Porous, large surface area, metastable zirconias, are of importance to catalytic, electrochemical, biological, and thermal insulation applications. Combustion synthesis is a very commonly used method for producing such zirconias. However, its rapid nature makes control difficult. A simple modification has been made to traditional solution combustion synthesis to address this problem. It involves the addition of starch to yield a starting mixture with a “dough‐like” consistency. Just 5 wt% starch is seen to significantly alter the combustion characteristics of the “dough.” In particular, it helps to achieve better control over reaction zone temperature that is significantly lower than the one calculated by the adiabatic approximation typically used in self‐propagating high‐temperature synthesis. The effect of such control is demonstrated by the ability to tune dough composition to yield zirconias with different phase compositions from the relatively elusive “amorphous” to monoclinic (>30 nm grain size) and tetragonal pure zirconia (<30 nm grain size). The nature of this amorphous phase has been investigated using infrared spectroscopy. Starch content also helps tailor porosity in the final product. Zirconias with an average pore size of about 50 μm and specific surface area as large as 110 m2/g have been obtained.

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A superhydrophobic coating, free of fluorinated and siloxane materials, has been prepared via reactive compatibilization of all organic blends of hydrophilic and hydrophobic materials. In this case, styrene acrylic emulsion and a combination of hydrophobic waxes (functional rice bran wax and functional polypropylene wax) are blended together in the presence of polycarbodiimide as the reactive compatibilizer. The effect of blending and crosslinking on surface morphology is studied by Fourier transform infrared spectroscopy analysis, microscopy analyses (SEM and AFM), contact angle, and surface energy measurements. After heat treatment and crosslinking, synergistic improvements of surface properties with a gradual trend toward superhydrophobicity are observed (water contact angle ≈144°and roll-off angle of <10°). The system is free of nanoparticles, and the desired surface morphology and microstructure is formed from the mixture of renewable (rice bran) wax and petrochemical (polypropylene) wax. These coatings are shown to have easy-cleaning as well as self-cleaning characteristics. Further, the coatings can withstand exposure to solvents as well as mechanical abrasion.

The structure property correlation of different commercial grades of high-impact polystyrene (HIPS) with varying polybutadiene rubber (PBR) content has been investigated. The average molecular weights of polystyrene, rubber content, gel content, swelling index, degree of grafting, morphology of rubber, and rubber particle size distribution were characterized and correlated with the mechanical properties of HIPS. The dynamic light scattering and transmission electron microscopy techniques were employed to characterize the loss of submicron tiny PBR gel particles. The obtained results reveal the fact that submicron tiny PBR gel particles that are lost during gel estimation by ultracentrifugation process lower the gel content and rubber efficiency, which significantly contribute to the overall impact performance evaluation of the final HIPS product.

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