【作者】 王耀；

【导师】 崔占臣； 杨柏；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2005， 博士

【摘要】 任何技术的创新都由相应领域材料学的快速发展来推动,光电信息通讯技术的发展正在广泛而深刻地影响着人们的生活和社会的进步。作为光电调制波导器件的基础,二阶非线性光学材料的研究正成为科学家们关注的热点。无论从材料的结构、性能,还是材料自身的成本和可加工性,有机聚合物二阶非线性光学材料都显示出了比无机晶体材料更加优越的应用前景。对有机聚合物二阶非线性光学材料的研究主要集中在各种新型发色团偶极分子的合成及宏观非对称有机聚合物膜的设计与开发等方面,而膜中发色团分子取向排列的稳定性是最受关注的问题之一。研制兼具大的非线性光学响应和高稳定性的二阶非线性光学有机聚合物膜材料是决定有机材料能否真正实用化的关键性课题。本论文正是基于这一思路,从新型有机聚合物非对称膜的结构设计出发,运用分子和超分子技术,分别在极化聚合物材料、Langmuir-Blodgett(LB)膜,组装膜等材料领域进行了有益的探索,设计并制备了三种可交联型高稳定性极化聚合物材料,一种可紫外光辐射聚合且具有特殊的非经典型LB 膜结构的二阶非线性光学Langmuir-Blodgett 膜材料,一种具有较高非线性光学响应且经紫外光曝光交联后显示很高热稳定性的有机聚合物组装膜材料。本论文根据电场对偶极分子的不均匀作用原理提出了在电场诱导下Layer-by-Layer 定向组装制备单层和多层二阶非线性光学聚合物膜材料的思想,并通过实验成功验证了该方法的可行性。此外,我们还对所得到的极化聚合物旋涂膜、LB 膜和组装膜进行了微观结构变化与宏观性质表现之间联系的研究;对得到的有机-无机杂化聚合物材料开展了初步调制波导器件方面的尝试。更多还原

【Abstract】 Recently, various novel and high performance second-order nonlinear optical (NLO) organic polymer materials, owing to their wide application in electro-optical (E-O) modulated devices and advantages superior to inorganic materials, have been prepared and investigated by numerous scientists. It is still considered to be a challenge for researchers to prepare novel polymer lattices with macroscopically non-centrosymmetric structure and in which chromophoric dipolar molecules arranged with orientation. We can define three general approaches to achieving noncentrosymmetric lattices of nonlinear optical chromophores: electric-field poling technique, Langmuir-Blodgett film technique and Layer-by-Lay (LBL) assembly technique. Accordingly, three types of NLO materials were classified: poled polymer materials, NLO LB film materials and NLO assembly film materials. The theory and development of these types of NLO organic polymer film materials have been reviewed in chapter 1. In this dissertation, we have provided some promising attempts to fabricate novel high performance and thermal stability NLO organic polymer films in the three fields of NLO organic polymer materials, respectively. In chapter 2, we have synthesized and characterized two side-chain crosslinkable PMMA and PS types of NLO polymers through sealed-tube polymerization method. We have evidently improved the thermal stability of poly [(1-(4-nitrophenyl)-2-(4-{[2-(methacryloyloxy) ethyl] ethylamino}-phenyl)diazene (DR1M))-co-(methyl methacrylate(MMA))](P1) and poly [(DR1M)-co-(styrene(St))] (P2), respectively, by copolymerizing with epoxy glycidyl methacrylate (GMA). Studied with DSC and TGA, the glass transition temperature of the two polymers is 125℃and 124℃respectively, approximately increased 30-50℃compared with that before crosslinked. The values of electro-optic coefficient (r33) of the polymer P1, P2 after crosslinked, measured with the simple reflection technique at 1.3 μm wavelengths, was 12.50 pm/v, 8.60 pm/v and they both kept around 75% of their initial values after 100h at room temperature. Two crosslinkable second-order nonlinear optical fluorinated polymers (P3, P4) were prepared by copolymerization of 2, 3, 4, 5, 6-pentafluorostyrene, GMA and DR1M via same technique. The crosslinkable polymers were characterized concretely and have large relative molecular weight, good organosolubility, excellent film-forming property. Polymer P3 and P4 possess high glass transition temperature (106-110 oC) and high thermal decomposition temperature (290-350 oC) after crosslinked. Furthermore, the polymer P3 films possess not only high values (12-16 pm/v) of electro-optic coefficient (r33) at 1.3 μm wavelengths but also the low optical loss (1.7 dB/cm) at 1.55 μm wavelengths, which is instructive for application of electro-optical devices. The above confirmed that the thermal stability of the poled polymer P1-P4 were improved significantly, owing to the crosslinking of the epoxy group in the copolymers. In addition, the organic chromophore ((3-Triethoxysilanyl-propyl)-carbamic acid 2-{ethyl-[4-(4-nitro-phenylazo)-phenyl] -amino}-ethyl ester (SG-DANS))-inorganic matrix hybrid materials have beenfabricated via sol-gel methodology and using the obtained hybrid materials, a polymer waveguide electro-optic modulator (Mach-Zehnder Interferometer) was fabricated and studied primarily. In chapter 3, a photopolymerisable SHG active Langmuir-Blodgett (LB) film of 1-(10-{[(10-nitro)-6,7-azobenzenl]-ether}-decyl)-3-(tetracosa-12,14-diynyl)urea (N-AEDTDU) with nontraditional architecture was fabricated based on the strong molecular interactions of hydrogen bonding. Further, the noncentrosymmetric and nontraditional structures of the LB monolayer and multilayer were proved by characterization of surface pressure-area (π-A) isotherm, Atomic force microscopy (AFM), UV-vis absorption spectroscopy, contact angle as well as second harmonic generation (SHG) equipments. The study of SHG activity demonstrated that the thermal stability of nonlinear optics of LB films was improved evidently after photopolymerization via UV irradiation. (A 17-layer LB multilayer film of NAEDTDU on one side of a quartz glass after irradiation retained >55 % of the origin polar order up to 120 °C.) Most interestingly, accompanied with the falling back of the environmental temperature, we discovered all the photopolymerized LB monolayer and multilayer films exhibited unique phenomenon of SHG rebounding from decreased intensity induced by heating, which is attributed to the photopolymerization of diacetylene. In chapter 4, a promising methodology for fabricating high thermally stable organic second-order NLO thin films containing low molecular weight chromophoric (LMWC) molecules was sustained by the electric field-induced layer-by-layer assembly. The new LMWC molecule but-2-enedioic acid mono-[2-({4-[4-(2-carboxy-2-cyano-vinyl)-phenylazo]-phenyl}-methyl-amino)-eth-yl]ester(BCPE) was first designed and synthesized successfully, which possesses two negative groups at both ends and still retains the molecular polarity after ionized.更多还原