Cellulose

Abstract This article covers nomenclature, sources, preparation, uses, microcrystalline cellulose, structural chemistry, reactions, solvents, and liquid crystals. Cellulose for commercial purposes comes mostly from wood and cotton, whereas cellulose for research comes from bacteria, algae, and ramie (also a textile fiber). Preparation includes pulping and purification, with a new alternative method of steam explosion. The pore structure of cellulose is mentioned, along with the build‐up of cellulose molecules into entire fibers. Emphasis is given to cellulose crystal structure, where recent research on the dominant natural form has made previous findings obsolete. Most cellulose is a mixture of two crystalline phases. Cellulose solutions are important to the rayon and cellophane industries, and new solvents are of interest because they may lessen pollution and might permit commercial production of stronger cellulosic materials through the formation of liquid crystals. Figures include the chemical and physical structures of the molecule, including in solution, the structure of a microfibril, and the unit cell structures of Cellulose I‐IV.