钾铯基地聚合物前驱体水热合成块体铯榴石

摘要

以偏高岭土为铝、硅源,以硅酸钾铯溶液为碱激发剂,无需添加任何沸石晶种和表面活性剂,室温制备了钾铯基地聚合物前驱体.将所制备钾铯基地聚合物前驱体在密闭蒸压反应釜环境中(180 ℃,0.8 MPa)水热晶化8 h,制备得到了块体铯榴石. 研究结果表明,钾铯基地聚合物前驱体为无定形物质;经水热晶化处理后,铯含量较高的样品中出现了铯榴石晶体,说明地聚合物凝胶原位转化为铯榴石晶体颗粒.原位转化生成的铯榴石晶体颗粒被地聚合物凝胶包裹和粘结,使得块体材料具有较高抗压强度.%(K,Cs)-geopolymer precursors have been synthesized by using metakaolin (MK) and potassium cesium silicate solutions as raw materials without any zeolites and surfactants.And the bulk pollucite mateials were obtained by the hydrothermal crystallization of (K,Cs)-geopolymer precursors under hydrothermal conditions of 180 ℃ and 0.8 MPa for 8 h.Results show the amorphous nature of (K,Cs)-geopolymer precursors.And the crystals with pollucite structure in the samples with higher content of Cs indicates the in-situ transformation of (K,Cs)-geopolymer gels under hydrothermal conditions.The in-situ formed pollucite particles could be bonded by non-transformed geopolymer gels to construct the bulk pollucite with high compressive strength.