Development of Ion Memorized Materials by Using Ion-Exchange Reactions

利用离子交换反应进行组份改性可以制备出具有各种独特特性的亚稳材料。在本研究中，我们利用离子交换合成了离子记忆材料，特别是在大量过量的类似离子存在下选择性吸收K^+和Br^-离子的K^+和Br^-离子记忆材料，并对亚稳材料的特性进行了研究。因此，在改性的氟云母和磷灰石上发现了优异的离子选择性。用Na^+和H^+离子取代带青石层间K^+离子[KMg_2LiSi_4O_<10>F_2]制备了两种改性氟云母（NaT和HT）。研究了Na^+、K^+、Mg^<2+>和Ca^<2+>离子在NaT和HT上的阳离子交换选择性。发现NaT和HT对阳离子的选择性顺序为K^+>>Mg^<2+>*Ca^<2+>>Na^+，且NaT和HT对K^+离子的吸附量不依赖于水溶液中共存的Na^+、Mg^<2+>和Ca^<2+>离子的浓度。结果表明，NaT和HT是K^+离子记忆离子交换剂，可用于Na^+、K^+、Mg^<2+>和Ca^<2+>离子体系中K^+离子的分离和固定化，如海水、体液等。以溴云母铅[PbBrAp；Pb_<10>(PO_4)_6Br_2]中的Cl^-离子取代Br^-，制备了改性磷灰石（PbBr_<2-x>Cl_xAp）。研究了Cl^-离子存在下Br^-离子在PbBr_<2-x>Cl_xAp和PbClAp上的阴离子交换选择性。PbBr_<2-x>Cl_xAp选择性吸附Br^-离子，而PbClAp几乎不吸附Br^-离子。结果表明，PbBr_<2-x>Cl_xAp具有Br^-离子记忆特性，可用于Br^-离子的分离和固定化。

The technique of the compositional modification by using ion exchange reactions can produce metastable materials with various unique characteristics. In this study, we have synthesized the ion memorized materials by means of the ion exchange, especially K^+ and Br^- ions memorized materials which selectively take up K^+ and Br^- ions in the presence of a large excess of analogous ins, and then have investigated the characteristics on the metastable materials. Consequently ,the outstanding ion selectivity was discovered on modified fluormicas and apaties.1. Two modified fluormicas(NaT and HT)were prepared by substituting Na^+ and H^+ ions for interlayer K^+ ions in taeniolites [KMg_2LiSi_4O_<10>F_2]. The cation exchange selectivities for Na^+, K^+, Mg^<2+>, and Ca^<2+> ions on NaT and HT have been examined. The orders of cation selectivities on NaT and HT were found to be K^+>>Mg^<2+>*Ca^<2+>>Na^+,and NaT and HT took up a regular amount of K^+ ions without depending on the concentrations of Na^+, Mg^<2+>, and Ca^<2+> ions, which coexisted in aqueous solution. From the results, it was concluded that NaT and HT were K^+ ion memorized ion exchanger, and could be utilized in the separation and immobilization of K^+ ions from the system including Na^+, K^+, Mg^<2+>, and Ca^<2+> ions, for example, seawater, body fluid, and so on.2. A modified apatite(PbBr_<2-x>Cl_xAp)was prepared by substituting Br^- for Cl^- ions in lead bromapatite [PbBrAp;Pb_<10>(PO_4)_6Br_2]. The anion exchange selectivities for Br^- ions in the presence of Cl^- ions on PbBr_<2-x>Cl_xAp and PbClAp have been examined. PbBr_<2-x>Cl_xAp selectively took up Br^- ions in spite of depending on the concentration of Br^- ions, while PbClAp scarcely took up Br^- ions. The results suggested that PbBr_<2-x>Cl_xAp exhibited the Br^- ion memorized characteristics, and was useful for the separation and immobilization of Br^- ions.