【作者】 金达莱；

【导师】 徐铸德； 岳林海；

【作者基本信息】 浙江大学 ， 物理化学， 2005， 博士

【摘要】 两亲性共聚物分子本身的微观相分离性质可在溶液中产生丰富有序的自组装结构,作为模板能诱导生成多形碳酸钙复合物。与过去多数在水溶液体系中的工作不同,论文创新性地采用混合溶剂体系,系统研究了溶剂效应对多种无机物的形貌调控作用。论文结合两亲共聚物的模板作用和混合溶剂效应的双重调控机制,合成出大量形貌新颖的碳酸钙复合物,并把这一方法拓展到了其它无机材料的合成中。研究结果表明,合理地组合运用这两种调控作用,是实现无机材料的分子设计和形貌控制合成的一条可能的途径。进一步辅以简便优化的合成工艺,将有希望发展成为一种理想的多形无机材料工业化生产路线。 论文中选择典型的可溶性两亲共聚物聚苯乙烯-丙烯酸(简称PS-PAA)为模板介质,研究了水溶液及小分子有机溶剂/水二元混合溶剂体系中,碳酸钙为主的多形无机材料的形成。通过SEM,XRD,TG-DTA,IR光谱,Raman光谱,粒径分析等现代分析测试手段,对材料进行外观形貌、尺寸,内部微结构等各种物化性质的表征,找出影响材料性质的合成工艺因素,来实现材料的设计合成,同时对材料的形成过程进行初步的机理推测。并通过对部分材料的应用性能探索研究,发掘其应用价值。 研究发现采用动态溶液化学沉淀反应方法,在PS-PAA为介质的水溶液体系中合成的碳酸钙复合物具有二级团聚结构。一次团聚体尺度在纳米级。二次团聚体为这些纳米颗粒的再次聚集,并形成各种形貌的复合物,尺度为微米级。PS-PAA分子量、反应温度、介质浓度、及搅拌速率等条件对复合物一次团聚及二次团聚的形貌,尺度及其结构都产生各自不同的影响效果。通过调节这些工艺条件,可以初步实现碳酸钙复合物的设计合成 应用红外光谱和拉曼光谱互为佐证地全面分析了球形碳酸钙复合物的物相组成,认为复合物由纳米尺度的方解石碳酸钙和离子化的PS-PAA钙盐组成。并通过IR-热重联用的分析方法,对复合物在TG曲线上产生各失重台阶所对应的物质进行提取并分析,进一步证实了复合物各物相的组成。 在物相组成分析的基础上,结合对碳酸钙微晶尺寸、形貌等结构表征,以及更多还原

【Abstract】 Amphiphilic copolymers, which have many ordered configurations existed in solution, can act as a good template in liquid reaction to induce the growth of multi-morphological inorganic composites. Differed from most previous work, this work creatively made use of binary solvents instead of aqueous solution to prepare calcite composite and systematically investigated the solvation effect on the product morphology. By using the copolymer template together with special solvents, calcite composites with novel shapes were synthesized. This method was further extended to the preparation of other new multi-morphological inorganic materials. Research results showed that both the template and the solvent would greatly influence the product shape and an appropriate combination of the two effects might open a way to realize molecular design and morphology control for inorganic materials.A typical amphiphilic copolymer of polystyrene（PS） and poly（acrylic acid）（PAA） was used as template to synthesize calcium carbonate in both aqueous solution and binary solvents. SEM, XRD, TG-DTA, IR, Raman spectra and particle-size analyser were used to investigate the morphology, size, texture and structure of the products. The relationship of the above characteristics with the preparation conditions was studied to explore the feasibility for the material design meanwhile a possible formation mechanism was suggested. In addition, some potential application study was carried on for the spherical CaCO₃ composite.The experiment results showed that the synthesized composites in aqueous solution were micron-sized aggregations composed of nano-scaled crystallite sub-units. It was also proved that the shape, size, texture, structure and other properties of the CaCO₃ aggregation were greatly effected by the copolymer’s molecular weight and concentration, reaction temperature, stirring rate, and the mass ratio of PS-PAA to CaCO₃. It revealed a possible way to realize molecular design for CaCO₃ composites through proper adjustments of these critical preparationconditions.The obtained spherical CaCO3 composite was analyzed by XRD, IR and Raman analysis. It was showed that the composite consisted of PS-b-PAA calcium salt and nano-scaled calcite crystallites. IR-TG combined analysis method further proved this standpoint.Based on the analysis of the composition, shape and crystal structure of the composites, combining with their thermal behavior as well as the critical micelle concentration （cmc） value of PS-PAA in the solution, it was found that the morphology and property of the composites were closely related to the copolymer configuration and motion mode in the solution. It strongly hinted there existed some geometrically matching configurations of PS-PA-Ca to calcite lattices. Besides, the water solvation effect around the reaction ions also played an important role during the formation of the composites.Porous calcite sphere was prepared by calcining the copolymer-containing spherical CaCC>3 composites at a very slow heating rate. A primary application study of this new material was carried on. It was found that this porous spherical CaCO3 composite acting as a lubricant additive could obviously decrease the frictional wear degree between the grater pairs.Instead of the aqueous solution, binary solvents, namely water mixed with another organic solvent such as acetone, isopropanol, glycol, THF or ether respectively, were used for further investigation. It was shown that the CaCOs composites prepared in binary solvents were mainly tropisic fringy-shaped. However, the competition of PS-PAA inducement effect with the solvation process led to a product shape change. With increasing the concentration of PS-PAA, the shape of CaCC>3 composites decreased in length and gradually changed from tropisic fringy to podgy double-pyramidal then to multi-armed flowery shape, finally to a spherical appearance with no more anisotropic. In addition, some unusual shapes such as mushroom liked or laminary shape could be obtained during the study. It seemed that the PS-PAA acted as a diversiform template in different mixed solvent systems.As to the case of MnCC>3, BaSO/t, BaC03 respectively, it was found that the inducement effect of PS-PAA no longer existed while the solvation effect could still realize morphology adjustment. For example, cubic MnCC>3 was obtained in alcohol/water mixed solution. Rod shaped BaSC>4 was synthesized in both alcohol/water and THF/water systems but the rod length was much longer in later case. Prismy BaCC>3 was prepared in ether/water system while it had isotropic particle shape if prepared in alcohol/water system.更多还原