Nanofibrous cellulose

Nakagaito AN, Yano H (2008) Toughness enhancement of cellulose nanocomposites by alkali treatment of the rein- forcing cellulose nanofibres. Cellulose 15 323-331 Nakagaito AN, Iwamoto S, Yano H (2005) Bacterial cellulose the ultimate nano-scalar cellulose morphology for the production of high-strength composites. Appl Phys A Mat Mater Sci Process 80 93-97... 

B. Ding, C. Li, Y. Hotta, J. Kim, O. Kuwaki and S. Shiratori, Conversion of an electrospun nanofibrous cellulose acetate mat from a super-hydrophilic to super-hydrophobic surface, Nanotechnology 17,4332-4339 (2006). 

Nanofibrillated fibres may also be used to make nonwovens using the wetlaid process. Fibrillation is the process of splitting fibres into fibrils or thin filaments, and is commonly conducted using wet mechanical beating to partially separate fibres into their component fibrils [16]. Nanofibrous cellulose has been produced from lyocell, cotton, and wood pulp, although the fibre diameter variation is high [17]. Fibril diameters between 0.05 and 0.5 pm have been observed, with an average of 0.3 pm, but a small number of microscale fibres (2—5 pm) are inevitable. 

Nanofibres can be produced by a number of methods. They can be extracted from natural materials (e.g., cellulose or protein fibres) via physical separation and/or chemical extraction. They can also be produced by means of drawing, template synthesis, phase separation, self-assembly and electrospinning. The details are briefly described below. 

Bhatnagar, A., Sain, M., 2005. Processing of cellulose nanofibre-reinforced composites. Journal of Reinforced Plastics and Composites 24 (12), 1259—1268. 

Eichhorn, S. J., Dufresne, A., and Aranguren, M. (2010). Review Current international research into cellulose nanofibres and nanocomnosites. I. Mater. Set. 45(1), 1-33. 

It is expected that the smaller size of these nanofibres will lead to a higher pressure drop and the interception and inertial impaction efficiencies will increase faster, which can more than compensate for the pressure drop inaease. Nanowebs have been used in many air filtration applications. Airborne contamination in the personnel cabins of mining equipment is of concern to mining workers, and it has been reported that nanofibre filter media can considerably reduce cabin dust concentration as compared to the standard (cellulose) filter media. ... 

Details of vegetable oil-based polymers conventional composites have been discussed in an earlier chapter. In this chapter, nanocomposites of vegetable oil-based polymers are discussed. Certain questions arise as to how much difference there is between these composites. The questions are significant when the same reinforcing agent is used in both cases. As an example, a vegetable oil-based polyurethane with alkali-treated chopped jute fibres in a conventional composite and cellulose nanofibres (obtained from jute fibres) in a vegetable oil-based polymer nanocomposite are discussed. The... 

Three different types of nanomaterials, based on their dimensional characteristics, are generally used to prepare polymer nanocomposites. These include nanomaterials with only one dimension in the nanometre range (e.g. nano-clay), those with two dimensions in the nanometre scale (e.g. carbon nanotubes) and those that have all three dimensions in the nanometre scale (e.g. spherical silver nanoparticles), as stated earlier. Thus nanosize thin layered aluminosilicates or nanoclays, layer double hydroxide (LDH), a large number of nanoparticles of metals and their oxides, carbon nanotubes and cellulose nanofibres are used as nanomaterials in the preparation of vegetable oil-based polymer nanocomposites. 

Nogi et al. [40], in 2005, used bacterial cellulose nanofibres to reinforce transparent polymers. The composites exhibited a highly luminous transmittance at a fibre content as high as 60 wt%, and a low sensitivity to matrices with a variety of refractive indices. The optical transparency was also insensitive to temperature increases up to 80°C. 

Visakh et used cellulose nanowhiskers or nanofibres isolated from... 

P. M. Visakh, S. Thomas, K. Oksman and A. P. Mathew, Cellulose Nanofibres and Cellulose Nanowhiskers Based Natural Rubber Composites Diffusion, Sorption, and Permeation of Aromatic Organic Solvents, Journal of Applied Polymer Science, 2012, 124, 1614. 

Abstract This chapter deals with the structure, properties and applications of natural fibres. Extraction methods of Natural Fibres from different sources have been discussed in detail. Natural fibres have the special advantage of high specific strength and sustainability, which make them ideal candidates for reinforcement in various polymeric matrices. Natural fibres find application in various fields like construction, automobile industry and also in soil conservation. It is the main source of cellulose, an eminent representative of nanomaterial. Extractions of cellulose from plant-based fibres are discussed in detail. Various mediods used for characterization of cellulose nanofibres and advantages of these nanofibres have also been dealt with. 

Keywords Animal fibre Cellulose Nanofibre Plant fibre... 

In recent years, considerable research has been done on the isolation of nanofibres from plants to use them as fillers in biocomposites [86-90]. Agricultural crop residues are one of the most valuable sources of natural cellulose nanofihres. It should be noted that in agricultural fibres, the cellulose microfibrils are less tightly wound in the primary ceU wall than in the secondary wall in wood, thus fibrillation... 

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