Neutrally colourless, transparent and thermally stable polynorbornenes via ring-opening metathesis polymerisation for near-infrared electroactive applications
作者:Wei-Ren Lian、Kun-Li Wang、Jyh-Chiang Jiang、Der-Jang Liaw、Kueir-Rarn Lee、Juin-Yih Lai
DOI:10.1039/c1jm10296f
日期:——
Two novel near-infrared (NIR) electrochromic polynorbornenes, poly(NBDTPA) and poly(HNBDTPA), containing electroactive chromophores, were prepared via ring-opening metathesis polymerisation from a new norbornene derivative (NBDTPA) using Grubbs' catalysts followed by hydrogen reduction. The glass transition temperatures (Tg) of poly(NBDTPA) and hydrogenated poly(HNBDTPA) were 141 °C and 91 °C, respectively. The 10% weight-loss temperatures of hydrogenated poly(HNBDTPA) and poly(NBDTPA) were up to 440 °C and 397 °C, respectively. Hydrogenated poly(HNBDTPA) film showed excellent transparency (up to 91%). Poly(NBDTPA) showed a cyclic voltammogram and electrochromic behaviour that was similar to poly(HNBDTPA). The cyclic voltammogram of a poly(HNBDTPA) film cast onto an indium-tin oxide (ITO)-coated glass substrate exhibited three reversible oxidation redox couples at 0.63, 0.82 and 1.23 V vs. Ag/Ag+ in acetonitrile solution. The electrochromic characteristics of poly(HNBDTPA) showed excellent stability and reversibility, with multi-stage colour changes from its colourless neutral form to green, light-blue and dark-blue with applied potentials of 0 to 1.75 V. The colour switching time and bleaching time of the poly(HNBDTPA) were 7.1 s and 4.2 s in the near-infrared region (1230 nm), and 7.4 s and 4.5 s in the UV-vis region (420 nm), respectively.
使用格拉布斯催化剂,通过开环偏聚法聚合新降冰片烯衍生物(NBDTPA),然后进行氢还原,制备了两种含有电活性发色团的新型近红外(NIR)电变色聚降冰烯--聚(NBDTPA)和聚(HNBDTPA)。聚(NBDTPA)和氢化聚(HNBDTPA)的玻璃化转变温度(Tg)分别为 141 ℃ 和 91 ℃。氢化聚(HNBDTPA)和聚(NBDTPA)的 10% 失重温度分别高达 440 ℃ 和 397 ℃。氢化聚(HNBDTPA)薄膜具有极佳的透明度(高达 91%)。聚(NBDTPA)显示出与聚(HNBDTPA)相似的循环伏安图和电致变色特性。在铟锡氧化物(ITO)涂层玻璃基底上浇铸的聚(HNBDTPA)薄膜的循环伏安图显示,在乙腈溶液中,与 Ag/Ag+ 相比,在 0.63、0.82 和 1.23 V 下存在三个可逆氧化还原偶。聚(HNBDTPA)的电致变色特性显示出极佳的稳定性和可逆性,在 0 至 1.75 V 的施加电位下,其颜色可从无色的中性形态多级变化为绿色、浅蓝色和深蓝色。聚(HNBDTPA)的颜色切换时间和漂白时间在近红外区域(1230 纳米)分别为 7.1 秒和 4.2 秒,在紫外可见光区域(420 纳米)分别为 7.4 秒和 4.5 秒。