|
Electrochemical gas sensors detect gases Due to many kinds of wide concentration range , small size , low price, high precision measurements in environmental monitoring and safety and other fields has been widely used. But there are also some kind of sensor problem that life is short. To solve this problem , but also to meet some special industries of the gas sensor performance requirements, people will focus on research into the research and development of new solid electrolyte , hoping to extend the life of the sensor and achieve its miniaturization. Currently, the most widely used is the Nafion membrane , but because of its conductivity by environmental humidity , difficult to retain water , which results in unstable performance of the sensor , coupled with the high cost of Nafion membrane , limiting the sensor in the actual application . Thus, the solution polymer solid electrolyte retention problems, and use of excellent performance , inexpensive alternative to Nafion membrane film solid-state gas sensors become difficult technologies. This article has excellent physical and chemical properties of polyvinylidene fluoride (PVDF) as the base , the use of the PVDF doped sodium orthosilicate , a strong acid grafted blend , high thermal stability , high proton conductivity and chemical stability 2 - acrylamido-2 - methylpropane sulfonic acid (AMPS) prepared by the method a new solid polymer electrolyte : the graft -modified blend of polyvinylidene fluoride with 2 - acrylamido-2 - methyl- propane sulfonic acid membrane (PVDF-g-PAMPS film) , a proton exchange membrane to improve water retention and conductivity. By studying the amount of the solvent , the amount of initiator , drying conditions, membrane film parameters on membrane performance , optimize performance superior polymer film preparation conditions : N- methyl pyrrolidone in a fixed amount of about 20ml ( i.e. 0.20gPVDF/ml NMP ) ; ammonium persulfate concentration 0.4g/100ml; drying temperature 80oC, holding time 4 hours . By infrared spectroscopy , thermal gravimetric analysis , scanning electron microscopy analysis of PVDF-g-PAMPS membrane structure and morphology , the results indicate that the composite membrane surface smooth , dense structure ; AMPS has been grafted onto the membrane , AMPS in the sulfonate evenly distributed throughout the film . Preparation of PVDF-g-PAMPS films were higher than the water retention and conductivity Nafion117, good mechanical properties of the film from the film cost , conductive film , film mechanical properties and the film has excellent water retention properties etc. .
|