Abstract
Three kinds of polymeric gels are copolymerized with a photo-crosslinkable prepolymer, ENTP-4000 or ENT-3400, and a functional monomer, acrylic acid AA, diethylacrylamide DEAA or NIPA. The applicability of the gel as an adsorbent for the temperature-swing adsorption (TSA) process was investigated with using nonionic surfactant Triton as a model adsorbate. The hydrophobic ENTP-AA gel was not suitable as an adsorbent for TSA because the desorption of surfactant from the gel was insufficient. On the other hand, both ENT-DEAA and ENT-NIPA gels showed reversible change in the adsorbed amount in the adsorption–desorption cycle. It was concluded that the ENT-DEAA and ENT-NIPA gels were promising for the TSA process. The equilibrated adsorbed amount of Triton increased with an increase in hydrophobicity of the surfactant and/or the temperature-sensitive functional group. The adsorption and desorption rates were much smaller than those of swelling and shrinking. These results indicate the importance of molecular design of the photo-crosslinked adsorbent gel and chemical engineering approach for practical application of TSA.
