Study On Preparation And Application Of HFIP Functionalized PS-b-PMPS For SAW Sensor

Surface acoustic wave (SAW) sensor is a kind of vapor sensor which has been utilized to detect and monitor explosive gases. The technology employs polymer coating on SAW sensor to collect and concentrate analyte(s) of interest. When the selective coating contacts analyte, the density and elasticity of film will be changed, so the spreading of Rayleigh wave on piezocrystal will be changed with the variety of sediment mass. The analyte(s) and its concentration can be detected by the change of oscillation frequency. It has high sensitive, convenient, fast, and many other advantages.Ring siloxane was prepared by anhydrous concentration, further, synthesis poly(styrene-b-methylphenylsiloxane) (PS-b-PMPS). The PS-b-PMPS was characterized by FT-IR, NMR, GPC and Ubbelohde viscometer. The product was synthesized from PS-b-PMPS and hexafluoroacetone (HFA), then, was functionalized by hexafluoroisopropanol (HFIP), the functionalized product was characterized by FT-IR, ion chromatograph and hydroxyl analysis. The polymer was coated on the piezocrystal by two methods of solvent evaporation and spin coating. In the gas supply system, dinitrotoluene (DNT) was used as explosives, and the responses of SAW sensor were tested at DNT concentration of 750mg/m3. The factors to adsorption were also discussed in this paper.The absorption of product will be better when it is prepared by HFA with PS-b-PMPS at 25℃in 20 hours, in carbon disulfide as solvent. It has high sensitivity with the best fluorin and hydroxyl as polymer coating on SAW sensor.