Cellulose nanocrystals properties

Beck, S., Roman, M., and Gray, D. G. (2005]. Effect of reaction conditions on the properties and behavior of wood cellulose nanocrystal suspensions, Biomacromolecules. 6(2], 1048-1054. 

Ling, S., Huang, J., Chang, P. R., Wey, S., Xu, Y., Zhang, Q. (2013). Structure and mechanical properties of new biomass-based nanocomposite Castor oil-based pol3uirethane reinforced with acetylated cellulose nanocrystal, Carbol dnPo, 95, 91-99. 

Dong, H., Strawhecker, KE., Snyder, J.F., Orlicki, J.A., Reiner, R.S., Rudie, A.W. Cellulose nanocrystals as a reinforcing material for electrospun poly(methyl methacrylate) fibers formation, properties and nanomechanical characterization. Carbohydr. Polym. 87, 2488-2495 (2012)... 

The glass transition temperature (Tg) of cellulose reinforced composites is an important parameter which influences different properties of the resulting composite such as mechanical behavior, matrix chains dynamics and swelling behavior. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) are used to evaluate the Tg value of cellulose nanocomposites. In some cases, the addition of cellulose nanocrystals into polymer matrices does not seem to affect the... 

Wang, N., Ding, E., Cheng, R. Preparation and liquid crystalline properties of spherical cellulose nanocrystals. Langmuir 24, 5 (2008)... 

However, thermal stability and mechanical properties of ANP are poor. Young s modulus and tensile strength of this kind of nanocellulose are 10—20 times lower than those of cellulose nanocrystals (loelovich, 2012a,b). Therefore, ANP of cellulose cannot be suitable as a reinforcing nanofiller. 

Ago, M., Jakes, J.E., Johansson, L.-S., Park, S., Rojas, O.J., 2012. Interfacial properties of lignin-based electrospun nanofibers and films reinforced with cellulose nanocrystals. Appl. Mater. Interfaces 4, 6849—6856. 

Lin, N., Dufresne, A., 2014. Surface chemistry, morphological analysis and properties of cellulose nanocrystals with gradiented sulfation degrees. Nanoscale 6, 5384—5393. 

Yang J, Han CR, Zhang XM, Xu F, Sun RG (2014) Cellulose nanocrystals mechanical reinforcement in composite hydrogels with multiple cross-links correlations between dissipation properties and deformation mechanisms. Macromolecules 47 4077-4086... 

This chapter focuses on the use of nanotechnology in the development of cellulose and chitin nanoctystals and their novel biomedical applications. It consists of four main sections. The first section is a brief introduction. The second section focuses on cellulose nanocrystals (CNCs) and their preparation procedure, physical properties, and surface modifications. Cationic modification of CNCs is also presented to produce positively charged CNCs. Various bioapplications of CNCs in bionanocomposites, drug delivery, and biosensors are discussed as well. The third section focuses on chitin nanoctystals (CHNCs). Except for a short introduction on chitin and its structure, the methods of isolation and characterization of chitin are discussed and the surface modifications and properties of CHNCs are summarized. The applications of CHNCs as reinforcing fillers in nanocomposites and several biomedical applications are discussed. The fourth section is a summary and perspective highlighting the future directions on the application of these natural nanoctystals in various key industries related to biomedicine. 

Stable aqueous suspensions of polysaccharide nanocrystals can be prepared by the acid hydrolysis of vegetable biomass. Different descriptors of the resulting colloidal suspended particles are used, including whiskers, mono-crystals and nanocrystals. The designation whiskers is used to describe elongated rod-like nanoparticles. These crystallites have also often been referred in the literature as microfibrils, microcrystals or microcrystallites, despite their nanoscale dimensions. Most of the studies reported in the literature refer to cellulose nanocrystals. A recent review described the properties and applications of cellulose whiskers in nanocomposites [31]. 

Table 14.1 Mechanical properties of NR films reinforced with cellulose nanocrystals and microfibrils (MF) cellulose extracted from the date palm tree obtained from the tensile tests Young s modulus ( ), strain at break ( R) and strength.

Enzyme hydrolysis and bleaching of sisal fibres was used for preparation of cellulose nanocrystals. The nanocrystals were dispersed in NR to form nanocomposites that exhibited increased modulus. Enzyme treatment provided nanoparticles that could be specifically prepared for varying thermomechanical properties. 

Ljungberg N, Cavaille J-Y, Heux L (2006) Nanocomposites of isotactic polypropylene reinforced with rod-like cellulose whiskers. Polymer 47 6285-6292 Lu Y, Weng L, Cao X (2005) Biocomposites of plasticized starch reinforced with cellulose crystallites from cottonseed linter. Macromol Biosci 5 1101-1107 Lu J, Wang T, Drzal LT (2008) Preparation and properties of microfibrillated cellulose polyvinyl alcohol composite materials. Compos Part A 39A 738-746 Magalhaes WLE, Cao X, Lucia LA (2009) Cellulose nanocrystals/cellulose core-in-shell nanocomposite assemblies. Langmuir. doi 10.1021Aa901928j Malainine ME, Mahrouz M, Dufresne A (2005) Thermoplastic nanocomposites based on cellulose microfibrils from Opuntiaficus-indica parenchyma cell. Compos Sci Technol 65 1520-1526 Marchessault RH, Sundararajan PR (1983) Cellulose. In Aspinall GO (ed) The polysaccharides. Academic, New York... 

Zimmermann T, Pdhler E, Schwaller P (2005) Mechanical and morphological properties of cellulose fibril reinforced nanocomposites. Adv Eng Mater 7 1156-1161 Zoppe JO, Peresin MS, Habibi Y et al (2009) Reinforcing poly(8-caprolactone) nanofibers with cellulose nanocrystals. ACS Appl Mater Interfaces 1 1996-2004... 

Bai W, Holbery J, Li K (2009) A technique for production of nanocrystalline cellulose with a narrow size distribution. Cellulose 16 455-465 Balasubramani M, Kumar TR, Babu M (2001) Skin substitutes a review. Bums 27 534—544 Barud HS, Barrios C, Regiani T et al (2008) Selfsupported silver nanoparticles containing bacterial cellulose membranes. Mater Sci Eng C-Biomim Supramol Syst 28 515-518 Battista OA (1950) Hydrolysis and crystallization of cellulose. Ind Eng Chem 42 502-507 Battista OA, Coppick S, Howsmon JA et al (1956) Level-off degree of polymerization. Relation to polyphase stracture of cellulose fibres. Ind Eng Chem 48 333-335 Beck-Candanedo S, Roman M, Gray DG (2005) Effect of reaction conditions on the properties and behavior of wood cellulose nanocrystal suspensions. Biomacromolecules 6 1048-1054... 

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