One-step facile synthesis of bulk zeolite A through metakaolin-based geopolymer gels
One-step facile synthesis of bulk zeolite A through metakaolin-based geopolymer gels
复制标题
通过偏高岭土基地质聚合物凝胶一步轻松合成块状沸石 A
DOI：
10.1007/s10934-015-0034-6
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发表时间：
2015-12-01
影响因子：
2.6
通讯作者：
Lu, Zhongyuan
中科院分区：
文献类型：
--
作者：
Duan, Jianxia;Li, Jun;Lu, Zhongyuan
提出了一种不需要任何表面活性剂和高压釜的一步法合成偏高岭土基地聚合物凝胶块体A型沸石的方法。当样品在烘箱中放置一段时间后，在土聚过程中，土聚物凝胶可以原位转化为A型沸石。研究了合成温度、固化时间、钠铝比和水胶比对A型沸石的结构、形貌和力学性能的影响。结果表明，在70℃下反应16h，可得到钠铝比为1.0、水胶比为0.7的高纯度、结晶度较高的A型沸石，非晶态的地聚合物凝胶可以使A型沸石微粒相互粘结，使大块样品具有一定的强度。并对体相A型沸石的形成机理进行了探讨。由于A型沸石相和地聚合物相共存，氮气吸附观察到了A型沸石中的微孔和中孔。压汞测孔也证实了大孔的存在，其孔径为0.9gμm，孔隙率为39.2%。
A one-step facile method without any surfactants and autoclaves has been proposed to synthesis bulk zeolite A through metalkaolin-based geopolymer gels. The geopolymer gels could be in situ transformed to zeolite A during geopolymerization process when the samples were kept in the oven for a period of time. Influence of the synthesis temperature, curing time, Na/Al ratio and water–binder ratio on the structures, morphology and mechanical properties of the bulk zeolite A has also been studied. Results indicated that highly purified and crystallined zeolite A with Na/Al ratio of 1.0 and water–binder ratio of 0.7 could be obtained at 70 °C for 16 h. The non-crystallined geopolymer gels would bond the micro-particles of zeolite A with each other, which make the bulk samples have certain strength. The formation mechanism of the bulk zeolite A has also been discussed. Micropores and mesopores in the bulk zeolite A have been observed by nitrogen adsorption because of the coexistence of zeolite A phase and geopolymer phase. Meanwhile, the mercury intrusion porosimetry also confirmed the existence of macro-pores with 0.9 μm of pore-size and 39.2 % of porosity in the bulk body.