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

• 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
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550798/
• 关键词: Layered double hydroxide; Hydrotalcite; Inorganic layered compound; Synthesis; Intercalation; Plate-like particle; low environment load; Aluminosilicate

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，由无毒且价格低廉的材料组成的板状无机颗粒受到了广泛的关注，然而，在本研究中，Ca-Al-NO_3的制备普遍困难。以层状双氢氧化物(LDH)为前驱体，采用插层技术，通过粉状生石灰(CaO)与Ca-Al-SiO_4 LDH的直接反应合成了前驱体。 NaAlO_2在碱性水溶液中发现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))六角板状颗粒，直径1～4μm最佳条件为：Ca/Al比3，合成温度323 K（1 h），老化温度373 K（2 h），通过LDH在473 K水热处理0.5〜2 h，得到粒径。增加到10～20μm，然后在298K下将这些LDH中的NO_3^-离子与硅酸盐离子进行离子交换，得到产物。 LDHs Ca_<0.72>Al_<0.28>(OH)_2(SiO_4)_<0.074>(0.43H_2O))在573〜1,173 K下加热0.5 h，在插层和水热处理过程中，得到片状颗粒形状。得到了以钙黄长石(Ca_2Al_2SiO_7)为主相的结晶材料。结论,我们成功地以石灰石、NaAlO_2等无毒、廉价的原料制备了片状硅铝酸钙颗粒。