Study On Surface Modification And Property Of ZnS Nanoparticles

ZnS is a wide-bandâ…¡-â…¥semiconductor material, the band gap of 3.68 eV at room temperature. When ZnS nano- particles'size is less than their Boer radius of the exciton (5 nm), it will show a significant quantum size effect, the absorption edge will be peaks and emission peak value move to blue at the same time. ZnS nanoparticles can be obtained with different optical properties through controlling particle size distribution. Therefore, research of ZnS nano-materials is of great significance and applied prospects. However, small particle size, large surface energy and other factors of ZnS nanoparticles can be easily aroused great aggregation, on the other hand, water- solubility of ZnS is worse, which is difficultly used in medical field. To solve the aggregation and water-solubility issues, surface modification will be applied. Nanoparticles surface modification will deal with the surface of particles by physical and chemical method so as to change the physical and chemical nature, such as atomic layer surface structure, functional group, the surface hydrophobicity, chemical adsorption and reaction properties, which is a science and technology in order to meet with needs of the nano-powder processing and application.In this paper, oleic acid / sodium dodecyl sulfate, stearic acid / sodium dodecyl sulfate are choosed as a composite surfactant modified ZnS nanoparticles in order to improve poor water-solubility and the compatibility of biological macromolecules. Hydrothermal method is used to prepare ZnS nanoparticles. Results show that ZnS nanoparticles are small, uniform division, good luminescent.The chief contents and results of this paper are listed below:1. Oleic acid / sodium dodecyl sulfate as surfactant modified the surface of ZnS nanoparticles. It is found ZnS nanoparticles prepared by hydrothermal method have small size, uniform division and good performance of the luminescent. Properties are charactered by XRD, TEM, PL and UV-Vis. The research results show that the properties of luminescence were affected in the condition of the techniques, such as dosages of oleic acid and sodium dodecyl sulfate, temperature, time and pH. The optimum reaction condition is discussed by using orthogonal experiment, luminescent intensity of performance as indicators. And under the optimum reaction condition of the ZnS nanoparticles have a good water-solubility by the second surface modification with SiO2.2. Stearic acid / sodium dodecyl sulfate as surfactant modified the surface of ZnS nanoparticles, which can get the product being nanoparticles, particle uniform distribution, and the good performance of the luminescent, inferred from XRD, TEM, UV-Vis and PL. The research results show that the properties of luminescence are affected in the condition of the techniques, such as dosages of stearic acid and sodium dodecyl sulfate, temperature, time and pH. Orthogonal experiment is use to get the optimum reaction condition and the temperature has the greatest impact among the factors.