Nanofillers nanoparticle loading

Also, the loss in available surface area due to overlapping and aggregation is quite substantial in the case of nanofiller. As illustrated in Fig. 41, the loss is directly dependent on the interparticle distance between the fillers and, hence, also on the filler loading. Introduction of these two terms into the IAF in the form of the correlation length between the nanoparticles (J ) and the filler volume fraction ( ), respectively, mitigates the problem. 

In their work, (Chang et al. 2010b, c) found that the incorporation of chitin nanoparticles imiformly dispersed in a starch matrix at low loading levels (till 5 wt %) led to improvements in mechanical parameters (tensile strength, elastic modulus, and Tg) and water vapor permeability. For higher filler contents, agglomeration occurred, but good interfacial interactions between the nanofiller and the starch could be observed. 

As shown in Figure 20.1, the number of filler particles at a given volume fraction (3% in the figures) rapidly increases as the size of particles decreases. As a consequence, compared to conventional polymer composites with conventional fillers, which normally require loadings of 20% or more, the distances between nanoparticles are drastically reduced to the nanometer range, even when relatively low concentrations of nanofillers are used. 

Silicone rubber (SR) nanocomposites with different dimensional nanofillers like OD (nanosilica, POSS, metal nanoparticle), ID (CNT, CNF), 2D (layered silicate, LDH, graphene) and 3D (graphite), etc., have been effectively reviewed in the up-to-date research work presented in this chapter covering their synthetic method, nanostructure and properties. It is noted that the SR nanocomposites exhibited improved mechanical, thermal, gas barrier properties, reduced flammability and biological properties at very low loading of fillers. However, it is concluded that such improvement in properties is only observed when fillers are uniformly dispersed and interact with SR chains. 

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