The sorption behavior of a fluorescent reagent into a polymer film was visualized by confocal laser scanning microscopy (CLSM), and the effects of the additives, film types, and film depth on the diffusion coefficient (D) of the fluorescence reagent were examined. Perylene and cellulose acetate (CA) were used as a fluorescent reagent and a polymer material, respectively. Perylene dissolved in the additives triethylene glycol diacetate (TEGDA) and glycerol triacetate (GTA) was added to the CA film. Then, the evaluation of two types of CA films, a closed-system cellulose acetate (CCA) sample and an open-system cellulose acetate (OCA) sample, was conducted. At optimized CLSM conditions (with a scanning range at a 20-lm depth from the CA film surface with 1-μm intervals and a scanning speed of 1 fps), the sorption of perylene at the inner CA film was determined. The D values of perylene in the CA film were calculated pursuant to Fick's second law. Higher D values of perylene mixed with TEGDA versus those of perylene mixed with GTA were commonly obtained for the CCA sample (TEGDA: 8.9 × 10-15 m 2/s > GTA: 1.7 × 10-15 m2/s) and the OCA sample (TEGDA: 11 × 10-15 m2/s > GTA: 3.3 × 10-15 m 2/s) because of the higher chemical affinity of TEGDA with perylene than that of GTA. Perylene indicated a higher D value and was homogeneously distributed in the case of the OCA sample; we found that diffusivity and distribution of perylene in CA film were largely affected by the multistratification treatment. We also proved that the deeper the film depth was, the lower the diffusivity of perylene was, regardless of the types of additives and films. The factors considered for the film-depth dependence of D were a gradual increase in the diffusion pathway for perylene caused by additive diffusion and the concentration dependence of the perylene D.
All Science Journal Classification (ASJC) codes
- Surfaces, Coatings and Films
- Polymers and Plastics
- Materials Chemistry