%0 Journal Article
%T Isolation of Cellulose Nanofibers: Effect of Biotreatment on Hydrogen Bonding Network in Wood Fibers
%A Sreekumar Janardhnan
%A Mohini Sain
%J International Journal of Polymer Science
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/279610
%X The use of cellulose nanofibres as high-strength reinforcement in nano-biocomposites is very enthusiastically being explored due to their biodegradability, renewability, and high specific strength properties. Cellulose, through a regular network of inter- and intramolecular hydrogen bonds, is organized into perfect stereoregular configuration called microfibrils which further aggregate to different levels to form the fibre. Intermolecular hydrogen bonding at various levels, especially at the elementary level, is the major binding force that one need to overcome to reverse engineer these fibres into their microfibrillar level. This paper briefly describes a novel enzymatic fibre pretreatment developed to facilitate the isolation of cellulose microfibrils and explores effectiveness of biotreatment on the intermolecular and intramolecular hydrogen bonding in the fiber. Bleached Kraft Softwood Pulp was treated with a fungus (OS1) isolated from elm tree infected with Dutch elm disease. Cellulose microfibrils were isolated from these treated fibers by high-shear refining. The % yield of nanofibres and their diameter distribution (<50£¿nm) isolated from the bio-treated fibers indicated a substantial increase compared to those isolated from untreated fibers. FT-IR spectral analysis indicated a reduction in the density of intermolecular and intramolecular hydrogen bonding within the fiber. X-ray spectrometry indicated a reduction in the crystallinity. Hydrogen bond-specific enzyme and its application in the isolation of new generation cellulose nano-fibers can be a huge leap forward in the field of nano-biocomposites. 1. Introduction Cellulose is the most important constituent of the cell wall and forms a framework around which all other cell wall polysaccharides like hemicellulose, lignin, and pectin are deposited during the plant cell growth [1]. 1.1. Cellulose Microfibrils Cellulose microfibrils are a self-assembly of cellulose chains that are synthesized by plasma membrane, which through a regular network of inter- and intramolecular hydrogen bonds are organized into perfect stereoregular configuration called microfibrils. Each chain is stabilized by intrachain hydrogen bonds formed between the pyranose ring oxygen in one residue and the hydrogen of the OH group on C3 in the next residue (O5 H-O3¡ä) and between the hydroxyls on C2 and C6 in the next residue (O2-H O6¡ä) [2]. Microfibrils are generated in the laboratory through a combination of high-energy refining in a PFI mill and subsequent cryocrushing under the presence of liquid nitrogen [3]. The
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