Organic vapor sensing properties and characterization of alpha-naphthylmethacrylate LB thin films

Abstract

Determination of organic vapor sensing properties of alpha-Naphthylmethacrylate (alpha-NMA) monomer based Langmuir-Blodgett (LB) thin films was aimed in this study. LB thin film fabrication was performed on quartz glass and quartz crystal substrates in order to investigate the characterization and organic vapor properties of alpha-NMA materials by using UV-Visible, Atomic Force Microscopy (AFM) and Quartz Crystal Microbalance (QCM) techniques. pi-A isotherm graph was taken and a suitable surface pressure value were primarily determined as 13 mN m(-1) for successful alpha-NMA LB thin film fabrication. Transfer ratio value was found to be >= 0.93 for quartz glass and quartz crystal substrates. The typical frequency shift per layer was obtained as 16.93 Hz/layer and the deposited mass onto a quartz crystal was calculated as 271.30 ng/layer (1.02 ng mm(-2)). The sensing responses of alpha-NMA LB films against dichloromethane, chloroform, toluene and m-xylene were measured by QCM system. Dichloromethane created the maximum shift in the resonance frequency than other organic vapors used in this study. Results exhibited that alpha-NMA LB thin films were potential candidates for organic vapor sensing applications, especially high sensitive detection of dichloromethane at room temperature.