Synthesis And Research Of Functional ZnO Nanoparticles And Their Series Surface Modifier Of Phosphate

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.