Coaxial Microchannel Liquid-Liquid Flow And Its Application In Microfiber Material Preparation

As a new platform for the material preparation,microfluidic technology has unique advantages in the preparation of materials with controllable morphology,size and structures.The aim of this study is to develop novel methods for microfiber material preparation.Based on the study of the basic law of three-phase flow,the systematic research on the regulation of microfiber morphology,size and structure during the preparation of materials by microfluidic technology was carried out.(1)Single and double coaxial microchannel were designed.Flow laws of three-phase fluids in these two types of microchannel devices were investigated and flow pattern plots were drawn.The regulation and scope of the laminar flow laid the foundation for the preparation of the microfiber material in the coaxial microchannel.(2)By adjusting the operating parameters such as the curing position,fluid flow rate,and fluid composition,anisotropic microfibers were prepared in single coaxial microchannel,such as non-axially symmetrical porous microfibers,gourd-shaped microfibers,and Janus microfibers;isotropic microfibers were prepared in double coaxial microchannel,such as axially symmetrical porous microfibers and hollow microfibers,etc.The size control law of Janus microfibers and hollow microfibers was investigated.Based on the N-S equation of the double coaxial laminar flow,a mathematical model for predicting the size of hollow microfibers was established.The predicted results of the model are in good agreement with the experimental results.(3)According to the physical law of nanoparticle interface adsorption,continuous preparation of anisotropic Janus and hollow composite microfiber were achieved by selectively adding nanoparticles to the continuous or non-solidified phase and the load was simply regulated.Because the method is universal,microfibers with other modifiers are prepared to make them more promising.