Acta Chimica Sinica ›› 2022, Vol. 80 ›› Issue (7): 921-928.DOI: 10.6023/A22010013 Previous Articles     Next Articles



齐子朋a, 高冬b, 朱志成d, 贺志远c,*(), 白国英a,*()   

  1. a 河北工业大学材料科学与工程学院 天津 300401
    b 河北工业大学生物物理研究所 天津 300401
    c 北京理工大学材料学院 北京 100081
    d 中能电力科技开发有限公司 北京 100034
  • 投稿日期:2022-01-08 发布日期:2022-04-05
  • 通讯作者: 贺志远, 白国英
  • 基金资助:
    国家重点研发计划国际合作项目(2020YFE0100300); 国家自然科学基金(22072036); 国家自然科学基金(21905072); 国家自然科学基金(22122206); 天津市自然科学基金(20JCQNJC00890); 河北省自然科学基金(B2020202034); 河北省自然科学基金(B2020202086); 河北省高等学校科学技术研究(BJ2020039)

Regulating Optical Properties of Water-Soluble Conjugated Polythiophene with Polyvinyl Alcohol

Zipeng Qia, Dong Gaob, Zhicheng Zhud, Zhiyuan Hec(), Guoying Baia()   

  1. a School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300401
    b Institute of Biophysics, Hebei University of Technology, Tianjin 300401
    c School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081
    d Zhongneng Power-Tech Development Co., Ltd., Beijing 100034
  • Received:2022-01-08 Published:2022-04-05
  • Contact: Zhiyuan He, Guoying Bai
  • Supported by:
    National Key Research and Development Program of China(2020YFE0100300); National Natural Science Foundation of China(22072036); National Natural Science Foundation of China(21905072); National Natural Science Foundation of China(22122206); Natural Science Foundation of Tianjin(20JCQNJC00890); Natural Science Foundation of Hebei Province(B2020202034); Natural Science Foundation of Hebei Province(B2020202086); Science and Technology Research Project of Higher Education in Hebei Province(BJ2020039)

Water-soluble conjugated polymers have attracted enormous attention because of their water solubility and attractive optical properties. However, they often suffer from low emission quantum yield due to their strong inter-chain interaction and concomitant exciton quenching, especially in the solid state. To enhance the emission of the water-soluble conjugated polymers, strategies of decreasing the aggregation tendency of the polymers and controlling the backbone conformations are often adopted. In this work, to solve the problem of aggregation-caused quenching of luminescent conjugated polymer dilute solution during drying, we regulate the aggregation behavior and backbone conformation of a water-soluble conjugated polythiophene (PMNT) with polyvinyl alcohol (PVA) by intermolecular interactions, e.g. hydrogen bonding, and obtained tunable emissive PMNT thin films. Specifically, when PMNT in solution state is blended with PVA, obvious red shift of absorption and emission maxima and higher fluorescence intensity are observed, indicating that PVA molecules isolate the PMNT chains, reduce the degree of chain flexibility and increase backbone rigidity. Furthermore, by varying dry methods, we obtained PMNT solid films of tunable light absorption/emission properties: the solid films fabricated through splat cooling and in-situ lyophilization preserve the optical properties of the mixed solution of PVA and PMNT; the films fabricated through heat drying exhibit the similar optical properties with those of PMNT solution without adding PVA. Moreover, the emission quantum yield of the solid film prepared by the lyophilization method was enhanced compared with that of the solid film prepared by heat drying. These results suggest that the aggregation/conformation regulations of PMNT solution by PVA are retained in different degrees dependent on the drying methods: heat drying only maintains the isolation effect of PVA on PMNT; lyophilization readily preserve the interactions between PVA and PMNT, locking their disperse states and conformations. This study provides a strategy for regulating the aggregation behaviors and optical properties of solid conjugated polymers from the perspective of drying method.

Key words: water-soluble conjugated polymer, optical property, aggregation behavior, freeze drying