Cellulose nanofibrils

B. Langlois. Fluid comprising cellulose nanofibrils and its use for oil mining. Patent WO 9802499, 1998. 

B. Langlois, G. Guerin, A. Senechal, R. Cantiani, I. Vincent, and J. Benchimol. Fluid comprising cellulose nanofibrils and its use for oil mining (fluide comprenant des nanofibrilles de cellulose et son application pour I exploitation de gisements petroliers). Patent EP 912653, 1999. 

It is important at this point to address the need for a new paradigm that was not recognized in the early work of Atalla and VanderHart. The title of the early articles was still defined in terms of the classical approach to cellulose structure in that the two forms of cellulose, and 1,3, were referred to as two distinct crystalline forms. Note was not taken at that point of the rapidly developing evidence that the lateral dimensions of most native cellulose fibrils were very limited and that cellulose nanofibrils have an inherent tendency to develop a right-handed twist when cellulose chain molecules aggregate. While this important development had shed some light on the controversies associated with many of the prior interpretations of diffractometric characterizations of native celluloses, it had not yet provided conclusive evidence that the interpretations based on the symmetry of the P2i space group for crystalline cellulose cannot be valid for native celluloses. It was the acquisition of the Raman spectra of Tunicate and Valonia celluloses that provided the conclusive evidence. 

Castro, C., Vesterinen, A., Zuluaga, R., Caro, G., Filpponen, 1., Rojas, 0. J., Kortaberria, G., and Ganan, P. (2014). In situ production of nanocomposites of poly(vinyl alcohol) and cellulose nanofibrils from Gluconacetobacter bacteria Effect of chemical crosslinking. Cellulose, in Press. 

Svagan, A.J., Samir, M.A.S.A., Berglund, L.A. Biomimetic foams of high mechanical performance based on nanostructured cell walls reinforced by native cellulose nanofibrils. Adv. Mater. 20, 1263-1269 (2008)... 

Several terms are used to denote the nanocellulose obtained by a technique of high-pressure (high-shear) mechanical disintegration of cellulose pulp, namely microfibrillated cellulose, nanofibrillated cellulose, nanofibers, etc. Here we use predominantly the term nanofibrillated cellulose. ... 

Indeed it has been found that the average axial modulus of a single cellulose nanofibril was 29—36 GPa (Tanpichai et al., 2012). From the calculations it follows that in this case the MFA of the nanofiber can be 10—12°, which corresponds to TS 0.8—1 GPa. In the transverse direction the mechanical characteristics of nanofibrils are considerably lower than in the axial direction (loelovich, 2012b). 

Films made from NFC can be optically transparent, if the cellulose nanofibrils are densely packed, and the interstices between the fibrils are small enough to avoid light scattering (Dufresne, 2013). However, it was shown that mechanical compression performed on the freeze-dried NFC did not result in transparency. It was suggested that the freeze-dried nanofibrils were compacted under load, but recovered after unloading, and the spaces created resulted in light scattering. 

Fujisawa, S., Okita, Y., Fukuzumi, H., Saito, T., Isogai, A., 2011. Preparation and characterization of TEMPO-oxidized cellulose nanofibril films with free carboxyl groups. Carbohydr. Polym. 84 (1), 579—583. 

Fukuzumi, H., 2011. Studies on Structure and Properties of TEMPO-Oxidized Cellulose Nanofibril Films. Tokyo University, Tokyo. 

Henriksson, M., 2008. Cellulose Nanofibril Networks and Composites—Preparation, Structure and Properties. KTH, Stockholm. 

Dong H, Snyder IF, Williams KS, Andzelm JW (2013) Cation-induced hydrogels of cellulose nanofibrils with tunable moduli. Biomacromolecules 14 3338-3345... 

Fall AB, Lindstrom SB, Sprakel J, WagbtTg L (2013) A physical cross-linking process of cellulose nanofibril gels with shear-controlled fibril orientatimi. Soft Matter 9 1852-1863... 

Acciaro R, Aulin C, Waghtig L et al (2011) Investigation of the formation, structure and release characteristics of self-assembled composite films of cellulose nanofibrils and temperature responsive microgels. Soft MattCT 7 1369-1377... 

Spagnol C, Rodrigues FHA, Pereira AGB, Fajardo AR, Rubira AF, Muniz EC (2012) Superabsorbent hydrogel composite made of cellulose nanofibrils and chitosan-grq/if-poly (acrylic acid). Carbohydr Polym 87 2038-2045... 

Cai ILL, Sharma S, Liu WY, Mu W, Liu W, Zhang XD, Deng YL (2014) Aerogel micro-spheres from natural cellulose nanofibrils and their application as cell culture scaffold. Biomacromolecules 15 2540-2547... 

---