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Processing and compatibilization effects on the phase morphology and the tensile behavior of blends of polystyrene and high‐density polyethylene (PS/HDPE) were investigated. As predicted by theory, high shear rates encountered during extrusion blending led to efficient minor phase emulsification in immiscible PS/HDPE blends for which the viscosity ratio approaches unity. Consequently, the emulsifying effect of a styrene/ethylene‐butylene/styrene (SEBS) compatibilizer was found to be negligible. In the subsequent molding process, disintegration, shape relaxation and coarsening of the minor phase domains were found to be responsible for the morphological evolution. In the compression molding process, morphological observations showed that the rate of minor phase coarsening followed the predictions of the Ostwald ripening theory, in agreement with the rheological analysis. In the injection molding process, minor phase coarsening was attributed to shear coalescence. Tensile tests performed on compression molded and injection molded blends showed that the mechanical behavior of PS/HDPE blends depend strongly upon the matrix orientation as well as the dispersed phase morphology and orientation. In both postforming operations, compatibilization effects on the morphological stability and the tensile behavior of PS/HDPE blends were found to be dependent upon the composition and the rheological behavior of the blend. Evidence of adhesion between the PS and HDPE phases was observed in the presence of SEBS in HDPE‐rich blends.

Tin oxide films were deposited by chemical vapor deposition on borosilicate and fused silica substrates using dibutyltin diacetate (DBTD) as tin feedstock and SbC]5 or CC13-CF3 as dopants. The film growth rate was measured as a function of dopant/DBTD ratio, temperature, and film thickness. Scanning electron microscopy and x-ray diffraction spectra of the films were used to determine the grain sizes and the preferential orientations of the crystallites in the film as a function of film thickness. Optical and electrical properties were measured. A model is proposed to elucidate the variation of transport properties of doped SnO2 as a function of film thickness. It could be shown with this model that the thickness dependence of the conductivity of doped SnO2:Sb and SnO2:F films could be analyzed in terms of carrier concentration taking into consideration deep-level compensation. The number of carriers is decreased by electron trapping at Sb(III) or Sn(II) surface states when antimony or fluorine are used as dopant, respectively. The model based on results of the literature related to a single crystal with (110) orientation is extended in this work to other crystallite orientations. The present analysis indicates that deep levels appear only on the grain boundary surfaces with (110), (211), and (301) orientations, and not on the (200) and (400) ones. The concentration of free carriers can be calculated on the basis of x-ray diffraction spectra indicating an estimate of the relative fraction of the crystallites with each orientation as a function of the film thickness. The conductivities of the films can be computed using this model and taking a single value for the electron mobility of 19 cm 2 (V-s) -1 for all film thicknesses and a total donor concentration of 2 • 102~ cm -3. All the obtained experimental data can be accounted for exclusively on the basis of film-thicknessdependent carrier concentration.