Preparation And Application Of Mesoporous Silica Microspheres Based On The Partitioned Cooperative Self-Assembly Process

Due to the integration of high specific surface area,pore volume and regular pore structure,mesoporous silica microspheres have found a wide range of applications in biomedicine,adsorption and separation,catalysis and soon.At present,the adjustment methods of pore structure and morphology mainly include changing the types of template or silicon source,adding different types of organic/inorganic additives,adjusting the reaction temperature,hydrothermal treatment temperature and pH value of reaction medium and so on.In this paper,two kinds of organic additive/silicon source combination of ethanol/sodium silicate and X/tetraethoxysilane were successfully used to prepare SBA-15-type mesoporous silica microspheres and KIT-6-type mesoporous silica microspheres by partitioned cooperative self-assembly process in the acidified P123 surfactant solution,respectively.Moreover,SBA-15-type mesoporous silica microspheres were used as carrier of class II poorly soluble drugs-indomethacin and its release performance was studied in simulating intestinal fluid.The detailed results shown below:(1)In the first part,SBA-15-type mesoporous silica microspheres were prepared successfully by using ethanol as cosurfactant and sodium silicate as precursor with PCSA process and applied to drug carrier.The main results are:Synthetic parameters,such as the amounts of ethanol,partitioned ratios and times,reaction temperature and hydrothermal temperature and so on,were found to have great influence on resultant porous structures and morphology.The typical S6-6h-4@36-13.5H-5Eth-140T shows the best spherical morphology and hierarchical mesoporous structure.The pore size and pore volume reach 11.3 nm and 0.78 cm3·g-1 for the first mode pore,and 27.7nm and 0.78 cm3·g-1 for the second mode pore,respectively.In drug loading and release experiments,it was found that IMC-P100 has the highest drug loading for large specific surface area,while IMC-P140 has a good mesoporous structure to achieve rapid release with a release rate of 92.9%at 90 min.(2)In the second part,KIT-6-type mesoporous silica microspheres with three-dimensional cubic structure were prepared successfully by PCSA process with the first time using X as cosurfactant and TEOS as precursor.The main results are:KIT-6-type mesoporous silica microspheres can be successfully prepared by adjusting reaction parameter(the amounts of X and HCl,reaction temperature,partitioned conditions,hydrothermal temperature)within a proper range.The typical sample shows the three-dimensional cubic structure(Ia3d)with unit cell constant reached 23.76 nm.The total pore volume,pore size and the specific surface area are 1.08 cm3·g-1,10.3 nm and 747m2·g-1,respectively.