ICNF 2017 - 3rd International Conference on Natural Fibers
Sabu Thomas
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Manufacturing of Nanomaterials from Agro-Wastes and
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Biography
Sabu Thomas is Professor and Director of Polymer Science and Engineering at the School of Chemical Sciences, as well as the Director of Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kerala, India. He received his Ph.D. in 1987 in Polymer Engineering from the Indian Institute of Technology (IIT), Kharagpur, India. He is a Fellow of the Royal Society of Chemistry. Prof. Thomas has (co-)authored more than 600 research papers in international peer-reviewed journals in the area of polymer composites, nanocomposites, membrane separation, polymer blends and alloys, polymeric scaffolds for tissue engineering and polymer recycling. Prof. Thomas has been involved in a number of books (54 books), both as author and editor. He has been ranked no. 5 in India with regard to the number of publications (listed in the panel of most productive scientists in the country). He received the coveted Sukumar Maithy Award for the best polymer researcher in the country for the year 2008 and he received the Loyalty Award in the “International Materials Technology Conference Exhibition” in 2016.
The research group of Prof. Thomas has received numerous awards and honors for excellent work in polymer science and engineering. The h index of Prof. Thomas is 77 and he has more than 25.300 citations. Prof. Thomas has 6 patents to his credit. Recently he has been awarded CRSI, Nanotech and MRSI awards. Prof. Tomas has supervised 66 PhD theses and has delivered more than 300 invited /plenary and key note talks over 30 countries.
Abstract
Green chemistry started for the search of benign methods for the development of nanoparticles from nature and their use in the field of antibacterial, antioxidant, and antitumor applications. Bio wastes are eco-friendly starting materials to produce typical nanoparticles with well-defined chemical composition, size, and morphology. Cellulose, starch, chitin and chitosan are the most abundant biopolymers around the world. All are under the polysaccharides family in which cellulose is one of the important structural components of the primary cell wall of green plants. Cellulose nanoparticles(fibers, crystals and whiskers) can be extracted from agrowaste resources such as jute, coir, bamboo, pineapple leafs, coir etc. Chitin is the second most abundant biopolymer after cellulose, it is a characteristic component of the cell walls of fungi, the exoskeletons of arthropods and nanoparticles of chitin (fibers, whiskers) can be extracted from shrimp and crab shells. Chitosan is the derivative of chitin, prepared by the removal of acetyl group from chitin (Deacetylation). Starch nano particles can be extracted from tapioca and potato wastes. These nanoparticles can be converted into smart and functional biomaterials by functionalisation through chemical modifications (esterification, etherification, TEMPO oxidation, carboxylation and hydroxylation etc) due to presence of large amount of hydroxyl group on the surface. The preparation of these nanoparticles include both series of chemical as well as mechanical treatments; crushing, grinding, alkali, bleaching and acid treatments. Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) are used to investigate the morphology of nanoscale biopolymers. Fourier transform infra-red spectroscopy (FTIR) and x ray diffraction (XRD) are being used to study the functional group changes, crystallographic texture of nanoscale biopolymers respectively. Since large quantities of bio wastes are produced annually, further utilization of cellulose, starch and chitins as functionalized materials is very much desired. The cellulose, starch and chitin nano particles are currently obtained as aqueous suspensions which are used as reinforcing additives for high performance environment-friendly biodegradable polymer materials. These nanocomposites are being used as biomedical composites for drug/gene delivery, nano scaffolds in tissue engineering and cosmetic orthodontics. The reinforcing effect of these nanoparticles results from the formation of a percolating network based on hydrogen bonding forces. The incorporation of these nano particles in several bio-based polymers have been discussed. The role of nano particle dispersion, distribution, interfacial adhesion and orientation on the properties of the eco friendly bio nanocomposites have been carefully evaluated.
