钛凝胶的光致变色和电致变色特性

Titania gel is very sensitive to change of color to blue-purple by UV irradiation and to brown color under extra electric field polarzation. The UV absorption spectra of the photochromic (PC) and electrochromic(EC) titania gel are different to that of the nanocrystalline TiO_2 which changes to blue color by UV irradiation or under extra electric field polarization. The steady-state ESR measurements at room temperature indicate that ESR signals of Ti3+ appeared in PC and EC titania gel with the g values corresponding to 1.9505 and 1.9512, respectively.     

热处理温度对铬掺杂二氧化钛表面结构和性质的影响

采用溶胶-凝胶法制备了铬掺杂二氧化钛(Cr-TiO₂), 并对经过不同温度烧结的Cr-TiO₂的结构、吸收光谱及样品中铬的氧化态等进行了表征. 实验结果表明, 在不高于723 K的温度烧结后, 铬以Cr^3＋的氧化物和Cr^6＋的铬酸盐或重铬酸盐的形式存在于TiO₂表面. 随着热处理温度的提高, Cr^6＋的含量逐渐增多. Cr-TiO₂在可见区400～550 nm的吸收带是由Cr^3＋的⁴A₂→⁴T₁跃迁和O→Cr^6＋的1t₁→2e电荷转移等引起的, 620～800 nm的吸收则是Cr^3＋的⁴A₂→⁴T₂跃迁的结果. 前者随着烧结温度的升高而增强, 后者则随着温度升高而下降.     

基于模板法构建手性小分子有机纳米管

Organic nanotubes from two kinds of chiral molecules, R-di-2-naphthylprolinol （DNP） with an asymmetric carbon atom and R-（＋）-1,1＇-bi-2-naphthol dimethyl ether （BNDE） with the conformational asymmetry, were prepared by the immersing technique using porous alumina membranes as the template. It was found that the nanotubes from DNP with an asymmetric carbon atom presented the same chirality as the solution with slight red shift of the CD signals upon the formation of the nanotubes, while no well-defined chirality could be identified for the nanotubes from BNDE with the conformational asymmetry.     

高效率变色WO3多聚体/1，10-DAD自组装薄膜的制备

A novel high-efficient photochromic self-assembly multilayered film has been fabricated from WO3 and 1,10-DAD solution using molecular deposition technique.The dependence of photochromic behavior on with WO3 in the WO3-polymer/1,10-DAD self-assembly film was discussed in comparison with WO3/4,4-BAMBp system.The results clearly show that organic molecules determine the charge density of the photo-induced charge-tracsfer complexes,andthus manipu-late the structure and the photochromic properties of the films.     

1,4-二氰基萘一维亚微米结构材料的制备及光学性能

用再沉淀法制备了1,4-二氰基萘（DCN）一维亚微米结构。通过改变制备条件分别得到了DCN的线状及管状一维结构。所制备的有机亚微米材料具有良好的结晶性,不同结构的生长取向存在一定的差别。由于DCN分子的有序堆积,亚微米结构的的发光比溶液的发光有一定的红移。通过对单根材料的表征发现,DCN亚微米结构具有良好的光波导性能。空心结构的光波导性能要明显优于实心结构,主要原因在于空气介质减小了光学损耗。     

Investigation of third-order nonlinear optical properties of two azo-nickel chelate compounds

This paper investigates the third-order nonlinear optical properties of two azo-nickel chelate compounds by the optical Kerr gate method at 830 nm wavelength with pulse duration of 120 fs. Both of the two compounds exhibited large third-order optical nonlinearity. The second-order hyperpolarizability,γ, of Compound 1 is of 1.0 × 10^-31 esu. Due to the charge transfer, the γ of Compound 2 with electron donor and acceptor group is 4.9 × 10^-31 esu, which is a four-time enhancement in comparison with Compound i. The absorption spectra show that the electron push-pull effect, which induces intramolecular charge transfer, leads to the increased optical nonlinearity.     

乙二铵多钼酸盐NH3CH2CH2NH3Mo3O10@4.4H2O的合成及其光致变色性质研究

利用乙二胺阳离子为模板,采用温和的反应条件制备出一种新的光致变色化合物NH3CH2CH2NH3Mo3O10·4.4H2O,经过元素分析、热重以及光谱测定,证明该化合物的无机骨架为(Mo3O10)∞^2-无穷长链。乙二胺阳离子通过氢键等超分子作用与无机骨架相连。实验发现该化合物具有良好的光致变色性能,与真空蒸镀MoO3不同的是,经紫外光照后,此化合物由白色变为红棕色,EXAFS(扩展X射线精细结构)研究结果表明紫外光照后,质子从乙二铵阳离子转移到Mo-O^-为其可能的机理。     

紫外光辐射对TiO2溶胶的影响研究

用紫外-可见吸收光谱、动态光散射与透射电镜研究紫外光辐射对T₂溶胶的影响,结果表明,光辐射使T₂溶胶在可见光区的吸收减少,紫外区吸收增加,吸收带隙增大.与非光辐射的T₂溶胶粒子相比,光辐射使T₂溶胶粒子分布均匀且平均粒径减小,提高了T₂纳米粒子在室温下的晶化程度.     

罗丹明B在TiO2薄膜和P-25涂层催化下光反应的比较

半导体光催化剂尤其是TiO₂由于表面的光生空穴具有很强的氧化能力^[1-2],能够完全降解有机物,在环境治理方面具有潜在的应用前景,因而日益引起人们的关注.目前,利用胶体溶液和颗粒悬浮体系光催化降解有机污染物的研究已经开展得十分广泛^[3-5].但是,从实用的角度来考虑,这一体系存在许多缺点,如反应后催化剂难于分离,颗粒不适宜作循环体系的处理等等,因此催化剂的固定日益迫切.为解决这一问题,近来已经有许多人在固定粉末催化剂以及制备催化剂薄膜方面^[6-8]进行了探索和尝试,但尚未得到理想的结果.因而发展高效固定化的催化剂仍然是极为重要的,同时对于薄膜催化机理的深入探讨也有利于在制备过程中有目的地提高膜的催化活性.