New efficient polyelectrolyte containing zwitterionic sulfobetaine salt for the high sensitive resistive humidity sensor

Abstract

New sulfobetaine zwitterion-containing copolymers were prepared by the copolymerization of [2-[(methacryloyloxy)ethyl]dimethyl] propyl ammonium bromide (MEPAB)/N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl) ammonium (DMMSA) for a humidity-sensitive polyelectrolyte. The poly(MEPAB-co-DMMSA)s with a composition of 10/0, 8/2, 6/4, 4/6, 3/7, 2/8 and 0/10 were used to prepare resistive-type humidity sensors. The electrical properties of poly(MEPAB-co-DMMSA) with different amounts of MEPAB and DMMSA were examined as a function of the relative humidity to determine the contribution of the two salts on the sensing properties (linearity and sensitivity). Resistance of the humidity sensors obtained from the copolymers MEPAB and DMMSA varied from 10 7 to 10 2 Ω between 30%RH and 90%RH, which is suitable for a humidity sensor operating at ambient humidity. The humidity-sensing properties of MEPAB were enhanced by doping with a sulfo-betaine-type salt with a significantly different dissociation constant. The temperature dependence, hysteresis, response time, water durability, and long-term stability at high temperature and humidity were also measured.

Complex Formation in the Sulfobetaine-Containing Entirely Ionic Block Copolymer/Ionic Homopolymer System and Their Temperature Responsivity

“…Zwitterionic betaine polymers having both anions and cations in one repeating unit have high moisturizing properties due to their structural specificity and have been used in cosmetics and the like for a long time. − Recently, these polymers have been found to have high biocompatibility because they have a structure similar to that of the lipids that make up the cells ,, and are applied to biomedical materials , and biosensors. , Furthermore, research is being conducted on energy materials to stabilize the interface. − …”

“…1−5 Recently, these polymers have been found to have high biocompatibility because they have a structure similar to that of the lipids that make up the cells 3,6,7 and are applied to biomedical materials 8,9 and biosensors. 10,11 Furthermore, research is being conducted on energy materials to stabilize the interface. 12−14 Betaine polymers are neutral in an aqueous solution, and the solubility changes depending on the concentration of the salt and the ionic species of the added salt.…”

Synthesis and solution property of acrylamide-sulfobetaine copolymers

“…DMAPS is able to copolymerize with various monomers [21][22][23][24][25]. McCormick et al [11,26,27] have synthesized a series of sulfobetaine (co)polymers by conventional freeradical techniques and found that the copolymers with 25 mol% or less of zwitterionic comonomer were soluble in deionized water and displayed a tendency to intermolecularly associate.…”

Preparation of flexible resistive humidity sensors with different electrode gaps by screen printing and their humidity-sensing properties

“…19,20 In general, humidity-sensitive characteristics are dependent upon the chemical structures of the polyelectrolyte humid membrane. [21][22][23][24][25][26] Their ionic moieties, such as cationic, anionic, and amphoteric, and their counter ions were directly related to sensitivity. 2,7,[27][28][29][30][31][32][33][34] In addition, the thickness of the humid membrane closely affects the humidity sensitivities, such as hysteresis and response time or recovery time.…”