Enhancement of sensing properties of thin poly(methyl methacrylate) films by VUV modification

Abstract

Surface modification of polymeric films by VUV light is an efficient method to tailor its properties and functionality for a variety of applications. Laser irradiation at 157 nm of poly(methyl methacrylate) (PMMA) thin films deposited on SiO2 layer, demonstrates a considerable increase of surface and bulk swelling during water vapour sorption in comparison to the non irradiated film areas. AFM images of surface morphology of the irradiated areas reveal that surface roughness depends on the irradiation conditions. Besides morphological changes, X-ray photoelectron spectros-copy (XPS) suggests chemical modification of the irradiated film areas. The enhanced surface swelling and the chemical modification increases the detection efficiency of water analyte in gas phase by many orders of magnitude. This method can be used to fabricate a polymer based sensor array and to engineer its detection efficiency.