Polymer-based nanocomposites capacity

In the past decade, clay-based polymer nanocomposites have attracted considerable attention from the research field and in various applications. This is due to the capacity of clay to improve nanocomposite properties and the strong synergistic effects between the polymer and the silicate platelets on both a molecular and nanometric scale [2,3], Polymer-clay nanocomposites have several advantages (a) they are lighter in weight than the same polymers filled with other types of fillers (b) they have enhanced flame retardance and thermal stability and (c) they exhibit enhanced barrier properties. This chapter focuses on the polymer clay-based nanocomposites, their background, specific characteristics, synthesis, applications and advantages over the other composites. 

Pt-M catalysts (M = Ru, Ni, Co, Sn and Au) based on polymer-MWNT nanocomposites were prepared using one-step y-irradiation. Two different types of functional polymers, poly(vinylphenylboronic acid) (PVPBAc) and polyvinylpyrrolidone (PVP), were used to prepare nanocomposites. The Pt-M catalysts obtained based on polymer-MWNT nanocomposites were then characterized by XRD, TEM and elemental analysis. The catalytic efficiency of the Pt-M catalysts based on polymer-MWNT nanocomposites was also examined for CO stripping and MeOH oxidation for use in a DMFC. The catalytic efficiency of the Pt-M catalyst based on polymer-MWNT nanocomposites for MeOH oxidation followed the order Pt-Sn > Pt-Co > Pt-Ru >Pt-Au>Pt-Ni catalysts. The CO adsorption capacity of the Pt-M catalyst based on polymer-MWNT nanocomposites for CO stripping decreased in the order Pt-Ru > Pt-Sn > Pt-Au > Pt-Co > Pt-Ni catalysts. 

The formation and equilibrium structure of polymer layered silicate nanocomposites, in particular with organically modified layered silicates, has been shown to be a strong function of the nature of the polymer (polar or apolar), the charge carrying capacity of the layered silicate, as well as the chain length and structure of the cationic surfactant. However, both the polymer/silicate compatibility and hybrid equilibrium structure for these nanocomposites are observed to be independent of polymer molecular weight. The experimental results have been summarized by Vaia et al. and a lattice based mean field theory has been developed to explain these results [26]. 

The synthesis of the CMK-n carbons is controlled to various pore shapes, connectivity, diameters (typically, 1-10 nm in diameter) and pore wall thickness. These carbons exhibit high specific surface areas (typically, the BET specific surface areas up to 2000 mV )> uniform pore diameters, large adsorption capacities, and high thermal, acid-base and mechanical stabilities. The CMK-type carbons are also suitable for the formation of well-defined nanocomposite with organic polymers, so that the nanopore walls can be modified with various functional groups. These carbons show new possibilities for various applications in adsorption, catalysis and electrochemistry. 

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