Polymer , generally emission maxima

The polarity of the microenvironment of poly(2-hydroxyethyl-methacrylate) in 1-propanol/water solution, expressed by the energy of the emission maximum of DNS fluorophore incorporated in the polymer side chain and the empirical solvent polarity parameter is shown in Figure 10. The polarity of the microenvironment of PHEMA is generally lower than that of alcohol/water. 

Properties of the microenvironment of soluble and cross-linked polymers were studied by the shift of bands in the electron spectra of solvatochromic reporter molecules embedded in polymer chains. Generally, the charge-transfer (CT) absorption spectra and emission spectra of a number of compounds were used to correlate solute-solvent interactions with physical and chemical properties of interest. The energy of the band maxima of these chromophores is quite solvent sensitive and is linearly correlated with empirical solvent polarity parameters. The observed shift of the maximum of the solvatochromic reporter embedded in the polymer chains, compared with a low-molecular weight analog in the same solvent, was interpreted in terms of a change in the polarity of the microenvironment of the polymer in solution. 

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