Cellulose composite fibers

Biological characterization of the cellulose-heparin fibers performed by measuring the clotting kinetics of human whole blood exposed to these fibers using thromboelas-tography showed cellulose/heparin composite fibers afford a prolonged clotting time in a concentration-dependent fashion. The observed results indicates that presence of 

CeO nanoparticles were attached to the surface of the nanofiber substrate due to the strong interfacial and electrostatic interactions between the carboxylic or hydroxyl groups of the cellulose nanofiber and the CeO nanoparticles, which is effectively prevented nanoparticle fall-off. Compared to the natural cotton cellulose nanofibers, the modified natural cotton cellulose nanofibers by hydrothermal incorporation of CeOj nanoparticles showed excellent protection against UV radiation because of the function of the CeO particles. This functional nanofiber will have potential applications in various areas, such as the medical, military, biological, and optoelectronic industrial fields including UV protection for data storage or memory devices, in the future. 

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X. Shi, Y. Hu, F. Fu, J. Zhou, Y. Wang, L. Chen, H. Zhang, J. Li, X. Wang, L. Zhang, Construction of PANI-Cellulose Composite Fibers with Good Antistatic Properties. /, Mater Chem. A 2014,2,7669. 

Vallejos ME, Peresin M, Rojas OJ (2012) All-cellulose composite fibers obtained by electrospinning dispersions of cellulose acetate and cellulose nanoctystals. J Polym Environ 20 1075-1083... 

Y. Kurokawa, T. Sano, H. Ohta, and Y. Nakagawa, Immobilization of enzyme onto cellulose-titanium oxide composite fiber. Biotech. Bioenerg. 42, 394—397 (1993). 

Fiber cement siding, which is produced from a blend of cement, sand, and cellulose fibers. This blend is extruded into board, which is then cured by pressurized steam. Unlike composites, fiber cement siding does not require surface treatment. Normally, a primer is applied first, followed by another coating to achieve the desired color. 

During the past 5-10 years a considerable increase in knowledge of the structure, chemistry, and processing of cellulose, as well as development of innovative cellulose products, has been observed. New frontiers involve sophisticated methods of structural analysis, environmentally safe cellulose-fiber technologies, as well as progressive work with bacterial nanocellulose, (bio)materials, and a broad spectrum of cellulose composites. 

Bledzki, A. Gassan, J. Composites reinforced with cellulose based fibers. Prog. Polym. Sci. 1999, 24, 221-274. 

U.S. Pat. No. 6,270,883 [98] describes reinforced composites containing less than 50% by weight of cellulose pulp fibers dispersed in a thermoplastic matrix comprising nylons, such as Nylon 6, Nylon 12, Nylon 66, or mixtures thereof, and the cellulose pulp comprising fibers with a lignin content less than 2% by weight. 

U.S. Pat. No. 6,255,368 [114] describes plastic cellulosic composite pellets comprising 20-60% by weight of polyethylene, polypropylene or polystyrene, 40-80% of cellulosic fiber (jute, kenaf, sisal, bamboo, rice hulls, corn husks, wood fiber, and wood flour) with an aspect ratio of between 2 and 20 and a trace of mineral coating (talc) dispersed on the surface of the pellet. 

Data in Table 4.6 show that both calcium carbonate and talc increase flexural modulus by about 40-60%, decrease impact resistance and energy to break by about 30-40%, and slightly increase moisture absorption. All these effects are generally known in the composite research and development, and slightly vary quantitatively by changing the particle size of minerals, a type of plastic, a type of cellulose (wood) fiber, density (specific gravity) of the matrix, and so on. 

Cellulose-cellulose composites ean be expected to show exceptional mechanical properties, depending on the quality of the interfaee between the fibers and the matrix, and on the reaction conditions for their preparation. This approach lends itself particularly well to assemblies with high hierarchieal orders in whieh various types of fibers could be brought into play on different industrial scales (Fig. 56). 

T. Nishino and N. Arimoto, All-cellulose composite prepared by selective dissolving of fiber surface. Biomacromolecules, 8 (2007) 2712-2714. 

In another study by Sdrobis et al. [57], the effect of modification on cellulose pulp fibers in LDPE was reported. They used unbleached and bleached kraft cellulose pulp fibers modified with oleic acid in cold plasma conditions as reinforcements. The melt-mixed composites contain up to 10 wt% of untreated and modified cellulose pulp fibers with LDPE. They reported that interfacial adhesion between cellulose and matrix could be improved through modification and most of the properties have been improved when the modified pulp fibers were incorporated into composite matrix. Variation of complex viscosity function of angular frequency for composites is shown in Fig. 11.11. 

A. Sdrobis, R.N. Darie, M. Totolin, G. Cazacu, C. Vasile, Low density polyethylene composites containing cellulose pulp fibers. Compos B. 43, 1873-1880 (2012)... 

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