有机空间位阻剂对NaP分子筛的调控作用

以粉煤灰中提取出的硅酸钠和铝酸钠为原料,通过水热合成法制备NaP型分子筛。通过正交实验优化了晶化时间、晶化温度和溶液硅水比等工艺参数,提出了通过空间位阻效应调控晶粒生长过程的方法,探索了结构空间位阻作用对NaP型分子筛生长过程晶型、粒径的调控规律。采用XRD、FI-IR、SEM、BET等手段对产物的晶型、粒径和形貌进行表征,并对不同条件下制备的NaP型分子筛的吸附性能进行了评价。结果表明,水热反应体系中引入空间位阻效应能有效调控Na P型分子筛的形貌和粒径;空间位阻效应的影响规律为环状结构链状结构,长链结构短链结构。吸附性能测试表明,Zn~(2+)有效吸附去除率可达99.8%。

Regulation of the crystal growth of NaP zeolite with organic steric hindrance agents

With sodium silicate and sodium aluminate extracted from fly ash as the raw materials, NaP zeolite was prepared by hydrothermal synthesis method; the synthesis parameters such as crystallization time, temperature and the ratio of silicon/H₂O were optimized via orthogonal tests. The method to regulate the crystal growth process was proposed through controlling the steric hindrance effect. The NaP zeolite was characterized by XRD, FT-IR, SEM and N₂ sorption; the effect of steric hindrance on the crystal phase and grain size was investigated. The results show that the morphology and grain size of NaP zeolite can be effectively regulated by introducing steric hindrance agents into the hydrothermal reaction system. The strength of steric hindrance effect of various agents follows the order of ring structure > linear structure, long chain structure > short chain structure. The adsorption test suggests that removal rate of Zn²⁺ exceeds 99.8% for NaP zeolite under the optimal adsorption conditions.