Nematic ordered cellulose materials

Solid-state cellulose can also be noncrystalline, sometimes called amorphous. Intermediate situations are also likely to be important but not well characterized. One example, nematic ordered cellulose has been described [230]. In most treatments that produce amorphous cellulose, the whole fiber is severely degraded. For example, decrystallization can be effected by ball milling, which leaves the cellulose as a fine dust. In this case, some crystalline structure can be recreated by placing the sample in a humid environment. Another approach uses phosphoric acid, which can dissolve the cellulose. Precipitation by dilution with water results in a material with very little crystallinity. There is some chance that the chain may adopt a different shape (a collapsed, sixfold helix) after phosphoric acid treatment. This was concluded because the cellulose stains blue with iodine (see Figure 5.12), similar to the sixfold amylose helix in the starch-iodine complex. 

The structure of cellulose is closely tied to its synthesis, and although many of the chapters discuss the synthesis of cellulose, the nature of the cellulose product is always kept in mind. A comprehensive account of the structure of cellulose and its polymorphism is provided by French and Johnson, and the structure and properties of a novel form of cellulose (nematic-ordered cellulose) is described by Kondo. Cellulose is the most abundant biomacromolecule in nature, and it is used in a variety of applications. In almost all cases, the applications of cellulose as an industrial material are dependent on its physical and chemical properties. Two chapters discuss novel applications of cellulose. Czaja et al. describe the use of microbial cellulose for applications in wound care and Kim discusses the usefulness of cellulose as a smart material, specifically the production of cellulose-based electroactive paper. 

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