Plants, cellulose fibers

The digestion of plant cellulose fibers to make paper is facilitated by a variety of inorganic compounds including NaOH, Na2S04 and S02. Bleaching agents (which act by oxidizing colored... 

Deep flat-sheet Alters consist of permeable boards made of plant cellulose fibers combined with granular compounds, such as diatomaceous earth or perlite, and possibly cation resins to increase the electrical charge. 

Chen W, Yu H, Liu Y, Hai Y, Zhang M, Chen P (201 la) Isolation and chaiactraization of cellulose nanofibers from four plant cellulose fibers using a chemical-ultrasonic process. Cellulose 18 433 2... 

BC is characterized by an ultrafine network structure composed of ribbon-shaped fibrils with an average diameter 100 times thinner than those of plant cellulose fibers (Figure 2.9) [4]. As a result, BC membranes are a highly porous material with substantial permeability for liquids and gases and high water uptake (water content >90%) [8]. 

The higher plant cellulosic fiber is sub-divided into non-woody fibers (straw, grass, bast, trunk, stem, frond, leaf, seed and fruit) and woody fibers (pine, rubber. Acacia, teak) (Nazir, 2013). Different plant biomass possesses different composition of cellulose (g/g) such as jute (61-71.5%), flax (71%), hemp (60.2-74.4%), ramie (68.6-76.2%), kenaf (31-39%), sisal (67-78%), pineapple leaf fiber (70-82%), henequen (77.6%), cotton seed (82.7%), rice... 

Chen, W., Yu, H., Liu, Y, Hai, Y, Zhang, M, Chen, P. Isolation and characterization of cellulose nanofibers fiom four plant cellulose fibers using a chemical-ulttasonic process. Cellulose 2011,18,433 2. 

The first successhil attempt to make textile fibers from plant cellulose can be traced to George Audemars (1). In 1855 he dissolved the nitrated form of cellulose in ether and alcohol and discovered that fibers were formed as the dope was drawn into the air. These soft strong nitrocellulose fibers could be woven into fabrics but had a serious drawback they were explosive, nitrated cellulose being the basis of gun-cotton (see Cellulose esters, inorganic esters). 

When used as substitutes for asbestos fibers, plant fibers and manmade cellulose fibers show comparable characteristic values in a cement matrix, but at lower costs. As with plastic composites, these values are essentially dependent on the properties of the fiber and the adhesion between fiber and matrix. Distinctly higher values for strength and. stiffness of the composites can be achieved by a chemical modification of the fiber surface (acrylic and polystyrene treatment [74]), usually produced by the Hatschek-process 75-77J. Tests by Coutts et al. [76] and Coutts [77,78] on wood fiber cement (soft-, and hardwood fibers) show that already at a fiber content of 8-10 wt%, a maximum of strengthening is achieved (Fig. 22). 

Nonwoven materials such as cellulosic fibers have never been successfully used in lithium batteries. This lack of interest is related to the hygroscopic nature of cellulosic papers and films, their tendency to degrade in contact with lithium metal, and their susceptibility to pinhole formation at thickness of less than 100 fjim. For future applications, such as electric vehicles and load leveling systems at electric power plants, cellulosic separators may find a place because of their stability at higher temperatures when compared to polyolefins. They may be laminated with polyolefin separators to provide high-temperature melt integrity. 

FIGURE 20-29 Cellulose structure. The plant cell wall is made up in part of cellulose molecules arranged side by side to form paracrys-talline arrays—cellulose microfibrils. Many microfibrils combine to form a cellulose fiber, seen in the scanning electron microscope as a structure 5 to 12 nm in diameter, laid down on the cell surface in several layers distinguishable by the different orientations of their fibers. 

Cellulose powder is a mechanically shortened cellulosic fiber, whereby the degree of polymerization remains almost intact. Microcrystalline cellulose is a partially purified and depolymerized cellulose, prepared by treating a-cellulose obtained from fibrous plant material with mineral acids. It occurs as a fine white odorless and... 

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