Phenyl-modified hybrid organic-inorganic microporous films as high efficient platforms for styrene sensing

Microporous organic-inorganic hybrid silica films have been designed as active platforms to realise a styrene gas sensor. The microporous film has been synthesized by using tetraethylorthosilicate and phenyltriethoxysilane as precursors and a triblock copolymer (Pluronic F127) as a template for the pores. Multilayer films have been employed to increase the performance of the sensor and infrared spectroscopy has been used to probe the absorbed styrene molecules. The sensing response has been investigated by repeated exposures to different concentrations of styrene gas from 10 to 100 ppm. The microporous film has shown a better response compared to dense layers because of the increased surface area and the presence of the phenyl groups that enable a selective adsorption-desorption of the styrene. The diffusion coefficient of the microporous hybrid films has been calculated using a monodimensional plane-sheet diffusion model. This study shows that the microporous hybrid films have great potential to be used as simple and effective sensing materials for styrene and other Volatile Organic Compounds.