Interfacing a Tetraphenylethene Derivative and a Smart Hydrogel for Temperature-Dependent Photoluminescence with Sensitive Thermoresponse
writer:Yingnan Jiang ,Xudong Yang,Cheng Ma,Chuanxi Wang, Yang Chen, Bai Yang,Kui Yu,Quan Lin,
keywords:Smart Hydrogel,emperature-Dependent, Photoluminescence
source:期刊
Issue time:2014年
We report, for the first time, the design and synthesis of thermoresponsive (TR) photoluminescent (PL)
hydrogel nanoparticles, with a core consisting of poly[styreneco-(N-isopropylacrylamide)] (PS-co-PNIPAM) and a PNIPAM-co-PAA shell. PAA represents polyacrylic acid which interacts with our emitting molecule 1,2-bis[4-(2-triethylammonioethoxy)phenyl]-1,2-diphenylethene dibromide (d-TPE). The electrostatic interaction between each water-soluble d-TPE molecule and two AA repeat units activates these d-TPE molecules to exhibit strong PL. Our d-TPE doped PS-co-PNIPAM/PNIPAM-co-PAA particles in water display remarkable TR PL: the emission intensity decreased in the course of heating from 2 to 80 °C and recovered during cooling from 80 to 2 °C. Such linear,
reversible, and sensitive TR PL is achieved by the use of both PAA and PNIPAM as the shell polymeric chain and by careful optimization of the d-TPE to AA feed molar ratio. Thus, the emission of the d-TPE molecule is affected sensitively by temperature. In addition to such an exceptionally temperature-dependent PL, the presence of CrO4
2? resulted in the decrease of the emission intensity, which was also temperature-dependent. The present study provides a unified conceptual methodology to engineer functional water-dispersible hydrogel nanoparticles that are stimuli-responsive with the potential to advance various PL-based applications.