Preparation And Research On The Scale-up Technology Of Ag-embedded Nano-TiO₂ Antibacterial Agent

In this paper, the preparation of Ag-embedded nano-TiO₂ antibacterial agent was researched and the status and development of antibacterial materials at home and abroad was introduced. We have developed a practicable process which establishes a good foundation for the future industrial production.The preparation of Ag-embedded nano-TiO₂ antibacterial agent has a systematic improvement in the basis of homogeneous precipitation. We determined the surfactant H-307 as the dispersing agent in experiments through comparing with gelatin. On this basis, the amplification effect on the product particle was researched by the scale-up experiment. We have determined the technology process, process parameters and equipments through the scale up experiment.The titanium solution was prepared by low-temperature acid dissolved in H₂TiO₃ after leaching and filtering, and the concentration was 110±15g/L; the introduction of Ag⁺ was chlorine silver colloid, surfactant H-307 for dispersants, hydrolysis temperature was 95±3℃, heating time was 30 minutes, hydrolysis time was 30 minutes. The time of phosphate precipitation reaction was 20 minutes; the sediments were washed by water and alcohol, calcinated after dried. the calcination conditions were 800±10℃for 4h. The final product was dried after surface treatment by adding dispersant.The product testing results were as follows: The product was basically spherical particles and narrow particle size distribution with an average diameter of 500nm by the laser particle size analyzer. The antibacterial tests showed that the powder had 98.0% antibacterial effect on E.coli, S.aures and C.albicans within 30 minutes with 100ppm (powder concentration) without illumination. The weatherable tests showed that the powder was no serious photochromic phenomenon and antibacterial properties remained at more than 95% after irradiated by sunlight for ten days.