Pillar Density Control and Properties of Sintered Body of Oxide Pillared Fluorine Micas

为了研究层间阳离子种类和层电荷对氧化物柱撑氟云母的形成和性能的影响，将具有不同层间阳离子种类和层电荷的合成可膨胀氟云母分别与由盐酸水解四异丙醇钛（TTIP）制备的羟基铝、羟基铬溶液和二氧化钛溶胶反应。结果总结如下。1)插层高度聚合的羟基铝离子导致铝含量的最高值，以及最高的耐热性氧化铝柱撑氟云母。2)发现氧化铝柱撑氟云母是可烧结的，在700 ℃下形成烧结体。3）用于插层的聚阳离子的阳离子交换选择性取决于主体晶体的层电荷，导致层间化合物的平均水解度对于层电荷较低的云母较大。4)阐明了反应条件与层间化合物平均水解速率的关系。5)当反应温度高于80 ℃时，羟基铬离子的聚合度较高。6）确定了形成复合物的最佳反应条件为：[TTIP/HCl]比为4，HCl浓度为1 mol/dm^3，反应时间为180 min，反应温度为50 ℃。7）云母层间阳离子种类对复合物的形成有很大影响，结果表明：层电荷对柱撑云母的二氧化钛含量和比表面积影响很<x->大，在层电荷x=0.6时，柱撑云母的二氧化钛含量和比表面积最大。这可以用膨胀性和阳离子交换能力之间的平衡来解释。9)二氧化钛柱撑氟云母的耐热性取决于二氧化钛含量。10)在较高温度下，部分层间二氧化钛从层间区被驱逐到云母晶面上，以云母的形式沉淀。

In order to clarify the influence of interlayr cation species and layr charge upon formation and properties of oxide pillared fluorine micas, synthetic expandable fluorine micas having different interlayr cations and layr charges were allowed to react with hydroxoaluminum, hydroxochromium solutions and titania sol prepared by hydrolyzing titanium tetraisopropoxide (TTIP) with hydrochloric acid, respectively. The results were summarized as follows. 1)Intercalation of highly polymelyzed hydroxoaluminum ions resulted in the highest value of Al-content as well as the highest thermal durability for alumina pillared fluorine micas. 2)Alumina pillared fluorine micas were found to be sinterable, forming sintered bodies at 700ﾟC.3)Cation exchange selectivity of polycations for intercalation depended on layr charge of host crystals, resulting in larger average hydrolysis degree of interlayr compounds for lower layr-charged micas. 4)The relation between reation conditions and average hydrolysis rates of interlayr compounds were clarified. 5)More highly polymerized hydroxochromium ions were intercalated when reacted above 80ﾟC.6)The most appropriate reaction conditions of complex formation were decided to be [TTIP/HCl] ratio of 4, concentration of HCl used being 1 mol/dm^3 with reaction time of 180 min at 50ﾟC.7)Interlayr cation species of host micas had the profound influence on complex formation, resulting on different titania contents and surface areas of pillared micas in the order of K^+<Na^+<Li^+.8)Na_<x->-system was greatly influenced by layr charge, giving a maximum of titania content at x=0.6. This can be explained in terms of the counterbalancing between expandability and cation exchange capacity. 9)Thermal durability of titania pillared fluorine micas depended on titania content. 10)Part of interlayr titania was expelled from interlayr region onto crystal surfaces of mica to precipitate as anatase at higher temperatures.