【作者】 许天翼；

【导师】 雷绍民；

【作者基本信息】 武汉理工大学 ， 矿物加工工程， 2008， 硕士

【摘要】 制备稳定、高效的负载型TiO₂光催化剂是近年来TiO₂光催化氧化技术研究的热点之一。本文以具有层状结构的蒙脱石为基体，利用蒙脱石很强的离子交换能力及层状结构特性，在其层间隙和表面负载TiO₂纳米晶体，在较低温度下制备具有较高光催化活性的二氧化钛／蒙脱石复合光催化剂。分别从TiO₂／蒙脱石复合环境矿物材料的制备、抗菌性能及其在涂料中的初步应用三个方面进行了研究。以期为TiO₂光催化型抗菌剂在乳胶涂料中的实际应用提供理论依据。1．纳米二氧化钛／蒙脱石复合体系的制备和表征本研究采用Sol-Gel法，选择Ti（OC₄H₉）₄-C₂H₅OH-HNO₃（1mol／L）-CH₃COOH体系以5：25：12：0．4的体积比制备钛溶胶，研究了理论负载量、固定化温度、干燥温度、焙烧温度等因素对复合材料光催化性能的影响，并得到了最优制备工艺条件：15 mmol／g的负载量，3％的蒙脱石矿浆浓度，25℃的固定化温度，70℃的干燥温度下制备二氧化钛／蒙脱石复合材料。该复合材料具有较高的光催化活性，当催化剂用量为2g／L时，光催化降解偶氮染料1h的脱色率为93．40％。采用XRD、FTIR和TEM技术从晶体结构、分子结构和表面形貌方面对复合体系进行表征分析。结果表明，复合体系中TiO₂以锐钛矿-金红石混晶相的形式均匀覆盖于蒙脱石表面，其平均晶粒直径为6．98 nm；其中锐钛矿含量占92．34％，金红石含量占7．65％；TiO₂进入了蒙脱石层间域。2．纳米二氧化钛／蒙脱石复合体系的抗菌性能研究以大肠杆菌和金黄色葡萄球菌作为不同革兰氏类型的细菌为代表，考察TiO₂／蒙脱石复合材料的抗菌性能。结果表明，TiO₂／蒙脱石复合光催化剂对大肠杆菌和金黄色葡萄球菌具有良好的杀菌性能，光照75分钟后，杀菌率都可以达到99．9％。大肠杆菌比会黄色葡萄球菌对光催化作用表现出更高的敏感性。TiO₂／蒙脱石在光照结束后一段时间内仍具有一定的“抗菌余效”。TiO₂／蒙脱石复合光催化剂对大肠杆菌和金黄色葡萄球菌的最小抑菌浓度（MIC）分别为390．6mg／L和781．25mg/L，符合同本抗菌协会对无机抗菌剂的抗菌性能的规定。初步考查了TiO₂／蒙脱石复合光催化抗菌剂在乳胶涂料中的应用，并参照相关标准对其抗菌性能进行评价。当TiO₂／蒙脱石复合材料用量为0．5％时，涂膜整体对大肠杆菌和金黄色葡萄球菌的抗菌率分别为88．89％和76．67％。适当地增大抗菌剂的用量有利于提高其抗菌性能。更多还原

【Abstract】 Preparation of efficient and stable laden-titanium dioxide photocatalyst is one of the research focus of photocatalysis oxidation technology in recent years. High efficient catalytic activity TiO₂/montmorillonite composite photocatalyst was prepared by supporting nano-TiO₂ in the interlayer and on the surface at a lower temperature with montmorillonite as support which has strong ion exchange property and layered structure characteristic. Three aspects of preparation of TiO₂/montmorillonite environmental mineral materials, its antibacterial performance and preliminary application in dope were researched in order to provide theoretical basis for the application of TiO₂ photocatalysis antibacterial agent in latex coating.1. Preparation and characterization of nano-titanium dioxide/montmorillonite composite photocatalystTitanium sol was prepared with the precursor of Ti（OC₄H₉）₄, C₂H₅OH, HNO₃ （1mol/L） and CH₃COOH by using sol-gel technique. The volume ratio of these reactants was 5: 25: 12: 0.4. The effect of theoretical loading amount, immobilization temperature, drying temperature and calcination temperature on photocatalytic activity of the composite photocatalyst is studied. The optimum synthesis conditions to prepare TiO₂/montmorillonite composite photocatalyst were obtained from the experimental results as follows: the mass concentration of montmorillonite suspension was 3%, the ratio of Ti（IV） to montmorillonite was 15 mmol/g, the immobilization temperature is 25℃and the drying temperature is 70℃. This photocatalyst has high efficient photocatalytic activity. The rate of decoloration for azo dye of TiO₂/ montmorillonite composite photocatalyst can reach 93.40% after 1 hour of the reaction time when the concentration of photocatalyst is 2g/L.X-ray Diffraction（XRD）, Transmission Electron Microscopy（TEM） and Fourier Transform Infrared Spectrum （FTIR） technologies were adopted to characterize and analyse the crystal structure and molecular configurations and surface appearances of the composite system. The results showed that TiO₂ was existed as anatase and rutile mixed-crystal phase which was uniformly covered on the surface of the montmorillonite in the composite system with the average crystal size of 6.98 nm. The ratio of anatase in the TiO₂ is 92.34% and rutile is 7.65%. The TiO₂ has been inserted into the interlayer of montmorillonite.2. The antibacterial performance of nano-titanium dioxide/montmorillonite composite photocatalystEscherichia coli and Staphylococcus aureus were selected as the target of different Gram type of bacteria to investigate the antibacterial performance dioxide/montmorillonite composite system. The results showed that dioxide/montmorillonite composite photocatalyst has efficient antibacterial performance to both Escherichia coli and Staphylococcus aureus. The bactericidal rate can reach 99.9% after 1 hour in light. Escherichia coli has exhibited higher sensitivity than Staphylococcus aureus. The titanium dioxide/montmorillonite displays certain residual disinfection effect in a period of time after the end of the illumination. The minimum inhibitory concentration of the dioxide/montmorillonite composite photocatalyst to Escherichia coli and Staphylococcus aureus are 88.89% and 76.67% respectively which reached the requirement of the Society of Industrial technology for Antimicrobial Articles（SIAA） to antibacterial performance of inorganic antibacterial agent.The preliminary application of dioxide/montmorillonite composite photo-catalysis antibacterial agent in latex coating were researched. It’s antibacterial performance was evaluated by a relevant standard. The bactericidal rate of the coating film to Escherichia coli and Staphylococcus aureus can reach 88.89% and 76.67% respectively. The antibacterial performance of the coating film can be improved with the increase of the dosage of antibacterial agent.更多还原