偶联噻吩引入对三苯胺成膜性提高及电致变色性能增强(英文)

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

合成了一种以三苯胺(TPA)为核、偶联噻吩为端基的有机小分子4,44-三[4-(2-联噻吩基)苯基]胺(TBTPA),并通过电化学聚合得到其相应的聚合物PTBTPA.运用电化学工作站和紫外-可见光谱仪连用对该聚合物膜的光谱电化学性质进行了测试.与先前已报道的三[4-(2-噻吩基)苯基]胺(TTPA)相比,TBTPA呈现出更好的电化学氧化还原活性.在电化学聚合过程中,PTBTPA膜呈现出更好的成膜性能且在不同的电位下可以显示三种颜色(深橙色、橄榄绿、暗灰色).此外,光谱电化学测试结果表明,与先前报道的PTTPA相比,PTBTPA具有更好的电致变色(EC)性能,高的颜色对比度(44.7%),更高的透射对比度(ΔT,在720及1100nm处对比度分别为49%和52%)及较快的响应时间(在720nm时为0.93s,在1100nm时为0.91s),同时,PTBTPA具有更高的着色效率(720nm时为198cm2·C-1,1100nm时为285cm2·C-1).从扫描电镜(SEM)照片得出PTBTPA薄膜呈现微球颗粒堆积形貌,颗粒粒径为500nm左右,比PTTPA的粒径小.良好的性能表明PTBTPA在电致变色器件上具有很大的应用前景.

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 ofreported poly（tris[4-（2-thienyl）phenyl]amine） （PTTPA）. PTBTPA also exhibited a higher optical contrast （△T） 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.