Nanocomposite nanobiocomposite

The new water soluble highly stable metal-polysaccharide nanocomposites of noble metals have been fabricated within the framework of the new approach to the synthesis of hybrid nanosized materials on the basis of arabinogalactan. Distinctive optical properties of the nanoparticles are demonstrated as the plasmonic resonance. Nanobiocomposites with target optical characteristics have a great potential to design promising multifunctional materials with controlled optical properties as well as new optical systems and optical markers in medicine. 

Nanobiocomposites are a specific class of nanocomposites [AVE 11, BOR 09a, CHI 09]. They are hybrid materials comprising fillers of nanometric size... 

We can show by DMTA and DSC that lamellar clays partially restrict the mobility of the starch chains [PAR 02], Nanoclays are also known for having an impact on the permeabihty to water vapor of the corresponding nanocomposites, particularly when they are correctly oriented. Park et al. looked at the permeabihty of nanobiocomposites to water vapor with different types of clay [PAR 02]. According to those authors, all the films analyzed showed decreased permeability to water vapor in comparison to the matrix alone. Such results were not confirmed in the case of OMMT-CS, which has a very highly plasticized matrix [CHI 10a]. In this case, the high affinity of the clay platelets with starch-rich phases creates preferential diffusion pathways through the glycerol-rich phases, in which the platelets tend to be absent. 

Deepshikha etal. have fabricated a novel nanobiocomposite bienzymatic amperometric cholesterol biosensor, coupled with cholesterol oxidase (ChOx) and horseradish peroxidase (HRP), based on the gold nanoparticle-decorated graphene-nanostructured PANI nanocomposite (NSPANI-AuNP-GR) film which was electrochemically deposited onto indium tin oxide (ITO) electrode from the nanocomposite (NSPANI-AuNP-GR) dispersion, as synthesized by in situ polymerization technique [166]. The... 

There are several methods for the creation of nanobiocomposites, some of which are considered for the preparation of chitosan/CNT nanocomposites. These methods are discussed below. 

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... 

Figure 6.3 TEM images of modified cellulose (A) and silver distribution (B and insert) for PLA/NCC/ silver nanoparticle ternary nanobiocomposite AFM images of (C) PVA nanocomposites containing BCNC and (D) PVA nanocomposite containing both BCNC and AgNPs. Reprinted with permission from [141,161].

Biocomposites consisting of the polymer matrix and natural fibers are environmen-tally-friendly material which can replace glass fiber-reinforced polymer composites, and are currently used in a wide range of fields such as the automotive and construction industries, electronic components, sports and leisure, etc. [1, 2]. Recently, the research on nanobiocomposites which are reinforced with both natural fiber and nanofiller is actively proceeding in order to offer higher thermal and mechanical properties, transport barrier, thermal resistivity and flame retardance in comparison with the conventional biocomposites [3-7]. Recently, nanoclay has become of increasing interest in nanocomposites because the characteristics of nanometer-scaled sihcate pellets, such... 

Figures 7.2 and 7.3 show the thermomechanical properties as dimensional stability and thermal expansion of PP matrix, PP/KE biocomposites and PP/KE/nanoclay nanobiocomposites with increasing temperatme from 30 C to 100°C. Figure 7.2 represents the KE fiber length effect on dimensional change curves of (a) PP nanocomposites, (b)...

Figure 7.2 TMA thermograms showing the thermomechanical behavior of PP matrix and PP nanocomposites and nanobiocomposites. I. Na. Sim et al.

Figure 7.6 shows the effect of KE fiber length on tensile properties of nanobiocomposites. The tensile strength decreased with the addition of KE and nanoclay on the contrary, the tensile modulus showed the opposite. The tensile modulus of PP/KE (1 mm) and PP/KE (10 mm) nanobiocomposites with 10 wt% nanoclay loading increased 78.8% and 118.2% respectively, compared to that of PP nanocomposites. This is... 

Applications of all the above nanocellulose-reinforced nanocomposites with thermoplastic and thermoset polymers are mainly considered to be in paper and packaging products, construction materials, automobiles, furniture, electronics, pharmaceuticals, and cosmetics. Figure 11.32 shows the application of nanobiocomposites. 

In melt extrusion, polymer is forced to flow under shear along with helical screw direction, which divided into number of zones based on their functions and the requirement for processing specific combination such as feed section, mixing and melting section, and compression section and takes the shape of the die at the other end. In melt intercalation, biofiller can be directly mixed mechanically with the polymer melt to form a homogeneous mixture. Method is very widely used for thermoplastic nanocomposites and can be applied to nanobiocomposite. Melt intercalation is highly specific for a polymer, which may lead to new hybrids. Moreover, absence of solvent in the technique leads to industrially economical as well as environment friendly by waste point of view (Ray et al., 2005). 

Y. Li et al. prepared nanobiocomposite of PLA and titanium dioxide by using in situ polymerization (2011). Covalent bonding between surface of titanium dioxide nanowire and PLA chains yields PLA nanocomposites through in situ melt condensation. Increases in the glass transition temperature and high thermal stability are found in the grafted PLA as compared to pure PLA. Grafting of PLA chains onto nanowire surfaces are confirmed by FTTR and TGA. 

Biodegradable polymers such as PVA, PVAc, and PGA have been used in bio-nanocomposites, but to a less extent compared to polymers such as PCL, PLA, and PHB. Nonetheless, these polymers, among other factors, can be used as model to prepare bionanocomposites with hydrophilic material such as clays and CNWs. Moreover, nanobiocomposites based on these polymers can be potentially used as bioscaffolds for cell growth among other applications. 

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