A STUDY ON PHOTOCONVERSION BY THE USE OF ULTRATHIN ORGANIC FILMS WITH ASYMMETRIC SURFACES

不对称表面超薄有机薄膜光转换的研究

基本信息

批准号：
07455342
负责人：
MATSUO Taku
金额：
$ 2.56万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

Photobiological processes, as represented by photosynthesis and vision, proceed in biological membranes. One of the marvelous properties of the biological membranes is the presence of asymmetric surfaces on extremely thin membranes (ca 10 nm in thickness).In the present study, extremely thin (25-60 nm) polymer membranes have been prepared by casting organic polymer solutions on water surface and the following new optochemical properties were discovered. (1) Second harmonic generation (SHG) at the asymmetric surface : Donor-acceptor interactions were successfully used for SHG at the thin membrane surfaces and also on quartz substrates. Amphiphilic porphyrins and viologens were useful for this purpose. Dynamic behaviors of adsorbed moleccules on the surface were elucidated by the SHG studies. (2) Photochemical electron-transport across thin organic films : Monolayr films, which contained donor-accceptor pairs, were fixed on electrode surface to generate photocurrents. Either metal porphyrin or ruthenium tris-bipyridine complex was useful as the donor, while viologen served as the excellent acceptor. Anodic photocurrents were observed on gold or ITO electrode in the pressence of triethanol amine in the aqueous solutions. (3) Photoacustic responses of ultrathin popymer films : The ultratin polymer films were impregnated with organic dyes, and chopped monochromatic light from a Xenon lamp was irradiated on the substrate-free polymer films. Either porphyrin or azo-compound was used as the dye. A single film was good enough to detect the photoacoustic signals. Relative sensitivity for a given thickness of the ultratin polymer film markedly exceeded that of spin coated film of the same polymer.

光生物学过程以光合作用和视力为代表，以生物膜进行。生物膜的奇妙特性之一是在非常薄的膜上存在不对称表面（厚度为10 nm）。在本研究中，已经通过在水表面上铸造有机聚合物溶液，并发现了以下新的光学化特性，从而制备了极其薄（25-60 nm）聚合物膜。（1）在不对称表面上的第二次谐波产生（SHG）：供体 - 受体相互作用在薄膜表面和石英底物上成功地用于SHG。两亲性卟啉和维科氏菌对此目的很有用。 SHG研究阐明了表面吸附分子的动态行为。（2）跨薄有机膜的光化学电子传输：固定在电极表面上以产生光电流的单层膜，其中包含供体摄像机对。金属卟啉或三吡啶二吡啶复合物的金属卟啉复合物作为供体有用，而Viologen则是出色的受体。在水溶液中三乙醇胺的压力中，在金或ITO电极上观察到阳极光电流。（3）超薄蛋白膜的光usustic响应：超蛋白聚合物膜被有机染料浸渍，并在无底物聚合物膜上照射了Xenon灯的切碎的单色光。卟啉或偶氮化合物用作染料。一部电影足以检测光声信号。对超蛋白聚合物膜的给定厚度的相对灵敏度显着超过了同一聚合物的自旋涂层膜的相对敏感性。