铝盐的水解聚合形态及其演变规律既是探明铝系絮凝剂作用机理、合成高效混凝剂的重要科学问题，也是地球环境中铝迁移转化和铝污染防治的重大科学问题，但却困扰了科学家近百年。因每一温度下都是多种形态并存其分布时刻变化，因而从中离析纯聚铝化合物很难，得到适合解结构的单晶更难。由于结构已知的聚铝形态数量有限，所以单体铝究竟如何演变成氢氧化铝迄今尚无统一认识。本项目将在前两个项目所测100℃及以下常压相图指导下制备出34种聚铝化合物，解析出17种晶体结构，得出两条演变机理，总结出SSSS 聚合模式和局部碱化度对称均衡原理，证明P-Al13比K-Al13絮凝性能更佳的基础上，测定100℃以上中压相图，离析聚铝纯品，捕获强制水解高级形态，培养单晶解结构；对难培养单晶的拟配备强有力粉末解结构软件和快速计算机解结构；对微小单晶拟用同步辐射法解结构；从而为最终得出完整统一的聚铝形态形成演变机理和聚合模型理论做贡献。

The hydrolyzation and polymerization species and their evolvement rules of Al salts is not only an important scientific problem for revealing the action mechanisms of Al-series flocculants and for synthesizing the highly efficient coagulants, but also a significant scientific problem for understanding the transport and transformation law of Al in the global environment and for preventing Al pollution, however, the problem has perplexed scientists for a century. Because various species coexist in a hydrolyzed Al solution at each temperature, the distribution of every species is going to change from monent to moment, it is difficult to isolate pure compounds from the solution and more difficult to grow a large enough single-crystal for structure solving. Also, because the structurally known Al species are very limited, how an Al monomer was developed into Al(OH)3 has still not been reached to a consensus. In our completed two NNSFC projects, 34 polyaluminum compounds were prepared under the direction of the phase diagrams determined at 25-100℃ and ordinary pressure;17 crystal structures were solved;2 evolution mechanisms were obtained, a SSSS polymerization mode and theory, and a local basification degree symmetrical equalization principle were summed up; and the flocculation performance of P-Al13 was proved to be more superior than K-Al13. Based on these achievements, this project will determine the phase diagrams during Al salts being hydrolyed at more than 100℃ and higher pressure, isolate more pure polyaluninum compounds, capture advanced species from NaOH hydrolyzed Al solution,grow single-crystals and solve their structures. For those species who are difficult to grow single-crystals, the structures will be solved from their powder XRD data by equipping powerful softwares and high speed computer. For those very small single-crystals,the structures will be solved by using the synchrotron radiation diffraction method. The final target is to do our best for obtaining a complete and unified evolution mechanism, polymerization model and theory of polyaluminum species.