Influence of intramolecularly compensated dipoles upon collision absorption in liquids

Thermal dewetting behavior of polystyrene composite thin films with organic-modified inorganic nanoparticles

The thermal dewetting of polystyrene composite thin films with oleic acid-modified CeO2 nanoparticles prepared by the supercritical hydrothermal synthesis method was investigated, varying the nanoparticle concentration (0-30 wt %), film thickness (approximately 50 and 100 nm), and surface energy of silanized silicon substrates on which the composite films were coated. The dewetting behavior of the composite thin films during thermal annealing was observed by an optical microscope. The presence of nanoparticles in the films affected the morphology of dewetting holes, and moreover suppressed the dewetting itself when the concentration was relatively high. It was revealed that there was a critical value of the surface energy of the substrate at which the dewetting occurred. In addition, the spatial distributions of nanoparticles in the composite thin films before thermal annealing were investigated using AFM and TEM. As a result, we found that most of nanoparticles segregated to the surface of the film, and that such distributions of nanoparticles contribute to the stabilization of the films, by calculating the interfacial potential of the films with nanoparticles.

Improved microwave Michelson interferometer operating at 140 GHz

Several major improvements have been made to a Michelson-type microwave interferometer operating at a frequency of 140 GHz. An enlarged dielectric cell, an improved measuring system, and a highly stable microwave system allow a precise determination of the complex dielectric constant for low-loss liquids. The effect of a mismatch in the microwave system is discussed and the computed behavior of the instrument is compared to that found experimentally. An experimental technique is described which takes account of the effect. Some results are presented for various solutions of nitrobenzene in benzene and for the alkane series of hydrocarbons. The values obtained are compared with values reported by other workers using different methods.