抄録
Supramolecular properties of polymers are originated from their highly-regulated molecular and morphological structures. Electroactive films of aromatic polymers deposited electrooxidatively on anodes have received much interest from fundamental and practical aspects. Hence, if the structure of the films could be highly controlled, they might have supramolecular properties. From this point of view, we aimed to develop a method for preparing the two- and three-dimensionally dense and uniform films. In previous work, we succeeded in preparing a three-dimensionally dense multilayer film of polyaniline having an high density (About 10 times as high as an ordinary one) by irradiating ultrasounds. However, a question has been remained open : What kind of ultrasonic phenomenon does the structure of the films control? In the present work, a cavitaion meter developed recently for monitoring the abilily of a variety of practical ultrasonic instruments was used to clarify that the cavitaion which is the most typical phenomenon of ultrasounds is inevitably required for control of the structure of the films in electropolymerization of aniline. Porous structures with grains were observed in the film polymerized without sonication and with sonication below the cavitation threshold, while there was no grain in that with sonicatiaon over the threshold. The film prepared with sonicatiaon over the threshold was so thin that linear traces derived from polishing scars of the Pt substrate appear on a SEM photograph. This fact indicates clearly that the structure of the polyaniline film is affected greatly by the cavitation.
