Synthesis And Characterization Of Mesoporous Materials And Organic-inorganic Composite Silica Microspheres

Nowadays microsphere and mesoporous materials are the hot-point of the research of material preparation. As the fast improvement of nano-material science, numerous new nano-material is synthesized and used in modern industry greatly. Microsphere and mesoporous, as the important part of nano-materials, are also receives more and more attention. In this paper, a new synthesis way is used to prepare the organic-inorganic composite microsphere and various mesoporous materials are synthesized by template method. The materials were characterized by BET, TEM, FTIR and DTA.The composite silica microsphere was obtained through the polymerization of urea and formaldehyde occurred in the silica sol that prepared from the hydrolyzation of tetraethyl orthosilicate. Through the test, it is found that the micro-structure of the microsphere can be changed by varies the molar ratio of the reactant and react condition. The microsphere synthesized as the molar ratio of formaldehyde to urea is two has a core-shell structure in it's micro-structure, and one of the molar ratio of formaldehyde to urea is one has a network structure. And in the latter condition, the micro-structure of the microsphere is changed from the network structure to core-shell structure as the proportion of formaldehyde and urea in reactant decrease simultaneously. According the characterization the synthesize mechanism is put forward to.A simple one-step procedure is described for the synthesis of mesoporous monolith and composite powder, in which hydrolyzation of tetraethyl orthosilicate and polymerization of urea and glyoxal occurred at the same time. The experiment result show that the white powder only product as the molar ratio of glyoxal to urea is below one. When the molar ratio of glyoxal to urea is above one, the porous and surface areas adjustment of the mesoporous materials can be achieved by varies the molar ratio of the reactant. According the characterization the synthesize mechanism of the mesoporous materials is discussed.