Theoretical and experimental study on the thermal stability of three dimensional zeolite framework

研究了三维沸石骨架的计算机模拟及其热稳定性。(1)为了表征和构建各种分子筛骨架。采用了基于图论的同心聚类（CCL）概念。给出了三维框架的系统推导。(2)引入取代节点矩阵法实现了Si和Al在沸石骨架上的分布。这也使观测到的核磁共振谱的理论估计和邓普西规则的有效性的研究成为可能。(3)分子筛骨架的热稳定性可通过分子动力学模拟测试。结果表明，结构的稳定性不受结构拓扑的影响，而受结构中Si/Al含量的影响较大。额外阴离子的包封对于提高骨架的稳定性是有效的。(4)在计算机模拟中，局部离子模型比完全离子模型更符合实际框架。这种模拟需要更合适的电位模型和参数。

Computer modelling of three dimensional zeolite frameworks and their thermal stability are invetigated.(1) In order to charcterize and construct various kinds of zeolite frameworks. the CCL (Concentric cluster) concept based onthe graph theory is applied. Sytematical derivation of three dimensional framework is shown.(2) Si and Al distributions on zeolite frameworks are realized by an introduction of substituted node matrix method. This also enables theoretical estimation of observed NMR spectrum and the investigation of validity of Dempsey's rule.(3) Thermal stability of zeolite frameworks can be tested by application of Molecular Dynamic simulation. According to it, the stability is not so effected on the framewrk topology, but on the Si/Al contents remarkably in the framework. The encapusulation of extra anions is effective for the promotion of framework stability.(4) In the computer simulation, the partial ionic model is more fitted on the real framework than the complete ionic model. More suitable potential models and parameters are needed for this kind of simulation.