Synthesis and optical properties of new chalcones containing 4-[bis(2-hydroxyethyl)amino]phenyl fragment

New chalcones with 4-[bis(2-hydroxyethyl)amino] phenyl fragment were obtained from 4-[bis(2-acetoxyethyl) amino]- benzaldehyde by the Claisen–Schmidt reaction. From their UV-VIS absorption and emission spectra, optical band gap values were calculated based on the Stokes shifts as well as the molar absorption coefficients and fluorescence quantum yields were estimated. The dependence of the absorption and emission maxima on solvent polarity and pH was evaluated.     

Determination of UV-transparent compounds by liquid chromatography using the UV detector

An indirect UV photometric detection technique is described in which a low concentration of a UV-absorbing compound (UVAC) is added to the mobile phase in reversed phase liquid chromatography, thereby making it possible for non UV-absorbing compounds such as the lower alcohols to be detected by the UV detector. This happens because the injected analyte may extract a portion of the UV absorbing compound from the mobile and/or stationary phase and the complex is co-eluted as a positive peak at the retention time of the analyte. Alternatively, the injected analyte may appear as a negative peak if the UV-absorbing compound is transferred to the mobile and stationary phases. In any case, the injected compound appears either as a positive or negative peak depending on the relative polarities and concentrations of all the compounds in the system. In addition, the resulting excess or deficiency of detection agent in the stationary phase is eluted separately as a positive or negative peak, indicating that the system has returned to equilibrium. In the work described herein, the chromatographic conditions and variables of the indirect photometric technique were studied to develop a quantitative HPLC method for UV-transparent compounds. It was found that under optimal conditions it is possible to determine some analytes quantitatively at concentrations as low as 0.05%.     

A robust spin-coated optical sensing device for rapid determination of predominant metal ions in wastewater streams

The potential of an optical sensing material for determination of metal ions in wastewater streams is presented. The initial results in the development of a chromo-ionophore-based optical sensor for metal ions are detailed. An azo dye species, 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (BrPADAP), together with an ionophore and plasticiser was immobilised in a film of poly(vinyl chloride) (PVC). Initial investigations using the dye-impregnated sensing film showed a reproducible and reversible response to Pb(II) ions in aqueous solution. The response of this sensing film to Pb(II) at pH 6 was found to be linear in the 0.1-10 mg/L range, with a %RSD of 1.55%. The film can be regenerated by immersion in a low-pH buffer solution. The authors demonstrate how this method shows potential for analysis using once-off sensing probes. The sensing film response for Pb(II) occurs within 30 s.     

Dendronized Polymers with High FTC-chromophore Loading Density:Large Second-order Nonlinear Optical Effects,Good Temporal and Thermal Stability

In this study,two new dendronized nonlinear optical(NLO)polymers were synthesized with high FTC chromophore loading density by introduction of high generation chromophore dendrons on the side chains.Due to their suitable molecular weights,both of them possessed good solubility in common solvents.They also inherited the advantages of dendrimers(large NLO coefficient),especially for PG2 whose NLO coefficient d33 value was as high as 282 pm·V^–1.Also,PG2 had a good temporal stability with 80%of its maximum value being retained at the temperature as high as 129℃.     

含偶氮苯并噻唑发色团的二阶非线性光学互穿网络聚合物

合成了含偶氮苯并噻吩（ＢＴ）发色团的聚氨酯／环氧树脂互穿网络聚合物（ＩＰＮ）,其中聚氨酯网络由（丙烯酸β羟丙酯 ＢＴ ２甲基丙烯酸酯）共聚物与苯酚封闭的双端异氰酸酯的ＢＴ １反应形成,而环氧树脂网络由含环氧基的ＢＴ与含ＢＴ的苯二胺反应形成．同时实施这二种反应即形成ＩＰＮ．ＩＰＮ经红外光谱、凝胶含量测定及ＤＳＣ等表征．其薄膜经１６０℃、８５ｋＶ电晕极化,由可见光谱测量及一维刚性取向气体模型计算得到宏观二阶非线性光学极化系数χ（２）为２１８×１０－７ｅ．ｓ．ｕ．,在１２０℃经２４０ｈ序参数几乎不变．     

电光高分子材料的最新研究进展

电光高分子材料由于其在光电子信息领域的潜在应用前景已得到了广泛关注和深入研究.本文在简要介绍电光效应及其材料等相关知识的基础上,综述了最近几年来电光高分子材料的研究进展,主要包括生色团的设计与合成,以及掺杂型、侧链型、主链型、交联型、互穿网络型和树枝型等聚合物材料体系的设计与合成.