Preparation And Application Of Functionalized Silica Gel Filler

As a widely used inorganic material,silica gel is widely used in many fields such as biological science,food science,chemistry,and pharmaceuticals due to its low price,high reactivity,good chemical stability,and large pore size and specific surface area.Bonding different groups onto silica gel materials can provide them with different properties.The most common silica gel bonding groups include amines,C18 long chains,and amino imidazole ionic liquids.However,currently,there are problems such as uncontrollable bonding amounts,and poor batch repeatability.In this paper,the preparation processes of ethylenediamine-N-propyl bonded silica(PSA),octadecyl modified silica(C18),and aminoimidazole modified silica were optimized using amorphous silica and spherical porous silica as substrates.The batch repeatability was verified and amplified for validation.It has been applied to the removal of ginkgolic acid from ginkgo biloba extract,the improvement of column packing process,and the synthesis of ionic liquids,respectively.This paper mainly includes the following research content:1.The relationship between the amount of ethylenediamine-N-propylsilylation reagent and trimethylchlorosilane as two key parameters in the PSA preparation process and the PSA bonding amount was discussed to achieve the preparation process requirements of adjustable PSA ion exchange capacity.A pilot scale experiment was conducted on the optimized preparation process to characterize the preparation repeatability through ion exchange capacity,infrared spectroscopy,and elemental analysis results,ensuring batch stability of the preparation process.The prepared PSA filling component was isolated and purified onto a small column and applied to the removal of harmful substances ginkgolic acid from the extract of Ginkgo biloba leaves.The content of ginkgolic acid was quantitatively analyzed using high-performance liquid chromatography(HPLC)specified in the Chinese Pharmacopoeia.The removal efficiency of PSA with different ion exchange capacities for ginkgolic acid was investigated,and the application prospect of PSA in the removal of ginkgolic acid was evaluated.2.Discussed the relationship between the amount of octadecyltrichlorosilane and trimethylchlorosilane as two key parameters in the preparation process of C18 silica gel and the amount of C18 bonding,achieving the preparation process requirements of stable and controllable C18 silica gel,and conducted pilot scale experiments on the optimized preparation process.The repeatability of the preparation was characterized through infrared spectroscopy and elemental analysis results to ensure batch stability of the preparation process.And prepare 5 μm grade octadecyl modified silicon spheres were filled into 150 mm and 250 mm stainless steel liquid chromatography columns,respectively.The column installation process was improved,such as the THF/isopropanol ratio of the homogenate,pressure time,pressure holding time,column flushing time,and column pressure,to make the sample peak tailing factor close to 1 and the theoretical plate number reach a higher level.Develop a stable preparation process for aminoimidazole modified silica gel,and conduct pilot scale experiments to produce batches of aminoimidazole modified silica gel with high stability and controllable bonding amount.By improving the synthesis process of ionic liquids,the conversion efficiency of C5 and C7 ionic liquids has reached a higher level.