Research On Preparation Method Of Porous Silica Packing Based On Ionic Liquid With Long Chain Alkyl As Porogen

In recent years,due to the inherent shortcomings of fully porous packing and higher requirements for efficient and rapid separation,surface porous SiO₂microsphere packing have been widely concerned by researchers because of their advantages in efficiently separating complex samples under low back pressure.Exploring and improving its preparation method has also become a research hotspot.In order to further optimize and develop the preparation technology of surface porous SiO₂ microsphere packing,this research systematic carried out the stable preparation of monodisperse non-porous SiO₂core and the construction method of the surface porous layer,and innovatively used imidazole ionic liquid as porogens The introduction of the agent into the construction of the porous structure provides a new choice for the preparation and structure control of the surface porous SiO₂microsphere packing.The main research contents and results are as follows:1.Research on the preparation process of non-porous SiO₂ microspheres.Obtaining uniform and monodispersed non-porous SiO₂ microspheres as the core is crucial to the final morphology of the surface porous SiO₂microspheres.Based on the"seed growth method",with the aid of modern precision instruments,the research on the stable preparation process of monodisperse non-porous SiO₂ microspheres was carried out;The study focused on the influence of water,salt dosage and silicon source addition rate on the spheric morphology and particle size of SiO₂ microspheres;On this basis,through process optimization,the stable and controllable preparation of monodisperse non-porous SiO₂ in the particle size range of 1.2～2.5μm can be achieved,which provides a basis for the preparation of porous SiO₂ packing with uniform morphology.The growth model of non-porous SiO₂ microspheres in the semi-batch preparation method is verified,which provides more basis for the refined preparation of the material.2.Research on the preparation method of surface porous SiO2 microspheres.Based on the unique structural advantages of surface porous microspheres,it has great potential in the development of high-performance chromatography packing materials.The non-porous SiO₂ microspheres prepared in the previous period were used as the core to carry out the research on the preparation method of surface porous SiO₂microspheres;and in view of the single type of porogen,an attempt was made to increase the types of porogens by using imidazole ionic liquids as porogens,and investigated the pretreatment method.The influence of the method of adding silicon source,the amount of catalyst,the oil phase reagent,the cosolvent and other factors on the morphology of the shell layer,and finally the uniform surface porous SiO₂microspheres were obtained.Compared with materials prepared by traditional porogen（CTAB）,this material has a larger pore size（18 nm）and a larger shell thickness（100 nm）in a single preparation,which is more valuable for industrial production;The introduction of imidazole ionic liquids provides a new idea for the regulation of pore structure in this method,and also provides a reference for the development of new types of porogens.3.Research on the preparation method of fully porous SiO₂ nanospheres.Based on the study of the concomitant products in the preparation of surface porous SiO₂microspheres,a new method for the preparation of fully porous SiO₂ nanospheres was established.And further investigated the influence of the amount of silicon source,the ratio of oil and water,and different porogens on the morphology of the microspheres.Finally,the controllable preparation of monodisperse fully porous SiO₂ microspheres with a particle size range of 75～350 nm is realized.And it expands the scope of application for imidazole ionic liquids.In this study,a porous silica-based packing was successfully prepared using imidazole ionic liquids as porogens.This packing is expected to play an important role in the separation and analysis of complex samples,and is helpful to promote the research of new chromatographic packings.