Cellulose nano whiskers from grass of Korea

Abstract

Polymer composites form a fascinating interdisciplinary area by bringing together biology and material science for wide verity of applications ranging from construction to biomedical technology. A deliberate interest in the development of eco-friendly material motivated the efforts toward research on cellulose composites due to its cheap, sustainable, recyclable, degradable nature and remarkable reinforcing properties at 167.5 GPa of Young’s modulus along the chain axis per theoretical estimations. The use of natural fiber for technical applications like automobile industry is restricted due to its incompatibility with generally hydrophobic host matrix and increase in weight of resulting products which provide a poor cost performance ratio. After resolving the incompatibility issues up to a satisfactory extent by adequate modification either in host or filler, it was assumed that dispersion and material properties may be enhanced with reduction in the size and increase in surface area by introducing nano fillers. Nano size (5-20 nm cross sections with length to several μm depending on source) rod like cellulose crystallites particles, known as cellulose nano whiskers (CNW), can be extracted from laterally stabilized fibrils bundle by removing amorphous region through controlled acid hydrolysis. These whiskers have been employed in reinforcing several polymers, which result in comparatively better mechanical properties. Nevertheless, such fibers have conquered many obstacles against industrial practices due to time consuming preparation procedure with very low yield, commercial unavailability, and most importantly, comparative higher cost through expensive source such as tunicate, bacterial, algal (valonia), brown algae (Oomycota) and commercially available microcrystalline cellulose. The low yield and availability of raw materials of these sources generally inhibit the penetration of this tremendous reinforcer for the development of daily use biodegradable products. The current attempt was made to obtain the cellulose nano whiskers from the cheapest source, grass of Koera for the first time, which may further broaden the use of these bio fillers ranging from commodity to constructive applications.