Wood cellulose, thermodynamics

Figure 4. Thermodynamics of water absorption on wood cellulose.

Thermodynamically controlled self-assembly of an equilibrated ensemble of POMs with [AlVWnO40]6 as the main component could act as a catalyst for the selective delignification of wood (lignocellulose) fibers (Figure 13.2) [55], Equilibration reactions typical of POMs kept the pH of the system near 7 during the catalysis that avoided acid or base degradation of cellulose. 

Natural products are a mixture of these two modifications. Cellulose Ip is dominant in plants and wood, and the percentage of cellulose present varies depending on the species and the treatments. For example, the cellulose Ip content of cotton linter and ramie is 77%. Cellulose I transformed into cellulose Ip by a hydrothermal treatment in an alkali solution or by heat treatment at 280 °C in an inert gas. For example, Horii et al. reported that cellulose Ip content increases to 90% by heat treatment at 260°C in 0.1 M NaOH aqueous solution [21]. This indicates that cellulose Ip is thermodynamically more stable than cellulose Almost pure cellulose Ip is obtained from tunicates Halocynthia roretzi). Cellulose h is reported to be the major component of bacterial and algal cellulose. The structural difference between I and Ip is said to be brought about by shear stress during biosynthesis of cellulose microfibrils. 

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