Cellulose substances

J. G. Huang, and T. Kunitake, Nano-precision replication of natural cellulosic substances by metal... 

The purification of linters consists in removing all non-cellulosic substances, such as fats and waxes, lignin, proteins, non-cellulosic carbohydrates and mineral substances. The process is carried out in two stages ... 

Andren, R. K. Proc. Symp. on Bioconversion of Cellulosic Substances into... 

Bioconversion of Cellulosic Substances into Energy, Chemicals, and Microbial Protein, New Delhi, Feb 1977, pp. 551-571. 

To determine the velocities of the aforementioned Reactions (a), (b), and (c), products will be isolated after short reaction times and their degrees of substitution and polymerization will be determined. By selecting proper experimental conditions, we expect to be able to prepare solutions of cellulose with various desirable DS s and DP s. The preparative possibilities of these rapidly obtainable solutions of cellulose, wood, or other cellulosic substances will be investigated. 

Mishra, C. Phansalkar, S. B. Rao, M. Seeta, R. Srinivasan, M. C. Jagannathan, V. In Bioconversion of Cellulosic Substances into Energy, Chemicals and Microbial Protein Goose, T. K., Ed. Swiss Federal Institute of Technology, CH-8092, Zurich, 1977 pp 387-395. 

Moo-Young, M., Chahal, D. S., Vlach, D., in Bioconversion of Cellulosic Substances into Energy, Chemicals, and Microbial Protein (ed.), Ghose, T. K., p. 457, ITT Delhi and SFIT Zurich (1978)... 

Ghose, T.K., and Bisaria, VS., Studies on the mechanism of enzymatic hydrolysis of cellulosic substances. 

Modern technology has caused a sharp decline in the value of wood and other cellulosic substances as fuel, but it has produced a significant increase in their application as industrial and constructional materials, and has created a concerted emphasis on the problems of pyrolysis and combustion. 

Fire may be defined as the interaction between fuel, energy, and environment. The type and magnitude of any fire that either develops into a destructive force or into a useful tool depends on the supply of fuel. Mass fires in natural environments, urban surroundings, farmland, and many industrial and miscellaneous installations mainly involve natural fuels that are cellulosic substances, such as wooden structures and objects, trees, dried vegetation, textiles, furniture, boards, paper, and paper products. 

The heat from the environment is transfened into the particle layer by layer and become the sensible heat of the cellulose substance. This situation remains until the outside layer of particle reaches an enough high temperature of about 660K, at which, the chemical reactions start to come into effect. Due to the reaction heat needed for pyrolysis, the temperature increase is suppressed significantly, and is turned to the chemical reaction stage of rather flat temperature profiles. The tenqierature is held between 650 1C to 750 K by endothermic pyrolytic reactions, which is much lower than the environmental temperature of 1073K. 

Toyama N, Ogawa K (1978) In Chose TK (ed) International Symposium on Bioconversion of Cellulosic Substances into Energy Chemicals and Microbial Proteins. IIT, New Delhi, India, p 305... 

Changes in strawberry cell wall components upon ripening were studied by solid-state 13C NMR.162 The separation between semi-rigid (primarily poly-galacturonic acid) and semi-mobile (non-cellulosic substances) domains became more distinct with ripening, whereas the ratio of non-cellulosic material (pectins and hemicellulose) to rigid cellulose decreased. The basic crystallite of strawberry cell walls appeared to be exceptionally small compared with other systems studied.162... 

Cellulosic substances have been used in various fields from commodities to industrial materials after mechanical and chemical modifications. Especially because chemically modified cellulosics have some unique functional properties, and also because of their biodegradability in most instances, the chemistry of cellulose has become one of the major areas in cellulose science. Figure 12 illustrates the chemical structure of cellulose in terms of chemical modifications. "" Three hydroxyl groups in the glucose residue, one primary and the other two secondary, are the sites for substitution reactions, which are the most common in cellulose derivatizations. The (1 4)-/3-glycoside bonds and other functional groups such as carboxyls and aldehydes present in most cellulosic material as minor groups are also possible sites for chemical modifications. 

General characteristics of cellulose Structure of cellulose Chemical properties of cellulose Welting and swelling Degradation of cellulose Effect of other factors on cellulose Substances accompanying cellulose Hemicellulascs Lignin... 

Kemell, M., Pore, V., Ritala, M., Leskela, M., Linden, M. Atomic layer deposition in nanometer-level replication of cellulosic substances and preparation of photocatalytic Ti02/ cellulose composites. J. Am. Chem. Soc. 127(41), 14178-14179 (2005)... 

Definition Soft white cellulosic substance composed of fibers surrounding the seeds of various plants (Genus Gossypium) It. powder of ground cotton fibers Properties Sp.gr. 1.6... 

Yu XI et al (2013) Preparation and electrochemical properties of porous silicon/carbon composite as negative electrode materials. J Inorg Mater. doi 10.3724/SP.J.1077.2013.12672 Yue L et al (2013) Porous silicon coated with S-doped carbon as anode material for lithium ion batteries. J Solid State Electrochem doi 10.1007/s/10008-012-1944-8 Zhang Y, Huang J (2011) Hierarchical nanofibrous silicon as replica of natural cellulose substance. J Mater Chem 21 7161-7165... 

Some ascidians possess two more cellulosic structures other than the tunic. These cellulosic structures have been observed by scanning electron microscopy after treatment with the Updegraff reagent (Updegraff 1969) that removes non-cellulosic substances. One of these cellulosic structures is a cellulose network that is distributed in the hemocoel (the tissue equivalent to a blood vessel of vertebrates) (Kimura and Itoh 1997), and the other is a coiled cord-like structure called the tunic cord (Kimura and Itoh 1998). 

JIN 11] Jin C., Yan R., Huang J., Cellulose substance with reversible photo-responsive wettability by surface modification , Journal of Materials Chemistry, vol. 21, pp. 17519-17525, 2011. 

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