Preparation Of Silica Chromatographic Materials Using Droplet Microfluidic Technologies

The stationary phase in a column is one of the most important parts of high performance liquid chromatography.In recent years,the researches about omics,such as proteomics and metabonomics,have put forward some higher requirements,which would need new technologies and methods to develop and produce chromatographic materials more efficiently.Moreover,some features of chromatographic packings are required,such as narrower size distributions,controllable hole structures and more complex functions for separating.Droplet microfluidics is an emerging field and it has been contributing to a huge scope of applications in the fields of bio(chemical)analysis and materials generation.With the advantages of the highly efficient mass-heat transfer,the high-throughput generation of mono-dispersive droplets and the efficient manipulations of single drop,droplet microfluidics has the ability to promote the development of preparation of chromatographic materials.In this thesis,we focused on two key points of high-throughput droplet generation and producing femtoliter droplets to set up several droplet generation platform.We also produced silica spherical packings with macropores and fully porous spherical silica materials.The thesis consists of four chapters as following:Chapter one systematically introduced the fundamental modes and platforms of droplet passive generation,the applications of droplet microfluidics on the synthesis of micro-/nano-materials,the traditional preparation methods of silica chromatographic stationary phases and the researches of droplet reactors on the preparation of spherical silica materials.This part provided the research with the theoretical foundation and the experimental methods so that we could aim at the fabrication of the platforms and the synthesis of silica microspheres strategically.In chapter two,we set up the droplet generation platforms based on the two principles of high-throughput droplet generation and producing femtoliter droplets.We made use of the materials of PDMS to fabricating the T-chips,flow-focusing chips,and the step-emulsification chips.In chapter three,we solidified the silica prepolymer droplets directly to produce silica spherical packings with macropores and combined the PICA method with the solvent exclusion method to prepare the fully porous spherical silica materials.Moreover,we also carried on the chromatography performance evaluation about the fully porous spherical silica materials.In chapter four,we summarized the studies and put forward the outlook of the research.