Investigation of ion adsorption properties of sulfobetaine gel and relationship with its swelling behavior

Adsorption and Desorption of Na⁺ and NO₃⁻ Ions on Thermosensitive NIPAM-<i>co</i>-DMAAPS Gel in Aqueous Solution

“…DMAAPS was synthesized by the same manner as that used in our previous studies [15][16][17], which was proposed by Lee and Tsai [18], by the ring-opening reaction of N,N-dimethylaminopropylacrylamide (DMAPAA, KJ Chemicals Co., Ltd., Japan) and 1,3-propanesultone (PS, Tokyo Chemical Industry Co., Ltd., Japan). A mixture of PS (75 g) or BS (79 g) and acetonitrile (75 g) was added dropwise with continuous stirring at 30°C for 90 min into a mixture of DMAPAA (100 g) and acetonitrile (200 g).…”

“…The phenomenon above can be explained as follows. At higher temperature, thermal motion weakens the interaction between the charged groups of DMAAPS (N + and SO3 − ) and cation Na + and anion (NO3 − ) from NaNO3 solution [15][16][17]20], as a result, the adsorption ability of copolymer decreased as temperature increased. The adsorption are less influenced by temperature change because gels prepared using high cross-linker concentration, the interaction is dominated by intra-group ionic pairs that is quite strong to be broken by thermal motion.…”

Effects of specific anions on the relationship between the ion-adsorption properties of sulfobetaine gel and its swelling behavior

“…In our previous study, the effects of the temperature and preparation conditions of the gels, such as the cross-linker and monomer concentrations, on the adsorption of cations and anions onto DMAAPS gel were investigated using Al(NO 3 ) 3 , Zn(NO 3 ) 2 , and NaNO 3 solutions with various concentrations [29]. The simultaneous adsorption of cations (Al 3þ , Zn 2þ , or Na þ ) and anions (NO 3 À ) was confirmed.…”

“…DMAAPS was synthesized using the same method reported in our previous study [29], which was proposed by Lee and Tsai [30]; this reaction involved the ring-opening of N,N-dimethylaminopropylacrylamide (DMAPAA; KJ Chemicals Co., Ltd., Japan) and 1,3-propanesultone (PS; Tokyo Chemical Industry Co., Ltd., Japan). A mixture of PS (75 g) and acetonitrile (75 g) was added dropwise with continuous stirring at 30 C for 90 min into a mixture of DMAPAA (100 g) and acetonitrile (200 g).…”

“…Poly(DMAAPS) was used to evaluate the transition behavior in response to temperature changes. The preparation procedures were the same as those described in our previous study [29]. N,N,N 0 ,N 0 -Tetramethylethylenediamine (TEMED; SigmaeAldrich Co., USA) and ammonium peroxodisulfate (APS; SigmaeAldrich Co., USA) were used as a polymerization accelerator and initiator, respectively.…”