Key Laboratory of Chemistry of Northwestern Plant Resources, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, PR China.
Colloids Surf B Biointerfaces. 2011 Nov 1;88(1):279-86. doi: 10.1016/j.colsurfb.2011.07.002. Epub 2011 Jul 12.
Novel fast-swelling porous guar gum-g-poly(sodium acrylate-co-styrene)/attapulgite (GG-g-P(NaA-co-St)/APT) superabsorbent hydrogels were prepared by simultaneous free-radical graft copolymerization reaction of guar gum (GG), partially neutralized AA (NaA), styrene (St) and attapulgite (APT) using N,N'-methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as an initiator in aqueous solution and the surfactant self-assembling templating pore-forming technique. Fourier transform infrared (FTIR) spectroscopy confirmed that the surfactant could be removed from the final hydrogel product by methanol/water (8:1, v/v) washing process and the surfactant only act as micelle template to form pores. The effect of surfactant type on the porous microstructure of the hydrogel was assessed by field emission scanning electron microscope (FESEM). It was shown that incorporation of proper amount of anionic surfactant sodium n-dodecyl sulfate (SDS) in the gelling process of the hydrogel can obviously enhance the swelling capacity and initial swelling rate. The salt-sensitivity of the SDS-added hydrogel in distilled water and 15 mmol/L NaCl, CaCl(2) solution or 15 mmol/L NaCl and CaCl(2) solution was investigated, and it was found that the swelling-deswelling capability is quite reversible. A similar reproducible on-off switching behavior was observed in the 1 mmol/L solution of phosphate buffer at pH 2.1 and 7.4.
新型快速溶胀多孔瓜尔胶-g-聚（丙烯酸钠-co-苯乙烯）/凹凸棒石（GG-g-P（NaA-co-St）/APT）超强吸水树脂是通过在水溶液中用 N,N'-亚甲基双丙烯酰胺（MBA）作为交联剂和过硫酸铵（APS）作为引发剂同时进行自由基接枝共聚反应，由瓜尔胶（GG）、部分中和的 AA（NaA）、苯乙烯（St）和凹凸棒石（APT）制备得到的，并且采用表面活性剂自组装模板成孔技术。傅里叶变换红外（FTIR）光谱证实，表面活性剂可以通过甲醇/水（8:1，v/v）洗涤过程从最终的水凝胶产物中去除，并且表面活性剂仅作为胶束模板形成孔。通过场发射扫描电子显微镜（FESEM）评估了表面活性剂类型对水凝胶多孔微观结构的影响。结果表明，在水凝胶的胶凝过程中加入适量的阴离子表面活性剂十二烷基硫酸钠（SDS）可以明显提高其溶胀能力和初始溶胀速率。研究了添加 SDS 的水凝胶在蒸馏水中和 15mmol/L NaCl、CaCl2溶液或 15mmol/L NaCl 和 CaCl2溶液中的盐敏性，发现溶胀-收缩能力具有相当的可逆性。在 pH 值为 2.1 和 7.4 的 1mmol/L 磷酸盐缓冲溶液中也观察到类似的可重复开启/关闭开关行为。
