Cellulose Essay

Cellulose is the most abundant, biodegradable, renewable polymer resources synthesized in the plants. It is estimated that 1010–1011 tons of biomass is synthesized and destroyed every year (Helbert et al., 1996). Cellulose is the polysaccharide constituent present in the cell walls of the grasses, reeds, stalks and woody vegetation. It consists of repeating units of linear β-1,4 glucose units (McCann et al.,1990). The cellulose fibers are bundled in the form of microfibrils of size range from few nanometers to few micrometers in length depending on the source of cellulose (Oksman et al., 2006). The microfibrils comprises of crystalline regions of long thread like bundles of molecules stabilized by inter and intramolecular hydrogen bonds between hydroxyl groups and oxygen of adjacent molecules separated by randomly oriented amorphous regions (Wyssling, 1968). The amorphous regions of the cellulose can easily be broken down by the controlled chemical treatment to obtain monocrystalline cellulose.

The cellulose microfibrils in the plant cell wall are surrounded and joined by loose network of other polysaccharides such as hemicellulose which is less crystalline than the cellulose. Hemicelluloses provide mechanical strength and toughness to the plant cell wall (Vincent, 2000). Along with hemicelluloses, other non-cellulosic materials like lignins and pectins (water binding polysaccharides) are also present in the cell wall. To obtain pure cellulose microfibrils, it is necessary to remove hemicelluloses, lignin and pectin from the cell wall. Isolation of cellulose nanofibers/microfibers from the plant cell walls is possible by the use of many processes: mechanical process (Nakagaito, 2004), chemical combined with mechanical methods (Di...

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... to grow again but the growth of bamboo leaves is comparatively much faster. Even after maturity, the leaves fall off from the tree as a biological waste. So the present study describes for the first time, according to best of our knowledge, the isolation of CNCs from the leaves of two different species of bamboo, use of CNCs and AgNPs for preparation of bionanocomposites and further characterization. We isolated CNCs from the leaves of two different species of bamboo by chemical combined with mechanical method and adopted green approach to prepare nanocomposites (CNCs/AgNPs) using in situ method. As the different species sources differ in terms of tissue structure and function, further analysis of the characteristics of CNCs and bionanocomposites of both the bamboo species was done for comparison. The bionanocomposites were tested for their antimicrobial activity.