Development of Next-generation Functional Materials Based on Isolated Macromolecules

以端部含有噻吩和低聚乙烯基团的两亲分子为模板，通过溶胶-凝胶法制备了新型介孔结构硅胶。复合材料与FeCl_3氧化引起二氧化硅通道内的噻吩聚合，在通过洗涤去除氧化剂后，在其中观察到由于形成的多噻吩而产生的荧光。荧光峰顶与从两亲化合物中单独获得的多噻吩的荧光峰顶发生了色移，表明二氧化硅通道中有效共轭长度可能延长。虽然单畴内的二氧化硅通道沿同一方向排列，但众所周知，由于畴的随机化，二氧化硅通道的取向在宏观上是无序的。对于微米范围的硅通道排列，最近提出了在硅衬底上的光刻图案凹槽处的溶胶-凝胶反应，并证明了它是有用的。与拥有这种技术的小组合作，成功地校准了多噻吩。平行于沟槽长轴和垂直于沟槽长轴的透射电镜观察清楚地表明，二氧化硅通道沿沟槽长轴排列。此外，通过荧光的各向异性发射证实，通道中的多噻吩也排列整齐。

Novel meso-structured silica gel was successfully obtained via sol-gel process using an amphiphile, containing thiophene and oligoethylene groups at its terminal positions, as a template. Oxidation of the composite with FeCl_3 caused polymerization of the thiophene within the silica channels, where fluorescence due to the formed polythiophenes observed, after removal of the oxidant by washing. Peak top of the fluorescence was bathochromically shifted from that observed for polythiophene obtained from the amphiphile alone, indicatging the possible elongation of the effective conjugation length in the silica channels. Although the silica channels in single domain are aligned in the same direction, it is well known that orientation of silica channels is macroscopically disordered because of the randomization of domains. For micrometer-range alignment of silica channels, sol-gel reaction at the lithographically patterned groove on the silicon substrate has been recently proposed and demonstrated to be useful. Collaboration with the group possessing this technique resulted in the successful alignment of polythiphenes. TEM observations of cross-sections parallel and perpendicular to the long axis of the groove clearly demonstrated that silica channels were aligned along with the long axis of the groove. Furthermore, polythiphenes in the channels were also aligned, as confirmed by anisotropic emission of the fluorescence.