In Situ Monitoring of Photo-Cross-Linking Reaction of Anthracene Chromophores in Polymer Langmuir−Blodgett Films by an Integrated Optical Waveguide Technique

Abstract

This paper focuses on waveguide technique versatility for direct observation of photochemical reactions in polymer ultrathin films. Monolayers from the copolymer of 9-anthrylmethyl methacrylate (AMMA) with neopentyl methacrylamide (nPMA) were deposited on a tapered quartz waveguide by the Langmuir−Blodgett (LB) technique, and spectroscopic properties of the copolymer (p(nPMA-AMMA)) monolayer were precisely monitored by an integrated optical waveguide technique. Magnitude of absorbance increased by a factor of 200, compared with transmission UV−vis spectroscopy. Consequently, a photo-cross-linking reaction of p(nPMA-AMMA) LB films was characterized easily and very accurately as a function of irradiation time.