Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (05): 996-1002.doi: 10.3866/PKU.WHXB201302282

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Enhanced Film-Forming and Electrochromic Properties by Incorporating Bithiophene into Triphenylamine

OUYANG Mi, FU Zhi-Yan, LÜ Xiao-Jing, CHEN Huan-Le, HU Bin, XIA Xu-Feng, ZHANG Cheng   

  1. State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, International Science & Technology Cooperation Base of Energy Materials and Application, College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014, P. R. China
  • Received:2012-12-07 Revised:2013-02-27 Published:2013-04-24
  • Supported by:

    The project was supported by the National Key Basic Research Program of China (973) (2010CB635108, 2011CBA00700), International Science and Technology Cooperation Program, China (2012DFA51210), and National Natural Science Foundation of China (51203138, 51273179).


An electrochromic (EC) material consisting of triphenylamine (TPA) core and peripheral bithiophene groups was synthesized, and the corresponding polymer was prepared by electrochemical oxidative cross-linking. The electrochemical properties of the 4,4',4?-tris[4-(2-bithienyl)phenyl]amine (TBTPA) monomer, and spectroelectrochemical and electrochromic properties of the poly(4,4',4?-tris [4-(2-bithienyl)phenyl]amine) (PTBTPA) polymer, were also systematically investigated. TBTPA possessing two thiophene groups exhibited better redox reversibility than that of the reported tris[4-(2-thienyl)phenyl] amine (TTPA). During electropolymerization, PTBTBA exhibited excellent film-forming property and strong adhesion to the ITO electrode, satisfying the basic requirements for achieving high EC performance. PTBTPA exhibited three different colors under various potentials (darkorange, olivegreen and dimgray). PTBTPA indicated enhanced EC performances and a higher contrast ratio of 44.7% compared with that of reported poly(tris[4-(2-thienyl)phenyl]amine) (PTTPA). PTBTPA also exhibited a higher optical contrast (ΔT) of 49% and 52% at 720 and 1100 nm, respectively. It showed fast switching responses of 0.93 and 0.91 s at 720 and 1100 nm, respectively, and higher coloration efficiencies of 198 and 285 cm2·C-1 at 720 and 1100 nm, respectively. Scanning electron microscopy (SEM) revealed that the PTBTPA film surface had accumulated clusters of globules, which were smaller than those of PTTPA. The superior performances of PTBTPA suggested its potential as an efficient EC material.

Key words: Triphenylamine core, Electropolymerization, Film-forming, Electrochromism, High optical contrast