Covalent Bonding of PANI and p‐Phenylenediamine‐Functionalized GO Using N,N′‐Dicyclohexylcarbodiimide as Dehydrating Agent for Electrochromic Applications

Abstract

AbstractIn this paper, a high‐performance organic/inorganic electrochromic material was synthesized by covalent bonding of polyaniline (PANI) and graphene oxide (GO). In the presence of N,N′‐dicyclohexylcarbodiimide (DCC) as dehydrating agent, GO was functionalized by p‐phenylenediamine (PPD) through an amidation reaction. Water‐processable PANI‐GO nanocomposites were prepared by copolymerization of aniline with PPD functionalized GO in the presence of poly(styrene sulfonate) (PSS) dopant in an aqueous medium. The structures and morphologies of PANI‐GO nanocomposites were characterized by Fourier‐transform infrared (FTIR) spectra, Raman spectra, transmission electron microscope (TEM) and scanning electron microscope (SEM). The results show that covalent bonding PANI‐GO nanocomposites possess better electrochemical and electrochromic properties over that of neat PANI. With 3 wt.% GO‐PPD loading, PANI‐GO‐3% exhibits the optimal electrochemical and electrochromic properties, among which the charge‐transfer resistance (RCT) is 29.4 Ω, the optical contrast is 0.72 and coloring/bleaching time is 4.45/4.28 s. Overdose GO‐PPD leads to negative influence on the contrast and switching speed, owing to the ion blocking effect brought by its two‐dimensional nanostructure.