An accurate method of the fluorescence probe approach based on an aggregation-induced emission (AIE) molecule (tetraphenylethylene) for measuring the solubility parameter of the polymer is reported. This method is distinctive in that the approach can make the polymer chain conformation in solution be related to the fluorescence intensity. Since the solubility parameter of the polymer is also closely linked to its chain conformation in solution, the solubility parameter can be determined by the fluorescence intensity. The range of the solubility parameter of polymethyl methacrylate (PMMA) tested by this method was from 9.00 cal1/2cm-3/2 to 10.00 cal1/2cm-3/2. The results are more accurate than those obtained from the traditional turbidimetric titration method, ranging from 8.60 cal1/2cm-3/2 to 12.15 cal1/2cm-3/2. According to the photoluminescence (PL) intensities spectra, the solubility parameters of PMMA and polyvinyl acetate (PVAc) are 9.19 cal1/2cm-3/2 and 9.85 cal1/2cm-3/2, respectively.
Keywords: aggregation-induced emission; conformation transition; luminescence; solubility parameter.