@article {46971, title = {Enhancing thermomechanical and chemical stability of polymer electrolyte membranes using polydopamine coated nanocellulose}, journal = {ACS Applied Energy Materials}, volume = {3}, year = {2020}, month = {FEB}, pages = {1988-1999}, type = {Article}, abstract = {

We report here an approach to enhance the chemical and thermomechanical stability of polymer electrolyte membranes without compromising proton conductivity. Multifunctional polydopamine coated nanocellulose (PNC) was prepared by oxidative polymerization of dopamine on nano cellulose fibers and subsequently incorporated in Nafion by solution blending. PNC had a very significant effect on the thermomechanical properties of Nafion showing up to 200\% improvement in the storage modulus at 90 degrees C. The PNC network also enhanced the dimensional stability of Nafion under constant stress. The 3 wt \% PNC composite membrane showed a drastic reduction in creep compliance of about 39.9\% and 46.5\% in J(max) at 30 degrees and 60 degrees C, respectively. Free radical scavenging properties of polydopamine also helped to significantly enhance the chemical stability of Nafion, which was ascertained by accelerated degradation tests conducted in Fenton{\textquoteright}s reagent at 70 degrees C over 40 days. F-19 CP MAS solid state NMR, FTIR, and tensile tests on the membranes show higher chemical stability of the 3 wt \% PNC composite membrane. The proton conductivity of the 3 wt \% PNC composite membrane at 90 degrees C and 100\% RH (similar to 125 mS/cm) was slightly higher than the Nafion membrane (similar to 94 mS/cm) at similar conditions. The retention of proton conductivity even with lower water uptake could be ascribed to proton hopping through polydopamine coated nanocellulose. Performance of the composite membrane was also evaluated in a single stack fuel cell and found to be better than recast Nafion. The benefits derived by this approach are not restricted to Nafion alone and shall broadly apply to many other polymer membranes.

}, keywords = {cellulose nanofibers, chemical stability, dimensional stability, fuel cell, polydopamine, polymer electrolyte membrane}, issn = {2574-0962}, doi = {10.1021/acsaem.9b02417}, author = {Ram, Farsa and Velayutham, Parthiban and Sahu, Akhila Kumar and Lele, Ashish K. and Shanmuganathan, Kadhiravan} } @article {48231, title = {Effect of oxalic acid and sulphuric acid hydrolysis on the preparation and properties of pineapple pomace derived cellulose nanofibers and nanopapers}, journal = {International Journal of Biological Macromolecules}, volume = {209}, year = {2022}, month = {JUN }, pages = {1745-1759}, type = {Article}, abstract = {

Nanocellulose is the {\textquoteleft}{\textquoteleft}green magnet{\textquoteright}{\textquoteright} which attracts a wide spectrum of industries towards it due to its availability, biodegradability, and possible smart applications. For the first time, pineapple pomace was being explored as an economic precursor for cellulose nanofibers. Nanofiber isolation was accomplished using a chemo-mechanical method and solution casting was adopted for the development of nanopapers. Moreover, the study examines the structural, optical, crystalline, dimensional, and thermal features of nanofibers isolated using different acid hydrolysis (oxalic acid and sulphuric acid) methods. Fourier-transform infra-red spectroscopy, 13C solid-state nuclear magnetic resonance spectroscopy, and X-ray diffraction analysis indicated the presence of type I cellulose. The transmittance, crystallinity index, and thermal stability of PPNFS (sulphuric acid treated fiber) were greater than PPNFO (oxalic acid treated fiber). The transmission electron microscopy and dynamic light scattering analysis confirmed the nanodimension of PPNFO and PPNFS. While comparing the optical and mechanical properties of nanopapers, PPNFS outperforms PPNFO. The tensile strength of the prepared nanopapers (64 MPa (PPNFO) and 68 MPa (PPNFS)) was found to be high compared to similar works reported in the literature. The prepared nanopaper is proposed to be used for food packaging applications.

}, keywords = {cellulose nanofibers, Cellulosic nanopapers, Pineapple pomace}, issn = {0141-8130}, doi = {10.1016/j.ijbiomac.2022.04.138}, author = {Neenu, K. V. and Dominic, C. D. Midhun and Begum, P. M. Sabura and Parameswaranpillai, Jyotishkumar and Kanoth, Bipinbal Parambath and David, Deepthi Anna and Sajadi, S. Mohammad and Dhanyasree, P. and Ajithkumar, T. G. and Badawi, Michael} } @article {49633, title = {Colocasia esculenta stems for the isolation of cellulose nanofibers: a chlorine-free method for the biomass conversion}, journal = {Biomass Conversion and Biorefinery}, volume = {14}, year = {2024}, month = {MAY}, pages = {10305-10318}, type = {Article}, abstract = {

The reuse of waste products is the green key to sustainability. The extraction of cellulose nanofibers from Colocasia esculenta stems is presented in the paper. The study proved that the waste biomass could be effectively re-engineered into highly valued cellulose nanofibers (CNFs). Cellulose nanofibers were extracted via a chemo-mechanical route. The pre-treatments included mild alkali hydrolysis (2\% NaOH) and chlorine-free bleaching (peroxide bleaching in an alkaline medium). Cellulose I-beta structure was confirmed using C-13 solid-state nuclear magnetic resonance spectroscopy and X-ray diffraction analysis. The elemental analysis of CNFs detected the elements, carbon and oxygen. The CNFs had a crystallinity and transmittance of 71.72\% and 60\%, respectively. Microscopic studies verified the elimination of non-cellulosic components and the fibrous nature of CNFs. Moreover, the fiber diameter of CNFs was 20-40 nm. Thermal analysis revealed good thermal stability of 335.8 degrees C (T-50) for nanofibers. Long-term aids are numerous in eco-friendly technology. Developing an eco-design will support zero waste ideals, lowers carbon dioxide emissions, and encourages a circular economy. Owing to the merits of natural fibers, they can be adopted in various sectors including packaging, automobile, aerospace, electronics, biomedical, construction, and furniture.

}, keywords = {acid hydrolysis, cellulose nanofibers, Colocasia esculenta stems, High crystallinity}, issn = {2190-6815}, doi = {10.1007/s13399-022-03171-z}, author = {Dominic, C. D. Midhun and Maheswary, S. and Neenu, V. K. and Sajadi, S. Mohammad and Rosa, Derval dos Santos and Begum, P. M. Sabura and Mathew, Mariya and Ajithkumar, T. G. and Parameswaranpillai, Jyotishkumar and George, Tresa Sunitha and Resmi, V. C. and Ilyas, R. A. and Badawi, Michael} }