凹凸棒石及其表面离子印迹聚合物对水溶液中Sr(Ⅱ)的吸附机制

ADSORPTION BEHAVIORS OF Sr(Ⅱ) IN AQUEOUS SOLUTION BY ATTAPULGITE AND ITS SURFACE ION-IMPRINTED POLYMER

以Sr(Ⅱ)为模板,壳聚糖为功能体,凹凸棒石为载体,γ-(2,3环氧丙氧)丙基三甲氧基硅烷为偶联剂,利用表面分子印迹技术和溶胶-凝胶法制备了凹凸棒石表面离子印迹聚合物。采用扫描电子显微镜、Fourier变换红外光谱对凹凸棒石及其表面离子印迹聚合物进行了表征,运用等离子体发射光谱技术探讨了pH值、吸附剂用量、静置时间对两者吸附行为的影响,考察了它们的饱和吸附容量和吸附效率,对比研究了凹凸棒石及其表面离子印迹聚合物对水溶液中Sr(Ⅱ)的吸附机制。结果表明:在最优化条件下,凹凸棒石表面离子印迹聚合物对水溶液中Sr(Ⅱ)有良好的吸附性能,饱和吸附容量为凹凸棒石的3.71倍,凹凸棒石表面离子印迹聚合物对Sr(Ⅱ)的识别性为凹凸棒石的3.0倍以上,为进一步建立专属性核废物处理模型提供了依据。

Sr（Ⅱ） ion-imprinting polymer was prepared by surface molecular imprinting technique and sol-gel process with Sr（Ⅱ） as the template,chitosan as the functional monomer,attapulgite as the support,and glycidoxypropyltrimethoxysilane as the coupling agent.The attapulgite prepared ion-imprinting polymer and were characterized with scanning electron microscope and Fourier trans-mission infrared spectrometry,and then their adsorption mechanism was discussed.With the help of inductively coupled plasma—atomic emission spectrometry（ICP-AES）,the factors affecting adsorption and selectivity,including pH,quiescent time,adsorbent amount,maximum capacity and selectivity coefficient were investigated.Under the optimum conditions,the ion-imprinted polymer has fast kinetics for the adsorption of Sr（Ⅱ）,and its maximum adsorption capacity is 3.71 times as that of attapulgite.Its selectivity is more than 3.0 times as that of attapulgite.A model for selective removal of target radioelements can be set up acc ording to the results.