Preparation Of Mesoporous Silica And Its Limiting Effect

Mesoporous materials have been research hotspot in the fields of catalysis,adsorption,separation,life sciences and chemical sensing.The kind of hollow mesoporous silica material has not only the characteristics of traditional mesoporous silica material,but also has a large cavity structure,the kind of hollow structure will have a "cage effect".The method and conditions for the rapid and inexpensive preparation of hollow mesoporous microspheres is a serious challenge that researchers face.In this research,the method and conditions for the rapid and inexpensive preparation of hollow mesoporous microspheres are explored.Then,the core structure of carbon quantum dots and hollow mesoporous microspheres is prepared by mesoporous effect of mesoporous materials.Materials made a series of studies and we got the following research.1.Using the dual template method in the ethanol system through the PAA and P123 two supramolecular interactions to form a hollow mesoporous template is a better solution to the P123 under alkaline conditions and silicon species charge does not match can not be very good as a mesoporous template problem.The results show that the mesoporous microspheres obtained from 0.7gPAA/0.7gP 123 have the best dispersibility and morphology with a BET specific surface area of 345.9 m2/g.2.The template P123 and CTAB are first successf:ully prepared as CQDs,where the quantum yield of CQDs obtained in P123 is 16.5%without surface passivation treatment.Then,three kinds of organic precursors of 2-methylimidazole,citric acid and glucose are transformed into CQDs in MCM-41 and SBA-15 mesoporous molecular sieve channels by impregnation method.It is proved that this method The fluorescence quantum yield of the prepared CQDs is mainly related to the precursors,and the quantum yield of CQDs prepared by using 2-methylimidazole as precursors in the absence of surface passivation can reach 16.9%and 16.3%.3.A general synthetic method is proposed to prepare composite nanomaterials based on the silica-core core-shell structure,that is,the hollow mesoporous microspheres are prepared by the cavitation of the hollow mesoporous microspheres core-shell structure nanomaterials.A suitable molar content of the precursors of Pd@SiO2 and ZnO@SiO2 core-shell structures is established using this cavity-limited method.