Fabrication, Characterization And Controllability Of Pointer-like And Patchy-porous Anisotropic Microparticles

Given the non-spherical shape or non-uniform properties, anisotropic microparticles have the superiority to address inherent function limitations of general homogeneous spherical microparticles. Over the years, with Janus, patchy and multicompartment particles as the basic types, multitudinous anisotropic microparticles with different structures and properties have been widely studied. With advantages including easy operation, excellent repeatability, low cost and high controllability of the products, microfluidic technology plays an important role in the research of anisotropic microparticles. While, researches about complex anisotropic microparticles are rarely reported, meanwhile, the completely independent synthesis and control of the overall and inner anisotropic features of microparticles is difficult to realize.Combing with SEM, micro-CT and microscopy imaging, microfluidic-based process was applied in this thesis. Pointer-like and patchy-porous microparticles were fabricated; the detailed microstructure was characterized; the structural parameters regulation and control experiment was conducted by varying reaction conditions. Additionally, the interfacial evolution mechanism of pointer-like structure was proposed and verified; magnetofluid was introduced to functionalize the microparticles; reason and solution of "skin" phenomenon of patchy-porous microparticles were studied; Raman spectrum was applied to investigate their rapid detection function. The main research conclusions are as follows:(1) Pointer-like anisotropic microparticles were fabricated with high reproducibility. The independent synthesis and control of the internal and external structures of anisotropic microparticles have been achieved. The detailed interfacial and morphological features has been fully observed and quantitatively analyzed. A structural control strategy with wide range and high precision was developed. The optimal synthesis conditions were confirmed. The application potential of pointer-like microparticles was preliminarily explored for microrheological measurement and magnetic line tracing.(2) The formation mechanism of pointer-like structure was found. Theory about interfacial properties difference which was due to the liquid transfer from outside to inside initiated by the osmotic pressure would broaden the understanding of the structure and morphology controllable synthesis of polymeric materials.(3) Synthesis method of the patchy-porous anisotropic microparticles was confirmed. Influence rules of various reaction conditions on microparticles parameters of both H2O2 and NH4HCO3 system were concluded. The "skin" problem of H2O2 system has been solved. Surficial patchy structure consisting of deposited Ag nanoparticles was obtained. The application potential of patchy-porous microparticles was preliminarily explored for particle adsorption rapid detection.