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Preparation of A Plate-like Particle of Calcium Aluminosilicate via Layered Double Hydroxide

层状双氢氧化物制备板状硅铝酸钙颗粒

基本信息

批准号：
14550798
负责人：
NARITA Eiichi
金额：
$ 2.37万
依托单位：
Iwate University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

A plate-like inorganic particle composed of non-toxic and low price materials has received considerable attention in recent years. However, the preparation of a plate-like inorganic particle is known to be generally difficult. In this study, Ca-Al-NO_3 layered double hydroxide (LDH) was synthesized as a precursor and intercalation technique was used for the preparation of Ca-Al-SiO_4 LDH. The precursor was synthesized by the direct reaction of powdered quick lime (CaO) with NaAlO_2 in alkaline aqueous solution. It was found that the Ca-Al--NO_3 LDH (d_<0030>0.87 nm, Ca_<0.72>Al_<0.28>(OH)_2(NO_3)_<0.14>(OH)_<0.14>(0.52H_2O)) particle with hexagonal plate-like shape and 1〜4 μm in diameter size was formed at the optimum condition : Ca/Al ratio 3, synthesis temperature 323 K (1 h), aging temperature 373 K (2 h). By the hydrothermal treatment of the LDH at 473 K for 0.5〜2 h, the particle diameter was increased to 10〜20 μm. Then, the ion-exchange of NO_3^-ion in these LDHs with silicate ion was carried out at 298 K and the resulting LDHs Ca_<0.72>Al_<0.28>(OH)_2(SiO_4)_<0.074>(0.43H_2O)) was heated at 573〜1,173 K for 0.5 h. During the intercalation and hydrothermal treatments, the plate-like particle shape was maintained and the crystalline material of gehlenite (Ca_2Al_2SiO_7) as main phase was obtained. In conclusion, we succeeded the preparation of a plate-like particle of calcium aluminosilicate from non-toxic and low price materials such as limestone and NaAlO_2.

近年来，由无毒且廉价的材料组成的板状无机颗粒受到了相当大的关注。然而，已知板状无机颗粒的制备通常是困难的。本文以Ca-Al-NO_3层状双氢氧化物（LDH）为前驱体，采用插层法制备了Ca-Al-SiO_4层状双氢氧化物（LDH）。以粉状生石灰（CaO）和NaAlO_2为原料，在碱性水溶液中直接反应合成前驱体。结果表明，在<0030><0.72><0.28><0.14><0.14>Ca/Al比为3，合成温度为323 K（1 h），陈化温度为373 K（2 h）的条件下，可制得直径为1 × 4 μm的六方片状Ca-Al-NO3 LDH（d_ 0.87 nm，Ca_ Al_（OH）_2（NO_3）_（OH）_（0.52 H_2O））。通过在473 K下对LDH进行0.5 ~ 2 h的水热处理，LDH的粒径增加到10 ~ 20 μm。然后，在298 K下进行NO_3 ~（2-）与硅酸根离子的离子交换，得到的LDHs（Ca_<0.72>Al_<0.28>（OH）_2（SiO_4）_<0.074>（0.43 H_2O））在573 ℃下加热0.5 h。在插层和水热处理过程中，片状颗粒的形状得到保持，并得到以钙铝黄长石（Ca_2Al_2SiO_7）为主相的晶体材料。总之，我们成功地从无毒、廉价的原料如石灰石和NaAlO_2中制备了板状的钙铝硅酸盐颗粒。