Fast swelling behaviors of thermosensitive poly(N‐isopropylacrylamide‐co‐methacryloxyethyltrimethyl ammonium chloride)/Na₂WO₄ cationic composite hydrogels

Abstract

A facile method was explored to synthesize thermosensitive poly[N‐isopropylacrylamide (NIPAM)‐co‐methacryloxyethyltrimethyl ammonium chloride (DMC)]/Na2WO4 cationic hydrogels via copolymerization of NIPAM and DMC in the presence of Na2WO4. Na2WO4 acted as both a physical crosslinking agent and a porogen precursor. The hydrogels were characterized by Fourier transform infrared spectroscopy, energy dispersive X‐ray, thermogravimetry, environmental scanning electron microscopy, and transmission electron microscopy. Effects of various salt solutions, pH solutions on swelling were investigated. Thermosensitivity of the hydrogels were also investigated in various polar solvents at different temperatures. The resultant hydrogel showed a fast swelling rate and good salt tolerance. The hydrogels reached the swelling equilibrium within 10 min. Moreover, the swelling ratio of the hydrogels increased with the increase of the polarity of the solvent. In the water, the swelling ratio decreased with the increasing of temperature, but remained at a high level even at 80 °C since the pore structure weaken the lower critical solution temperature effect of PNIPAM. The swelling ratio increased instead in low polar solvent, while it became negligible in nonpolar solvent with the increasing of temperature. The whole swelling kinetics was fit for Schott's pseudo‐second order model. The hydrogels have a great potential as catalysts and smart materials. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46375.

Thermal analysis of solvatomorphic decakis (dimethylammonium) dihydrogendodecatungstate hydrates

“…There is an emerging interest about thermal decomposition of POMs having ammonium cations for the synthesis of metal oxides to be used as catalysts [1][2][3][4]. Alkylamino polytungstates [4][5][6][7], containing reducing alkylammonium cations with oxidizing polytungstate anions, are particularly interesting because of the possibility of self-oxidation, and because the cation may be volatilized. Recently, some polymorphic and solvatomorphic dimethylammonium dihydrogendodecatungstates have been synthesized [4,8,9].…”

Facile Synthesis of Hydrogel-Based Ion-Exchange Resins for Nitrite/Nitrate Removal and Studies of Adsorption Behavior

“…The sharp peaks at 1732 cm −1 and 1683 cm −1 were attributed to C=O stretching of ester groups in PEGDA and PEGDA-MTAC/AMHC respectively [ 53 ]. The broad peak at 1107 cm −1 was due to the C–O stretching vibration of ester groups of in PEGDA and PEGDA-MTAC/AMHC [ 53 , 54 ]. The modified adsorbent PEGDA-MTAC/AMHC showed the corresponding peaks of pure PEGDA and MTAC/AMHC.…”

NIR laser-responsive liquid metal-loaded polymeric hydrogels for controlled release of doxorubicin

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