International Advanced Research Centre for Powder Metallurgy and New Materials, Balapur P.O., Hyderabad 500 005, India.
J Colloid Interface Sci. 2011 Dec 1;364(1):24-30. doi: 10.1016/j.jcis.2011.07.087. Epub 2011 Aug 12.
Synthesis of bi-functional silica particles by a simple wet chemical method is described where the mixture of ultra fine nanoparticles (1-3 nm) of titania and silver were attached on the silica particle surface in a controlled way to form a core-shell structure. The silica surface showed efficient bi-functional activity of photo-catalytically self cleaning and antibacterial activity due to nanotitania and nanosilver mutually benefiting each other's function. The optimum silver concentration was found where extremely small silver nanoparticles are formed and the total composite particle remains white in color. This is an important property in view of certain applications such as antibacterial textiles where the original fabric color has to be retained even after applying the nanosilver on it. The particles were characterized at each step of the synthesis by X-ray photoelectron spectroscopy, UV-visible spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and electron energy loss spectroscopy. Bi-functional silica particles showed accelerated photocatalytic degradation of methylene blue as well as enhanced antibacterial property when tested as such particles and textiles coated with these bi-functional silica particles even at lower silver concentration.
采用简单的湿化学方法合成双功能二氧化硅粒子，其中将超细微纳米粒子（1-3nm）的二氧化钛和银混合物以受控的方式附着在二氧化硅粒子表面上，形成核壳结构。由于纳米二氧化钛和纳米银相互促进彼此的功能，因此二氧化硅表面表现出高效的光催化自清洁和抗菌活性的双功能活性。发现最佳的银浓度是形成极细的银纳米粒子并且复合颗粒的总复合颗粒保持白色的地方。这是一个重要的特性，考虑到某些应用，如抗菌纺织品，即使在其上施加纳米银，原始织物的颜色也必须保持不变。通过 X 射线光电子能谱、紫外可见光谱、X 射线衍射、扫描电子显微镜、透射电子显微镜和电子能量损失光谱对合成过程中的每一步进行了表征。双功能二氧化硅粒子在测试时显示出加速的亚甲基蓝光催化降解以及增强的抗菌性能，即使在较低的银浓度下，作为此类粒子和涂覆有这些双功能二氧化硅粒子的纺织品也是如此。
