不同脱水方式对瓜尔胶基多孔复合高吸水凝胶溶胀性能的影响

Effect of Dehydrating Methods on the Swelling Properties of the Porous Guar Gum-Based Superabsorbent Composite

以十二烷基苯磺酸钠(SDS)胶束作为孔模板,水溶液中瓜尔胶(GG)、丙烯酸(AA)和凹凸棒粘土(APT)接枝聚合制备了瓜尔胶-g-聚丙烯酸钠/凹凸棒粘土(GG-g-PNaA/APT)复合高吸水凝胶,考察了甲醇、乙醇、丙酮脱水溶剂及冷冻过程对复合凝胶平衡溶胀倍率和溶胀速率的影响。扫描电镜表征表明,结合冷冻-甲醇脱水,复合凝胶表面呈蜂窝状的均匀多孔结构。甲醇、乙醇、丙酮脱水对复合凝胶溶胀性能影响顺序为甲醇>乙醇>丙酮。以甲醇脱水为例,结合冷冻过程,可使复合凝胶的初始溶胀速率常数(Kis)从11.4771g/(g·s)提高到17.6336g/(g·s),提高了53.6%。冷冻-甲醇脱水是一种简便的洗除SDS胶束、保持网络孔形貌,提高凝胶溶胀性能的干燥方式。

Using the self-assembled anionic surfactant sodium n-dodecyl sulfonate（SDS）micelles as porous templating,a novel guar gum-g-poly（sodium acrylate）/attapulgite（GG-g-NaA/APT）superporous composite was prepared by the grafting copolymerization of guar gum（GG）,acrylic acid（AA）and attapulgite（APT）in aqueous solution.The investigation of dehydrating solvent,methanol,ethanol,acetone,and freezing procedure on the equilibrium swelling ratio and swelling rate of the porous superabsorbent composite were carried out.SEM demonstrates that the morphologies of the composite,which are dehydrated by freezing-methanol procedure,display homogeneous and well-defined pore.The effect of methanol,ethanol and acetone dehydration on the swelling properties of the composite is the following order：methanol〉 ethanol〉acetone.For freezing-methanol dehydrating composite,the initial swelling rate constant（Kis）in distilled water is improved from 11.4771g/（g·s）to 17.6336g/（g·s）,and enhanced 53.6%.The obtained superporous superabsorbent composite displays rapid salt,pH stimuli-responsiveness,which can be used as drug release material and metal ions absorption.Freezing-methanol dehydration is a simple procedure for washing SDS micelles and keeping the superporous structure in the superabsorbent composite 3Dnetwork.