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Active transport of Selective Metal Ions by Thermo-Sensitive Polymer Gel

热敏聚合物凝胶选择性金属离子的主动运输

基本信息

批准号：
12650762
负责人：
SAKAI Yasuzo
金额：
$ 2.3万
依托单位：
Utsunomiya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

With the aim of developing polymeric gels sensitive to external stimuli and able to reversibly adsorb and release divalent ions, co-polymer gels (pNIPA/MA) of N-isopropylacrylamide and methacrylic acid monomers were prepared. Cu, Co, Ni, and Pb ions were used for target divalent ions. The gels shows in a strong affinity to target ions at 45 ℃, deswelling state, but the affinity is diminishes at the swelling state, 25 ℃. The pNIPA/MA gel adsorbed Cu, Co, Ni ions at the deswelling state, and released the metal ions at the swelling state. Therefore, Cu ion was transported from higher temperature liquid (45 ℃) to lower temperature liquid (25 ℃) against gradient of Cu ion concentration. It is possible that the pNIPA/MA gel removed Cu ion less than 1 ppm at 45 ℃, and concentrated that to more than 100 times at 25 ℃. For development of separation speed, acceleration of thermal responsibility was also investigated on pNIPA gel. The pNIPA gel prepared in a hydrophobic tubing as a matrix, PTFE or silicone, deswelled faster than that prepared in a hydrophilic tubing. The hydrophobic matrix was suitable for preparation of the fast-responsive pNIPA gel. The kinetic parameters of deswelling were also investigated in the presence of sugars as hydrophilic probes. Furthermore, another type of thermo-sensitive gel having an upper critical solution temperature was investigated by using N-acetylacrylamide. The gels shows considerable change of volume by changing of temperature in water-alcohol system.

为了开发对外界刺激敏感、能可逆吸附和释放二价离子的聚合物凝胶，制备了N-异丙基丙烯酰胺/甲基丙烯酸共聚凝胶(pNIPA/MA)。以铜、钴、镍、铅离子为靶二价离子。凝胶对目标离子的亲和力在45℃、去溶胀状态下表现出较强的亲和力，而在溶胀状态下，25℃时亲和力减弱。PNIPA/MA凝胶在溶胀状态下吸附铜、钴、镍离子，在溶胀状态下释放金属离子。因此，与铜离子浓度的梯度相反，铜离子从高温液体(45℃)向低温液体(25℃)迁移。在45℃时，pNIPA/MA凝胶对Cu2+的去除小于1ppm，而在25℃时，对Cu2+的去除可达100倍以上。为了提高分离速度，还对pNIPA凝胶的热响应性进行了研究。以聚四氟乙烯或有机硅为基质的疏水管内制备的pNIPA凝胶比亲水管内制备的凝胶脱水速度更快。该疏水基质适合制备快速响应的pNIPA凝胶。在以糖为亲水探针的条件下，研究了脱水动力学参数。此外，还利用N-乙酰丙烯酰胺对另一种具有较高临界溶解温度的热敏凝胶进行了研究。在水-醇体系中，凝胶的体积随温度的变化而发生显著变化。