Diffusion energies of oxygen diffusing into polystyrene (PS)/poly (N-isopropylacrylamide) composites

摘要

Diffusion coefficient of oxygen penetrating into polystyrene (PS) latex/poly (N-isopropylacrylamide) (PNIPAM) microgel composite films were measured using Fluorescence technique. Three different (5, 15, and 40 wt%) PS content films were prepared from PS/PNIPAM mixtures. Diffusivity of PS/PNIPAM composite films were studied by diffusion AAR_af1 measurements which were performed over the temperature range of 24-70℃. Pyrene was used as the fluorescent probe. The diffusion coefficients (D) of oxygen were determined using the Stern-Volmer fluorescence quenching method combined with Fickian transport and were computed as a function of temperature for each PS content film. The results showed that D values were strongly dependent on both temperature and PS content in the film. Diffusion energies were measured and found to be dependent on the composition of the composite films.