100)/SiO2 substrate and mesoporous SBA-15 has been studied by using Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). Contact angle technique is employed to study the adsorption kinetics of methanol on SiO(100)/SiO2 and thermal stability of adlayer. Thermogravimetric (TGA) technique is used to understand the thermal behavior of methanol layer on SBA-15. Adsorption kinetics fit fairly well with Langmuir isotherms giving adsorption rate constant, k(a) = 0.0021 W s(-1). FTIR results show formation of methoxy silicon (SiOCHA silicon polyhydride (SiH2), carboxylate, molecular water and hydroxyl groups on Si(100)/SiO2 surface and only methoxy silicon on SBA-15. XPS results confirm methanol adsorption and support FTIR results. The methanol adlayers are found to be thermally stable up to a temperature of similar to 262 degrees C on both Si(100)/SiO2 and SBA-15 and decompose between 262 and 450 degrees C. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Adsorption, desorption, kinetics, Methanol, SBA-15, Si(100)/SiO2, thermal stability}, issn = {0927-7757}, doi = {10.1016/j.colsurfa.2006.03.021}, author = {Mirji, S. A. and Halligudi, Shivaraj B. and Mathew, Nevin T. and Ravi, V. and Jacob, Nalini E. and Patil, K. R.} } @article { ISI:000245763600001, title = {Anionic vinyl polymerization - 50 years after Michael Szwarc}, journal = {Progress in Polymer Science}, volume = {32}, number = {2}, year = {2007}, month = {FEB}, pages = {173-219}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

We present a review on the present status of anionic polymerization of important non-polar and polar vinyl monomers. After presenting the historical background-the {\textquoteleft}{\textquoteleft}pre-Szwarc{\textquoteright}{\textquoteright} era-we discuss the mechanisms of this polymerization, in particular several types of carbanions, their ion-pairs and their aggregates occurring in the initiation and propagation of non-polar and polar monomers, including recent developments. Finally, we discuss some important scientific and industrial applications of anionic polymerization. (c) 2007 Elsevier Ltd. All rights reserved.

}, keywords = {Anionic polymerization, carbanions, history, ion-pairs, kinetics, mechanisms}, issn = {0079-6700}, doi = {10.1016/j.progpolymsci.2007.01.003}, author = {Baskaran, Durairaj and Mueller, Axel H. E.} } @article { ISI:000250234900007, title = {Fabrication of an effusive molecular beam instrument for surface reaction kinetics - CO oxidation and NO reduction on Pd(111) surfaces}, journal = {Catalysis Letters}, volume = {119}, number = {1-2}, year = {2007}, month = {NOV}, pages = {50-58}, publisher = {SPRINGER}, type = {Article}, address = {233 SPRING STREET, NEW YORK, NY 10013 USA}, abstract = {

A simple molecular beam instrument (MBI) was fabricated for measuring the fundamental parameters in catalysis such as, sticking coefficient, transient and steady state kinetics and reaction mechanism of gas/vapor phase reactions on metal surfaces. Important aspects of MBI fabrication are given in detail. Nitric oxide (NO) decomposition and NO reduction with carbon monoxide (CO) on Pd(111) surfaces were studied. Interesting results were observed for the above reactions and they support the efficiency of the MBI to derive the fundamental parameters of adsorption and catalysis. Sustenance of CO oxidation at 400 K is dependent mostly on the absence of CO-poisoning; apparently, CO + O recombination is the rate determining step \<= 400 K. NO adsorption measurements on Pd(111) surface clearly indicating a typical precursor kinetics. Displacement of the chemisorbed CO by NO on Pd(111) surfaces was observed directly with NO + CO beams in the transient kinetics. It is also relatively easy to identify the rate-determining step directly from the MBI data and the same was demonstrated for the above reactions.

}, keywords = {carbon monoxide, catalysis, kinetics, molecular beam, nitric oxide, Pd(111)}, issn = {1011-372X}, doi = {10.1007/s10562-007-9184-8}, author = {Thirunavukkarasu, Kandasamy and Gopinath, Chinnakonda S.} } @article { ISI:000250122000026, title = {Gas sorption and transport in polyarylates: effect of substituent symmetry and polarity}, journal = {Journal of Membrane Science}, volume = {303}, number = {1-2}, year = {2007}, month = {OCT}, pages = {244-251}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The gas sorption properties of polyarylates based on bisphenol-A possessing symmetric/asymmetric substitution by nonpolar -CH3 group and symmetrically linked terephthalic acid were examined. The effects of substitution of polar bromine on terephalic acid moiety of polyarylate based on asymmetrically substituted bisphenol were also studied for physical, sorption and transport properties. The estimation of dual mode sorption parameters, solubility and diffusion coefficient revealed that nature of the substituent and substitution type plays a crucial role in depicting permeation properties. An asymmetric substitution by -CH3 group increased solubility coefficient of pure gases (N-2, O-2, CH4 and CO2) up to 27\% and symmetric substitution increased the same up to 106\%. This was coupled with 7-35\% increase in solubility selectivity in both cases of substitution, which ascertained the usefulness of methyl group substitution in polyarylates based on terephalic acid. The pressure dependency of solubility coefficients and solubility selectivity was also investigated for these polyarylates. The sorption and transport properties of these polyarylates correlated well with physical properties of polyarylates and gases studied. The sorption/desorption kinetics of symmetrically substituted TMBisA-T was performed in order to deduce time dependent sorption behavior and to evaluate diffusivity coefficient. The apparent diffusion coefficients from sorption kinetics, desorption kinetics and from steady-states permeation-sorption were compared. The diffusion coefficients of CH4 and N-2 deduced by these methods correlated well with each other. (C) 2007 Elsevier B.V. All rights reserved.

}, keywords = {Diffusion, kinetics, permeation, polyarylates, Sorption}, issn = {0376-7388}, doi = {10.1016/j.memsci.2007.07.018}, author = {Karadkar, Prasad B. and Kharul, Ulhas K. and Bhole, Yogesh S. and Badhe, Yogesh P. and Tambe, Sanjeev S. and Kulkarni, Bhaskar D.} } @article { ISI:000251763600036, title = {Modeling of bubble column slurry reactor for reductive alkylation of p-phenylenediamine}, journal = {Chemical Engineering Science}, volume = {62}, number = {24, SI}, year = {2007}, note = {8th International Conference on Gas-Liquid and Gas-Liquid-Solid Reactor Engineering, Indian Inst Technol Delhi, New Delhi, INDIA, DEC 16-19, 2007}, month = {DEC}, pages = {7290-7304}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A bubble column slurry reactor (BCSR) model has been developed for the reductive alkylation of p-phenylenediamine (PPDA) with methyl ethyl ketone (MEK) to N, N{\textquoteright}-di-secondary-alkyl-p-phenylenediamine (Di-amine). This particular reaction system is commercially relevant and involves a combination of parallel and consecutive reactions comprising equilibrium non-catalytic (homogeneous) and catalytic (heterogeneous) steps. The proposed model is based on the {\textquoteleft}mixing cell approach{\textquoteright}. In this work the mixing cell approach has been extended by including a liquid backflow stream from all but the bottommost mixing cell. The model incorporates the contributions of gas-liquid and liquid-solid mass transfer, heat effects, and complex multistep reaction kinetics. CFD model is used to estimate the extent of backflow among mixing cells and its dependence on operating parameters. The effect of gas and liquid velocities, catalyst loading, inlet PPDA concentration, and temperature on the conversion, selectivity, global rate of hydrogenation, and temperature rise is discussed. The comparison of the current approach with the traditional mixing cell model is discussed. The BCSR model presented here will be useful to provide guidelines for designing and improving overall performance of bubble column reactors. (C) 2007 Elsevier Ltd. All rights reserved.

}, keywords = {bubble columns, CFD, kinetics, Mathematical modeling, Reductive alkylation}, issn = {0009-2509}, doi = {10.1016/j.ces.2007.08.065}, author = {Chaudhari, Amit S. and Rampure, Mohan R. and Ranade, Vivek V. and Jaganathan, Rengaswamy and Chaudhari, Raghunath V.} } @article { ISI:000246869200003, title = {New technique to study kinetics of chain conformation in polyaniline films}, journal = {Polymer Journal}, volume = {39}, number = {4}, year = {2007}, month = {FEB}, pages = {296-297}, publisher = {SOC POLYMER SCIENCE JAPAN}, type = {Article}, address = {TSUKIJI DAISAN NAGAOKA BLDG, 2-4-2 TSUKIJI, CHUO-KU, TOKYO, 104, JAPAN}, keywords = {Conformation, kinetics, laser, polyaniline, reflection}, issn = {0032-3896}, doi = {10.1295/polymj.PJ2006188}, author = {Harima, Yutaka and Kishimoto, Kazuya and Ogawa, Fumiyuki and Jiang, Xiaoqing and Patil, Rahul} } @article {51}, title = {Organotin-oxometalate coordination polymer catalyzed oxyfunctionalization of monoterpenes}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {270}, number = {1-2}, year = {2007}, month = {JUN}, pages = {177-184}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, keywords = {Heck reaction, kinetics, Palladacycle}, issn = {1381-1169}, doi = {10.1016/j.molcata.2007.01.035}, author = {Bordoloi, Ankur and Lefebvre, F. and Halligudi, Shivaraj B.} } @article { ISI:000256178900021, title = {Heteropolyacid supported on acidic clay: a novel efficient catalyst for alkylation of ethylbenzene with dilute ethanol to diethylbenzene in presence of C-8 aromatics}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {285}, number = {1-2}, year = {2008}, month = {APR}, pages = {155-161}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Vapor phase alkylation of ethylbenzene with ethanol to diethylbenzene is industrially relevant. Diethylbenzene is an important raw material for the conversion of divinyl benzene monomer. Conventionally, it is prepared from diacetophenone by reduction. It is also prepared by vapor phase alkylation of ethylbenzene with ethylene using zeolitic catalysts. The efficacy of dodecatungsotphosphoric acid (DTPA) supported on acid treated clay has been evaluated in the current work in the alkylation of ethylbenzene with 80\% (w/w) ethanol. 15\% (w/w) DTPA/K-10 clay was found to be an efficient and robust catalyst. The use of aqueous ethanol and a mixed C-8 stream lowers the cost of production. A kinetic model is developed by studying the important process parameters with 15\% (w/w) DTPA/K-10 as the catalyst. (c) 2008 Elsevier B.V. All rights reserved.

}, keywords = {Alkylation, diethylbenzene, Heteropolyacid, kinetics, Solid acids}, issn = {1381-1169}, doi = {10.1016/j.molcata.2007.11.018}, author = {Bokade, Vijay V. and Yadav, Ganapati D.} } @article { ISI:000255455300004, title = {Reaction kinetics of liquid phase air oxidation of p-cresol to p-hydroxybenzaldehyde}, journal = {Applied Catalysis A-General}, volume = {339}, number = {1}, year = {2008}, month = {APR}, pages = {28-35}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The kinetics of liquid phase oxidation of p-cresol to p-hydroxybenzaldehyde has been investigated using insoluble cobalt oxide (CO3O4) catalyst at oxygen partial pressures in the range 0.1-1.5 MPa, reaction temperatures 333-393 K, p-cresol concentrations 0.49-1.53 kmol/m(3) and catalyst loadings 0.38-3.03 kg/m(3). The effects of oxygen partial pressure, reaction temperature, p-cresol concentration and catalyst loading on the initial rate of reaction have been studied. The initial rate varied linearly with catalyst loading up to 1.5 kg/m(3) beyond which it was independent of the catalyst loading while first-order dependence was observed with variation in oxygen partial pressure. A rate expression has been proposed considering Langmuir-Hinshelwood (LH) type mechanism, based on the initial rate data. A batch reactor model was also developed based on the kinetics studied and the concentration time profile predicted by the model was in good agreement with the experimental data. The activation energy for the liquid phase oxidation of p-cresol was found to be 39.6 kJ/mol. (c) 2008 Elsevier B.V. All rights reserved.

}, keywords = {Co3O4, kinetics, p-cresol oxidation, XPS, XRD}, issn = {0926-860X}, doi = {10.1016/j.apcata.2008.01.006}, author = {Kshirsagar, V. S. and Nadgeri, J. M. and Tayade, P. R. and Rode, C. V.} } @article { ISI:000262769700020, title = {Class II alpha-mannosidase from aspergillus fischeri: energetics of catalysis and inhibition}, journal = {International Journal of Biological Macromolecules}, volume = {44}, number = {1}, year = {2009}, month = {JAN}, pages = {112-115}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Energetics of the catalysis of Class II alpha-mannosidase (E.C.3.2.1.24) from Aspergillus fischeri was studied. The enzyme showed K(cat)/K(m) for Man (alpha 1-3) Man, Man (alpha 1-2) Man and Man (alpha 1-6) Man as 7488, 5376 and 3690 M(-1) min(-1), respectively. The activation energy, Ea was 15.14, 47.43 and 71.21 kJ/mol for a1-3, alpha 1-2 and alpha 1-6 linked mannobioses, respectively, reflecting the energy barrier in the hydrolysis of latter two substrates. The enzyme showed K(cat)/K(m) as 3.56 x 10(5) and 4.61 x 10(5) M(-1) min(-1) and E(a) as 38.7 and 8.92 kJ/mol, towards pNP alpha Man and 4-MeUmb alpha Man, respectively. Binding of Swainsonine to the enzyme is stronger than that of 1-deoxymannojirimycin. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {alpha-Mannosidase, Energy of activation, kinetics, Swainsonine}, issn = {0141-8130}, doi = {10.1016/j.ijbiomac.2008.10.012}, author = {Shashidhara, K. S. and Gaikwad, Sushama M.} } @article { ISI:000267267000126, title = {Defluoridation of water using as-synthesized Zn/Al/Cl anionic clay adsorbent: equilibrium and regeneration studies}, journal = {Journal of Hazardous Materials}, volume = {167}, number = {1-3}, year = {2009}, month = {AUG}, pages = {873-878}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Zn/Al/Cl anionic clay has been synthesized by co-precipitation method and applied for adsorption of fluoride in aqueous medium. Equilibrium adsorption data were fitted to Langmuir, Freundlich, Temkin, and Generalized isotherm equations. Thermodynamic parameters like Delta G and Delta H values show the feasibility and exothermic nature of the adsorption process. Influence of solution pH and presence of other anions on fluoride adsorption by the clay has also been studied. Presence of carbonate in water was found to have an adverse effect on fluoride adsorption by the clay. pH(pzc) of the clay has been found to be 8.97. A two-step 1st order kinetic model was used to explain the fluoride adsorption kinetics of the as-synthesized clay. It was possible to regenerate the adsorbent with an aqueous solution of 0.01 M NaOH and the effect of regeneration on fluoride adsorption was reported up to five regeneration cycles. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Adsorption, Anionic clay, Fluoride, Isotherm, kinetics, Regeneration}, issn = {0304-3894}, doi = {10.1016/j.jhazmat.2009.01.069}, author = {Mandal, Sujata and Mayadevi, S.} } @article { ISI:000262582400008, title = {Kinetic evidence for the influence of subsurface oxygen on palladium surfaces towards CO oxidation at high temperatures}, journal = {Chemistry-an Asian Journal}, volume = {4}, number = {1}, year = {2009}, month = {OCT}, pages = {74-80}, publisher = {WILEY-V C H VERLAG GMBH}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

Transient state kinetics of the catalytic oxidation of CO with 0, on Pd-surfaces has been measured under isothermal conditions by using a molecular beam approach. Systematic studies were carried out as a function of reaction temperature and CO+O(2) composition. With sufficient kinetic evidence, we have demonstrated the positive influence of subsurface oxygen towards CO-adsorption and oxidation to CO, at high temperatures (600-900 K) on Pd-surfaces, and the likely electronic nature of the surface changes with oxygen in the subsurface. These studies also provide a direct proof for CO-adsorption with a significantly reactive sticking coefficient at high temperatures on Pd-surfaces exhibiting a significant subsurface O-coverage.

}, keywords = {Adsorption, kinetics, Oxidation, Palladium, surface analysis}, issn = {1861-4728}, doi = {10.1002/asia.200800278}, author = {Gopinath, Chinnakonda S. and Thirunavukkarasu, Kandasamy and Nagarajan, Sankaranarayanan} } @article { ISI:000268905100015, title = {Kinetics of arylation of 3-bromo-benzophenone with n-butylacrylate using NC palladacycle catalyst}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {309}, number = {1-2}, year = {2009}, month = {AUG}, pages = {111-116}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The kinetics of arylation of n-butylacrylate (n-BA) with 3-bromo-benzophenone (BBP) using a monomeric palladacycle complex [Pd(ppy)(PPh(3))(OTs)](ppy=2-phenylpyridine) catalyst has been studied. The effect of concentration of the substrate, base (NaOAc), and catalyst was studied at three different temperatures (413-433 K). The rate was found to be first order with respect to catalyst, first order tending to zero order with respect to n-butylacrylate and NaOAc concentrations. The rate passed through a maximum with variation of BBP concentration. The observed results have been explained on the basis of formation of Pd species (PdX(2), PdX(3)(-), PdX(4)(2-), and Pd(2)X(6)(2-)) which are inactive for the Heck reaction. Various empirical rate equations were considered to fit the rate data and the best fitting model has been selected. The rates predicted by model were found to be in good agreement with the observed experimental data. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Arylation, Heck reaction, kinetics, Palladacycle}, issn = {1381-1169}, doi = {10.1016/j.molcata.2009.05.003}, author = {Atla, Shashi B. and Rajurkar, Kalpendra B. and Kelkar, Ashutosh A. and Chaudhari, Raghunath V.} } @article { ISI:000276206700037, title = {Kinetics of reductive alkylations of phenylenediamines: influence of substrates isomeric structure}, journal = {Chemical Engineering Science}, volume = {65}, number = {1, SI}, year = {2010}, note = {20th International Symposium on Chemical Reaction Engineering, Kyoto, JAPAN, SEP, 2008}, month = {JAN}, pages = {232-239}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Reductive alkylation of ortho-, meta- and para-phenylenediamines (PDAs) with methyl ethyl ketone (MEK) has been studied in a semi-batch slurry reactor in the presence of a commercial 3\% Pt/Al(2)O(3) catalyst. It was observed that the PDA isomers differ remarkably from each other in their activity in reductive alkylation and product distribution. The activity was found to decrease in the following order: PPDA \> OPDA \> MPDA. To understand the substrate structure-activity correlation, the homogeneous equilibrium reactions involved in the alkylation step and the overall catalytic reactions were studied separately. Kinetics of reductive alkylation of PDAs with MEK as a solvent and alkylating agent with 3\% Pt/Al(2)O(3) catalyst was studied in a semi-batch slurry reactor over a temperature range of 373-453K and pressure range of 2.07-6.21 MPa. Semi-batch slurry reactor models were developed and kinetic parameters were estimated by fitting the integral batch reactor data at different temperatures to understand the influence of different reaction steps on the activity and selectivity of different products. Published by Elsevier Ltd.

}, keywords = {Batch, catalysis, kinetics, Multiphase reactions, Phenylenediamines, Reaction engineering, Reductive alkylation}, issn = {0009-2509}, doi = {10.1016/j.ces.2009.06.065}, author = {Roy, Debdut and Chaudhari, Amit S. and Chaudhari, Raghunath V.} } @article { ISI:000288434800016, title = {Kinetics studies and mechanism evolution of the epoxidation of styrene over nanoporous Au doped TS-1}, journal = {Polish Journal of Chemical Technology}, volume = {12}, number = {4}, year = {2010}, month = {JAN}, pages = {72-78}, publisher = {VERSITA}, address = {SOLIPSKA 14A-1, 02-482 WARSAW, POLAND}, abstract = {

{A kinetic investigation of the slurry phase epoxidation of styrene with hydrogen peroxide has been carried out, for the first time, over nanoporous Au doped TS-1 catalyst, in a batch reactor, in the temperature range of 313-333 K. It was found that product selectivity and the rate of reaction are greatly influenced by concentrations of styrene and hydrogen peroxide. Kinetics studies reveal that the mechanism of the reaction is of the {\textquoteleft}{\textquoteleft}Redox{\textquoteright}{\textquoteright} type. The rate equation

}, keywords = {Au/TS-1, epoxidation, kinetics, styrene, Styrene oxide}, issn = {1509-8117}, doi = {10.2478/v10026-010-0054-6}, author = {Saxena, Samidha and Dwivedi, Reena and Bhadauria, Sheenu and Chumbhale, Vilas R. and Prasad, Rajendra} } @article { ISI:000274292700015, title = {Polymer-supported palladium-imidazole complex catalyst for hydrogenation of substituted benzylideneanilines}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {317}, number = {1-2}, year = {2010}, month = {FEB}, pages = {111-117}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The polymer-supported palladium-imidazole complex catalyst was synthesized and characterized by various techniques Such as elemental analysis, IR spectroscopy and TG analysis. The physico-chemical properties such as bulk density, Surface studies by BET method and swelling studies of catalyst in different solvents were investigated. XPS Studies were carried out to identify the oxidation state of palladium in the catalyst. The morphology of the support and the catalyst was studied using scanning electron microscope. Using the synthesized catalyst, hydrogenation of benzylideneaniline and a few of its para Substituted derivatives was carried out at ambient conditions. The influence of variation in temperature, concentration of the catalyst as well as the substrate on the rate of reaction Was Studied. The catalyst showed an excellent recycling efficiency over six cycles without leaching of metal from the polymer support. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Benzylideneaniline, Hydrogenation, kinetics, Polymer-supported palladium-imidazole complex catalyst}, issn = {1381-1169}, doi = {10.1016/j.molcata.2009.10.030}, author = {Udayakumar, V. and Alexander, S. and Gayathri, V. and Shivakumaraiah and Patil, K. R. and Viswanathan, B.} } @article { ISI:000274490400085, title = {Reductive dechlorination of gamma-hexachlorocyclohexane using Fe-Pd bimetallic nanoparticles}, journal = {Journal of Hazardous Materials}, volume = {175}, number = {1-3}, year = {2010}, month = {MAR}, pages = {680-687}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Nanoscale Fe-Pd bimetallic particles were synthesized and used for degradation of lindane (gamma-hexachlorocyclohexane) in aqueous solution. Batch studies showed that 5 mg/Lof lindane was completely dechlorinated within 5 min at a catalyst loading of 0.5 g/L and the degradation process followed first-order kinetics. GC-MS analysis in corroboration with GC-ECD results showed the presence of cyclohexane as the final degradation product. The proposed mechanism for the reductive dechlorination of lindane involves Fe corrosion-induced hydrogen atom transfer from the Pd Surface. The enhanced degradation efficiency of Fe-Pd nanoparticles is attributed to: (1) high specific surface area of the nanoscale metal particles (60 m(2)/g), manyfold greater that of commercial grade micro- or milli-scale iron particles (similar to 1.6 m(2)/g); and, (2) increased catalytic reactivity due to the presence of I{\textquoteright}d on the Surface. Recycling and column studies showed that these nanoparticles exhibit efficient and sustained catalytic activity. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Bimetallic, Cyclohexane, Degradation, kinetics, Lindane, Nanoparticles}, issn = {0304-3894}, doi = {10.1016/j.jhazmat.2009.10.063}, author = {Nagpal, Varima and Bokare, Alok D. and Chikate, Rajeev C. and Rode, Chandrashekhar V. and Paknikar, Kishore M.} } @article { ISI:000292011000004, title = {Eutectic mixture-directed kinetics of Diels-Alder reaction}, journal = {Indian Journal of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical \& Analytical Chemistry}, volume = {50}, number = {6}, year = {2011}, month = {JUN}, pages = {788-792}, publisher = {NATL INST SCIENCE COMMUNICATION-NISCAIR}, address = {DR K S KRISHNAN MARG, PUSA CAMPUS, NEW DELHI 110 012, INDIA}, abstract = {

In the search for environmentally benign solvent media, a new class of solvents composed of mixtures of carbohydrates with urea or methylated urea has been noted to be effective in enhancing the reaction rates of a bimolecular organic reaction like the Diels-Alder reaction of cyclopentadiene with methyl acrylate. The viscosity of these media appears to be an important parameter in controlling the second order kinetics.

}, keywords = {carbohydrates, Cycloaddition, Diels-Alder reaction, Dimethylurea, kinetics, Reaction rates, solvent effects, Urea, viscosity}, issn = {0376-4710}, author = {Nagare, Amit S. and Kumar, Anil} } @article { ISI:000288015800010, title = {Kinetics of hydroformylation of 1-octene in ionic liquid-organic biphasic media using rhodium sulfoxantphos catalyst}, journal = {Chemical Engineering Science}, volume = {66}, number = {8}, year = {2011}, month = {APR}, pages = {1631-1639}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Biphasic hydroformylation of 1-octene was performed using rhodium sulfoxantphos catalyst dissolved in [BuPy][BF(4)] ionic liquid. Preliminary experiments proved this system to retain the catalytic complex within the ionic liquid phase and to maintain a high selectivity towards the linear aldehyde (n:iso ratio of 30) over several cycles. Process parameter investigation showed a first order dependence of the initial rate with respect to the catalyst and 1-octene concentrations, but a more complex behavior with respect to hydrogen (fractional order) and carbon monoxide partial pressures (inhibition at high pressures). Different mathematical models were selected based on the trends observed and evaluated for data fitting. Also, rate models were derived from a proposed mechanism, using Christiansen matrix approach. To calculate concentrations of substrates in the catalytic phase as required by this kinetic modeling, solubility measurements were preformed for the gases (pressure drop technique), as well as for 1-octene and n-nonanal (thermogravimetry analysis). (C) 2011 Elsevier Ltd. All rights reserved.

}, keywords = {Biphasic catalysis, Butylpyridinium tetrafluoroborate, kinetics, Parameter identification, Reaction engineering, solubility}, issn = {0009-2509}, doi = {10.1016/j.ces.2010.12.040}, author = {Deshpande, R. M. and Kelkar, Ashutosh A. and Sharma, A. and Julcour-Lebigue, C. and Delmas, Henri} } @article { ISI:000309786400075, title = {Discovering bisdemethoxycurcumin from curcuma longa rhizome as a potent small molecule inhibitor of human pancreatic alpha-amylase, a target for type-2 diabetes}, journal = {Food Chemistry}, volume = {135}, number = {4}, year = {2012}, month = {DEC}, pages = {2638-2642}, publisher = {ELSEVIER SCI LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

Curcuma longa rhizome is used extensively in culinary preparations in Far East and South-East Asia. Health benefits of curcuminoids from C. longa as antioxidants, anti-cancer and anti-inflammatory molecules have been well documented. We report here for the first time that Bisdemethoxycurcumin (BDMC) from C. longa, acts as an inhibitor to inactivate human pancreatic alpha-amylase, a therapeutic target for oral hypoglycemic agents in type-2 diabetes. Bioactivity guided isolation of rhizome isopropanol extract led to the identification by HPLC and NMR of BDMC as a lead small molecule inhibitor of porcine and human pancreatic alpha-amylase with an IC50 value of 0.026 and 0.025 mM, respectively. Kinetic analysis revealed that using starch as the substrate, HPA exhibited an uncompetitive mode of inhibition with an apparent K-i of 3.0 mu M. The study gains importance as BDMC could be a good drug candidate in development of new inhibitors of HPA and of functional foods for controlling starch digestion in order to reduce post-prandial hyperglycemia. (C) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {BDMC, Curcuma longa, Human pancreatic amylase, kinetics, Type-2 diabetes}, issn = {0308-8146}, doi = {10.1016/j.foodchem.2012.06.110}, author = {Ponnusamy, Sudha and Smita S. Zinjarde and Bhargava, Shobha and Rajamohanan, P. R. and RaviKumar, Ameeta} } @article { ISI:000307351500021, title = {High viscosity of ionic liquids causes rate retardation of Diels-Alder reactions}, journal = {Science China-Chemistry}, volume = {55}, number = {8, SI}, year = {2012}, month = {AUG}, pages = {1633-1637}, publisher = {SCIENCE PRESS}, address = {16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA}, abstract = {

Second order rate constants, k (2) have been determined for three bi-molecular Diels-Alder reactions to demonstrate that the high viscosity of ionic liquids can be a detrimental property in carrying out Diels-Alder reactions, if ionic liquids are employed as solvent media. It is possible to enhance the reaction rates of the reaction if a co-solvent is mixed in pure ionic liquid used as a solvent.

}, keywords = {Diels-Alder reactions, ionic liquids, kinetics, viscosity}, issn = {1674-7291}, doi = {10.1007/s11426-012-4684-9}, author = {Kumar, Anil and Pawar, Sanjay S.} } @article { ISI:000305033900088, title = {Kinetics of hydrogenation of lauric acid in a batch slurry reactor using Ru-Sn/TiO2 catalyst}, journal = {Asian Journal of Chemistry}, volume = {24}, number = {6}, year = {2012}, month = {JUN}, pages = {2767-2771}, publisher = {ASIAN JOURNAL OF CHEMISTRY}, address = {11/100 RAJENDRA NAGAR, SECTOR 3,, SAHIBABAD 201 005, GHAZIABAD, INDIA}, abstract = {

Ru-Sn catalyst was prepared in-house by impregnation method. This catalyst was found to be stable for four recycles. The rate of hydrogenation of lauric acid (LAC) using Ru-Sn/TiO2 catalyst was found to be linearly dependent on catalyst loading, lauric acid concentration old hydrogen partial pressure. The rate data obtained from kinetic study were fitted to simple rate equation based on Langmuir-Hinshelwood (L-H) type model. Based on kinetic data the hydrogenation of lauric acid over Ru-Sn/TiO2 catalyst is proposed to occur by I dual site mechanism the activation energy for hydrogenation of lauric acid to lauryl alcohol (LAOH) using Rii-Sn/TiO2 catalyst was found to be 77.2 kJ/mol.

}, keywords = {Hydrogenation, kinetics, Langmuir-Hinshelwood model, Ru-Sn/TiO2 catalyst}, issn = {0970-7077}, author = {Shinde, S. B. and Deshpande, R. M.} } @article { ISI:000306193700016, title = {Kinetics of the Heck reaction in biphasic organic-ethylene glycol medium}, journal = {Reaction Kinetics Mechanisms and Catalysis}, volume = {106}, number = {2}, year = {2012}, month = {AUG}, pages = {457-473}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

PdCl2(bipy) was found to be an efficient and stable catalyst in biphasic medium (organic-glycol) for the Heck reaction. The kinetics of the Heck coupling of styrene with iodobenzene using the same catalyst was studied in a biphasic medium in a temperature range of 393-413 K. The rate was found to have a first order dependence tending to a fractional order, on the iodobenzene as well as catalyst concentration. The rate was found to have a complex dependence on the styrene concentration and passes through a maximum, showing typical substrate inhibition kinetics. The rate had a first order dependence on the base (morpholine) concentration. The trends observed for the influence of the different parameters on the activity of the catalyst are in agreement with the established mechanism for Heck reaction. An empirical rate model has been proposed to fit the observed rate data. The activation energy was found to be 72.91 kJ/mol. This is the first time that kinetic modeling of Heck reaction in a biphasic medium (organic-glycol) has been attempted.

}, keywords = {Biphasic catalysis, Heck reaction, kinetics, PdCl2(bipy) complex}, issn = {1878-5190}, doi = {10.1007/s11144-012-0437-1}, author = {Jagtap, Sangeeta Vijay and Deshpande, Raj Madhukar} } @article { ISI:000326058500009, title = {Crystallization kinetics of Sn-MFI molecular sieve formation by dry gel cross mark conversion method}, journal = {Microporous and Mesoporous Materials}, volume = {182}, year = {2013}, month = {DEC}, pages = {73-80}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The conversion of amorphous stannosilicate dry gel into crystalline molecular sieve with MFI structure (Sn-MFI) was achieved by dry gel conversion (DGC) method at 413, 443 and 473 K. For comparison purpose, Sn-MFI molecular sieve with similar SiO2/SnO2 mole ratio was also obtained by hydrothermal crystallization route. Crystallization curves were established by conducting time dependant studies on progressive crystallization processes for both the systems. The values of activation energy of nucleation (E-n), activation energy of crystallization (E-c), and their pre-exponential factors (InA(n), InA(c) respectively) were calculated from Arrhenius plots. Compared to the hydrothermal method, shorter induction period was observed when DGC method was employed. Both the E-n (49.70 kJ/mol) and E-c (52.82 kJ/mol) for DGC method were found to be lower than that of the E-n (55.70 kJ/mop and E-c (60.23 kJ/mol) for hydrothermal method. The kinetics parameters viz. K and q were derived from kinetic expressions and DGC method showed higher value of K and lower value of q compared to hydrothermal crystallization method at identical temperature. Various DGC method parameters such as water content at the bottom of autoclave and SiO2/SnO2 mole ratio have shown the influence on the kinetics of crystallization of Sn-MFI. (C) 2013 Elsevier Inc. All rights reserved.

}, keywords = {Crystallization, DGC, kinetics, Nucleation, Sn-MFI}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2013.08.026}, author = {Niphadkar, P. S. and Tangale, N. P. and Joshi, P. N. and Awate, S. V.} } @article { ISI:000311935400073, title = {Influence of contact medium and surfactants on carbon dioxide clathrate hydrate kinetics}, journal = {Fuel}, volume = {105}, year = {2013}, month = {MAR}, pages = {664-671}, publisher = {ELSEVIER SCI LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

Carbon dioxide (CO2) hydrate formation kinetic was investigated in a fixed bed crystallizer at constant pressure (3.55 MPa) and temperature (274 K). Porous media of three different silica gels were used, with a mesh size of 60-120, 100-200 and 230-400 having different surface area. The observed trends indicate that silica gel with larger surface area leads to higher gas consumption as well as reduces the induction time. The effect of pore diameter and particle size distribution has already been reported in a previous study [1]. In this study the effect of additives on hydrate formation kinetics were also investigated. The additives studied were nonionic surfactant Tween-80 (T-80), cationic dodecyltrimethylammonium chloride (DTACl) and anionic Sodium Dodecyl Sulphate (SDS). Out of the three surfactants used in this study, SDS was found to be most effective in enhancing the rate of hydrate formation as well as reducing the induction time. The current result shows significant improvement in water to hydrate conversion in silica gel media compared to quiescent water or surfactant-water system under similar conditions. (C) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {Carbon dioxide capture, Clathrate hydrate, kinetics, Silica gel, Surfactants}, issn = {0016-2361}, doi = {10.1016/j.fuel.2012.10.031}, author = {Kumar, Asheesh and Sakpal, Tushar and Linga, Praveen and Kumar, Rajnish} } @article { ISI:000318292400036, title = {Photopolymerization of bis-aromatic and alicyclic based solid urethane acrylate macromonomer in the presence of large excess of reactive diluent Kinetics and modeling}, journal = {Journal of Thermal Analysis and Calorimetry}, volume = {112}, number = {2}, year = {2013}, month = {MAY}, pages = {805-813}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

A solid urethane acrylate macromonomer with bis-aromatic as well as alicyclic moieties was synthesized and the kinetics of photopolymerization reactions were studied in the presence of varying concentration of photoinitiator and large excess of reactive diluent using photo DSC. The studies show that the rate of maximum polymerization was found to increase with increase in concentration of photoinitiator while a decrease was observed by an increase in temperature. The final conversion showed a decrease at highest isothermal condition due to vitrification. Estimation of kinetic parameters including applicability of autocatalytic and modified autocatalytic models were investigated by nonlinear regression. It was observed that the modified models gave a better fit with the experimental data and kinetic parameters showed a decrease with increase in temperature and an increase with increase in concentration of photoinitiator.

}, keywords = {Autocatalytic model, kinetics, Levenberg-Marquardt method, Photopolymerization}, issn = {1388-6150}, doi = {10.1007/s10973-012-2619-5}, author = {Harikrishna, Reghunathan and Ponrathnam, S. and Rajan, C. R. and Tambe, S. S.} } @article { ISI:000328434500029, title = {Photopolymerization kinetics of bis-aromatic based urethane acrylate macromonomers in the presence of reactive diluent}, journal = {Progress in Organic Coatings}, volume = {77}, number = {1}, year = {2014}, month = {JAN}, pages = {225-231}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

The present work deals with the photopolymerization of bis-aromatic based urethane acrylate macromonomers in the presence of excess end capping agent as reactive diluent and estimation of their kinetic parameters. Formulations were made by independently homogenizing the macromonomers with photoinitiators of three different classes. Three different compositions of photoinitiators were used to study the effect of concentration of photoinitiator on cure kinetics. These compositions obtained were tested for photo curing performance using photo DSC under polychromatic radiation. The heat flows against time were recorded for all formulations under isothermal condition and the rates of polymerization, peak maximum times as well as the percentage conversions were estimated. It was observed that due to a longer timescale for reaction diffusion, formulations with macromonomer containing propoxylated backbone showed higher conversions than the corresponding ethoxylated analogue. The photopolymerization and kinetic estimations of the formulations including evaluation of kinetic model are discussed. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {Bimolecular termination model, kinetics, Macromonomer, Photopolymerization}, issn = {0300-9440}, doi = {10.1016/j.porgcoat.2013.09.006}, author = {Harikrishna, Reghunathan and Ponrathnam, S. and Rajan, C. R.} } @article { ISI:000340517700011, title = {Photopolymerization kinetics of block polyether based terminal urethane methacrylate with/without cross-linker}, journal = {Advances in Polymer Technology}, volume = {33}, number = {3}, year = {2014}, month = {FEB}, pages = {21418}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

The present work deals with the photopolymerization of difunctional macromonomer with a polyether chain and urethane methacrylate terminations. Macromonomeric formulations were prepared by mixing macromonomer with two different concentrations of photoinitiator. Formulations were also prepared by the addition of 10 wt\% of soft-segmented difunctional cross-linker to the abovementioned macromonomic formulations. All formulations were then subjected to photopolymerization studies and the effects of light intensity on the photopolymerization kinetics were studied at two different isothermal conditions using photo differential scanning calorimetry (Photo DSC) with polychromatic radiation. The isothermal heat flow against time was recorded for all formulations and the kinetic parameters were noted. It was observed that the rate of maximum polymerization as well as peak maximum time showed a general trend. However, the ultimate conversion as well as the conversion at maximum rate did not show any trend due to diffusional restrictions imparted by the increase in viscosity with conversion. The photopolymerization of the formulations and curing kinetics including evaluation of autocatalytic model are discussed. (C) 2014 Wiley Periodicals, Inc.

}, keywords = {kinetics, Macromonomers, Modeling, Photo DSC, Photopolymerization}, issn = {0730-6679}, doi = {10.1002/adv.21418}, author = {Reghunathan, Harikrishna} } @article { ISI:000329385800009, title = {Reaction kinetics and modeling of photoinitiated cationic polymerization of an alicyclic based diglycidyl ether}, journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms}, volume = {318}, number = {B}, year = {2014}, month = {JAN}, pages = {263-268}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Photoinitiated cationic polymerization of cycloaliphatic diepoxides had received tremendous attention, while studies with lesser polymerizable diglycidyl ethers are comparatively less reported. The present work deals with the photoinitiated cationic polymerization of cyclohexane dimethanol diglycidyl ether followed by estimation of kinetic parameters. The effects of concentration of photoinitiator and temperature on curing performance were studied using photo differential scanning calorimeter or photo DSC with polychromatic radiation. It was observed that the rate of polymerization as well as ultimate conversion increased with increasing concentration of photoinitiator and temperature. The influences of gelation as well as diffusional restrictions have remarkable effect on cure performance. The kinetic parameters as per autocatalytic kinetic model were studied by Levenberg-Marquardt nonlinear regression method instead of conventional linear method for obtaining more accurate values of apparent rate constant. It was observed that the model fits with data from initial stages to almost towards the end of the reaction. The activation energy was found to be higher than the values reported for more reactive cycloaliphatic diepoxides. The value of pre-exponential factor increased with increase in activation energy showing influence of gelation at early stages of reaction. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {Autocatalytic model, kinetics, Levenberg-Marquardt method, Photopolymerization}, issn = {0168-583X}, doi = {10.1016/j.nimb.2013.10.004}, author = {Harikrishna, Reghunathan and Ponrathnam, S. and Tambe, S. S.} } @article { ISI:000344379900113, title = {Synthesis of green nano iron particles (GnIP) and their application in adsorptive removal of As(III) and As(V) from aqueous solution}, journal = {Applied Surface Science}, volume = {317}, year = {2014}, month = {OCT}, pages = {1052-1059}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

{The present study reports a new approach to synthesise nano iron particles using leaf extract of Mint (Mentha spicata L.) plant. The synthesised GnIPs were subjected to detailed adsorption studies for removal of arsenite and arsenate from aqueous solution of defined concentration. Iron nanoparticles synthesised using leaf extract showed UV-vis absorption peaks at 360 and 430 nm. TEM result showed the formation of polydispersed nanoparticles of size ranging from 20 to 45 nm. Nanoparticles were found to have core-shell structure. The planer reflection of selected area electron diffraction (SAED) and XRD analysis suggested that iron particles were crystalline and belonged to fcc (face centred cubic) type. Energy-dispersive X-ray analysis (EDAX) shows that Fe was an integral component of synthesised nanoparticles. The content of Fe in nanoparticles was found to be 40\%, in addition to other elements like C (16\%), 0 (19\%) and Cl (23\%). FT-IR study suggested that functional groups like NH

}, keywords = {Adsorption, Arsenate, Arsenite, Iron nanoparticles, kinetics, M. spicata L.}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2014.09.042}, author = {Prasad, Kumar Suranjit and Gandhi, Pooja and Selvaraj, Kaliaperumal} } @article { ISI:000365283700043, title = {Cationic photopolymerization kinetics of neat coating formulations involving poly(propylene glycol) diglycidyl ether and glycerol diglycidyl ether}, journal = {Journal of Thermal Analysis and Calorimetry}, volume = {122}, number = {3}, year = {2015}, month = {DEC}, pages = {1445-1454}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

Kinetic analysis of formulations based on poly(propylene glycol) diglycidyl ether and glycerol diglycidyl ether was carried out using photodifferential scanning calorimeter. The effects of formulation monomer ratios at different temperatures were studied as photocalorimetric optimization studies of formulation ratios involving diglycidyl ethers are less reported. The nature of cure was found to depend more on the in situ physical parameters rather than on the mechanism of the reaction. The variations in the observed kinetic parameters can be related to interplay of mobility of reactive species, distance of counter ion and the diffusional restrictions. The final conversion was found to increase with increase in poly(propylene glycol) diglycidyl ether content, while the thermal stability increased with an increase in glycerol diglycidyl ether content. Autocatalytic kinetic model was also evaluated, and the system underwent early gelation. The studies show that the intermediate formulations are promising compositions for surface-coating applications.

}, keywords = {Coatings, Diglycidyl ether, kinetics, PhotoDSC, Photopolymerization}, issn = {1388-6150}, doi = {10.1007/s10973-015-4967-4}, author = {Harikrishna, Reghunathan} } @article { ISI:000357869100005, title = {Influence of low-dosage hydrate inhibitors on methane clathrate hydrate formation and dissociation kinetics}, journal = {Energy Technology}, volume = {3}, number = {7, SI}, year = {2015}, month = {JUL}, pages = {717-725}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

This work investigates the effect of low-dosage hydrate inhibitors (LDHIs) on methane hydrate formation and dissociation. The hydrate inhibitors used in this study were the sodium salt of polyacrylic acid, a polysaccharide chitosan, and the linear sulfated polysaccharide i-carrageenan; the inhibiting behavior of these additives were compared with that of the commonly used hydrate inhibitor polyvinylpyrrolidone for methane hydrate formation. A LDHI concentration of 1wt\% was found to increase the induction time relative to that at a LDHI concentration of 0.1wt\%. Chitosan was found to be better than the others in reducing nucleation and the growth rate of the hydrate at a concentration of 1wt\%. At a lower concentration of 0.1wt\%, nucleation inhibition was minimal, however, growth inhibition was significant. The effect of these inhibitors on the decomposition rate of the hydrate was also studied, and the decomposition kinetics at a constant driving force in excess of three-phase equilibrium is reported.

}, keywords = {gas uptake, hydrates, inhibitors, kinetics, thermal stimulation}, issn = {2194-4288}, doi = {10.1002/ente.201500004}, author = {Kumar, Asheesh and Sakpal, Tushar and Kumar, Rajnish} } @article { ISI:000353000600003, title = {Inhibition effect of N,N-diglycidyl-4-glycidyloxy aniline on photosensitized cationic polymerization of formulations involving resorcinol diglycidyl ether and poly(propylene glycol)diglycidyl ether}, journal = {Journal of Photochemistry and Photobiology A-Chemistry}, volume = {303}, year = {2015}, month = {APR}, pages = {17-27}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Cationic photopolymerization studies of poly(propylene glycol)diglycidyl ether with and without 25 wt\% of resorcinol diglycidyl ether were carried out in presence of bis(4-methylphenyl)iodonium hexafluorophosphate as photoinitiator. Analyses were carried out using polychromatic radiation at different temperatures in a photo differential scanning calorimeter. The formulations showed an enhancement in the rate of polymerization on addition of resorcinol diglycidyl ether. The same formulations when subjected to photosensitized polymerization in presence of 1-chloro-4-propoxy-9H-thioxanthen-9-one, showed a reverse behavior in rate due to partial absorption of radiation by resorcinol diglycidyl ether. Studies carried out on by the addition of N,N-diglycidy1-4-glycidyloxy aniline as inhibitor on the photosensitized formulations showed higher scavenging activity by inhibitor. The addition of nitrogen containing epoxy monomer as inhibitor can lead to its possible crosslinking within the matrix on polymerization along with a decrease in rate of polymerization without compromising on the final observed conversion. This effect can occur readily for non vitrifying systems. Thus, this observation provides an insight into its possible usage in a rate controlled photopolymerizable epoxy formulations. The photopolymerization kinetics were found to depend on the nature of generation, propagation and scavenging of active centers which are heavily dependent on diffusional restrictions imparted by in situ viscosity of the system. The kinetic estimations as well as evaluation of autocatalytic kinetic model are investigated. (C) 2015 Elsevier B.V. All rights reserved.

}, keywords = {Glycidyl ether, Inhibition, kinetic model, kinetics, Photopolymerization, Photosensitization}, issn = {1010-6030}, doi = {10.1016/j.jphohtochem.2015.02.001}, author = {Harikrishna, Reghunathan} } @article { ISI:000352508300032, title = {Reactivity and operational stability of N-Tailed TAMLs through kinetic studies of the catalyzed oxidation of orange II by H2O2: synthesis and x-ray structure of an N-Phenyl TAML}, journal = {Chemistry A-European Journal}, volume = {21}, number = {16}, year = {2015}, month = {APR}, pages = {6226-6233}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

{The catalytic activity of the N-tailed (biuret) TAML (tetraamido macrocyclic ligand) activators [Fe{4-XC6H3-1,2-(NCOCMe2NCO)(2)NR}Cl](2-) (3; N atoms in boldface are coordinated to the central iron atom; the same nomenclature is used in for compounds 1 and 2 below), [X

}, keywords = {Hydrogen peroxide, iron, kinetics, Oxidation, reaction mechanisms}, issn = {0947-6539}, doi = {10.1002/chem.201406061}, author = {Warner, Genoa R. and Mills, Matthew R. and Enslin, Clarissa and Pattanayak, Shantanu and Panda, Chakadola and Panda, Tamas Kumar and Sen Gupta, Sayam and Ryabov, Alexander D. and Collins, Terrence J.} } @article { ISI:000363949300020, title = {Removal of methylene blue (MB) dye from water environment by processed Jowar Stalk [Sorghum bicolor (L.) Moench] adsorbent}, journal = {Clean Technologies and Environmental Policy}, volume = {17}, number = {8}, year = {2015}, month = {DEC}, pages = {2349-2359}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

The present paper discusses the results of the study of adsorption of methylene blue on activated carbon, derived from cheap and abundantly available agro-residue of Jowar Stalk (JS) [Sorghum bicolor (L.) Moench] on suitable heat and acid treatment. The physico-chemical and morphological characteristics of processed carbon of JS origin were studied using X-ray diffraction, scanning electron microscopy, Brunauer, Emmett and Teller surface area, and Fourier transform infrared spectrophotometry analyses. The batch studies revealed optimum values of adsorption parameters such as pH, adsorbent dosage, agitation speed, grain size, temperature, and contact time as 7, 1.5 g l(-1), 200 rpm, finer than 75 A mu m, 30 A degrees C, and 7 h, respectively. The adsorption isotherm data were best described by Langmuir isotherm model with a maximum adsorption capacity of 176.05 mg MB g(-1) JS activated carbon at 30 A degrees C, which is higher than that available with adsorbents used by past researchers. In terms of cost-effectiveness, JS carbon shows its superiority over commercially available carbon.

}, keywords = {Adsorption, Isotherms, kinetics, Methylene blue, Processed Jowar Stalk [Sorghum bicolor (L.) Moench]}, issn = {1618-954X}, doi = {10.1007/s10098-015-0977-y}, author = {Dod, Ramesh and Banerjee, Goutam and Saini, D. R.} } @article { ISI:000377466600023, title = {Crystallization kinetics for carbon dioxide gas hydrate in fixed bed and stirred tank reactor}, journal = {Korean Journal of Chemical Engineering}, volume = {33}, number = {6}, year = {2016}, month = {JUN}, pages = {1922-1930}, publisher = {KOREAN INSTITUTE CHEMICAL ENGINEERS}, address = {F.5, 119, ANAM-RO, SEONGBUK-GU, SEOUL 136-075, SOUTH KOREA}, abstract = {

The phase change from germ nuclei to growth nuclei and subsequent volume transformation in a crystallization process was modeled by Avrami equations. The phase change during the hydrate formation was fitted with the classical Avrami model by utilizing gas uptake data. The idea is to understand the difference in growth behavior of hydrate crystals when in small pores compared to a stirred tank reactor which does not pose any physical restrictions to hydrate growth. The parameters n and k of the Avrami equation were determined explicitly for CO2 hydrate formation.

}, keywords = {Avrami Equation, CO2 Capture \& Sequestration, Fixed Bed, Gas hydrates, kinetics}, issn = {0256-1115}, doi = {10.1007/s11814-016-0040-7}, author = {Kumar, Asheesh and Khatri, Dishant and Lee, Ju Dong and Kumar, Rajnish} } @article {45648, title = {Effect of the amino acid L-histidine on methane hydrate growth kinetics}, journal = {Journal of Natural Gas Science and Engineering}, volume = {35}, year = {2016}, month = {SEP}, pages = {1453-1462}, type = {Article}, abstract = {

In the present study, the effect of a polar amino acid, L-histidine on methane hydrate growth kinetics has been investigated. Methane hydrate formation experiments were carried out in a stirred tank reactor setup at pressure and temperature conditions of 274.15 K and 5.0 MPa respectively. Two different concentrations (0.1 and 1 wt \%) of L-histidine were studied. Hydrate growth through molecular dynamic (MD) simulation was also studied; pressure and temperature conditions for the simulations were set at 10.0 MPa and 270.0 K, while the concentration of L-histidine was kept fixed at 0.94 wt \%. Hydrate formation runs using MD simulation were carried out with optimal concentration of methane in water. The presence of L-histidine in the system was found to significantly enhance methane hydrate growth kinetics as compared to pure water for both experimental and MD simulation runs. Final gas consumption with 1 wt \% L-histidine was found to be comparable to that with 1 wt \% SDS, the most commonly used additive for hydrate promotion studies. L-histidine is a benign additive which offers considerable enhancement in methane hydrate formation kinetics and can be utilized for various hydrate based technologies such as methane storage and transport. (C) 2016 Elsevier B.V. All rights reserved.

}, keywords = {Amino acid, Crystal growth, Gas hydrate, kinetics, Molecular dynamic simulation}, issn = {1875-5100}, doi = {10.1016/j.jngse.2016.05.052}, author = {Bhattacharjee, Gaurav and Choudhary, Nilesh and Kumar, Asheesh and Chakrabarty, Suman and Kumar, Rajnish} } @article {45634, title = {Mechanistic and spectroscopic investigations of Ru3+-catalyzed oxidative degradation of azidothymidine by heptavalent manganese at environmentally relevant pH}, journal = {Desalination and Water Treatment}, volume = {57}, year = {2016}, month = {DEC}, pages = {28349-28362}, type = {Article}, abstract = {

The rapid increase in the population across the world has increased the consumption of pharmaceutical substances. These pharmaceutical substances have penetrated into the water through various ways. Mechanistic and spectroscopic investigations of Ru3+-catalyzed oxidative degradation of azidothymidine (AZT) by heptavalent manganese was studied for the first time. The values of pH-dependent apparent second-order rate constant show that Ru3+ accelerates the rate of the oxidative degradation of AZT by heptavalent manganese eight times faster than uncatalyzed reaction. Ru3+ catalytic oxidative degradation of AZT by heptavalent manganese was greatly depending on the pH. The removal of the AZT by heptavalent manganese in the presence of Ru3+ shows unit order with respect to heptavalent manganese, Ru3+, and AZT. The influences of dielectric constant, ionic strength, pH, addition of monomer, variation in catalyst concentration, etc. on the rate of the reaction were studied thoroughly and discussed in detail. The eight different products produced during the reaction were analyzed using the high-resolution mass spectrometry. Activation parameters were determined from variation in temperature during the reaction. The catalytic plausible mechanism was projected in which Ru3+ is oxidized to higher oxidation states of ruthenium by heptavalent manganese at environmentally relevant pH.

}, keywords = {Azidothymidine, catalysis, Degradation, Heptavalent manganese, kinetics, Mechanism}, issn = {1944-3994}, doi = {10.1080/19443994.2016.1187090}, author = {Kulkarni, Raviraj M. and Bhamare, Vijaykumar S. and Santhakumari, B.} } @article {45829, title = {Oxidative transformation of antiretroviral drug zidovudine during water treatment with permanganate: reaction kinetics and pathways}, journal = {Desalination and Water Treatment}, volume = {57}, year = {2016}, month = {FEB}, pages = {24999-25010}, type = {Article}, abstract = {

The presence of the pharmaceutical substances in the water has been reported by many studies and has attracted attention across the world. The mechanistic insight into oxidation of antiretroviral drug zidovudine (ZDV) by potassium permanganate was investigated between the pH values 3.0 and 9.0. The pH-dependent second-order rate constants were determined and rate constants decreased with an increase in pH. The products of the reaction were identified by high-resolution mass spectrometry. A probable mechanism is proposed which involves the formation of an intermediate complex between permanganate and ZDV, which further undergoes degradation in subsequent fast steps to form various oxidized products. The different parameters like effect of initially added products, solvent polarity, ionic strength, temperature, and pH on the rate of the oxidative degradation of ZDV by permanganate were systematically studied. The various activation parameters were determined from the effect of variation in temperature on the oxidative degradation of ZDV by permanganate in acidic medium and discussed in detail.

}, keywords = {Degradation, kinetics, Mechanism, Permanganate, Zidovudine}, issn = {1944-3994}, doi = {10.1080/19443994.2016.1149110}, author = {Kulkarni, Raviraj M. and Bhamare, Vijaykumar S. and Santhakumari, B.} } @article { ISI:000362736300014, title = {Selective solid-phase extraction of metal for water decontamination}, journal = {Journal of Applied Polymer Science}, volume = {133}, number = {1}, year = {2016}, month = {JAN}, pages = {42849}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

Metal-contaminated industrial effluent is a major concern for human health. Therefore, the removal of metal is of primary importance. In this study, metals were selectively extracted from water. Selective metal recovery was studied with a crown-ether-based polymer, wherein the selectivity was observed for strontium over lead. Parameters influencing the metal recovery, such as the contact time, adsorbent dosage, and metal-ion concentration, were evaluated. Interestingly, the adsorption rate of strontium was exponentially increased for the initial 4 h, and lead was adsorbed exponentially after 6 h. Notably, 98\% strontium adsorption and 64\% lead adsorption were obtained in 24 h. The Langmuir adsorption isotherm was in good agreement and demonstrated that the reactive sites of the adsorbent were homogeneous with monolayer metal adsorption with an adsorbent. The Freundlich adsorption isotherm was not obeyed by both metals. The pseudo-first-order and pseudo-second-order kinetics indicated that strontium was adsorbed by chemisorption and lead was adsorbed by physisorption. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 132, 42849.

}, keywords = {Adsorption, copolymers, crosslinking, kinetics, radical polymerization}, issn = {0021-8995}, doi = {10.1002/app.42849}, author = {Mane, Sachin and Ponrathnam, Surendra and Chavan, Nayaku} } @article { ISI:000381182700004, title = {Spectacular rate enhancement of the diels-alder reaction at the ionic liquid/n-hexane interface}, journal = {Chemphyschem}, volume = {17}, number = {13}, year = {2016}, month = {JUL}, pages = {1969-1972}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

The use of the ionic liquid/n-hexane interface as a new class of reaction medium for the Diels-Alder reaction gives large rate enhancements of the order of 10(6) to 10(8) times and high stereoselectivity, as compared to homogeneous media. The rate enhancement is attributed to the H-bonding abilities and polarities of the ionic liquids, whereas the hydrophobicity of ionic liquids was considered to be the factor in controlling stereoselectivity.

}, keywords = {Diels-Alder reaction, Interfaces, ionic liquids, kinetics, stereoselectivity}, issn = {1439-4235}, doi = {10.1002/cphc.201600006}, author = {Beniwal, Vijay and Manna, Arpan and Kumar, Anil} } @article {43891, title = {Intensification of extraction of curcumin from Curcuma amada using ultrasound assisted approach: Effect of different operating parameters}, journal = {Ultrasonic Sonochemistry}, volume = {38}, year = {2017}, month = {SEP}, chapter = {437-445}, abstract = {

Curcumin, a dietary phytochemical, has been extracted from rhizomes of Curcuma amada using ultrasound assisted extraction (UAE) and the results compared with the conventional extraction approach to establish the process intensification benefits. The effect of operating parameters such as type of solvent, extraction time, extraction temperature, solid to solvent ratio, particle size and ultrasonic power on the extraction yield have been investigated in details for the approach UAE. The maximum extraction yield as 72\% was obtained in 1 h under optimized conditions of 35 degrees C temperature, solid to solvent ratio of 1:25, particle size of 0.09 mm, ultrasonic power of 250 W and ultrasound frequency of 22 kHz with ethanol as the solvent. The obtained yield was significantly higher as compared to the batch extraction where only about 62\% yield was achieved in 8 h of treatment. Peleg{\textquoteright}s model was used to describe the kinetics of UAE and the model showed a good agreement with the experimental results. Overall, ultrasound has been established to be a green process for extraction of curcumin with benefits of reduction in time as compared to batch extraction and the operating temperature as compared to Soxhlet extraction.

}, keywords = {Acrylamide, Cavitation, Curcumin Extraction, Design, Enhancement, Functionalized Silica, kinetics, Microwave, Nanoparticles, Natural-products, Optimization, Phenolic-compounds, Process Intensification, Solid-liquid Extraction, Ultrasound}, issn = {1350-4177}, doi = {10.1016/j.ultsonch.2017.03.040}, author = {Shirsath, S. R. and Sable, S. S. and Gaikwad, S. G. and Sonawane, S. H. and Saini, D. R. and Gogate, P. R.} } @article {43870, title = {NiZn double hydroxide nanosheet-anchored nitrogen-doped graphene enriched with the gamma-NiOOH phase as an activity modulated water oxidation electrocatalyst}, journal = {Nanoscale}, volume = {9}, year = {2017}, month = {SEP}, pages = {12590-12600}, type = {Journal Article}, chapter = {12590-12600}, abstract = {

Herein, we report a facile solvothermal process to synthesize an active electrocatalyst for the oxygen evolution reaction (OER) in an alkaline medium by anchoring nanosheets of a NiZn double hydroxide over nitrogen doped reduced graphene oxide after enriching the system with the γ-NiOOH phase. This catalyst possesses a thin, porous and open layered structure, which makes the system more efficient and accessible for a better electrochemical water oxidation reaction. Moreover, we experimentally demonstrated that incorporation of Zn via a single-step solvothermal method provides an easy approach to obtain plenty of exposed γ-NiOOH phases to make the system more viable for OER with a small overpotential of 290 mV at 10 mA cm-2 and a Tafel slope of 44 mV per decade. In addition to this, the oxophilic nature of Zn in the (Zn)Ni-LDH/N-rGO catalyst helps to improve the long-term stability of the whole system. The obtained results open up possibilities for the design of future robust OER electrocatalysts by the use of very cheap and abundant materials like Ni and Zn in place of expensive Ir and Ru in the present commercial electrocatalysts.

}, keywords = {catalysis, Efficient Electrocatalyst, kinetics, Metal, Nickel-Hydroxide, oxide, Oxygen Evolution Reaction, performance, XPS Spectra, zinc}, issn = {2040-3364}, doi = {10.1039/c7nr02225e}, author = {Nadeema, Ayasha and Dhavale, Vishal M. and Kurungot, Sreekumar} } @article {44201, title = {Kinetic promotion of methane hydrate formation by combining anionic and silicone surfactants: scalability promise of methane storage due to prevention of foam formation}, journal = {Journal of Chemical Thermodynamics}, volume = {117}, year = {2018}, month = {FEB}, pages = {248-255}, type = {Article}, abstract = {

Methane storage in its solid hydrate form has recently come up as a rather attractive and low risk option for large scale storage of the gas owing to its mild storage conditions, high gas retention capacity and benign (non-explosive) character. However, it has its fair share of limitations with the slow rate of hydrate formation being one of the most prominent. The addition of surfactants like Sodium dodecyl sulfate (SDS) to the hydrate forming system significantly speeds up the process of methane hydrate formation but the large amount of foam generated by these surfactants during the process of hydrate formation and dissociation stands as a major roadblock towards the scaling up of the technology. In the current work, a small amount of a silicon based surfactant has been proposed to be used as antifoam in conjunction with an anionic surfactant SDS to eliminate the foam generation while at the same time promote the kinetics of methane hydrate formation. The idea is simple, cost effective and can be a potential game-changer in the quest to develop a commercially scalable hydrate based methane storage technology. (C) 2017 Elsevier Ltd.

}, keywords = {Antifoam, Gas hydrate, kinetics, Methane storage, scale-up, Silicone surfactant}, issn = {0021-9614}, doi = {10.1016/j.jct.2017.09.029}, author = {Bhattacharjee, Gaurav and Barmecha, Vivek and Kushwaha, Omkar S. and Kumar, Rajnish} } @article {44239, title = {Reaction engineering for continuous production of silver nanoparticles}, journal = {Chemical Engineering \& Technology}, volume = {41}, year = {2018}, month = {JAN}, pages = {157-167}, type = {Article}, abstract = {

A scalable process for the production of silver nanoparticles that allows for complete conversion of the limiting reactant is analyzed in detail. The kinetics of silver nanoparticle synthesis using citrate reduction are investigated and used for development of a reaction engineering model to facilitate the reactor design. The effect of temperature, pH, concentration and mixing (axial dispersion) on the rates of nucleation and growth are analyzed quantitatively. An approach that considers reaction kinetics coupled with quality of dispersion is developed for reactor design as well as selection of reactor configurations for the synthesis of specific particle sizes. The developed approach has been applied for continuous production of 10-L suspension silver nanoparticles with very narrow particle size distribution.

}, keywords = {kinetics, particle size distribution, rate constant, Reactor design, Silver nanoparticle production}, issn = {0930-7516}, doi = {10.1002/ceat.201700035}, author = {Deshpande, Javdeep B. and Kulkarni, Amol A.} } @article {46060, title = {Hydrodynamic cavitation using vortex diode: an efficient approach for elimination of pathogenic bacteria from water}, journal = {Journal of Environmental Management}, volume = {242}, year = {2019}, month = {JUL }, pages = {210-219}, type = {Article}, abstract = {

The present study successfully demonstrates greener methodology of hydrodynamic cavitation using rotational flows for disinfection of water. Disinfection of two model microbial strains-gram-negative (Escherichia colt) and gram-positive (Staphylococcus aureus) using vortex diode was evaluated. The removal efficacy was quantified for two different cavitation reactors. Practically complete elimination of E. coli was achieved (99\%) after 1 h of cavitation at a pressure drop of only 0.5 bar. However, elimination of S. aureus using vortex diode was observed to be lower in comparison to the removal of E. coli and only 60\% disinfection could be achieved under similar conditions, which can be subsequently enhanced up to 98\% by increasing pressure drop. The results were compared with another cavitating device that employs linear flow for cavitation, orifice. The reactor geometry has significant impact on the disinfection process and orifice was found to require significantly higher pressure drop (10 bar) conditions for disinfection and for eliminating grain-positive bacteria with high efficiency. A plausible mechanism for disinfection was proposed to elucidate the role of cavitation in cell destruction leading to death of cells through the rupture of cell wall, oxidative damage and possible DNA denaturation. Also, a cavitation model using per pass disinfection was developed that can provide meaningful physical description of the disinfection process as against the conventional first order reaction rate model. This study would provide meaningful insight into cavitation process based on hydrodynamic cavitation for the destruction of both gram-negative and gram-positive bacteria from various water sources, including industrial wastewaters.

}, keywords = {Cavitation, Disinfection, kinetics, pollution, Wastewater treatment}, issn = {0301-4797}, doi = {10.1016/j.jenvman.2019.04.057}, author = {Jain, Pooja and Bhandari, Vinay M. and Balapure, Kshama and Jena, Jyotsnarani and Ranade, Vivek V. and Killedar, Deepak J.} } @article {45489, title = {Kinetics of hydroformylation of 1-decene using carbon-supported ossified HRh(CO)(TPPTS)(3) catalyst}, journal = {International Journal of Chemical Kinetics}, volume = {51}, year = {2019}, month = {FEB}, pages = {112-122}, type = {Article}, abstract = {

The kinetics of hydroformylation of 1-decene has been investigated using a carbon-supported ossified HRh(CO)(TPPTS)(3)/Ba catalyst in a temperature range of 343-363 K. The effect of concentration of 1-decene, catalyst loading, partial pressure of H-2 and CO, and stirring speed on the reaction rate has been investigated. A first-order dependence was observed for catalyst concentration and hydrogen partial pressure. The rate showed a typical case of substrate inhibition for high 1-decene concentration. The rate varied with a linear dependence on P-CO up to a CO partial pressure of 5-6 MPa in contrast to the general trends; for most of the rhodium-phosphine catalyzed hydroformylation reactions, severe inhibition of rate is observed with an increase in CO pressure. A rate equation has been proposed, which was found to be in good agreement with the observed rate data within the limit of experimental errors. The kinetic parameters and activation energy values have been reported.

}, keywords = {1-decene, Hydroformylation, kinetics, ossification, supported ossified}, issn = {0538-8066}, doi = {10.1002/kin.21234}, author = {Pagar, Nitin S. and Deshpande, Raj M.} } @article {46224, title = {Methane hydrate dissociation in the presence of novel benign additives}, journal = {Energy Procedia}, volume = {158}, year = {2019}, pages = {5856 - 5865}, abstract = {

The apparent drawbacks of the classical approaches towards dissociation of natural gas hydrates have resulted in a paradigm shift into the development of new hybrid hydrate dissociation practices combining the various basic hydrate dissociation techniques. Another approach that can be followed to maximize the efficiency of gas production from natural gas hydrate reserves is the identification of benign additives which when used even in sparingly small concentrations may enhance the kinetics of hydrate dissociation. In the present work, a class of such additives, never reported before, have been unveiled and christened as Low Dosage Hydrate Dissociation Promoters (LHDPs). The additives were first short listed from a wide potential pool using a lab scale ( 250 ml) stirred tank reactor setup and then further studied using a bench scale ( 2.35 l) reactor setup where they were injected in the form of a water-additive stream to dissociate hydrates. The dissociation approach followed in the case of the bench scale reactor experiments was a combination of the thermal stimulation and depressurization processes along with the element of injection of additives. For both sets of experiments (lab and bench scale), the newly identified LHDPs were found to enhance the kinetics of methane hydrate dissociation as compared to pure water. It was observed that concentration of additive and its flow rate also affect the kinetics of methane hydrate dissociation. An energy and efficiency analysis for the hydrate dissociation method in the case of bench scale rector revealed that additive presence enhanced the energy ratio and thermal efficiency four fold as compared to pure water.

}, keywords = {Depressurization, Dissociation, Energy Ratio, kinetics, LHDP, methane hydrate, Thermal Efficiency, thermal stimulation}, issn = {1876-6102}, doi = {https://doi.org/10.1016/j.egypro.2019.01.540}, url = {http://www.sciencedirect.com/science/article/pii/S1876610219305648}, author = {Gaurav Bhattacharjee and Vivek Barmecha and Nilesh Choudhary and Nawal K. Pande and Parivesh Chugh and Rajnish Kumar} } @article {46444, title = {Methane recovery from marine gas hydrates: a bench scale study in presence of low dosage benign additives}, journal = {Applied Energy}, volume = {253}, year = {2019}, month = {NOV }, pages = {113566}, type = {Article; Proceedings Paper}, abstract = {

De-pressurization is one approach which has been found to be economically feasible for methane recovery from marine hydrates. Hydrate dissociation being an endothermic process suggests that de-pressurization alone would not be sufficient and some additional stimulation would be required for sustained production from one such reservoir. Thermal stimulation may overcome the challenge posed by the endothermic dissociation process; however, economically it may not be ideal. A possible way out is to use thermal stimulation, but at relatively low temperatures as compared to conventional practice. This would be economical and can be accomplished in the presence of small doses of additives mixed in with the water stream used for thermal stimulation. In the present study, a number of benign additives were identified which when used in low concentrations enhance the kinetics of methane hydrate dissociation compared to pure water. Additives were first shortlisted from a wide potential pool using quantum mechanical calculations. These additives were later tested for their efficacy in stirred tank reactor to quickly identify the best additives for the job and few selected additives were then studied in a larger bench scale setup (fixed bed configuration) where they were injected in the form of an additive-water stream to dissociate already formed hydrates. Factors such as toxicity of the additive, fluidity of additive-water stream, foam formation on mixing of additive with water, etc. were also taken into account. An energy and efficiency analysis revealed that reported additives enhance the energy ratio and thermal efficiency of the process as compared to pure water stimulation.

}, keywords = {Bench scale, kinetics, Marine hydrate, methane hydrate, Methane recovery, Natural gas hydrate, Process}, issn = {0306-2619}, doi = {10.1016/j.apenergy.2019.113566}, author = {Bhattacharjee, Gaurav and Choudhary, Nilesh and Barmecha, Vivek and Kushwaha, Omkar S. and Pande, Nawal K. and Chugh, Parivesh and Roy, Sudip and Kumar, Rajnish} } @article {47168, title = {Molecular dynamics study on growth of carbon dioxide and methane hydrate from a seed crystal}, journal = {Chinese Journal of Chemical Engineering}, volume = {27}, year = {2019}, month = {SEP}, pages = {2074-2080}, type = {Article}, abstract = {

In the current work, molecular dynamics simulation is employed to understand the intrinsic growth of carbon dioxide and methane hydrate starting from a seed crystal of methane and carbon dioxide respectively. This comparison was carried out because it has relevance to the recovery of methane gas from natural gas hydrate reservoirs by simultaneously sequestering a greenhouse gas like CO2. The seed crystal of carbon dioxide and methane hydrate was allowed to grow from a super-saturated mixture of carbon dioxide or methane molecules in water respectively. Two different concentrations (1:6 and 1:8.5) of CO2/CH4 molecules per water molecule were chosen based on gas-water composition in hydrate phase. The molecular level growth as a function of time was investigated by all atomistic molecular dynamics simulation under suitable temperature and pressure range which was well above the hydrate stability zone to ensure significantly faster growth kinetics. The concentration of CO2 molecules in water played a significant role in growth kinetics, and it was observed that maximizing the CO2 concentration in the aqueous phase may not result in faster growth of CO2 hydrate. On the contrary, methane hydrate growth was independent of methane molecule concentration in the aqueous phase. We have validated our results by performing experimental work on carbon dioxide hydrate where it was seen that under conditions appropriate for liquid CO2, the growth for carbon dioxide hydrate was very slow in the beginning. (C) 2019 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.

}, keywords = {Cage dynamics, CH4 recovery, CO2 sequestration, F-4 order parameter, kinetics, Natural gas hydrate, Thermodynamics}, issn = {1004-9541}, doi = {10.1016/j.cjche.2019.02.006}, author = {Nakate, Prajakta and Ghosh, Bappa and Das, Subhadip and Roy, Sudip and Kumar, Rajnish} } @article {46039, title = {Ring opening polymerization of lactide: kinetics and modeling}, journal = {Chemical Engineering Communications}, volume = {206}, year = {2019}, month = {SEP }, pages = {1159-1167}, type = {Article}, abstract = {

The ring opening polymerization (ROP) kinetics of L-lactide was studied in bulk at 150, 160, and 180 degrees C using stannous octoate [Sn(Oct)(2)] catalyst and 1-pyrene butanol co-catalyst. The effect of different parameters namely, time and co-catalyst to catalyst ratio was studied on the properties of polylactide. The experimental results showed high conversion of L-lactide. The kinetics of L-lactide ROP follows the co-ordination insertion mechanism. The experimental results obtained were studied to account for the reversible activation, propagation, termination, and validated by modeling using MATLAB. The model developed successfully predicts the monomer conversion and the kinetics of L-lactide ROP.

}, keywords = {1-pyrene butanol, Average molecular weights, GPC, kinetics, L-Lactide, Modeling and simulation, Polymerization temperature, Proton NMR, ROP, Stannous octoate}, issn = {0098-6445}, doi = {10.1080/00986445.2018.1550395}, author = {Metkar, Sangeeta and Sathe, Vivek and Rahman, Imran and Idage, Bhaskar and Idage, Susheela} } @article {46889, title = {Kinetics of hydroformylation of camphene using rhodium-phosphite catalyst}, journal = {International Journal of Chemical Kinetics}, volume = {52}, year = {2020}, month = {JUL}, pages = {485-495}, type = {Article}, abstract = {

Kinetics of hydroformylation of camphene was investigated in the presence of [Rh(CO)(2)(acac)]/P(OPh)(3) catalyst in a temperature range of 363-383 K. The influence of parameters such as stirring speed, camphene, catalyst, ligand concentrations, and partial pressures of H-2 and CO on the activity and selectivity of the catalyst has been studied. The rate showed a first-order dependence with respect to catalyst and camphene concentrations. The effect of partial pressure of hydrogen showed fractional order dependence. The plots of rate versus excess ligand, that is, (P(OPh)(3)) concentration and rate versus CO partial pressure passed through maxima and showed typical substrate/ligand inhibited kinetics. An empirical rate equation has been proposed and found to be in good agreement with the observed rate data. The kinetic parameters and activation energy were also evaluated.

}, keywords = {camphene, homogeneous, Hydroformylation, kinetics, rhodium-phosphite}, issn = {0538-8066}, doi = {10.1002/kin.21364, Early Access Date = APR 2020}, author = {Pagar, Nitin S. and Rajurkar, Kalpendra B. and Deshpande, Raj M.} } @article {46677, title = {Understanding the role of solvent properties on reaction kinetics for synthesis of silica nanoparticles}, journal = {Chemical Engineering Journal}, volume = {398}, year = {2020}, month = {OCT}, pages = {125427}, type = {Article}, abstract = {

The effect of various alcoholic solvents and their compositions on the size of silica particles synthesized through hydrolysis and condensation of tetraethyl orthosilicate (TEOS) is studied. The alcohols used are: Methanol, ethanol, propanol, i-propanol, butanol, pentanol, hexanol, octanol, decanol and do-decanol. Ethanol was used as a co-solvent with the higher molecular weight alcohols. Silica particles of size between 100 nm and 2 mu m were obtained by changing solvent composition. Concentrations of total soluble silica and silicic acid were measured and used for exploring the kinetics of hydrolysis and condensation reactions. Polarity, steric hindrance and viscosity of solvent were found to have a strong influence on the rate constants and size of silica nanoparticles. An attempt is made to correlate both final particle size and rate constants with dielectric constant, Wiener index and viscosity of the solvent.

}, keywords = {condensation, Hydrolysis, kinetics, silica particles, Solvents, Stober process}, issn = {1385-8947}, doi = {10.1016/j.cej.2020.125427}, author = {Bari, Atul H. and Jundale, Rajashri B. and Kulkarni, Amol. A.} } @article {47049, title = {Hydrate-based carbon capture process: assessment of various packed bed systems for boosted kinetics of hydrate formation}, journal = {Journal of Energy Resources Technology-Transactions of the ASME}, volume = {143}, year = {2021}, month = {MAR }, pages = {033005}, type = {Article}, abstract = {

The case for developing novel technologies for carbon dioxide (CO2) capture is fast gaining traction owing to increasing levels of anthropogenic CO2 being emitted into the atmosphere. Here, we have studied the hydrate-based carbon dioxide capture and separation process from a fundamental viewpoint by exploring the use of various packed bed media to enhance the kinetics of hydrate formation using pure CO2 as the hydrate former. We established the fixed bed reactor (FBR) configuration as a superior option over the commonly used stirred tank reactor (STR) setups typically used for hydrate formation studies by showing enhanced hydrate formation kinetics using the former. For the various packing material studied, we have observed silica gel with 100 nm pore size to return the best kinetic performance, corresponding to a water to hydrate conversion of 28 mol\% for 3 h of hydrate growth. The fundamental results obtained in the present study set up a solid foundation for follow-up works with a more applied perspective and should be of interest to researchers working in the carbon dioxide capture and storage and gas hydrate fields alike.

}, keywords = {air emissions from fossil fuel combustion, Carbon dioxide capture, combustion of waste, Fixed bed reactor, fuel combustion, Gas hydrate, hydrates, kinetics, Silica gel}, issn = {0195-0738}, doi = {10.1115/1.4048304}, author = {Arora, Amit and Kumar, Asheesh and Bhattacharjee, Gaurav and Balomajumder, Chandrajit and Kumar, Pushpendra} } @article {46661, title = {Kinetics of 1-decene hydroformylation in an aqueous biphasic medium using a water-soluble Rh-sulfoxantphos catalyst in the presence of a cosolvent}, journal = {International Journal of Chemical Kinetics}, volume = {53}, year = {2021}, month = {MAR}, pages = {333-344}, type = {Article}, abstract = {

The kinetics of hydroformylation of 1-decene has been studied in an aqueous biphasic medium using a water-soluble Rh-sulfoxantphos catalyst in the presence of N-methyl pyrrolidone as a cosolvent at 383-403 K. The rate was found to be first order, with concentrations of catalyst and olefin and partial order, with concentrations of hydrogen in the liquid phase. The plot of rate versus excess ligand and CO concentrations passed through maxima, indicating negative order dependence at higher concentrations. These trends have been interpreted based on the established hydroformylation mechanism. High selectivity towards the linear aldehyde was maintained (n: iso ratio \> 30). An empirical rate equation has been proposed which was found to be in good agreement with the observed rate data within the experimental error. The activation energy was evaluated to be 74.76 kJ/mol.

}, keywords = {1\&\#8208, aqueous\&\#8208, biphasic, cosolvent, decene, Hydroformylation, kinetics, rh\&\#8208, sulfoxantphos}, issn = {0538-8066}, doi = {10.1002/kin.21446, Early Access Date = OCT 2020}, author = {Pagar, Nitin S. and Deshpande, Raj M.} } @article {47627, title = {Mechanistic investigations on the catalytic transfer hydrogenation of lignin-derived monomers over Ru catalysts: theoretical and kinetic studies}, journal = {ACS Sustainable Chemistry \& Engineering}, volume = {9}, year = {2021}, month = {OCT}, pages = {14040-14050}, type = {Article}, abstract = {The hydrodeoxygenation (HDO) reaction of oxygenated compounds such as lignin-derived phenolics is well studied using molecular H-2 as a hydrogen source, yet the use of high pressures discourages its use on an industrial scale. As an alternative, the catalytic transfer hydrogenation (CTH) pathway provides in situ hydrogenation species, which reduces the need for the high-pressure infrastructure required when molecular hydrogen is used. Nevertheless, this strategy is scantly studied, and in lieu with this, herein we report the kinetic and mechanistic investigations of the CTH strategy for the HDO of guaiacol, phenol, anisole veratrole, and eugenol to their respective products. For potential commercialization purposes, low loading of metal, milder reaction conditions, and high selectivity toward desired products with a high H/C ratio were considered while designing catalysts (0.5 wt \% Ru on SiO2-Al2O3, SiO2, Al2O3-acidic, Al2O3-basic, and Al2O3-neutral) for these reactions. As high as 74\% cyclohexanol yield from guaiacol was achieved at 225 degrees C in the presence of isopropyl alcohol (IPA) as the hydrogen source and over the Ru/Al2O3-acidic catalyst reduced at 150 degrees C. A detailed kinetic study is carried out to understand the interaction of the substrate and intermediates with the catalyst and the influence of reaction parameters on the product formation. It was observed that the cisisomer of 2-methoxycyclohexanol rapidly undergoes further conversion than the trans-isomer. The experimental observations are substantiated through density functional theory (DFT) studies on Ru(0001) and guaiacol molecule complexes. DFT studies indicate that the adsorption of the cis-isomer is more exothermic as compared to that of the trans counterpart, and the underlying electronic factors are elucidated using charge density difference and density of states plots.}, keywords = {catalytic transfer hydrogenation, Cyclohexanol, DFT, Hydrodeoxygenation, kinetics, lignin monomers, Supported metal catalysts}, issn = {2168-0485}, doi = {10.1021/acssuschemeng.1c02942}, author = {Khan, Tufeil Sartaj and Singh, Dheerendra and Samal, Pragnya Paramita and Krishnamurty, Sailaja and Dhepe, Paresh Laxmikant} } @article {48095, title = {Use of isoperibolic reaction calorimeter for the study of reaction kinetics of acetic anhydride hydrolysis reaction: effect of acetic anhydride and water ratio}, journal = {Chemical and Process Engineering-Inzynieria Chemiczna I Procesowa}, volume = {43}, year = {2022}, month = {DEC}, pages = {255-264}, type = {Article; Proceedings Paper}, abstract = {

Reaction kinetics of acetic anhydride hydrolysis reaction is being studied at a fixed reaction temperature and ambient pressure using an isoperibolic reaction calorimeter. Temperature versus time data along with heat and mass balance is used to determine the kinetics parameters i.e. activation energy and Arrhenius coefficient. It has been studied with the varying volumetric ratio of acetic anhydride and water; and kinetics parameters were compared and plotted for each ratio. Such a study has not been done previously to determine the kinetics dependency on varying the acetic anhydride water ratio. As the acetic anhydride hydrolysis reaction is exothermic in nature, the present study will help to decide the safe and suitable operating conditions such as concentration and temperature for conducting this reaction at plant scale. The kinetic data presented can be used further for the mathematical modeling and simulation of such exothermic hydrolysis reactions.

}, keywords = {acetic anhydride, Hydrolysis, kinetics, reaction calorimeter, Water}, issn = {0208-6425}, doi = {10.24425/cpe.2022.140829}, author = {Kumar, Rajendra and Tiwari, Anurag Kumar} } @article {49135, title = {Activity performance and kinetics for glycerol carbonylation with urea over Zn-Co mixed metal oxide catalyst}, journal = {Canadian Journal of Chemical Engineering }, volume = {101}, year = {2023}, month = {APR}, pages = {2075-2093}, type = {Article}, abstract = {

Efficient carbonylation of glycerol using urea with Zn-Co mixed metal oxide (MMO) catalyst has been achieved. Various methods of catalyst preparation were explored for glycerol carbonate (GC) synthesis. The optimized method of catalyst preparation was found to be co-precipitation (CP) with a Zn:Co ratio of 70:30, achieving 81\% glycerol conversion with 97\% GC selectivity. X-ray diffraction (XRD) studies revealed the formation of ZnO, Co-3 O-4, and spinel ZnCo2O4 phases. Thermal treatment given to the catalyst allows insertion of Zn cations into Co3O4 lattice forming ZnCo2O4 phase which was also evidenced in X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Herein, for the first time, reaction kinetics was studied to propose the rate equation, based on which a plausible reaction pathway is proposed involving two-site adsorption of glycerol (basic site) and urea (acidic site), which undergo carbonylation followed by cyclization into GC. A recycle study and hot filtration test have proven the reusability of the catalyst.

}, keywords = {Carbonylation, cyclic carbonate, Glycerol, kinetics, mixed metal oxide}, issn = {0008-4034}, doi = {10.1002/cjce.24587}, author = {Kondawar, Sharda E. and Kasar, Gaytri B. and Khatua, Angshuman S. and Rode, V, Chandrashekhar} } @article {48975, title = {Etherification of biomass-derived glycerol to oxygenated fuel additives using dodecatungstophosphoric-silica-supported catalyst: characterization and kinetic studies}, journal = {Biomass Conversion and Biorefinery }, volume = {13}, year = {2023}, month = {NOV}, pages = {16285-16295}, type = {Article}, abstract = {

Commercial biodiesel production is becoming popular due to its sustainability and reduced greenhouse gas emissions in comparison to fossil fuels. Biodiesel production involves the co-generation of crude glycerol that is not directly viable. Valorization of glycerol is essential from techno-economic perspective to achieve goals of circular economy. In this study, the glycerol etherification was carried out using tert-butyl alcohol in presence of dodecatungstophosphoric/silica (DTP/SiO2) catalyst for production of tert-butyl glycerol ethers that can be used as fuel additives. A series of DTP/SiO2 catalysts were prepared with various compositions by impregnating heteropoly acids (HPA, H3PW12O40). The product analysis was performed to monitor mono-, di-, and tri-tert-butyl glycerol ethers. The kinetic studies were conducted based on Langmuir-Hinshelwood model. The rate constants were determined from experimental data by regression analysis. The catalysts were characterized by X-ray diffraction, SEM/EDX, and thermogravimetric analysis. Varying DTP loadings resulted in different catalytic activities. Activation energy (38.23 kJ/mol), activation enthalpy (25.94 kJ/mol), activation entropy (-163.8 J/mol/K), and Gibbs free energy of activation (88.67 kJ/mol) were attained for DTP/SiO2 (20\%) catalyst that exhibited the best selectivity for di-tert-butyl glycerol ethers.

}, keywords = {Catalytic, etherification, fuel additives, Hinselwood, Impregnation, kinetics, Langmuir}, issn = {2190-6815}, doi = {10.1007/s13399-023-04880-9}, author = {Magar, Subhash B. and Kapoor, Ashish and Jana, Sumit Kumar and Pal, Dan Bahadur and Rode, Chandrashekhar V.} } @article {49134, title = {Multistep molecular mechanism of amyloid-like aggregation of nucleic acid-binding domain of TDP-43}, journal = {Proteins- Structure Function and Bioinformatics}, volume = {91}, year = {2023}, month = {MAY}, pages = {649-664}, type = {Article}, abstract = {

TDP-43 protein is associated with many neurodegenerative diseases and has been shown to adopt various oligomeric and fibrillar states. However, a detailed kinetic understanding of the structural transformation of the native form of the protein to the fibrillar state is missing. In this study, we delineate the temporal sequence of structural events during the amyloid-like assembly of the functional nucleic acid-binding domain of TDP-43. We kinetically mapped the aggregation process using multiple probes such as tryptophan and thioflavin T (ThT) fluorescence, circular dichroism (CD), and dynamic light scattering (DLS) targeting different structural events. Our data reveal that aggregation occurs in four distinct steps-very fast, fast, slow, and very slow. The {\textquoteleft}{\textquoteleft}very fast{\textquoteright}{\textquoteright} change results in partially unfolded forms that undergo conformational conversion, oligomerization and bind to ThT in the {\textquoteleft}{\textquoteleft}fast step{\textquoteright}{\textquoteright} to form higher order intermediates (HOI). The temporal sequence of the formation of ThT binding sites and conformational conversion depends upon the protein concentration. The HOI further undergoes structural rearrangement to form protofibrils in the {\textquoteleft}{\textquoteleft}slow{\textquoteright}{\textquoteright} step, which, consequently, assembles in the {\textquoteleft}{\textquoteleft}very slow{\textquoteright}{\textquoteright} step to form an amyloid-like assembly. The spectroscopic properties of the amyloid-like assembly across the protein concentration remain similar. Additionally, we observe no lag phase across protein concentration for all the probes studied, suggesting that the aggregation process follows a linear polymerization reaction. Overall, our study demonstrates that the amyloid-like assembly forms in multiple steps, which is also supported by the temperature dependence of the kinetics.

}, keywords = {aggregation pathway, amyloid-like assembly, conformational conversion, kinetics, oligomers}, issn = {0887-3585}, doi = {10.1002/prot.26455}, author = {Pillai, Meenakshi and Jha, Santosh Kumar} } @article {49233, title = {Efficient glycolysis of used PET bottles into a high-quality valuable monomer using a shape-engineered MnO nanocatalyst}, journal = {CATALYSIS SCIENCE \& TECHNOLOGY}, volume = {14}, year = {2024}, month = {SEP }, type = {Journal Article}, keywords = {Catalyst, kinetics, Nanorods, Oxidation, Oxides, POLY(ETHYLENE-TEREPHTHALATE), WASTE}, issn = {2044-4753}, doi = {10.1039/d4cy00823e}, author = {Swapna, Bhattu and Singh, Nittan and Patowary, Suranjana and Bharali, Pankaj and Madras, Giridhar and Sudarsanam, Putla} } @article {49418, title = {Kinetic investigation on palladium-catalyzed carbonylation of allyl alcohol}, journal = {International Journal of Chemical Kinetics}, year = {2024}, month = {OCT}, type = {Article; Early Access}, abstract = {

Palladium-catalyzed carbonylation of allyl alcohol to 3-butenoic acid has been investigated. A significant effect of halide promoters, p-tolylsulfonic acid (TsOH), water, solvents, and PPh3 concentration activity and selectivity has been studied. Detailed kinetics of this reaction was investigated in a temperature range of 363-383 K. The influence of parameters such as stirring speed, allyl alcohol, catalyst, benzyltriethylammonium chloride (BTEAC), TsOH concentrations, and CO partial pressures on the activity and selectivity has been studied. An empirical rate equation was suggested and found to be fairly consistent with observed rate data. In addition, the activation energy and kinetic parameters were evaluated.

}, keywords = {allyl alcohol, Carbonylation, halide promoters, kinetics, Mechanism, Palladium}, issn = {0538-8066}, doi = {10.1002/kin.21767}, author = {Tonde, Sunil S. and Rajurkar, Kalpendra B. and Pagar, Nitin S.} }