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Better Optical Properties (good + optical_property)
Selected AbstractsStilbene-containing polyactylenes: Molecular design, synthesis, and relationship between molecular structure and NLO propertiesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 13 2008Xinyan Su Abstract Polyacetylenes (P1,P4) containing different stilbene groups, [(CHC) PhCHCHPhR]n(ROCmH2m+1 (m = 4 (P1), 10 (P2), 16 (P3)), or NO2 (P4)) were designed and synthesized, respectively, using [Rh(nbd)Cl]2 as a catalyst. Their structures and properties were characterized and evaluated by FTIR, 1H-NMR, 13C-NMR, GPC, and UV, PL, respectively. The optical limiting and nonlinear optical properties were investigated by using a frequency doubled, Q-switched, mode-locked Continuum ns/ps Nd:YAG laser system and their optical limiting mechanism was discussed. It is surprising to see that the stilbene pendants endow the polyacetylenes with a high thermal stability (Td , 270 °C), novel optical limiting properties and large third-order nonlinear optical susceptibilities (up to 4.61 × 10,10 esu). The optical limiting mechanism is mainly originated from reverse saturable absorption of molecules. In addition, it is found that the polymer with electron accepted NO2 moiety exhibits better optical properties than that with electron donated alkoxy group because of larger , electron delocalization and dipolar effect. The strong interaction between stilbene pendants and the polyene main chain significantly results in red-shift of fluorescence emitting peak. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4529,4541, 2008 [source] Optical properties of highly transparent polypropylene cast films: Influence of material structure, additives, and processing conditionsPOLYMER ENGINEERING & SCIENCE, Issue 4 2006Katharina Resch Polypropylene homopolymers and ethylene/propylene-random-copolymers formulated with and without anti-blocking additives were extruded to cast films with an industrial scale extruder equipped with a soft box, a specific air knife that expels a higher volume of air at lower velocity. The films were analyzed as to their optical properties haze and clarity. A comprehensive topographical characterization was performed using atomic force microscopy (AFM) and confocal microscopy. To obtain morphological information on a nanometer scale AFM phase imaging, micro-thermal analysis and small angle X-ray scattering (SAXS) were done. A significant effect of additives and processing conditions on the film topography and the optical properties was revealed. The films without anti-blocking and antacid aids showed the best optical properties and lowest vertical roughness fluctuations. In contrast, the addition of anti-blocking and antacid aids reduced the optical properties associated with an increase in surface roughness. While for films without anti-blocking aids an enhanced soft box condition resulted in lower vertical fluctuations of roughness and better optical properties, the behavior was in reverse for films with anti-blocking aid. By means of SAXS crystalline lamellae with a thickness of about 2.5 nm were detected. High-resolution phase imaging AFM yielded thicker crystal lamellae on the film surface. POLYM. ENG. SCI., 46:520,531, 2006. © 2006 Society of Plastics Engineers. [source] CdSe quantum dot in a ZnSe nanowire as an efficient source of single photonsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 4 2009A. Tribu Abstract We report on our development of fabrication of CdSe QD in ZnSe nanowire. We have been able to obtain high quality structures with very good optical properties. This has allowed us to measure photon emission from single quantum dots and to demonstrate photon antibunching. We show that this new type of II,VI quantum dot is very promising for high temperature operation. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Fabrication of GaN dot structures on Si substrates by droplet epitaxyPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2006Toshiyuki Kondo Abstract Nanosized GaN dot structures were fabricated on Si(111) substrate by droplet epitaxy using an rf plasma MBE system. The size and density of the GaN dots could be controlled by changing the amount of Ga supplied. By reducing the Ga supply, a maximum dot density of 3.3 × 1011 cm,2 was realized. Photoluminescence measurements at room temperature showed band edge emission with negligible yellow luminescence, which indicates a good optical property of GaN dots grown by this technique. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | |||||||||||||