Chinese Journal of Applied Chemistry ›› 2019, Vol. 36 ›› Issue (4): 440-450.DOI: 10.11944/j.issn.1000-0518.2019.04.180207

• Full Papers • Previous Articles     Next Articles

Study on Self-assembly Behaviors of an Amphiphilic Block Polymer by Terminally Grafting Tetraphenylethene-Based Aggregation-Induced Emission Active Moietys

CHENG Jinhua,JIANG Hongji()   

  1. Institute of Advanced Materials,National Jiangsu Synergetic Innovation Center for Organic Electronics and Information Displays,Key Laboratory of Organic Electronics and Information Displays,Nanjing University of Posts and Telecommunications,Nanjing 210023,China
  • Received:2018-06-05 Accepted:2018-09-21 Published:2019-04-01 Online:2019-04-02
  • Contact: JIANG Hongji
  • Supported by:
    Supported by the National Major Basic Research Program of China(No.2012CB933301), the National Natural Science Foundation of China(No.21574068), the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.YX03001)

Abstract:

Poly(N-isopropylacrylamide)(PNIPAM) is an amphiphilic thermosensitive polymer with the hydrophilic amide group and the hydrophobic isopropyl group in the side chain. A reversible phase change occurs due to intermolecular interaction with the change of outside temperature. Tetraphenylethene derivatives have advantages of easy-to-synthesize, highly efficient chemical modification feasibility, aggregation-induced emission(AIE) characteristic and high quantum yield. Therefore, a macromolecular initiator F was prepared by the polymerization of N-isopropylacrylamide through single electron transfer-living free radical polymerization with tetraphenylethene derivative as the initiator. Then styrene was used as comonomer to convert the active PNIPAM initiator to an amphiphilic block polymer G, which was characterized by gel permeation chromatography and Fourier transform infrared spectra. Using tetraphenylethene-based AIE-active initiator as the research object of reference, the photophysical properties of amphiphilic block polymer at different temperatures and concentrations were studied to correlate the AIE activity with the amphiphilic nature of the block polymer in detail. It was found that the fluorescence intensity of AIE-active initiators decreased with the increase of temperature at the same concentration of dispersion, while the fluorescence intensity of the block polymer increased firstly, and then decreased after the temperature exceeded 37 ℃. Under the same conditions, by changing the concentrations of AIE-active initiators and block polymer in tetrahydrofuran/water mixed solvents, we found that the fluorescence intensity of AIE-active initiator decreased with the decrease of concentration, while the change tendency of fluorescence intensity for block polymer was similar as those obtained from the temperature changes. It is feasible to investigate the self-assembly behaviors of the amphiphilic block polymer by grafting the AIE active moiety to the terminal of polymer.

Key words: living free radical polymerization, block polymer, aggregation-induced emission, self-assembly