Bionanocomposites preparation

Some NR-based nanocomposites with bio-based nanoreinforcements like chi-tin whiskers, starch nanocrystals, cellulose whiskers. A lot of work on bionanocomposites of NR has been reported by Alain Dufresne and coworkers.But most of these studies use latex blending technique without vulcanization, for the bionanocomposites preparation. There are less reports available on vulcanized rubber-based bionanocomposites prepared by master batch processing and two-roll mill mixing, which have the potential to be adapted for commercial use. ... 

Attributed to the demand for facile and low-risk vaccine administration, the needle-free, nasal delivery routes are sought and investigated [164]. Herein, bionanocomposites prepared by a combination of fibrous clay and polysaccharides... 

In situ polymerization is a method of bionanocomposite preparation whereby the nanostructured reinforcement, usually layered clays, is dispersed in a liquid monomer or a monomer dissolved in a suitable solvent for a certain amount of time, allowing monomer molecules to diffuse between the layers. Upon further addition of initiator or exposure of appropriate source of light or heat, the polymerization takes place in situ forming the nanocomposite. 

The use of chitosan bionanocomposites with hydroxyapatite has also been reported in the literature as potential biomaterials. Chitosan (CS)/hydroxyapatite (HA) bionanocomposites prepared by in situ hybridization, according to Hu et al. [205] can be potentially applied in internal fixation of bone fractures. Also, Zhang et al. 

Ray et al. [265] developed hionanocomposites based on PLA with OMMT by simple melt extrusion and found that intercalated nanocomposites exhibited remarkable improvement of materials properties as compared to PLA without clay. They also [266] used synthetic fluorine mica modified with N-(coco alkyl)-N,N-[bis(2-hydroxyethyl)-N-methylammonium cation for bionanocomposite preparation and found that all nanocomposites exhibited remarkable improvement of various materials properties with simultaneous improvement in biodegradability compared to neat PLA. The addition of MMT modified with trimethyl octadecylammo-nium cation to PLA, which was intercalated and well distributed in the matrix, was reported by Ray et al. [267] to produce PLA hionanocomposites with improved properties, especially their biodegradability in a compost environment (Figure 11.21). 

Zhang YJ, Shen YE, Han DX et al (2007) Carbon nanotubes and glucose oxidase bionanocomposite bridged by ionic Uquid-like unit preparation and electrochemictil properties. 

Gilberto, S. Julien, B. Alain, D. Cellulosic bionanocomposite A review of preparation, properties and applications. Polymers 2010, 2 (4), 728-765. 

Siqueira, G., Bras, J., and Dufresne, A. (2010). Cellulosic bionanocomposites A review of preparation, properties and applications,... 

In another study Feng et al. [86] presented the stmcture and properties of new thermoforming bionanocomposites based on chitin whiskers-graft-polycaprolac-tone. The synthesized material was characterized by FTIR, SEM, TEM and XRD. The surface and mechanical properties were also determined and discussed. Ha-riraksapitak et al. [87] prepared a neat hyaluronan-gelatin scaffolds and chitin-whisker-reinforced hyaluronan-gelatin scaffolds. The obtained cylindrical scaffolds obtained were about 10 mm in diameter and 2 mm in height, whereas the disc-shaped scaffolds were about 1 mm in thickness these were later cut into a desired shape and size for the mechanical property assessment. 

Preparations of Si02-chitin/carbon nanotubes (CNTs) bionanocomposites have also been reported by many researchers [90]. The use of nanomaterials such as CNTs to fabricate matrices for biosensors is one of the most exciting approaches because nanomaterials have a unique structure and high surface to volume ratio [90]. The surfaces of nanomaterials can also be tailored in the molecular scale in order to achieve various desirable properties [91]. The diverse properties of nanocomposite materials such as unique structure and good chemical stability enable them to provide a wide range of applications in sensor technology [92]. 

Fig. 3.17 Reaction scheme for the preparation of Si02-chitin/CNTs bionanocomposites [90]...

Figure 8.13 (a) Scheme of the preparation of IL-graphene. Reprinted from reference [103] by permission of The Royal Society of Chemistry, (b) Illustration showing the construction of the IL-graphene-GOD bionanocomposite. Reprinted from reference [104]. Cop3n-ight 2012, with permission from Elsevier. 

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. 

Mallakpour S, Barati A. Preparation and characterization of optically active poly(amide-imide)/Ti02 bionanocomposites containing A-trimelUtylimido-L-isoleucine linkages using ionic liquid and ultrasonic irradiation. J Polym Res 2012 19(2) l-8. 

Greiner A, Wendorff JH (2007) Electrospinning a fascinating method for the preparation of ultrathin fibers. Angew Chem Int Ed 46 5670-5703 Grunnert M, Winter WT (2002) Nanocomposites of cellulose acetate butyrate reinforced with cellulose nanocrystals. J Polym Environ 10 27-30 Habibi Y, Dufresne A (2008) Highly filled bionanocomposites from functionalized polysaccharide nanocrystals. Biomacromolecules 9 1974-1980... 

Zhang, Y., et al. Caibon nanotubes and glucose oxidase bionanocomposite bridged by ionic liquid-like unit Preparation and electrochemical properties. Biosens. Bioelectron. 23(3), 438-443 (2007)... 

Sadegh-Hassani, F., Mohammadi Nafchi, A. Preparation and characterization of bionanocomposites films based on potato starch/halloysite nanoclay. Int J. Biol. Macromol. 67, pp. 458 62 (2014)... 

In order to prepare PLA nanocomposites with highly dispersed cellulose nanocrystals and porous PLA-based scaffolds with enhanced mechanical properties and thermal stability, CNCs have been incorporated into PLA fibres by electrospinning method. Fibrous biocomposite mats consisting of PLA and CNCs have been electrospun from solvent or solvent mixtures such as l,l,l,3,3,3-hexafluoro-2-propanol (HFP), DMF/chloro-form and DMF/tetrahydrofuran (THF). The electrospun PLA/CNCs bionanocomposites have demonstrated rapid in vitro biodegradability and cytocompatible properties, and could be potentially suitable in tissue engineering. ... 

Bionanocomposites are an ecological alternative to conventional nanocomposites based on petroleum-derived polymers, as they are based on biodegradable polymers obtained from renewable resources. Biomass is the source of agropolymers like starch and cellulose and also of monomers used to chemically synthesize polymers like polylactic acid (PLA). Other kinds of biopolymers, e.g., xanthan gum and poly (hydroxyalkanoates), are produced by microorganisms. Even though most of the bionanocomposites reported in the hterature are based on layered sihcates, the number of examples illustrating the use of fibrous clays in the preparation of new bionanocomposites is growing rapidly. 

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