纳米TiO_2/SiO_2复合食品抗菌材料

以水玻璃和Ti(SO4) 2 为原料 ,制备出了多孔的纳米TiO2 /SiO2 复合粒子 ,在后处理过程中 ,利用无机包覆剂溶解度随温度的变化 ,在复合粒子表面包覆了一层无机结晶膜 ,经热处理除去包覆剂后 ,得到了以单分散纳米复合粒子组成的复合微粉。对复合微粉进行比表面和孔容测试 ,并运用XRD和TEM进行了表征 ,发现TiO2 以 12 .6nm的纳米晶粒的形式被多孔的SiO2 包覆 ,所形成的复合粒子则约为 2 0nm。为了了解复合微粒的灭菌效果 ,运用纳米TiO2 和复合粉末对 4种保健食品进行对照灭菌实验 ,两个月以后 ,测得含复合微粒的样品中的菌落总数为 5 0～12 0个 /g ,是相应保健食品企业标准许可菌落数的 0 .2 5 %～ 0 .7% ,为相应空白样和纳米TiO2 粉样品菌落数的 0 .5 2 %～ 0 .97%和 3 3 .3 %～ 83 .3 %。

Nanometer TiO_2/SiO_2 Composite Antibacterial Materials for Foodstuffs

Porous nanometer TiO 2/SiO 2 composite particles are prepared with Ti(SO 4) 2 and water glass as raw materials.During the process of washing and drying,inorganic surface modifier (NS-1) was employed to form inorganic film on nanometer composite particles,taking advantage of the solubility change with temperature of the inorganic modifier.Naturally,monodisperse composite powder was obtained after the decomposition of inorganic modifier by heat treatment.By means of specific surface area and pore volume determinations,XRD and TEM,characteristics of the composite particles were investigated.It was indicated that TiO 2 in the form of 12.6 nm crystal particles is coated with porous SiO 2 film,and the size of composite particles is about 20 nm.In order to learn the sterilization effect of the TiO 2/SiO 2 composite nanometer powder,nanometer TiO 2 and the composite powder were applied to several kind of health food.After two months,the total numbers of bacteria in the samples containing composite powder were only 50 to 120 units per gram,only 0.25%-0.7% of the enterprise standards of corresponding health food,0.52%-0.97% of the bacteria numbers of blank samples and 33.3%-83.3% of those of samples containing pure nanometer TiO 2 powder.