Synthesis Of Periodic Mesoporous Organosilicas And Their Optical Properties

The hybrid organic-inorganic mesoporous materials with organic group in the structure process both the features of inorganic mesoporous materials and the properties in regulating the flexibility and hydrophilic/hydrophobic of the materials. As is known to all, inorganic mesoporous materials possess regular pore structure, extremely high specific surface area and large pore volume. The hybrid organic-inorganic mesoporous materials synthesized through the Grafting method or Co-Condensation method have two disadvantages that the pore is blocked or the structure of the materials are damaged. We can synthesize the hybrid organic-inorganic mesoporous materials without those defects by the Co-Condensation method of periodic mesoporous organosilicas with bridgeing groups (PMOs). The organic group of these materials locates in the framework and distributes uniformly, so it is no influence for the structure of the mesoporous materials. With these better property PMOs can apply in catalytic industry, functional materials, medicinal chemistry, environment protection and and many other application areas.In this paper, we prepare a series of inorganic mesoporous materials, luminescent PMOs, and energytransfer PMOs with alkylviologen and short chains cationic trimeric surfactant C10-2-10-2-10as the structure-directing agent. The samples were characterized by small angle X-ray diffraction. N2adsorption/desorption analysis, high-resolution transmission electron microscopy, fluorescence spectrum and the uv/visible diffuse. Through the analysis of data, we can get the following conclusion:(1) Using short chains cationic trimeric surfactant C10-2-10-2-10as the structure-directing agent, we prepare the new PMOs. And the ordering of pore structure of the PMOs is becoming worse with the increase of the amount of the precursor of organosilicon. As the content of organosilicon is40%, the sample has the ordered structure in the pore as well as i the pore wall.(2) Using mixed surfactants (C10-2-10-2-10and bioctylviologen) as the template, we synthetize the ordered inorganic mesoporous. With increasing the amount of the bioctylviologen, the ordering of the material becomes lower. The diameter of the serial of the samples is in the range of2.4-2.8nm.(3) The functional PMOs is successfully synthesized with mixed surfactant (C10-2-10-2-10and bioctylviologen) as the template. The obtained materials possessed2D-hexagonal periodic structure. The charge transfer complex is composed of the bioctylviologen in the mesochannel and the naphthalene in the framework. In this system, the energy transfer from the donor (naphthalene) to the acceptor (bioctylviologen). But energy transfer efficiency is lower. One of the reasons is the low content of the Organic silicon groups in the framework.