The Surface Modification Of Porous Silicon Carbide Ceramics And Fume Filtration Performance Research

In recent years, haze become the focus of attention, while the core material of haze are ash, soot and other particles, that deposited in the air.and easily inhaled to harm the lung. The exhaust of diesel vehicles produced carbon particles, it is one of the main causes of haze. Diesel exhaust treatment currently rely on wall-flow filter traps particles, because of the complex diesel operating conditions, high temperature exhaust emissions, thus requiring filtering wall with a high temperature, oxidation, corrosion, and other fine features, and porous SiC unique because of its excellent performance has become a popular choice for filter material and become a hot topic in the field of materials science. Its wide variety of sources of raw materials, low cost, conventional preparation methods varied.In this paper, the porous structure of natural wood, with beech as a template using a unique liquid silicone impregnation method for preparing biomorphic porous silicon carbide, the resulting product performance is excellent, with good pore structure, has great advantages in terms of energy conservation, but there are still some limitations in the filtration of ultrafine particles, when biomorphic silicon carbide filter nanoscale particles, high porosity can effectively capture small particles, but also causing the permeability decreases, engine exhaust back pressure reduce its life. So prepare good permeability and high collection efficiency of porous silicon carbide will be the focus of our problem.Therefore,this study simulate human respiratory system, analogy bronchial cilia structure surface, Molten Salts reactions method and Sol-gel method are used for the surface modification of porous SiC ceramics, chemical reaction mechanism which lead to mullite and aluminum borate whiskers growth has been studied respectively. characterized by a variety of means to find good growth in silicon carbide whisker morphology of the substrate.By building diesel combustion flue gas filter performance test platform to test the filtering properties of the modified materials, keep the air flow through the constant temperature control of small amplitude variations were tested blank particulate concentration of diesel particulate matter concentration in the combustion flue gas, flue gas after carbonization particulate matter concentration of silicon ceramic filter, through the particle concentration SiC / mullite, will control the experimental data were analyzed to obtain structure-activity relationship between filtration performance and microstructure of silicon carbide diesel fumes through modified / mullite material filtered, particle concentration values measured significantly lower, indicating trapping particulate filter performance is stronger than before the modification, but also for the modified porous ceramic structure of mullite whiskers prepared on the modified late experiments made boot.