Effect Of Interface Interactions Research Articles

Effect of interface interaction on the field localization at the boundary between the constant-index and graded-index media

Effect of interface interaction on the field localization at the boundary between the constant-index and graded-index media

Effects of interface interaction and microphase dispersion on the mechanical properties of PCL/PLA/MMT nanocomposites visualized by nanomechanical mapping

Microphase dispersions and interface interactions are crucial for high performance polymer nanocomposites. However, it remains a challenge to evaluate their effects quantitatively. In this work, poly(ε-caprolactone) (PCL)/poly(lactic acid) (PLA)/montmorillonite (MMT) nanocomposites were chosen as the model nanocomposites, and the effect of MMT on the microphase dispersions and interface interactions were studied and compared with PCL/PLA blends. Using the atomic force microscope (AFM) based nanomechanical mapping, the interface interactions and microphase evolution under tensile were visualized. The Young's moduli map shows a significantly increased interface width of 91.0 ± 15.3 nm for PCL/PLA/MMT nanocomposites compared with 28.7 ± 4.2 nm for PCL/PLA blends. Moreover, the morphology evolution and the onsite changes of microscopic mechanical properties for PCL/PLA/MMT nanocomposites under tensile were visualized and compared with PCL/PLA blends. The results can therefore provide more insights into understanding the complicated toughening mechanism of ternary nanocomposites.

From microstructure to mechanical properties of compatibilized polylactide/thermoplastic starch blends

ABSTRACTBio‐degradable polymer blends of polylactic acid/thermoplastic starch (PLA/TPS) were prepared via direct melt blending varying order of mixing of ingredients fed into the extruder. The effect of interface interactions between PLA and TPS in the presence of maleic anhydride (MA) compatibilizer on the microstructure and mechanical properties was then investigated. The prepared PLA/TPS blends were characterized by scanning electron microscopy, differential scanning calorimetry (DSC), tensile, and rheological measurements. Morphology of PLA/TPS shows that the introduction of MA into the polymer matrix increases the presence of TPS at the interface region. DSC results revealed the reduction of glass transition temperature of PLA with contributions from both TPS and MA. The crystallization temperature was decreased by the addition of MA leading to reduction of overall crystallization of PLA/TPS blend. The mechanical measurements show that increasing MA content up to 2 wt % enhances the modulus of PLA/TPS more than 45% compared to the corresponding blends free of MA compatibilizer. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44734.

Effect of Interface Interaction on the Segmental Dynamics of Poly(vinyl acetate) Investigated by Local Dielectric Spectroscopy.

The segmental dynamics of poly(vinyl acetate) (PVAc) thin films were measured in the presence of an aluminum interface and in contact with an incompatible polymer, poly(4-vinylpyridine). The local dielectric relaxation was found to be faster in thin films than in the bulk; however, no differences were observed for the various interfaces, including a PVAc/air interface. These results show that capping of thin films, even with a rigid material, does not necessarily affect the dynamics, the speeding up herein for capped PVAc was equivalent to that for the air interface. The insensitivity of the dynamics to the nature of the interface affords a means to engineer thin films while maintaining desired mechanical properties. Our findings for PVAc also may explain the discordant results that have been reported in general for the effect of air versus rigid interfaces on the local segmental relaxation of thin films.

Fibrillar morphology of elastomer‐modified polypropylene: Effect of interface adhesion and processing conditions

AbstractThe effect of interface interaction and processing conditions combined with the viscosity ratio of elastomer domains to the polypropylene (PP) matrix (ηd/ηm, subscript d and m designate the dispersed phase and the matrix, respectively) on fibril formation was investigated. A close to unity viscosity ratio, high interface interaction between the two phases, and a high shear rate in molding were found to result in fibril dispersion. A low‐viscosity elastomer tended to form fibrils also. A high extrusion shear rate seems to have no effect on fibrillar formation, but the dispersion size (Dn) decreased from 0.25 to 0.19 μm with an increasing screw speed from 120 to 160 rpm. The Izod impact strength of blends appears to be optimum when a fine and uniform and nonfibril morphology of the elastomer in PP is formed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2085–2092, 2002

Effects of interface interaction on the Mie resonance absorption of gold nanoparticles dispersed within pores of mesoporous silica

Mesoporous silica with Au nanoparticles loaded within its pores were prepared by in situ sonochemical reduction of chloroauric acid (HAuCl 4). The optical absorption has been investigated for the Au nanoparticles dispersed within pores of monolithic mesoporous silica after subsequent annealing treatment. Charge transfer at the interfaces between Au nanoparticles and pore walls is introduced qualitatively to discuss the red-shift of Mie resonance absorption band with decreasing the Au particle size.