【作者】 闫峰；

【导师】 魏东炜；

【作者基本信息】 天津大学 ， 化学工艺， 2007， 硕士

【摘要】 声表面波(surface acoustic wave,SAW)传感器是一类新兴检测化学毒气和爆炸物的传感器,因其独特的优越性,近年来受到广泛的关注。涂在SAW化学传感器上的聚合物敏感膜涂层与被测气体之间能发生可逆吸附作用,当涂膜与被测气体发生作用时,会引起膜密度和弹性等性质发生变化,从而使在压电晶体表面上传播的瑞利波速度随其表面沉积的质量而变化,导致振荡频率发生变化。通过检测振荡频率的变化,能获知是否存在某种气体和被吸附气体的浓度。本文将研究Poly(methyl(3,5-bis(hexafluoroisopropanol)phenyl)siloxane)聚(甲基(3,5-二(六氟代异丙醇)苯基)硅氧烷)(SXPHFA)膜材料的合成工艺,通过阴离子聚合开环的方法合成不同分子量聚甲基苯基硅氧烷(PMPS),用红外光谱、GPC等方法进行表征。将PMPS与六氟丙酮气体在不同条件下反应,得到目标产物SXPHFA,并进行红外、氟元素、羟基含量的表征。用溶剂蒸发法和旋涂法将聚合物涂在SAW基片表面。装配配气系统,用甲基磷酸二甲酯(DMMP)为化学战剂模拟物进行检测,精确测试在一定气体含量下SAW化学传感器对模拟气体的响应值。通过控制引发剂的加入量,可以得到在3500～35000范围内分子量不同且分布窄的PMPS。在合成SXPHFA过程中,考察了溶剂、反应时间、温度对产物的影响,根据表征结果对工艺条件进行筛选。确定以CS2为溶剂,0℃下反应10小时的最佳工艺条件。在吸附性检测中,讨论了溶液浓度及涂膜方法对响应值的影响。更多还原

【Abstract】 Surface acoustic wave (SAW) sensor is a new kind of sensor to detect chemical poison gas and explosives. This sensor attracted considerable attention because of its many advantages. 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 concertration can be detected by the change of oscillation frequency.The synthesis approachs of coating material, poly (methyl (3, 5-bis (hexafluoro- isopropanol) phenyl) siloxane) (SXPHFA), are studied in the paper. Poly (methylphenylsiloxane) (PMPS) with different molecular weights is synthesized by anionic ring-opening polymerization, characterized by infrared spectrum and GPC. The SXPHFA was synthesized from PMPS and hexafluoroaceton (HFA) and characterized by infrared spectrum, 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, dimethyl methyl phosphonate (DMMP) was used as simulation gas, and the responses of SAW sensor were tested at DMMP concertration of 500mg/m3.PMPS with narrow molecular mass distribution of molecular weight between 3500 and 35000 was obtained by adding different amounts of initiator. In the synthesis of SXPHFA, the influences of reaction time, solvent, reaction temperature and catalyzer are investigated. By the result of Characterization, best process conditions were selected. The best condition for the reaction time is 10 hours, the solvent is CS2, and the best reaction temperature is 0℃. In the adsorption test, the influences of solution strength and coating methods on response are discussed.更多还原