Directive Evidence for the Creation of Micropores in UV-Irradiated Poly(MethylMethacrylate)

摘要

Films of Poly-Methyl Methacrylate including azobenzene were prepared by castingpolymer solutions containing the probe or by exposing pre-irradiation films to the vapor of azobenzene. Under similar conditions, films which had been irradiated imbided more azobenzene than annealed, unirradiated films or irradiated films which had been annealed above glass transition temperature. These materials were irradiated at 335 nanometers and the amount of trans azobenzene which had been formed was monitored spectrophotometrically. The largest amount of photoisomerization was observed for the pre-irradiated samples which has been penetrated by azobenzene from the vapor, indicating that the created free volume allowed the isomerization to proceed more easily. Polymers, PMMA, Benzene compounds, Porous materials, Irradiation, Isomerization. (JG)