For zinc blende ZnS, it is found that the previously estimated frequency of the LA mode at X point in the Brillouin-zone boundary is much smaller than the value obtained from other experiments and our calculation. Considering the involvement of LA phonon at X point, we reassign the second-order Raman active modes and some CHIR-99021 manufacturer other modes which have not yet been understood so far. This work clarifies some of the controversial Raman mode assignments in zinc blende and wurtzite ZnS.”
“In this work, the additive effects of the poly(ethylene oxide) (PEO) on the Young’s moduli of two
kinds of polypropylene (PP)/fibrous cellulose (FC) composite were studied using the Kerner-Nielsen equation. In the case of the PP/maleated PP (MAPP)/FC + PEO composite, all the values of the moduli with the various PEO contents were selleck products in good agreement with the theoretical values obtained from the Kerner-Nielsen equation. Whereas the moduli of the PEO/FC + PP/MAPP composite followed the Kerner-Nielsen equation about 6 vol % of the PEO content and then unexpectedly deviated. In the scanning electron
microscopy (SEM) observation, the PP/MAPP/FC + PEO composite was found to have a sea-island morphology corresponding to the PP/MAPP/FC matrix and the PEO phase. This morphology had been unchanged against the increase of the PEO content. Whereas in the case of the PEO/FC + PP/MAPP composite, the SEM micrographs showed that that the interface between the FC and the PP became worse with the increase of the PEO content, indicating that the formation of the PP/MAPP/FC matrix was blocked by the excess PEO. The deviation of the Young’s moduli from the Kerner-Nielsen equation was due to the blocking of the PEO. It was found that the adequate combination of the PEO and the MAPP was able to supply the increase of the toughness of the PP/FC composite by investigating the dependence of the PEO/FC + PP/MAPP selleck chemical composite on the
MAPP content. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 1656-1663, 2009″
“A method for modeling the effect of microencapsulation on the electro-optical behavior of polymer cholesteric liquid crystal (PCLC) flakes suspended in a host fluid is introduced. Several microencapsulation configurations in an applied ac electric field are investigated using COMSOL MULTIPHYSICS software in combination with an analytical model. The field acting on the flakes is significantly altered as various encapsulant materials and boundary conditions are explored. The modeling predicts that test cells with multiple materials in the electric field path can have a wide range of electro-optic responses in ac electric fields.