苝聚集体随机激光的近场散射增强

本文通过物理模拟发现苝聚集体纳米粒子有很强的近场散射. 苝聚集体由异丁基取代聚倍半硅氧烷(POSS)苝(DPP)构成,其理论模拟得到的近场散射增强被实验证实. 同时,由聚集体的二硫化碳溶液激发出相干随机激光. 近场增强源自于通过化学键连接的POSS基团,相干随机激光源自于苝发射团. 本文通过分子设计发展出一种新的随机激光体系,为后续一系列交叉研究打开了大门,相关交叉研究主要涵盖无序光子学的分子设计等领域.     

双光子吸收材料二苯乙烯衍生物的合成及光谱性质

设计、合成并用红外光谱、1H NMR、元素分析表征了三种用于双光子吸收材料的二苯乙烯衍生物,4,4′-双(二苯氨基-反式-苯乙烯基)联苯(BPSBP),4,4′-双(二乙氨基-反式-苯乙烯基)联苯(BESBP)和4,4′-双(9-咔唑基-反式-苯乙烯基)联苯(BCSBP)。实验结果表明三者最强的单光子吸收出现在350～400 nm之间,且单光子吸收和荧光光谱中表现出明显的溶剂化显色效应,揭示了分子内对称电荷转移的本质,双光子荧光光谱则揭示了单光子和双光子吸收具有相同的发射机理。利用双光子上转换荧光法测试发现,三种双光子吸收材料在800 nm飞秒激光的激发下具有较大的吸收截面,分别为892,617和483 GM,这表明在双光子领域有潜在的应用价值。     

天然橡胶-黄腐酸的非均相接枝聚合

腐植酸是一种组份和结构很复杂的天然大分子。利用腐植酸中的自由基进行烯类单体在腐植酸上的接枝聚合反应,已有报道,但尚未见到腐植酸与双烯聚合物反应获得接枝聚合物的报道。巩县风化煤黄腐酸是腐植酸中分子量较小(M_n=1035)的部分,它的结构特点已进行过较详细的表征。本文以这种黄腐酸为原料,在60℃下,以苯为天然橡胶的溶剂,以水为黄腐酸的溶剂,以过氧化苯甲酰为引发剂,聚合得到了天然橡胶与黄腐酸的接枝聚合物,并对接枝聚合物进行了一些表征。     

A Simple Model to Describe the Requirement of Realizing All-Optical Poling

All-optical poling （AOP） of a crosslinkable polymer based on hexamethoxymethyl melamine （HMMM） and Disperse red 1 （DR-1） is investigated. It is＇found that the saturation second harmonic generation （SHG） intensity decreases significantly with the increase of the sample temperature from 33℃ to 63℃. From the perspective of energy equilibrium, the main factors of AOP are analysed, and by introducing the classical ideal gas model, a simple inequation is first deduced to describe the requirement of realizing AOP.     

High-sensitivity temperature sensor based on Bragg grating in BDK-doped photosensitive polymer optical fiber

A single-mode polymer optical fiber (POF) with highly photosensitive core doped with benzil dimethyl ketal (BDK) is fabricated and used for writing Bragg grating through the two-beam interference method. The Bragg wavelength of the grating is about 1570 nm, while the full-width at half-maximum (FWHM) of the reflection peak is 0.3 nm. The temperature response of POF Bragg grating is theoretically analyzed and experimentally measured in contrast to silica optical fiber Bragg grating (FBG). The result shows that the temperature character of POF Bragg grating is negative, which is opposite to the silica optical FBG. The absolute value of the temperature response of POF Bragg grating is one order of magnitude higher than that of the silica optical FBG, making POF Bragg grating appear to be very attractive for constructing temperature sensors with high resolution.     

Effects of Laser-Induced Heating on the Photoinduced Birefringence in Azobenzene-Side-Chain Copolymer

The photoinduced birefringence was observed in the polymer poly[2-(4-(4-cyanophenyl) diazenyl phenyloxy) ethoxyl methacrylate] with a cw 532nm laser. The az, obenz, ene polymer character has been studied under the con-ditions of various illuminating time and light intensities. By analysing the processes of reorientation, the egect of laser-induced heating has been introduced to the buildup of photoinduced birefringence in azobenzene-side-chain copolymer. The curves for the buildup of birefringence were fitted with a modified fimction, i.e., biexponential curves and Gaussian curves. The relationship among all the parameters has also been presented. With the modified fitting fimction, we obtain a better fitting result.     

基于DVD光头的双光子光致漂白三维光存储

基于现有的DVD光头物镜与音圈电机，根据光致漂白的双光子吸收气维光信息存储原理，以钛蓝宝石飞秒脉冲激光进行双光子光信息写入和读出，利用音圈电机进行选层，在新型光致漂白材料二苯乙烯衍生物中进行光致漂白二进制编码信息的存储和读出实验研究；实现了三层光信息存储，信息点间距和信息层间距分别为4μm和15μm；用Matlab软件读出信息的信号强度并对其进行了识别，识别结果与写入的二进制编码信息完全一致。实验证明了用DVD光头进行双光子三维光数据存储的可行性，表明双光子吸收光致漂白技术可以与现有CD／DVD兼容，为实现多层高密度和超高密度光信息存储打下基础。     

侧链型偶氮聚合物液晶在不同温度条件下的光致取向

在高于和低于玻璃化转变温度 (Tg)的温度范围内 ,研究了聚甲基丙烯酸 ( 6 [4 ( 4 氰基偶氮苯 )苯氧基 ]己酯 ) (Poly( 6 [4 ( 4 cyanophenylazo)phenoxy]hexylmethacrylate) (PM6ABCN) )聚合物膜的光致取向行为 .实验结果表明 ,在温度低于Tg 时 ,实验温度对取向速率没有影响 ;高于Tg 温度时 ,取向的速率随温度升高而变大 ,取向过程的表观活化能为 3 2 76kJ mol.通过对Tg 温度以下的光致取向进行分析 ,对光致取向过程提出了一个新的微相模型 ,微相内的温度能够达到Tg 以上 ,而实验中控制的样品宏观温度不变 ;高于Tg 温度时的光致取向过程受到宏观温度的控制 ,其表观活化能远远小于热致的各向同性相I(Isotropicphase,I)到向列相N(Nematicphase,N)相转变表观活化能 ( 3 40 2kJ mol) ,表明光致取向过程对温度的依赖性较小     

聚苯胺的电化学合成实验

本文将新型有机固体导电材料聚苯胺的电化学合成引入大学高分子化学实验。合成方法简便易行。把高分子化学的新进展引入到高年级教学，有助于扩展学生的知识面。聚苯胺在外加电场变化时会发生颜色变化，使整个实验过程生动有趣，也可以用于课堂演示教学。