Post Harvest Processing 78 Enzyme/Zinc Chloride Pretreatment of Short- Staple Cotton Fibres for Energy Reduction during Nano-Fibrillation by Refining Process N. Vigneshwaran1*, Vilas Karande1, G.B. Hadge1, S.T. Mhaske2 and A.K. Bharimalla1 1Nanotechnology Research Lab, Chemical and Biochemical Processing Division, Central Institute for Research on Cotton Technology, 2Department of Polymer and Surface Engineering, Institute of Chemical Technology, Matunga, Mumbai–400019, India e-mail:
[email protected] Abstract—Cellulose is a renewable, biodegradable and the most abundant biopolymer available on the Earth. Natural Cellulosic fibers are synthesized mainly in plants and cellulose constitutes 40-50% of wood, 80% of flax and 90% of cotton fibers. Microfibrils are defined as the fibers of 0.1-1.0 μm diameter, with high aspect ratio and nanofibrils are at least one dimension in nanometer scale (1-100 nm). Nanofibrils of cellulose have potential use in high efficiency filters, tissue scaffolds and as reinforcing agent in composites. In this work, we have processed short-staple cotton fibres through refining process for the production of nanofibrils. The refining process, through shear force, pumps water into the secondary layer and loosens the compactness of fibrillar structure by disrupting the hydrogen bonding. To enhance the efficiency of refining process, pretreatments using enzyme / zinc chloride were developed to open up the primary layer. Cellulase enzyme pretreatment hydrolyzed the surface molecules in cellulose while zinc chloride act as a swelling agent thereby increasing the accessibility to secondary layer. Since the refining is a continuous process with very low residence time, minimum of 30 passes were required for complete fibrillation resulting in huge energy consumption.