Side-chain-type sulfonated poly (arylene ether ketone)s containing naphthalene moieties with a degree of sulfonation (Ds) from 0.2 to 1.9 were synthesized. Humidity sensors were fabricated by cast coating on silver–palladium interdigital microelectrodes. The properties of this series of materials in terms of water absorption, glass transition temperature, and humidity sensing were characterized in detail. The investigations on the humidity sensing performance showed that with the increase in the Ds, the hysteresis of our materials exhibits an increasing trend first, followed by a decrease. This special phenomenon has not been reported before and caught our attention. From the results of humidity sensing properties, among the materials, the one with 0.2 Ds is promising for applications in humidity sensing due to its small hysteresis and fast response to varied relative humidity (RH). For a better understanding of the humidity sensing behavior of the sensor, complex impedance spectra were also measured. In the long-term stability measurement, the deviation of the measured impedance of the sensor at 97% RH is not obvious, proving good stability in a humid environment.
RathiKPalK. Impact of doping on GO: fast response–recovery humidity sensor. ACS Omega2017; 2: 842–851.
2.
FoucaranASorliBGarciaM, et al.Porous silicon layer coupled with thermoelectric cooler: a humidity sensor. Sensor Actuat A Phys2000; 79: 189–193.
3.
SajidMKimHBYangYJ, et al.Highly sensitive BEHP-co-MEH: PPV + Poly (acrylic acid) partial sodium salt based relative humidity sensor. Sensor Actuat B: Chem2017; 246: 809–818.
4.
ParkKJGongMS. A water durable resistive humidity sensor based on rigid sulfonated polybenzimidazole and their properties. Sensor Actuat B Chem2017; 246: 53–60.
5.
YangBManoharAPrakashGK, et al.Anhydrous proton-conducting membrane based on poly-2-vinylpyridinium dihydrogenphosphate for electrochemical applications. J Phys Chem B2011; 115: 14462–14468.
6.
SuPGUenCL. A resistive-type humidity sensor using composite films prepared from poly (2-acrylamido-2-methylpropane sulfonate) and dispersed organic silicon sol. Talanta2005; 66: 1247–1253.
7.
LvXHongLJLiY, et al.Synthesis and humidity sensitive properties of pyrrole-based polyelectrolytes. J Appl Polym Sci2009; 112: 1287–1293.
8.
SuPTsaiW. Humidity sensing and electrical properties of a composite material of nano-sized SiO2 and poly (2-acrylamido-2-methylpropane sulfonate). Sensor Actuat B Chem2004; 100: 417–422.
9.
LiYYangMJSheY. Humidity sensors using in situ synthesized sodium polystyrenesulfonate/ZnO nanocomposites. Talanta2004; 2: 707–712.
10.
RubingerCPLMartinsCRDe PaoliMA, et al.Sulfonated polystyrene polymer humidity sensor: synthesis and characterization. Sensor Actuat B:Chem2007; 123: 42–49.
11.
KawalecAJasekKPasternakM. Measurements results of SAW humidity sensor with nafion layer. Eur Phys J Special Top2008; 154: 123–126.
12.
ZhangFLiaMZhangH, et al.A method for standardizing the manufacturing process of integrated temperature and humidity sensor based on fiber Bragg grating. Opt Fiber Technol2018: 46: 275–281.
13.
WangFHicknerMKimYS, et al.Direct polymerization of sulfonated poly(arylene ether sulfone) random (statistical) copolymers: candidates for new proton exchange membranes. J Membrane Sci2002; 197: 231–242.
14.
WangZNiHZhaoC, et al.Physical and electrochemical behaviors of directly polymerized sulfonated poly(arylene ether ketone sulfone)s proton exchange membranes with different backbone structures. J Appl Polym Sci2009; 112: 858–866.
15.
SambandamSRamaniV. SPEEK/functionalized silica composite membranes for polymer electrolyte fuel cells. J Power Sources2007; 170: 259–267.
16.
NaRHuoGZhangS, et al.A novel poly(ethylene glycol)–grafted poly(arylene ether ketone) blend micro-porous polymer electrolyte for solid-state electric double layer capacitors formed by incorporating a chitosan-based LiClO4 gel electrolyte. J Mater Chem A2016; 4: 18116–18127.
17.
LiaoJChuYWangJ, et al.Dielectric and gas transport properties of the films of thermally stable poly(arylene ether ketone)s containing content-tunable benzimidazole moiety. J Appl Ploym Sci2015; 132: 41280–41289.
18.
LiuCMaoHZhengJ, et al.In situ surface crosslinked tight ultrafiltration membrane prepared by one-step chemical reaction-involved phase inversion process between activated PAEK-COOH and PEI. J Membr Sci2017; 538: 58–67.
19.
QiDZhaoCZhuangZ, et al.Novel humidity sensitive materials derived from naphthalene-based poly (arylene ether ketone) containing sulfobutyl pendant groups. Electrochim Acta2016; 197: 39–49.
20.
QiDZhaoCZhangL, et al.Novel in situ-foaming materials derived from a naphthalene-based poly(arylene ether ketone) containing thermally labile groups. Polym Chem2015; 6: 5125–5132.
21.
MatsuguchiMUmedaSSadaokaY, et al.Characterization of polymers for a capacitive-type humidity sensor based on water sorption behavior. Sensor Actuat B: Chem1997; 49: 179–185.
22.
FengH. Modeling of vapor sorption in glassy polymers using a new dual mode sorption model based on multilayer sorption theory. Polymer2007; 48: 2988–3002.
23.
LiGZhaoCLiX, et al.Novel side-chain-type sulfonated diphenyl-based poly(arylene ether sulfone)s with a hydrogenbonded network as proton exchange membranes. Polym Chem2015; 6: 5911–59120.
24.
WangBHongLLiY, et al.Considerations of the effects of naphthalene moieties on the design of proton-conductive poly(arylene ether ketone) membranes for direct methanol fuel cells. ACS Appl Mater Interfaces2016; 8: 24079–24088.
25.
TesfayeMKushnerDIMcCloskeyBD, et al.Thermal transitions in perfluorosulfonated lonomer thin-films. ACS Macro Lett2018; 7: 1237–1242.
26.
BanerjeeSKarKK. Impact of degree of sulfonation on microstructure, thermal, thermomechanical and physicochemical properties of sulfonated poly ether ether ketone. Polymer2017; 109: 176–186.
27.
SongJMShinJSohnJY, et al.Ionic aggregation characterization of sulfonated PEEK ionomers using by X-ray and DMA techniques. Macromol Res2012; 20: 477–483.
28.
LafiAGAHayJN. State of the water in crosslinked sulfonated poly(ether ether ketone). J Appl Polym Sci2013; 128: 3000–3009.
29.
ZhangLZhangGZhaoC, et al.High proton-conducting polymer electrolytes based on pendent poly(arylene ether ketone) with H-bond for proton exchange membranes. Int J Hydrog Energy2013; 38: 12363–12373.
30.
ZhuangZLiYQiD, et al.Novel polymeric humidity sensors based on sulfonated poly (ether ether ketone)s: influence of sulfonation degree on sensing properties. Sensor Actuat B Chem2017; 242: 801–809.
31.
PotreckJUyarFSijbesmaH, et al.Sorption induced relaxations during water diffusion in S-PEEK. Phys Chem Chem Phys2009; 11: 298–308.
32.
SimonSEspucheEGouanveF, et al.Influence of chemical structure on hydration and gas transport mechanisms of sulfonated poly(aryl ether ketone) membranes. J Phys Chem B2012; 116: 12750–12759.
33.
GengWYuanQJiangX, et al.Humidity sensing mechanism of mesoporous MgO/KCl–SiO2 composites analyzed by complex impedance spectra and bode diagrams. Sensor Actuat B Chem2012; 174: 513–520.
34.
ZhaoHZhangTQiR, et al.Organic-inorganic hybrid materials based on mesoporous silica derivatives for humidity sensing. Sensor Actuat B Chem2017; 248: 803–811.
35.
SongXQiQZhangT, et al.A humidity sensor based on KCl-doped SnO2 nanofibers. Sensor Actuat B Chem2009; 138: 368–373.
