Fibrils cellulose

We have shown by our ISO brightness and Ak measurements that the lignin was attacked by the reactive species created by the y irradiation. The results indicate that the reactive species created attack indiscriminately the phenolic hydroxyl or coniferalde-hyde groups and the quinone groups. The decrease in physical properties is associated with die attack on the micro fibrils cellulose. However, at 3000 krad/h, the increase in the ISO brightness is smaller than the one observed around 300 krad/h for the TMP, while the physical properties of the pulp are affected more profoundly at 3000 krad/h than at 300 krad/h. The physical properties of the P-TMP behave similarly, while the increase in brightness is negligible at 3000 krad/h for P-TMP. 

In contrast to BC, cellulose from wood is composed of fibers that are about one hundred times thicker [17] (Fig. 4a). Because of the complex and expensive cultivation of BC (sophisticated medium and long cultivation time), it is also a challenge to produce nano-fibrillated celluloses from wood. The substructures of wood are only accessible by chemical treatment [16] and mechanical disintegration procedures. 

In the last 25 years, there have been efforts to reduce wood fibers in size. As a first step, in the early 1980s Turbak et al. [18] developed a micro-fibrillated cellulose (MFC). Today, there are different ways to produce materials with controlled fiber diameters. 

Samir, M.A.S.A., Alloin, F., Paillet, M., Dufresne, A. Tangling effect in fibrillated cellulose reinforced nanocomposite. Macromolecules. 37, 4313-4316 (2004a)... 

Nakagaito, AJSl., Yano, H. The effect of morphological changes from pulp fiber towards nano-scale fibrillated cellulose on the mechanical noperties of high-strength plant fiber based composites. Appl. Phys. A. 78, 547-552 (2004)... 

Seydibeyog lu MO, Oksman K (2008) Novel nanocomposites based on polyurethane and micro fibrillated cellulose. J Compos Sci Technol 68 908-914... 

Fibrillar fines obtained from cellulosic fibres are known for their unique structure, material characteristics, and potential applications (Hubbe et al. 2008). An amorphous lignin and hemicellulose matrix separates the elementary nanofibrils in natural vegetable fibres. Based on raw material sources, pretreatment and subsequent defibrillation procedures will produce a broad spectrum of fibril structures as well as nomenclatures used to describe them. Thus, we find various terms adopted in the field, such as nanoscale-fibrillated cellulose, cellulosic fibrillar fines, cellulose aggregate fibrils, and microfibrillar cellulose. 

Equivalent amounts of calcium hydroxide suspensimi were added to preformed fibrillated cellulosic gels, in order to obtain 2 1 and 1 1 PCC-pulp fibril mixtures, which were then carbonated to cocrystallise PCC with colloidal-, fine and coarse rhombohedral-, and scalenohedral-t3q)e structures. Reference PCC precipitates, composed of four different morphologies, were crystallised in the absence of cellulosic fibrils. The experimental precipitation conditions were similar for composite and reference PCC filler samples. 

Okubo K, Fujii T, Yamashita N (2005) Improvement of interfacial adhesion in bamboo polymer composite enhanced with micro-fibrillated cellulose. JSME Int J Series A-Solid Mech Mater Eng 48 199-204... 

Schumann DA, Wippermaim J, Klemm DO et al (2009) Artificial vascular implants frran bacterial cellulose preliminary results of small arterial substitutes. Cellulose 16 877-885 Seydibeyoglu MO, Oksman K (2008) Novel nanocomposites based on polyurethane and micro-fibrillated cellulose. Compos Sci Technol 68 908-914 Shoda M, Sugano Y (2005) Recent advances in bacterial cellulose production. Biotechnol Bioprocess Eng 10 1-8... 

Vartiainen, J., Pohler, T., Sirola, K., Pylkkanen, L., Alenius, H., Hokkinen, J.,. .. Laukkanen, A. (2011). Health and environmental safety aspects of friction grinding and spray drying of micro-fibrillated cellulose. (3), 775-786. 

Zhu, J. Y, Sabo, R., Luo, X. (2011). Integrated production of nano-fibrillated cellulose and eel-lulosic biofuel (ethanol) by enzymatic fractionation of wood fibers. (5), 1339-134. 

In addition to conventional vegetal cellulose fibers (Figure 1 A), other forms of cellulose have been assessed in the last few years. The use of micro and nano-cellulose fibers, namely whiskers, obtained from a marine species (Samir, 2005), bacterial cellulose produced by some bacterial strains (Pecoraro, 2008) as well as micro- or nano-fibrillated cellulose prepared by mechanical, enzymatic or chemical treatments of the vegetal fibers (Nakagaito, 2004), for the development of high performance composite materials is attracting researchers from diverse fields (Dufresne, 2008 Lee, 2009), as the addition of very modest amounts of nano fibers leads to new composite materials with superior mechanical properties and new functionalities (Klemm, 2009) when compared with their conventional cellulose fibers counterparts. 

Huang XS, Netravali AN. Environmentally friendly green materials from plant-based resources modification of soy protein using gellan and micro/nano-fibrillated cellulose. J Macromol Sci A Pure Appl Chem 2008 45 899-906. 

Samir MASA, Alloin F, Paillet M, Dufresne A (2004) Tangling effect in fibrillated cellulose reinforced nanocomposites. Macromolecules 37 4313-4316 Sanchez-Garcia MD, Lopez-Rubio A, Lagaron JM (2010) Natural micro and nanobiocomposites with enhanced barrier properties and novel functionalities for food biopackaging applications. Trends Food Sci Technol 21 528-536... 

Fibrillated cellulosic fibres, such as LyoceU fibres, contain fibres having much smaller diameters and are thus promising resources of cellulosic micro- and nanoscale fibres for air, water, and hydraulic filtrations. They can be blended with nonfibril-lated synthetic staple fibres in a wet-laid nonwoven fabric to form high-efficiency and high-capacity glass fibre-free filtration media. ... 

M. O. Seydibeyoglu, and K. Oksman, Novel nano composites based on polyurethane and micro fibrillated cellulose. Compos. Sci. Technol. 68, 908-914 (2008). 

Lopez-Rubio, A., Lagaron, J.M., Ankerfors, M., Lindstrom,T., Nordqvist, D., Mattozzi, A. and Hedenqvist, M.S. (2007). Enhanced flhn forming and film properties of amylopectin using micro-fibrillated cellulose. Carbohydrate Polymers, 68(4), 718-727. 

Iwatake et al. developed a sustainable green composite by reinforcing PLA with micro fibrillated cellulose (MFC) and needle-leaf bleached kraft pnlp (NBKP), which improved the nano fiber network to large extent (2008). At 10 wt % nano fiber dispersion of MFCs in PLA, Young modulus and tensile strength improved by 40% and 25% without any reduction in yield strain, whereas NBKP reported rednction in yield strain and strength by 30% and 50% respectively. 

Suzuki, K., Sato, A., Okumura, H., Hashimoto, T., Nakagaito, A.N., Yano, H., 2014. Novel high-strength, micro fibrillated cellulose-reinforced polypropylene composites using a cationic polymer as compatibilizer. Cellulose 21, 507—518. 

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