Nanocomposite application areas

Polypropylene (PP) has wide acceptance for use in many application areas. However, low thermal resistance complicates its general practice. The new approach in thermal stabilization of PP is based on the synthesis of PP nanocomposites. This paper discusses new advances in the study of the thermo-oxidative degradation of PP nanocomposite. The observed results are interpreted by a proposed kinetic model, and the predominant role of the one-dimensional diffusion type reaction. According to the kinetic analysis, PP nanocomposites had superior thermal and fireproof behavior compared with neat PP. Evidently, the mechanism of nanocomposite flame retardancy is based on shielding role of high-performance carbonaceous-silicate char which insulates the underlying polymeric material and slows down the mass loss rate of decomposition products. 

Introducing nanoscale porosity into silicon dramatically lowers its stiffness and hardness in a tunable maimer over a wide range. Available data is collated on Young s modulus and Viekers hardness as a function of porosity and layer morphology. There is little quantitative data on fracture toughness and strength, but theoretical work predicts that optimized nanocomposites could be very mechanically durable. The exceptional plasticity recorded for individual silicon nanowires is yet to be demonstrated in mesoporous sihcon. A number of application areas are highlighted that rely heavily on the mechanical properties of porous silicon. 

Polyimides (PI) are widely used in microelectronics and photonics because of their outstanding electrical properties, heat resistance, and chemical stability [10-12], Pl/clay nanocomposites have been reported to reduce the coefficient of thermal expansion, amount of moisture absorption, and dielectric constant for improved performance in these application areas already mentioned [13-22], For example, Yano et al. [13] prepared a PI (pyromellitic anhydride-4,4 -oxydianiline)/clay composite film [(PMDA-ODA)/clay] by solution-mixing of polyamic acid (PAA) and a dimethylacetamide (DMA) dispersion of clay. They used dodecylamine as the clay modifier, and the film showed reduced thermal... 

Nanocomposites can be defined as combinations of different materials where at least one of the components is distributed on the nanoscale. Nanocomposite particles are particles with at least one component being structured on the nanoscale. Several types of inorganic materials have been combined with polymer materials to produce nanocomposite particles, for example, titanium dioxide, clay platelets such as laponite (LRD) and montmorillonite (MMT), calcium carbonate and iron oxides. In general, beneficial properties of the composite are expected, mainly in the area of mechanical properties, barrier properties and dispersion properties (better dispersion of the inorganic particles in the polymer matrix). Many research groups are working on incorporation of clay platelets either intercalated or (partially) exfoliated in polymer materials. Application areas of the anticipated materials are often in coatings, adhesives, films for barrier properties and plastics. 

Similar efforts have been made in other application areas. In gas separation, the addition of Ti02 nanoparticles to polyvinyl acetate improved the thermal stability of the resulting membranes, which was demonstrated by an inaease in the glass transition temperature (Ahmad and Hagg 2013). In this case, it was found that the addition of Ti02 up to 10 wt% improved both the permeability and selectivity of the membranes for gas separation, including H2, CO2,02, and N2. Similar observations were made on the effect of silica nanoparticles on the permeability of CO2 and CH4 for two types of nanocomposite membranes based on polyester urethane and polyether urethane (Hassanajili et al. 2013). Khan et al. (2013) studied mixed matrix membranes composed... 

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