新型PMMA/SiO_2/DR1非线性光学杂化材料的制备及表征

通过溶胶-凝胶法将硅烷染料DR1ASD、含硅氧烷PMMA和TEOS在酸催化条件下共水解-缩合制备了新型非线性光学杂化材料PMMA/SiO2/DR1,并运用FT-IR、SEM、UV-vis、DSC/TG和UV-vis等测试方法对其结构和性能进行表征.测试结果表明:杂化材料中有机相和无机相之间通过共价键结合,无相分离出现;杂化材料的玻璃化转变温度(Tg)和热分解温度(Td)分别达到165℃和405℃;电晕极化后杂化材料具有较高的生色团取向有序度(Φ=0.238),并表现出良好的取向稳定性,80℃条件下3h后依然有初始值的79%.     

光漂白对极化聚合物薄膜非线性效应的影响

利用Cerenkov倍频辐射对极化聚合物薄膜在光漂白下二阶非线性效应的变化进行了研究。 实验表明光漂白能破坏有机聚合物中极化分子的取向稳定性,造成其二阶非线性效应衰减。实验测得漂白后交联型材料的二阶倍频信号衰减了28%,而侧链型材料则衰减了75%。     

基于吡啶盐的热固性交联聚氨酯的合成与非线性光学性质的研究

合成了双芪唑盐的衍生物,双四苯硼（反式）－4,4′－二[p-（（N－乙基－N－羟乙基）氨基）苯乙烯基]-N,N′－（1,6－己基）－二吡啶盐。该生色团与2,4－二异氰酸酯甲苯及三乙醇胺反应生成了交联的聚氨酯体系。Marker条纹法测得聚合物的二阶非线性系数d33为12．5pm/V。利用紫外－可见光谱吸收法测定了聚合物薄膜电晕极化后的生色团取向度,考察了在室温及100℃的取向稳定性。结果表明在100℃放置1200h序参数为0．46,保持为初始的65％。用双脂数函数拟合了聚合物的退极化曲线。     

超声机械共混法制备聚酰亚胺／nano-A12O3·SiO2杂化材料工艺研究

采用均苯四甲酸二酐（PMDA）及4，4’-二氨基二苯基醚（ODA）为基本原料，以N，N’-二甲基乙酰胺（DMAc）为溶剂制备聚酰胺酸（PAA）溶液。由于纳米粒子的表面能很大，易团聚和二次团聚。为了解决这个问题，采用了超声机械共混法，使球型nano-A12O3，nano-SiO2和孔型nano-SiO2均匀分散在聚酰胺酸胶液中，按照一定工艺要求制备聚酰亚胺，无机纳米杂化薄膜。利用红外光谱（FT-IR）和原子力显微镜（AFM）对杂化材料进行结构和表面形貌测试与表征。并对超声波机理进行探讨。结果表明：利用超声法制备聚酰亚胺杂化材料，高聚物与纳米粒子之间有相互作用，杂化薄膜中无机纳米粒子分散均匀，且平均粒度在30nm左右。     

聚酰亚胺/二氧化硅杂化材料取向稳定性的研究

以5,5'-(六氟异丙基)-二-(2-氨基苯酚)(6FHP)和4,4'-(六氟异丙基)-苯二酸酐(6FDA)或均苯四甲酸酐(PMDA)为单体,合成了含氟聚酰亚胺.采用溶胶-凝胶法得到了不同无机组分含量的热稳定性高的杂化材料,测定了它们的电光系数,其电光系数γ33在测试持续500min后保持其初始值的95%以上,说明材料可用于电光器件化.通过测定膜的极化前后的紫外-可见光谱,得到了取向发色团的序参数Ф(0.27～0.38),经60h序参数几乎不变.通过一维刚性气体模型研究了材料的宏观二阶非线性光学系数χ(2),结果表明材料的极化效率较高,设计合理,有较好的取向稳定性.     

PPESK／SiO2杂化材料的制备及动态力学性能研究

以含二氮杂萘酮结构聚芳醚砜酮（PPESK）为基体，正硅酸乙酯（TEOS）为原料，N-甲基吡咯烷酮（NMP）为共溶剂，采用溶胶-凝胶方法制备出不同二氧化硅质量百分含量的PPESK／SiO2杂化材料。利用动态热机械分析仪（DMA）对PPESK／SiO2杂化均质薄膜进行动态力学性能测试和表征。结果表明，杂化材料中SiO2组分含量及扫描频率对PPESK／SiO2杂化材料的动态力学性能及玻璃化转变过程都有一定程度影响。SiO2含量的增加，杂化材料的力学损耗峰温度移向高温区，并且峰值升高；随着扫描频率的增加，杂化材料的损耗因子峰移向高温。同时采用Arrhenius方程计算PPESK／SiO2杂化材料在α转变时分子运动活化能。另外，还考察了SiO2粒子含量对PPESK／SiO2杂化材料的力学性能的影响。     

一类新型的聚氨酯类二阶非线性光学材料

报道了一类新型的含对硝基苯偶氮苯烷基胺发色团的热交联型二阶非线性光学聚合物的合成和极化工艺。将分散红－１９、甲苯二异氰酸酯和三乙醇胺预反应生成的溶胶－凝胶液旋转涂膜后在１６０℃电晕极化１ｈ可制得光学性质良好的极化膜。采用可见光谱测定了极化膜取向发色团的序参数及其取向的热稳定性。用一维刚性取向气体模型计算极化膜的二阶非线性光学极化系数ｘ＾（２）达１０＾－７ｅｓｕ量级。该极化膜有良好的取向稳定性，在１     

聚醋酸乙烯酯／二氧化硅杂化材料的制备与性能研究

以硅酸钠在HCL溶液中的水解，经四氢呋喃（THF）萃取，制备聚硅酸溶胶，再与聚醋酸乙烯酯（PVAC）的THF溶液混合，经溶胶-凝胶过程制备了PCAC/SiO2有机/无机杂化材料。用扫描是镜（SEM），红外光谱（IR），X射线衍射，热失重及透光率等的分析测试，对制备的PVAC/SiO2杂化材料进行了结构与性能的研究。结果表明：本法制备的杂化材料中SiO2在PVAC的基体中分布均匀，SiO2在非晶态的PVAC中亦呈无定形态，杂化材料的硬度、软化温度和热分解温度都比纯PVAC有较大的提高；SiO2含量少于40%的杂化材料其断裂伸长率、屈服强度和断裂强度也比纯PVAC提高；另外，还发现在制备过程中加入少许偶联剂KH-570后，杂化材料中的有机-无机相间的相容性增加，不易发生相分离，材料的透光性能也大为改善。     

水性聚氨酯脲傲性纳米CaCO3有机-无机杂化材料的制备方法

本发明涉及水性聚氨酯脲（PUU）催溶胶改性纳米CaCO3杂化水分散液的制备方法。其制备特点在于，以粒径10nm～100nm的硅溶胶改性纳米CaCO3水分散液代替部分水，采用原位法直接对聚氨酯脲预聚体进行分散，从而得到高固含量（25％-30％）的有机-无机杂化材料。该杂化材料在室温时具有很好的稳定性，且高固含量使其具有节...     

HEC／SiO2有机—无机杂化材料的制备与性能

以羟乙基纤维素（HEC）和四甲氧基硅烷（TMOS）为原料，利用溶胶-凝胶技术，通过TMOS在HEC水溶液中的水解-缩聚反应制得了HEC/SiO2凝胶材料。探讨了反应体系pH值、H2O与TMOS的体积比率和HEC用量等因素对HEC/TMOS水解-缩聚体系凝胶时间和光学性能的影响。借助差示扫描量热法考察了HEC/SiO2杂化材料的热性能。并利用扫描电镜观察了HEC凝胶与SiO2凝胶复合前后的微观结构特征。结果表明，随着HEC用量和TMOS浓度的增大，水解-缩聚体系凝胶时间缩短，可见光透过率降低；随pH值的增大，可见光透过率降低，凝胶时间变化较为复杂；HEC/SiO2杂化材料是以HEC凝胶为柔性连续用，SiO2凝胶为刚性分散相的两相体系，该体系热性能较好，玻璃化转变温度为235℃。     

Characteristics of organic inverters using vertical- and lateral-type organic transistors

The characteristics of vertical-type organic static induction transistors (OSITs) were compared with those of lateral-type organic field effect transistors (OFETs). From these experiments, it was confirmed that the OSITs can operate at a voltage one order less than that required for OFETs. We also fabricated two types of organic inverter based on OSITs and OFETs and investigated their transfer characteristics. These results demonstrate that it is possible to decrease the operational voltage of organic inverters from ± 20 V to ± 2 V by using two OSITs with higher on/off ratios.     

Tetrathiapentalene-based organic conductors

The synthesis, structure and properties of tetrathiapentalene-based (TTP) organic conductors are reviewed. Among various TTP-type donors, bis-fused tetrathiafulvalene, 2,5-bis(1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene (BDT-TTP) and its derivatives afford many metallic radical cation salts stable down to low temperatures, regardless of the size and shape of the counter anions. Most BDT-TTP conductors have a β-type donor arrangement with almost uniform stacks. Introduction of appropriate substituents results in molecular packing that differs from the β-type. A vinylogous TTP, 2-(1,3-dithiol-2-ylidene)-5-(2-ethanediylidene-1,3-dithiole)-1,3,4,6-tetrathiapentalene (DTEDT) has yielded an organic superconductor (DTEDT)₃Au(CN)₂ as well as metallic radical cation salts, regardless of the counter anions. (Thio)pyran analogs of TTP, namely (T)PDT-TTP and its derivatives produce molecular conductors with novel molecular arrangements. A TTP analog with reduced π-electron system 2,5-bis(1,3-dithian-2-ylidene)-1,3,4,6-tetrathiapentalene (BDA-TTP) has afforded several organic superconductors. Highly conducting molecular metals with unusual oxidation states (+1, +5/3 and neutral) have been developed on the basis of 2,5-bis(1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene (BDT-TTP) derivatives and analogous metal derivatives M(dt)₂ (M = Ni, Au).     

Tetrathiapentalene-based organic conductors

Abstract

The synthesis, structure and properties of tetrathiapentalene-based (TTP) organic conductors are reviewed. Among various TTP-type donors, bis-fused tetrathiafulvalene, 2,5-bis(1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene (BDT-TTP) and its derivatives afford many metallic radical cation salts stable down to low temperatures, regardless of the size and shape of the counter anions. Most BDT-TTP conductors have a β-type donor arrangement with almost uniform stacks. Introduction of appropriate substituents results in molecular packing that differs from the β-type. A vinylogous TTP, 2-(1,3-dithiol-2-ylidene)-5-(2-ethanediylidene-1,3-dithiole)-1,3,4,6-tetrathiapentalene (DTEDT) has yielded an organic superconductor (DTEDT)₃Au(CN)₂ as well as metallic radical cation salts, regardless of the counter anions. (Thio)pyran analogs of TTP, namely (T)PDT-TTP and its derivatives produce molecular conductors with novel molecular arrangements. A TTP analog with reduced π-electron system 2,5-bis(1,3-dithian-2-ylidene)-1,3,4,6-tetrathiapentalene (BDA-TTP) has afforded several organic superconductors. Highly conducting molecular metals with unusual oxidation states (+1, +5/3 and neutral) have been developed on the basis of 2,5-bis(1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene (BDT-TTP) derivatives and analogous metal derivatives M(dt)₂ (M = Ni, Au).     

Thienoacene-based organic semiconductors

Thienoacenes consist of fused thiophene rings in a ladder-type molecular structure and have been intensively studied as potential organic semiconductors for organic field-effect transistors (OFETs) in the last decade. They are reviewed here. Despite their simple and similar molecular structures, the hitherto reported properties of thienoacene-based OFETs are rather diverse. This Review focuses on four classes of thienoacenes, which are classified in terms of their chemical structures, and elucidates the molecular electronic structure of each class. The packing structures of thienoacenes and the thus-estimated solid-state electronic structures are correlated to their carrier transport properties in OFET devices. With this perspective of the molecular structures of thienoacenes and their carrier transport properties in OFET devices, the structure-property relationships in thienoacene-based organic semiconductors are discussed. The discussion provides insight into new molecular design strategies for the development of superior organic semiconductors.     

Anisotropic organic glasses

While the last decades have seen considerable efforts to control molecular packing in organic crystals, the idea of controlling packing in organic glasses is relatively unexplored. Glasses have many advantageous properties that crystals lack, such as macroscopic homogeneity and compositional flexibility, but packing in organic glasses is generally considered to be isotropic and highly disordered. Here we review and compare four areas of recent research activity showing control over anisotropic packing in organic glasses: (1) anisotropic glasses of low molecular weight organic semiconductors prepared by physical vapor deposition, (2) the use of mesogens to produce anisotropic glasses by cooling equilibrium liquid crystal phases, (3) the preparation of highly anisotropic glassy solids by vapor-depositing low molecular weight mesogens, and (4) anisotropic films of polymeric semiconductors prepared by spin-coating or solution casting. We delineate the connections between these areas with the hope of cross-fertilizing progress in the development of anisotropic glassy materials.