The Preparation Of Ag/tio₂ Nanoparticles And It's Application In Antibacterial Plastics

Antibacterial plastic is a new kind of functional plastic. It is due to be filled with antibacterial agents that the material has the antibacterial activity. Because the antibacterial capacity of antibacterial plastic is long,steady,economical and convenient , it is widely used in medical appliances, chemical building materials, catering equipment, household appliances, telephones, telecommunications and plastic packaging materials of high health requirements, etc. Thus, it has a very broad market prospects. Considering the above reasons, our research focused on"preparation of TiO₂/Ag nanoparticles and its application on antibacterial plastics",and the thesis consists of the following contents:1.Silver nanoparticles were synthesized in water-in-oil micro emulsion using silver nitrate solubilized in the water core of a microemulsion as source of silver ions , ascorbic acid solubilized in the water core of another one as reducing agent , isooctane as the continuous phase , and sodium bis (2-ethylhexyl) sulfosuccinate as the surfactant. The influence of AgNO₃ concentration, ascorbic acid concentration and the molar ratios of water to surfactant (W) in microemulsionon on the silver nanoparticles have been investigated by TEM, UV-Vis spectra and Zetasizer Nano. As a result ,the silver nanoparticles possessed good dispersivity, and their diameters were about 10 nm when the concentration of AgNO₃ was 0.2 mol / L, the concentration of ascorbic acid was 0.2 mol / L and the water core radius (W) was 10. The antibacterial property of the silver nanoparticles indicated the E.coli was completely killed when the concentration of the silver nanoparticles was 10μg/mL.2. TiO₂/Ag colloidal were synthesized in water-in-oil microemulsion use using silver nitrate and TiO₂ solubilized in the water core of a microemulsion as precursor, ascorbic acid solubilized in the water core of another one as reducing agent, isooctane as the continuous phase, and sodium bis (2-ethylhexyl) sulfosuccinate as the surfactant. 1)TiO₂/Ag colloidal what was prepared at room temperature have good dispersion,and the average diameter of Ag was 20 nm. 2) The antibacterial activity of TiO₂ can be greatly improved by adding nano-silver, the TiO₂/Ag antibacterial material which is made by 3% Ag-TiO₂ achieve the optimal antibacterial performance. 3) The antibacterial activity of TiO₂/Ag can be influenced by the size of TiO₂ particles, and TiO₂/Ag antibacterial material which was made by smaller size of TiO₂ particles has better antibacterial properties. 4) TiO₂/Ag antibacterial material has good anti-bacterial persistence. 3. Antibacterial PP plastic were prepared by using TiO₂/Agantibacterial material. After surface modification by silane coupling agent, TiO₂/Ag antibacterial powder which were uniformly distributed in the PP concentrate is well comparable with PP plastic. The results showed that,the antibacterial PP concentrate have excellent and long-acting antibacterial activity,also the antibacterial rates of PP concentrate were all above 92% against Escherichia. Coli and StaPhylococcus aureus. Compared with normal PP plastic, the tensile strength, notched impact strength and flexural strength of antibacterial PP plastic are little effected.