【作者】 王挺；

【导师】 蒋新；

【作者基本信息】 浙江大学 ， 应用化学， 2004， 硕士

【摘要】 本文研究吸附相反应技术在乙醇—水体系中制备纳米TiO₂／SiO₂复合材料。论文首先综述了纳米复合材料和纳米TiO₂的应用，对目前的一些纳米复合材料的制备方法按照论文的思路进行了分类。详细阐述了利用纳米反应器制备纳米复合材料的几种方法（反相微乳液、多孔材料和层状硅酸盐）的机理、特点和应用，并对比了传统制备纳米复合材料的方法和利用纳米反应器制备纳米复合材料方法的优缺点。 论文中着重介绍了利用纳米反应器制备纳米复合材料的新方法——吸附相反应技术，结合现有的文献阐述吸附相反应技术的机理和特点，列举了目前的研究进展，对文献进行了总结说明。同时总结文献之中没有深入或者没有涉及到的方面，在这个基础之上提出了论文的研究思路。 针对新的体系，作者通过对文献和现有分析手段的研究设计了一系列的实验。首先用溶剂置换实验验证了纳米反应器的存在且是反应和粒子生长的场所；再结合卡尔—费休水分测定仪测定了吸附体系中水分的变化，计算了SiO₂表面吸附层的厚度。为了探讨吸附相反应技术中的过程机理，作者设计了温度、浓度以及反应时间等实验，并结合X射线衍射仪（XRD）、透射电子显微镜（TEM）、电子能谱仪等各种表征手段，得出了吸附过程和反应过程的各自机理。吸附机理有四个特点：①吸附层分布较广；②吸附层本身不均匀且吸附层变化也不均匀；③吸附层对温度非常敏感；④吸附层的变化直接影响粒子最终形貌。吸附相反应技术中使用的反应器是纳米级的吸附层，因而吸附层中的钛酸丁酯水解反应也与传统的液相法有着不同的机理：①水解反应的速率较小；②吸附层的钛酸丁酯水解反应分成三个阶段，后两个反应对温度都不敏感且敏感性也不同；③扩散速率对温度的敏感性最小。 论文最后总结论文工作的同时，提出了论文没有解决的问题，为以后吸附相反应技术更进一步的研究工作明确了方向。更多还原

【Abstract】 In-situ preparation of TiO2 nanoparticles on nano SiO2 in water-ethanol binary mixtures was studied in this dissertation. First, the research and application of nanocompsites and nano TiO2 were reviewed and the author introduced the preparation methods of nanocomposites in response to the dissertation. The author generalized the principles, characteristics and applications of traditional methods. And several kinds of preparation methods of nanocompsites via nanophase reactor （Reverse Microemulsion, Multipores Material and Layer Silicate） were represented detailed. Their principles, characteristics and applications were introduced, the advantage and disadvantage of this method were also generalized contrasted with traditional methods.A new preparation method of nanocompsites via nanophase reactor, called adsorption phase reactor technology, was presented. The principle and characteristic of this technology was represented combined with literatures. The literatures were generalized and the researches at present were illustrated with examples. Then the aspect which was not discussed deeply or not involved was also summarized. And on base of it the investigated orientation of this dissertation was presented.The author designed a series of experiment against the new system by the research on the literatures. Solvent replacement experiment provided direct evidence that there was water-rich adsorption layer and the reaction took place in the layer. The changes of the water in adsorption system were determined by KF-1 water microdetector and from these data the volume of the adsorption layer on SiO2 was calculated. By the blank experiment, the change of SiO2 after the experiment was found. TEM, XRD and electronic energy spectrum indicated uniform TiO2 particles laid over surface of SiO2. For discussing mechanics of the process in adsorption phase reactor technology, the author designed temperature, concentration and reaction time experiments. Then the adsorption and reaction mechanics were gained with kinds of analytical methods. Themechanics of adsorption had four characteristics: （1）The distribution of adsorption layer was very abroad; （2）The adsorption layer and the change of adsorption layer were non-uniform; （3）The influence of temperature on adsorption layer was very sensitive; （4）The change of adsorption layer could affect final pattern of TiO₂ nanoparticles. The hydrolysis reaction of tetrabutyl titanate in adsorption was special because the reactor was nanophase, the mechanics of hydrolysis reaction had three characteristics: （1）The hydrolysis reaction rate of tetrabutyl titanate was small; （2） The hydrolysis reaction in adsorption layer had three process, the influence of temperature on the last two process was small and different; （3） The diffusion rate was the most insensitive to temperature.At last, the work in dissertation was generalized and the problems which were unsolved in paper were represented base of this. The orientation of research in future was pointed out.更多还原