Self-Assembling Semiconducting Polymers鈥擱ods and Gels from Electronic Materials
详细信息 查看全文
- 作者：Andrew P.-Z. Clark ; Chenjun Shi ; Benny C. Ng ; James N. Wilking ; Alexander L. Ayzner ; Adam Z. Stieg ; Benjamin J. Schwartz ; Thomas G. Mason ; Yves Rubin ; Sarah H. Tolbert
- 刊名：ACS Nano
- 出版年：2013
- 出版时间：February 26, 2013
- 年：2013
- 卷：7
- 期：2
- 页码：962-977
- 全文大小：761K
- 年卷期：v.7,no.2(February 26, 2013)
- ISSN：1936-086X
文摘
In an effort to favor the formation of straight polymer chains without crystalline grain boundaries, we have synthesized an amphiphilic conjugated polyelectrolyte, poly(fluorene-alt-thiophene) (PFT), which self-assembles in aqueous solutions to form cylindrical micelles. In contrast to many diblock copolymer assemblies, the semiconducting backbone runs parallel, not perpendicular, to the long axis of the cylindrical micelle. Solution-phase micelle formation is observed by X-ray and visible light scattering. The micelles can be cast as thin films, and the cylindrical morphology is preserved in the solid state. The effects of self-assembly are also observed through spectral shifts in optical absorption and photoluminescence. Solutions of higher-molecular-weight PFT micelles form gel networks at sufficiently high aqueous concentrations. Rheological characterization of the PFT gels reveals solid-like behavior and strain hardening below the yield point, properties similar to those found in entangled gels formed from surfactant-based micelles. Finally, electrical measurements on diode test structures indicate that, despite a complete lack of crystallinity in these self-assembled polymers, they effectively conduct electricity.