Synthesis, characterization and antibacterial assessment of high surface area mesoporous silica sphere and its metal oxide-decorated nanocomposites

• Main Authors: Yong-Xuan Hou, 侯詠軒
• Other Authors: Dong-Hau Kuo
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/5bdqc9

碩士 === 國立臺灣科技大學 === 材料科學與工程系 === 104 === In this research, mesoporous silica spheres with uniform size were successfully prepare by sol-gel method. The system consists of cetyltrimethylammonium bromide (CTAB) surfactant as a main template, tetraethyl orthosilicate (TEOS) as the silicon precursor, and different kinds of polymers as the second/third polymer in aqueous-phase or oil-in-water phase to synthesis mesoporous silica sphere. By using potassium hexacyanoferrate as ethching agent, mesoporous silica spheres were etched to extend the pore size. By simply changing the amount of second/third polymers in the system, mesoporous silica spheres had the diameter of 290 ~ 613 nm, pore size of 1.86 ~ 4.10 nm, total pore volume of 0.572 – 1.02 cm^3/g, and surface area of 865 ~1286 m^2/g. The potassium hexacyanoferrate was used to etch mesoporous silica sphere. After etching, original pore sizes of 1.86 nm and 3.82 nm were extended to 3.08 nm and 4.60 nm, respectively and the silica sphere kept its shape. When reaction temperature was increased from room temperature to 75 ℃, mesoporous silica sphere diameter about 155 ± 22 nm and remained spherical. However, the average pore size extended from 3.82 to 8.62 nm, total pore volume increased from 1.01 to 2.2 cm^3/g, and specific surface area up to 1021 m^2/g. In addition, four kinds of metal oxide semiconductor nanoparticles such as silver(I) oxide、copper(I) oxide、nickel(II) oxide, and cerium(Ⅳ) oxide were uniformly deposited on mesoporous silica spheres with high specific surface area through chemical synthesis method for the purpose of antibacterial application. We used the metal oxide/silica composite spheres to test antibacterial effect. The chosen strains were gram-positive type bacteria - Staphylococcus aureus (S.aureus). The initial bacterial concentration of 1 × 10^8 CFU/mL was prepared for antibacterial test in a dark room and in the 20-watt LED light condition. The data showed that both silver(I) oxide/silica and copper(I) oxide/silica composite spheres had performed the excellent antibacterial activity to completely sterilize bacteria in one hour no matter in the dark or under the 20 W-LED illumination. Owing to their large and accessible pores and high surface area, the mesoporous silica sphere exhibited excellent performance in adsorption of methylene blue dye with a maximum adsorption capacity of 50.25 mg/g.