@article { ISI:000268215200019, title = {Vapour sensing with conductive polymer nanocomposites (CPC): polycarbonate-carbon nanotubes transducers with hierarchical structure processed by spray layer by layer}, journal = {Sensors and Actuators B-Chemical}, volume = {140}, number = {2}, year = {2009}, month = {JUL}, pages = {451-460}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

The development of conductive polymer nanocomposite (CPC) sensors for volatile organic compounds (VOC) detection has been carried out using a spray layer by layer (LbL) process. This technique was successfully used to hierarchically structure polycarbonate-multiwall carbon nanotubes (PC-CNT) solutions into a double percolated architecture as attested by atomic force microscopy (AFM) and optical microscopy (OM). PC-CNT vapour sensing behaviour was investigated as a function of CNT content, films thickness, vapour flow and vapours solubility parameter. The response ranking A(r)(toluene)\>A(r)(methanol)\>A(r)(water)of PC-CNT was found to be coherent with kappa(12) Flory-Huggins interaction parameters provided that signals are normalised by analyte molecules number. Signals shape was interpreted to the light of Langmuir-Henry-Clustering (LHC) model and found to be proportional to vapour content. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Atomic force microscopy, carbon nanotube, Chemo-electrical behaviour, Conductive polymer nanocomposite, Vapour Sensing, Volatile organic compounds}, issn = {0925-4005}, doi = {10.1016/j.snb.2009.05.006}, author = {Lu, Jianbo and Kumar, Bijandra and Castro, Mickael and Feller, Jean-Francois} } @article { ISI:000328443300015, title = {Surface induced collapse of A beta(1-42) with the F19A replacement following adsorption on a single walled carbon nanotube}, journal = {Biophysical Chemistry}, volume = {184}, year = {2013}, month = {DEC}, pages = {108-115}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Spontaneous adsorption of the A beta peptide on the surface of a single-walled carbon nanotube, resulting in the prevention of its intrinsic propensity to form collapsed states, could be a plausible means to hinder the peptide{\textquoteright}s initial nucleation and self-assembly. We report here the effects of sharply reducing both aromatic and hydrophobic character within the peptide{\textquoteright}s central hydrophobic core on its free and surface behavior. In such an altered peptide, complete surface adsorption is found to induce, rather than prevent, the adsorbed peptide{\textquoteright}s collapse. The weakened surface interactions of the central hydrophobic core allow its greater translational mobility on the surface, thereby facilitating interactions that lead to compaction. Both the adsorption and the subsequent collapse are accompanied by a loss of surface hydration in the modified peptide. We further find that such a two-step dewetting leads to hydration levels comparable to that obtained after compaction of the free peptide. These insights may be leveraged for designing molecular surfaces for disrupting intrinsic A beta behavior. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {Adsorption, Amyloid beta peptide, carbon nanotube, Lateral mobility, molecular dynamics simulation, Surface induced collapse}, issn = {0301-4622}, doi = {10.1016/j.bpc.2013.09.008}, author = {Jana, Asis K. and Sengupta, Neelanjana} } @article { ISI:000364355500053, title = {Carbon nanohorn-derived graphene nanotubes as a platinum-free fuel cell cathode}, journal = {ACS Applied Materials \& Interfaces}, volume = {7}, number = {43}, year = {2015}, month = {NOV}, pages = {24256-24264}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Current low-temperature fuel cell research mainly focuses on the development of efficient nonprecious electrocatalysts for the reduction of dioxygen molecule due to the reasons like exorbitant cost and scarcity of the current state-of-the-art Pt-based catalysts. As a potential alternative to such costly electrocatalysts, we report here the preparation of an efficient graphene nanotube based oxygen reduction electrocatalyst which has been derived from single walled nanohorns, comprising a thin layer of graphene nanotubes and encapsulated iron oxide nanopartides (FeGNT). FeGNT shows a surface area of 750 m(2)/g, which is the highest ever reported among the metal encapsulated nanotubes. Moreover, the graphene protected iron oxide nanoparticles assist the system to attain efficient distribution of Fe-N-x and quaternary nitrogen based active reaction centers, which provides better activity and stability toward the oxygen reduction reaction (ORR) in acidic as well as alkaline conditions. Single cell performance of a proton exchange membrane fuel cell by using FeGNT as the cathode catalyst delivered a maximum power density of 200 mW cm(-2) with Nafion as the proton exchange membrane at 60 degrees C. The facile synthesis strategy with iron oxide encapsulated graphitic carbon morphology opens up a new horizon of hope toward developing Pt-free fuel cells and metal-air batteries along with its applicability in other energy conversion and storage devices.

}, keywords = {carbon nanohorns, carbon nanotube, electrocatalyst, fuel cell, oxygen reduction reaction}, issn = {1944-8244}, doi = {10.1021/acsami.5b07802}, author = {Unni, SreeKuttan M. and Illathvalappil, Rajith and Bhange, Siddheshwar N. and Puthenpediakkal, Hasna and Kurungot, Sreekumar} } @article { ISI:000374873100022, title = {Various types of separation membranes}, journal = {Current Science}, volume = {110}, number = {8}, year = {2016}, month = {APR}, pages = {1426-1438}, publisher = {INDIAN ACAD SCIENCES}, address = {C V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIA}, abstract = {

Membrane-based separation is a superior alternative to conventional processes in many separation problems of practical importance. For maximum effectiveness, both high selectivity and flux are desirable. This article summarizes the global efforts at designing new membrane materials, particularly carbon nanotube (CNT)-based membranes, to achieve the twin objectives mentioned above. Interest in CNT emanates from the excellent transport property of molecules through its frictionless smooth walls, with/without functionalization at the end tips. Permeation of water through graphene oxide (GO) channels, which are otherwise impermeable to solutes, has also generated considerable interest, and GO is being viewed as a promising material for separations. The performances of conducting polymers like polypyrrole, polyaniline, polythiophene-3, 4-ethylenedioxythiophene and their different composites have been studied as a function of changes in morphology and redox behaviour, and this aspect too is covered in the present article. Also, the dependence of the separation performances based on the size, charge and hydrophobic/hydrophilic properties has been discussed in detail. Advances in understanding will have an important bearing on future developments in separation science.

}, keywords = {carbon nanotube, conducting polymers, flux, graphene oxide, permeability, separation membranes}, issn = {0011-3891}, author = {Das, Debasree and Datta, Anindya and Contractor, Aliasgar Qutub} } @article {46940, title = {FeNx/FeSx-anchored carbon sheet-carbon nanotube composite electrocatalysts for oxygen reduction}, journal = {ACS Applied Nano Materials}, volume = {3}, year = {2020}, month = {MAR}, pages = {2234-2245}, type = {Article}, abstract = {

Even though various Pt-free electrocatalysts for oxygen reduction reaction (ORR) have been introduced, many of them are found to be active only in alkaline conditions. Considering Nafion, phosphoric acid-doped polybenzimidazole (PBI), and so on as the prominent ionomer membranes, used in the commercially available polymer electrolyte membrane fuel cells (PEMFCs), it becomes important that any development on the Pt-free catalysts should ensure the better ORR performance under acidic conditions. The present work effectively tackles this issue, where an ORR-based catalyst could be prepared with simultaneous incorporation of both Fe-N and Fe-S active sites on in situ generated carbon sheets which are spatially separated by the carbon nanotube (CNT) network. This catalyst shows ability to perform under both acidic and basic conditions. This has been achieved by growing a polyethylenedioxythiophene polymer network in the presence of CNT and melamine followed by its pyrolysis under an inert atmosphere. The catalyst formed at 900 degrees C (PMCNT-900) displays 0.94 V onset potential for ORR under acidic electrolyte conditions, which corresponds to 60 mV overpotential compared to its 40 wt \% Pt/C counterpart. Interestingly, in single cell demonstration of Nafion-based PEMFC with PMCNT-900 as the cathode catalyst, the system delivered a maximum power density (PD) of 500 and 275 mW/cm(2) at 60 degrees C under H-2-O-2 and H-2-air feed conditions, respectively. On the other hand, in a single cell test in the anion exchange membrane fuel cell (AEMFC) mode, a maximum power density of 65 mW/cm(2) at 50 degrees C could be achieved with the same cathode catalyst, which is a comparable value obtained while employing Pt/C as the cathode. These results, thus, infer to the efficiency of the catalyst to facilitate ORR under the extreme pH conditions, and particularly its performance under acidic condition reveals its prospect as a potential Pt-free electrocatalyst to serve in the Nafion-based systems.

}, keywords = {carbon nanotube, electrocatalyst, fuel cell, oxygen reduction reaction, Pt-free ORR}, issn = {2574-0970}, doi = {10.1021/acsanm.9b02335}, author = {Bhange, Siddheshwar N. and Soni, Roby and Singla, Gourav and Ajithkumar, T. G. and Kurungot, Sreekumar} } @article {48140, title = {Wearable fabric supercapacitors based on CNTs and polyhedral ZnO with a wide potential window}, journal = {International Journal of Energy Research}, volume = {46}, year = {2022}, month = {MAY}, pages = {8186-8200}, type = {Article}, abstract = {

Wearable electronic devices such as health monitors, sensors, and e-skin can be powered by lightweight, high-power supercapacitors. Using a binder-free and low-temperature hydrothermal method, polyhedral ZnO nanoparticles were grown on carbon nanotube (CNT)-decorated cotton fabric, which is friendly to human skin and highly wearable, inexpensive, and thus commercially viable. The concentration of the starting material, zinc acetate, was varied to optimize the electrochemical performance. The evenly spaced polyhedral ZnO facilitated efficient permeation of the electrolyte into the active material. The fabric filaments were decorated with CNTs to enhance electron transfer and the overall electrochemical processes. The symmetric cell comprised of cotton fabric decorated with ZnO polyhedron/CNT showed no discernible change in the cyclic voltammetry curves even after 500 bending cycles, demonstrating the mechanical durability of the electrode. The potential window of 1.6 V using a Na2SO4/K2SO4 aqueous dual-ion electrolyte improved the long-term electrochemical stability and increased the energy storage capacity. The capacitance retention was 94\% after 5000 cycles at a current density of 1 A center dot g(-1), indicating long-term electrochemical stability. A specific capacitance of 375 F center dot g(-1) at a current density of 5 A center dot g(-1) and energy density of 33.3 Wh center dot kg(-1) at a power density of 2000 W center dot kg(-1) were recorded for the optimized electrode. Highlights Polyhedral ZnO was grown on cotton fabric using a hydrothermal process. The electrochemical performance was optimized by varying the zinc acetate concentration. The highest specific capacitance was 375 F center dot g(-1) at a current density of 5 A center dot g(-1). Under optimal conditions, the capacitance retention was 94\% at N = 5000 cycles. The energy density of the electrode was as high as 33.3 Wh center dot kg(-1).

}, keywords = {carbon nanotube, Cotton fabric, hydrothermal process, wearable supercapacitor, ZnO polyhedron}, issn = {0363-907X}, doi = {10.1002/er.7720}, author = {Samuel, Edmund and Joshi, Bhavana and Park, Chanwoo and Aldalbahi, Ali and El-Newehy, Mohamed and Lee, Hae-Seok and Yoon, Sam S.} }