The Design, Preparation And Performance Of Sulfonated Poly(Aryl Ether Ketone)s Humidity Sensor

With the development of industry and the improvement of people’s life,we have greater demands for the detection and controlling the environmental humidity.As one of the core components of humidity sensor,humidity sensing material has the function of sensing relative humidity(RH).In recent years,sulfonated poly(arylene ether ketone)s(SPAEKs)have been applied in the research of humidity sensing materials due to they can response to changing relative humidity,they have good moisture resistance stability and film forming ability.In this dissertation,the sulfonated poly(arylene ether ketone)s with sulfonation degrees of 0.2,1.0 and 1.9 were synthesized,and their structures were determined by ~1H-NMR spectra.The humidity sensing elements were fabricated on the Ag-Pd interdigital microelectrodes by solution casting coating.The humidity response characteristics of Na-type and H-type sulfonated poly(arylene ether ketone)s were studied.Polybenzimidazole(PBI)was then used as macro-crosslinking agent to modify the H-type sulfonated poly(arylene ether ketone)s with a degree of sulfonation of 1.9.Firstly,we investigated the change of humidity sensing performance of Na-type sulfonated poly(arylene ether ketone)s with different sulfonation de-grees(SPAEK-Na),through water-uptake test,response sensitivity test,hys-teresis analysis,response/recovery time test and stability test.It was found that with the increasing of degree of sulfonation,the hysteresis of the materials showed a trend of increasing first and then decreasing.The hysteresis of the Na-type sulfonated poly(arylene ether ketone)s with the degree of sulfonation of 0.2,1.0 and 1.9 were 3%RH,10%RH and 6%RH,respectively.Among them,the response and recovery time of SPAEK-Na with the degree of sul-fonation of 0.2 was relatively short,which was 1 s and 200 s.Secondly,the humidity response characteristics of H-type poly(arylene ether ketone)s were studied.Compared with Na-type sulfonated poly(arylene ether ketone)s,this kind of materials have much shorter response and recov-ery time.As the degree of sulfonation increased to 1.9,the response/recovery time decreased to 1 s/70 s.Lastly,in order to improve the humidity response characteristics of the materials,the H-type poly(arylene ether ketone)with a degree of sulfonation of 1.9 was compounded with a large molecule crosslinker polybenzimidazole.In PBI/SPAEK system,the hysteresis value of 5 wt%PBI/SPAEK was only 0.9%RH,and the response and recovery time were 1 s and 40 s,respectively.In addition,the composite material modified by PBI has good repeatability.In two cyclic dynamic tests,the impedance values of 11%RH,33%RH,53%RH,65%RH,75%RH and 97%RH are completely consistent.As a result,the PBI modified sulfonated poly(arylene ether ketone)based humidity sensing mate-rials exhibit excellent humidity response performance,and have a good pro-spect for researching in the field of humidity sensing.