Rainbow polyaniline: chemical–electrochemical parallel polymerization for the production of rainbow color polyaniline as a morphological composite

ABSTRACT

Polyaniline (PANI) was synthesized via a “chemical–electrochemical parallel polymerization (CEP)” wherein chemical and electrochemical polymerizations were simultaneously performed, which afforded the production of morphological composite in homopolymers. The chemical structure of the synthesized PANI was confirmed using infrared absorption spectroscopy. The generation of polarons (radical cations in the main chain) as charge carriers was confirmed through electron spin resonance in the doped state. The liquid surface on the polymerization solution (water) and PANI thin layer deposited on a glass substrate exhibited metallic color. Moreover, the surface reflection color was confirmed via measurements using angle-reflection-dependent spectroscopy. The structural color of the PANI was derived from a periodic structure prepared via CEP.

Graphical Abstract

KEYWORDS:

• Chemical-electrochemical polymerization
• reflection spectra
• morphological composite
• structural color

Acknowledgments

We would like to thank the OPEN FACILITY, Research Facility Center for Science and Technology, University of Tsukuba.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Mai Ichikawa

Mai Ichikawa is a currently Graduate school (Master course) student in University of Tsukuba.

Hiromasa Goto

Hiromasa Goto, Dr., Prof., received his PhD with a focus on liquid crystalline conjugated polymer from University of Tsukuba under supervision of Prof. Hideki Shirakawa (2000 Nobel Prize laureate). H. Goto continues research on polymer liquid crystals and synthetic metals at the historical former Shirakawa lab. He developed electrochemical and chemical  polymerization in liquid crystal and crystal. He likes to perform educational experiments with scientific demonstration for children.