http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Synthesis and Miscibility Phenomena of Polyvinyl Butyral of Varying Vinyl Alcohol Contents
Kajiyama, Tisato,Karasz, Frank E,Rooney, Mikle,David, Don J,Jeong, Hwan Keong,MacKnight, Wiliam J 한국공업화학회 1998 응용화학 Vol.2 No.1
Polyvinyl butyrals(PVBs) of systematically varying vinyl alcohol content have been synthesized and characterizing using wet chemistry, IR, DSC and TGA. The miscibility of polyvinyl hutyral(PVB)/polymethyl methacrylate(PMMA) blends was studied by DSC, DMTA and SEM as a function of PMMA and vinyl alcohol(VA) content differences between the respective blend components. It is found that a blend of PVB containing 23 wt% VA with PMMA at a weight ratio of 80:20, repectively, was thermodynamically miscible. The miscibility parameter(MP) model used to estimate potential areas of compatibility/miscibility is based on the use of solubility parameters and the estimated region of compatibility/miscibility agrees with the experimental results.
Emission tuning study of RGB blends. Interaction of two EL polymers and a red dye
Jeferson Ferreira de Deus,Ali Cirpan,Frank Karasz,Leni Akcelrud 한국물리학회 2010 Current Applied Physics Vol.10 No.2
A study of light emission in photo- and electroluminescence in blends composed of a blue and a green emitting polymers with a red dye was performed. To gain information about the tunability of the RGB mixture, the blends varied in composition. The polymers were poly(2,7-9,90-dihexylfluorenediyl) (blue),poly(9,9-di-hexylfluorenediyl divinylene-alt-1,4-phenylenevinylene) (green) and the dye was 4-(dicyanomethylene)-2-methyl-6-(dimethylaminostyryl)-4H-pyrane (red). It was verified that in photoluminescence Forster type energy transfer plays the main role in the emission. In solution a large concentration of the acceptors is needed to attain the transfer radii, whereas in the solid state, the transfer is very sensitive to small variations in the acceptor content, with large changes in emission spectra. The band gaps of the components allowed a cascade energy transfer mechanism. In electroluminescence, apart from the energy transfer mechanism, an important role is played by the trapping of charge carriers, resulting in significant differences between the PL and EL spectra.
Spectroscopic Evidence for Aggregation of Stilbene Derivatives in Solution
Aguiar, M.,Akcelrud, L.,Pinto, M.R.,Atvars, T.D.Z.,Karasz, F.E.,Saltiel, Jack Korean Society of Photoscience 2003 Journal of Photosciences Vol.10 No.1
The absorption, fluorescence and fluorescence-excitation spectra of concentrated toluene solutions of selected para substituted trans-stilbene derivatives provide strong evidence for aggregation. A red-shifted fluorescence spectrum peaking at 420 nm gains in intensity as the stilbene concentration is increased. The excitation spectrum of this new emission is well to the red of the normal stilbene absorption spectrum, consistent with the appearance of a red shifted shoulder in the UV spectrum. Formation of a fluorescent ground state dimer (or higher aggregate) is proposed to account for these observations. The presence of polar substituents is crucial to the formation of this ground state complex.