Morphology Effect Of Mesoporous Silica On The Loading And Delivery Of Avermectin

Pesticide is one of the factors which play a leading role in agricultural development. The decomposition and erosion of the pesticide ingredients in a large field is the main problems in the traditional pesticide application method, it not only led to the loss of pesticides, but also bring the deterioration of the environment at the same time. Pesticide control release technology provides technical support for solving these problems. Pesticide carrier is the key to controlled release of the pesticide. The surface area and pore volume of mesoporous silica are huge, which make it as a kind of good drug carrier. Based on mesoporous silica as the carrier, this paper is to research the morphology effect of mesoporous silica on the load and delivery of avermectin from the channel of the spatial structure, pore diameter, specific surface and pore volume.1. The mesoporous silica of different types and pore size was synthesized. Wo synthesized 11 kinds of mesoporous silica and research the adsorption behavior on the abvermectin. The aperture, entrance, and specific surface of mesoporous silica was determined by the nitrogen adsorption test. Detect the concentration of abamectin through HPLC, loadings are obtained through the difference method The consequence exhibit that, the loadings of the 2D open-framework structure of mesoporous silica is higher than the 3D channel structure of silica. Loadings of 2D open-framework structure of mesoporous silica is 80 mg/g-160 mg/g, Loadings of 3D open-framework structure of silica is 33 mg/g～77 mg/g. Pore size, specific surface and the entrance is the determinant of load. For the 2D channel, the larger the aperture, the larger the drug load; For 3D channel, the larger the surface and entrance, the larger the drug load.2. Research the release of the avermectin which was absorbed into mesoporous silica in the ethanol aqueous solution of 30%. Detect the concentration of abamectin through HPLC. The experimental results show that the four kinds of silica are possible to control the release of the avermectin as a carrier, The time sustained release is about 14 d. When release quantity is 50% The released time of SB A-15 is 91h, SBA-16 is 126h, MCM-41 is 90h,MCM-48is 113h.3. Fitted the avermectin release curve through the first order kinetics and the Higuchi model, identified that the release curve of the four kinds of mesoporous silica in line with the Higuchi model, The consequence exhibit that the release mechanism belongs to the diffusion.4. Through analyzing the results of the load and release, summarized the mesoporous silica topology effect on the controlled release of abamectin from the channel of the spatial structure, pore diameter, specific surface and pore volume. The consequence exhibit that the MCM-41 and SBA-15 are more suitable as a controlled release carrier of abamectin...