Molecular Structure Modification and Characterization of Langmuir-Blodgett Films made of Amphiphilic Polysilane through Ionizing Radiation

电离辐射对两亲性聚硅烷制成的 Langmuir-Blodgett 薄膜的分子结构改性和表征

• 批准号: 05808042
• 负责人: ASAI Keisuke
• 金额: $ 1.09万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05808042/
• 关键词: Polysilane; Amphiphilic Polysilane; Langmuir-Blodgett Film; Photoconductivity; Amphiphile; UV Spectrum; 両親媒性; LB膜; イオン励起発光; パルスラジオリシス; PMPS; 過渡吸収スペクトル

Since the last decade, polysilane derivatives have been elicited great interest as fundamental polymer materials showing lelctronic semiconductivity, nonlinear optical property, high hole drift mobility, and so on. These interesting physical properties of polysilane derivatives are essentially attributed to the delocalization of sigma-electrons of the Si backbone. However, it is hardly to say that the conjugated system is extended over the entire silicon skeleton, therefore, it is common consensus that a silicon skeleton is divided into several conjugated silicon segments. The question is which determine the hole transport phenomenon in intermolecular or interesting hopping. Then, electronic and optical characterization of highly polarized polysilane films may predict the electronic structure of silicon skeleton and inter-and intra-molecular relation.In the present work, poly (methylphenylsilane) : PMPS and poly (beta-phenethylmethylsilane) : PMbeta-PhS employed as an initial polysilane, and amphiphilic polysilanes were obtained by the salt formation between chloromethylated PMPS or PMbeta-PhS and (CH_3) _2C_nH_<2n+1>N.Chlorine anion exchanged by several kinds of counter anions and the polymer piled up to 1000 layrs. Optical spectroscopy of these piled LB films represented piezochromic shifts in their absorption spectra. High dense excitation of these amphiphilic polymers showed a deference in emission spectra of polarized and dense LB films (400-500nm broad emission) and random solvent casted films (another longer emission band at 580-600nm). These two emission bands were assigned to intramolecular exciplex formation between ammonium groups and silicon skeleton and intermolecular one, respectively. It can be condluded that energy relaxation processes are different in LB films in comparison with amorphous films, intermolecular energy transfer can be neglected in LB films of amphiphilic polysilanes.

近十年来，聚硅烷衍生物作为具有电子半导体性、非线性光学性质、高空穴漂移迁移率等的基础高分子材料引起了人们的极大兴趣。聚硅烷衍生物的这些有趣的物理性质本质上归因于硅主链的西格玛电子的离域。然而，很难说共轭体系延伸到整个硅骨架上，因此，普遍的共识是将硅骨架分成多个共轭硅段。问题是由什么决定分子间或有趣的跳跃中的空穴传输现象。然后，高偏振聚硅烷薄膜的电子和光学表征可以预测硅骨架的电子结构以及分子间和分子内关系。在目前的工作中，聚（甲基苯基硅烷）：PMPS 和聚（β-苯乙基甲基硅烷）：PMbeta-PhS用作初始聚硅烷，通过氯甲基化PMPS或PMbeta-PhS与(CH_3)之间形成盐获得两亲性聚硅烷_2C_nH_<2n+1>N.氯阴离子被多种抗衡阴离子交换，聚合物堆积达1000层。这些堆积的 LB 薄膜的光谱表现出其吸收光谱的压致变色位移。这些两亲聚合物的高密度激发显示出偏振和致密LB膜（400-500nm宽发射）和无规溶剂浇铸膜（580-600nm处的另一个较长发射带）的发射光谱的差异。这两个发射带分别归属于铵基团与硅骨架之间的分子内激基复合物形成和分子间激基复合物形成。可以得出结论，与非晶态薄膜相比，LB薄膜的能量弛豫过程不同，两亲性聚硅烷的LB薄膜中分子间的能量转移可以忽略不计。

项目成果

S.Seki,M.Ando,T.Yamaki,Y.Nakashiba,K.Asai,K.Ishigure,and S.Tagawa: "Molecular Interaction in Langmuir-Blodgett Films of Amphiphilic Polysilanes" Journal of Photopolymer Science and Technology. 5(1). 89-100 (1995)

S.Seki、M.Ando、T.Yamaki、Y.Nakashiba、K.Asai、K.Ishigure 和 S.Takawa：“两亲性聚硅烷 Langmuir-Blodgett 薄膜中的分子相互作用”光聚合物科学与技术杂志。