Versatile polyamides with new triphenylamine monomer based on dinaphtho furan as core for electrochromic/electrofluorochromic device, TNP detection and memory storage

Abstract

In order to obtain a versatile electrochromic (EC) and electrofluorochromic (EFC) material with good processability, stable redox properties, high optical contrast and fast response, a novel diamine monomer, N1, N1'-(dinaphtho[2,1-b:1',2'-d] furan-5,9-diyl) bis(N1-(4-methoxyphenyl) benzene- 1,4-diamine) (DNFTPA-NH2), which introducing an oxa[5]helicene core into two electron-rich triphenylamine (TPA) blocks is designed and synthesized. Subsequently, four polyamides (PAs) were obtained via polycondensation of diamine with dicarboxylic acids, denoted as DNFTPA-CA, DNFTPA-OA, DNFTPA-NA and DNFTPA-SA, respectively. The four PAs show excellent solution processability and thermal stability, and cyclic voltammograms (CV) with excellent redox reversibility. Among them, DNFTPA-SA shows marked optical contrast of 34 % at 831 nm and rapid switching time (color/bleach, 3.23s/0.39s) between 0 V and 1.0 V, with no significant decay after 5000 s cycle. DNFTPA-CA exhibits high fluorescence (PL) quantum efficiency of 27 %, which is sensitive to explosive trinitrophenol (TNP) with a low detection limit of 7.24 × 10−2 μM. Given the practical application, it is deemed necessary to prepare EC/EFC device. The findings demonstrate the value of PAs for practical applications in EC/EFC device. Moreover, PAs used in memory devices with sandwich structure of ITO/PAs/Al demonstrate non-volatile flash-type behavior with excellent stability within 10000 s and current switching ratios up to 103. Thus, it provides a facile strategy for the design of polymers in the devices of EC/EFC, PL sensing detection and memristor.