Modification Investigation And Application Of Hms In Reducing Harm Substance In Cigarette Smoke

Hexagonal mesoporous solid (HMS), which has the properties of adjustable regular pore canals, extremely high specific surface area and great thermal stability, has caused extensive concern in physical, chemical and materials industry. Such kind of materials have low density but high porosity, good permeability and selectivity of gas, and when the pore size is small enough, size effect and surface effect will be apprent. The mesoporous materials or mesoporous composite can be synthesized using the template or the technique of self-assembly. Nowadays, the research of their assembly mechanism and the methods of improving their performance so that they can be used in catalytic complex environment, drug or other fields has become the hottest research point in and out of the country.Sol-gel method is commonly used in the synthesis of HMS. By mixing the silicon source, surfactant and water, then treat the mixture with suitable temperature in a certain time, the solid precipitation can be gained. The final products are obtained after washing, drying, extraction or calcination of the precipitation.The paper is to optimise the traditional synthesis methods of HMS through orthogonal experiments. The mesoporous structure, morphology, pore size distribution, surface area and water thermal stability, which can be characterized by XRD, TEM, FT-IR, Raman, UV-Vis, XPS, TG, DSC and other modern analytical methods, are researched through the calcination temperature, organic solvents and other heteroatom's incorporation like La3+, Fe3+, Al3+ ions. Furthermore, the self-assembly mechanism of heteroatom's incorporating into mesoporous skeleton was deeply studied by then.To make the properties of nanoparticles fully played and create some special quality which does not belong to nanoparticles and mesoporous solid itself , the composite materials TiO2-HMS, which have the high specific surface area and consist of HMS and nanometer TiO2 particles coated with HMS, were synthesized by introducing highly dispersed nano-titanium sol into self-assembling system. Thus, the materials own both the HMS's quality and nanometer TiO2's special catalytic properties. Composites of WPr-HMS and WLa-HMS, which were made up of Pr and La phase nanowires incapsulated with HMS, were synthesized by introducting appropriate blending agent into the self-assembly system. The sintering temperature that may affect the properties, structure of the composites were studied. Also, the self-assembly mechanism of nano-linear complex coated with HMS was preliminary investigated. Yet, there is no relevant report about the synthesis and properties of this kind of composite in the relating literature.The mesoporous and composite synthesized were used as the additives packed into cigarettes'filter to remove the harmful substances in the cigarettes. Through detecting, it was found that nicotine, tar, carbon monoxide, low molecular weight aldehydes and ketones, and other harmful substances decreased significantly.