【作者】 李明罡；

【导师】 王子忱；

【作者基本信息】 吉林大学 ， 物理化学， 2008， 博士

【摘要】 本论文是表面活性剂合成与无机纳米粉体合成修饰两个领域的相互结合的实例之一。在论文中根据纳米ZnO的性质选择磷酸酯作为修饰改性剂,有目的性的合成了多种修饰效果的磷酸酯产品,并结合纳米ZnO合成方法,采用不同方法有效的对纳米ZnO进行改性和修饰,提高纳米ZnO的性能。第一章为前言,介绍了纳米ZnO的结构、性质、应用和基本合成方法以及磷酸酯类表面活性剂的分类、性质、应用及发展前景,阐述了本论文主要的研究目的、意义及主要内容。第二章中,以ZnSO4和NaOH为原料,采用一步液相反应法,直接得到纳米ZnO产品,反应条件温和,时间短,不需要经过高温后处理过程,使纳米ZnO的原位修饰合成成为可能;第三章中,以PEG600磷酸酯合成为例,讨论了各反应条件对最终产物组成和性质的影响,介绍了磷酸酯产品组成的分析方法,合成了系列PEG磷酸酯产品;在第四章中,以第三章中的最佳磷酸化条件为依据,结合不同体系的具体情况,调整反应条件,合成了高单酯含量的高碳醇、甲基丙烯酸羟酯和芳烷基酚聚氧乙烯醚(农乳600)三大系列的磷酸酯产品,并分别对其进行分离提纯,得到高纯度的磷酸酯,为其对纳米ZnO的修饰奠定基础;在第五章中,以第二章中建立的液相直接合成法为基础,使用第四章中自行合成的磷酸酯为修饰剂,分别采用两种不同的方法,对纳米ZnO进行表面功能化修饰,得到了表面疏水型和表面带有可反应双键的两种功能化磷酸酯。本论文阐述了功能化纳米ZnO及其系列磷酸酯修饰剂的合成方法,考察了各因素对产品影响,为表面活性剂合成与粉体合成修饰两个领域的相互结合用提供了有利的依据。更多还原

【Abstract】 ZnO nanoparticles are important industrial materials and widely applied in paint, rubber, ceramic and glass areas. Furthermore, the synthesis way of ZnO nanoparticles, the selection of surface modifiers and the processing step for ZnO nanoparticles are necessary to be thought. Nowadays, the preparation of well dispersed ZnO nanoparticles and modified nano-materials is a new challenge to us. Searching the new energy-efficient method to make ZnO nanoparticles, finding the cost-effective surface modification, and using appropriate modifications to realize ZnO surface functionality are three ways of improving product quality, reducing product cost and enhancing product competitiveness. The selection and synthesis of surface modification is important to achieve orientation modification ability of ZnO nanoparticles. The combination of surfactant and inorganic powders is a way to synthesize new modifications and it will make us pay attention to the later decoration of product. According to this meaningful instruction, this paper developed the synthesis method of ZnO nanoparticles, designed a series of octadecyl dihydrogen phosphate surfactants especially for the modification of ZnO nanoparticles. After the application of these surfactants, the effective control of test and the introduction of new synthesis ways, we obtained ZnO nanoparticles with different functions.A new synthetic method is charged with ZnSO4 and NaOH solution reacted rapidly in a moderate condition. In this reaction, Zn2+ and OH- ions combine very soon and lots of nuclei are created. The nuclei are hard to grow bigger because the concentration of ions decreases too fast. Under a certain temperature and alkaline atmosphere, the nuclei will dehydrate rapidly into wurtzite ZnO nanoparticles. The diameters of ZnO particles are between 10 - 40 nm. Large amount of pore structures come into being during the fast reaction, with average diameters of 0.63 nm. Furthermore, every factor in the reaction will affect the property of the final products. The pH value is determined by the ratio of reactants and it is the key factor for the changing from precursor Zn(OH)2 to ZnO particles. The formation speed of nuclei is determined by reaction temperatures and it will decide the particle volume of the final products. Moreover, anions from Zinc source are important factors for the formation of nuclei and transition of crystal type. We establish a new synthesis method here and a series of reaction conditions are tested and discussed, which is of great use to synthesize ZnO particles modifying by octadecyl dihydrogen phosphate surfactant.Taking polyphosphoric acid as phosphate reagents, we design a series of high phosphoric monoester content reagents named serial PEG phosphate surfactants. PEG600 as a study object, we put PEG600 and polyphosphoric acid together to make phosphorylation reaction, and successfully get PEG600 phosphate. Furthermore, we improve potentiometric titration to test ester ratio. Low-molecular-weight PEG always contains some water and the reaction will be influenced by water, and the final products will be in the high phosphate content and the conversion of raw materials will decline. So we must do dehydration to Low-molecular-weight PEG before reaction. In the reaction of phosphorylation, time, temperatures, material ratios and hydrolysis time are all important to the final product yield. We take PEG600 best reaction conditions as the basis. PEG400, PEG1000, PEG2000, PEG6000 and PEG10000 react with polyphosphoric acid and a series of PEG phosphate surfactants are available, which are the basis of the application of PEG phosphate ester.The optimal reaction condition for PEG phosphorylation is considered as a standard. According to this, different reaction systems are adjusted in a certain level. At last, series of high-carbon-alcohol phosphate ester, methacrylic 2-hydroxyethyl phosphate ester and aryl-alkyl phenol polyoxyethylene of phosphate ester are obtained. All these reaction systems can get high ester ratio. In the preparation of high-carbon alcohol phosphate ester, we use n-hexane as a solvent to control system viscosity, and in the end of the reaction, we put H2O2 into the system to eliminate solution color. The final product has a good color and monoester content can reach more than 85%. We use ether as extraction solvent to get a higher purity carbon-alcohol phosphate. During the Synthesis of methacrylic 2-hydroxyethyl phosphate ester, in order to prevent the oxidation and polymerization of the double bond, nitrogen gas is applied. Hydroquinone is joined as inhibitor to prevent the polymerization of the double bond. Lower the reaction temperature in the end of reaction to protect ester bond, the step of pyrophosphate hydrolysis is cancelled. We use ethyl acetate as extraction agent to get purer hydroxyethyl methyl ester phosphate products. During the preparation series of aryl-alkyl phenol polyoxyethylene, the reactant is mixed completely to avoid a coloration of final product before reaction. After a simple adjustment of reaction condition , we get the suitable series of aryl-alkyl phenol polyoxyethylene phosphate eater. The dichloroethane is selected as the extraction to reach refined products. The synthesis and separation of these three series of products, makes a good foundation for the application of ZnO nano-particles.We used laboratory synthesized and purified series of high-carbon-alcohol phosphate ester and methacrylic 2-hydroxyethyl phosphate ester as modifiers, and made surface modification to the product based on the direct preparation of nanosized ZnO in aqua phase. Among them, hydrophobic nanosized ZnO products were prepared via in-situ modification technology using series of high-carbon-alcohol phosphate ester. The influence of the high-carbon-alcohol lengths, the modifier concentration and the modifying temperatures on the modified effect was discussed respectively.The in-situ modification synthesis at the presence of series of high-carbon-alcohol phosphate ester could achieve satisfactory effect, and did not affect other properties of nanosized ZnO products. When using series of methacrylic 2-hydroxyethyl phosphate ester, we applied disposal after synthesis, and obtained nanosized ZnO with surface double bond activated. Using IR analysis, we could see the activated double bond had been successfully introduced to the surface of the nanosized ZnO powder, which achieved a good modifying effect.This thesis is one of the examples of the compact combination of surface modifier synthesis and inorganic powder synthesis and modification, which shows the intrinsic link of the two fields, and introduces a new thought to the designing of the surface modifiers and the synthesis and modification of the inorganic nanomaterials, and has a guiding significance to promote the application and industrialization of the inorganic nanomaterials.更多还原