Novel Starburst Triarylamine-Containing Electroactive Aramids with Highly Stable Electrochromism in Near-Infrared and Visible Light Regions

Abstract

A series of solution-processable near-infrared (NIR) electrochromic aromatic polyamides with starburst triarylamine units in the backbone were prepared by the phosphorylation polyamidation from a newly synthesized diamine monomer, N,N-bis[4-(4-methoxyphenyl-4′-aminophenylamino)phenyl]-N′,N′-di(4-methoxyphenyl)-p-phenylenediamine, and two aromatic dicarboxylic acids. These polymers were highly soluble in many organic solvents and showed useful levels of thermal stability associated with high glass-transition temperatures and high char yields (higher than 66% at 800 °C in nitrogen). The polymer films showed reversible electrochemical oxidation and electrochromism with high contrast ratio both in the visible range and NIR region, which also exhibited high coloration efficiency (CE), low switching time, and relatively high stability for long-term electrochromic operation. At the first oxidation stage, the polyamide Ia thin film revealed high coloration efficiency in NIR (CE = 290 cm2/C) region with reversible...