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ABSTRACT The homogeneous polycarbonate/poly(acrylonitrile-butadiene-styrene) (PC/ABS) nanocomposite thin films were prepared by a facile solvent casting method using phenylene modified-mesoporous silica materials as additives and dichloromethane as a solvent. The physicochemical analyses using small-angle X-ray scattering, nitrogen adsorption-desorption, solid-state 13C and 29Si nuclear magnetic resonance, and scanning electron microscope were investigated to provide clear physical and chemical properties for modified-mesoporous materials and nanocomposite films. Tensile tests were performed at room temperature according to ASTM D638. Rheological properties were also analyzed to observe any variance of solid-liquid property. As a compatibilizer and a reinforcing filler, mesoporous (organo-)silicas showed enhanced features in rheological and mechanical properties. The sound absorption coefficient was measured by the impedance tube up to 6400 Hz according to ISO 10534-2. It was found that the PC/ABS nanocomposites containing mesoporous materials can be used as a sound-proofing support material depending on fabrication process. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45777. [ABSTRACT FROM AUTHOR]

The article presents a one-dimensional (1D) model for particle distribution using coating thickness at different drying times and conditions, which includes sedimentation, evaporation, and Brownian diffusion. The model system is made up of monodisperse silica particles in water, and the transient particulate distributions were imaged during its drying using cryogenic scanning electron microscopy (cryoSEM). It is concluded that certain limiting cases of the drying regime maps can be computed analytically.

Phenomenological studies on mechanical hemolysis in rotary blood pumps have provided empirical relationships that predict hemoglobin release as an exponential function of shear rate and time. However, these relations are not universally valid in all flow circumstances, particularly in small gap clearances. The experiments in this study were conducted at multiple operating points based on flow rate, impeller speed, and tip gap clearance. Fresh bovine red blood cells were resuspended in phosphate-buffered saline at about 30% hematocrit, and circulated for 30 min in a centrifugal blood pump with a variable tip gap, designed specifically for these studies. Blood damage indices were found to increase with increased impeller speed or decreased flow rate. The hemolysis index for 50-µm tip gap was found to be less than 200-µm gap, despite increased shear rate. This is explained by a cell screening effect that prevents cells from entering the smaller gap. It is suggested that these parameters should be reflected in the hemolysis model not only for the design, but for the practical use of rotary blood pumps, and that further investigation is needed to explore other possible factors contributing to hemolysis. [ABSTRACT FROM AUTHOR]

In this study, polypropylene (PP)/clay nanocomposites containing different concentrations of ethylene‐methacrylic acid ionomer (i.e. Surlyn®) were prepared, and the effect of ionomer on clay dispersion was studied via WAXD, rheology, SEM, and TEM. The role of the ionomer in the nanocomposites was compared with that of maleic anhydride grafted PP (PP‐g‐MA), which has been widely used as a compatibilizer in making PP/clay nanocomposites. With an increase in the concentration of compatibilizer, the position of d001 peak of OMMT shifted toward a lower angle for PP‐g‐MA system, while the position remained almost unchanged for Surlyn system, in which a larger interlayer spacing (d001) was found with respect to the former. In rheology, the addition of the ionomer led to a gradual increase in both moduli and complex viscosity, and the nonterminal behavior at low frequency was observed in both systems. In addition, the ternary hybrid containing 20 wt % Surlyn achieved the largest enhancement in relative viscosity, which was more than that of the nanocomposite prepared from pure Surlyn or pure PP, presumably indicative of the existence of strong interaction between the components. Finally, SEM and TEM micrographs demonstrated that exfoliated structure was preferred for PP/Surlyn/OMMT hybrids, while intercalated morphology for PP/PP‐g‐MA/OMMT. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4024–4034, 2007 [ABSTRACT FROM AUTHOR]

Examines the effect of graft ratio on the dynamic moduli of acrylonitrile-butadiene-styrene copolymer. Complication on the dependence of rheological properties on the graft ratio; Mechanism of maximum storage modulus; Occurrence of morphological change.

Discusses a study which developed a numerical algorithm based on finite element method (FEM) for solving non-Newtonian fluid flow with the moving free surface problem encountered in polymer processing. FEM formulation of governing equations; Verification of the numerical algorithm in a fountain flow; Simulation of the two-dimensional/full three-dimensional viscous fluid buckling problem using the algorithm.