Preparation of Melamine-formaldehyde Microspheres and Microcapsules Based on Poly(glutamic acid) by Template Method

Melamine-formaldehyde (MF) microspheres were prepared by dispersion polymerization. The influences of pH value and reaction time on partical size, surface potential and solubility of MF microspheres were studied. Using MF microspheres as templates, hollow PGA/CS microcapsules were fabricated by layer-by-layer self-assembly technique. The templates and microcapsules were characterized by polarization microscope, nano-granularity and potential analyzer, IR and TEM. The results show that the partical size and surface potential of MF microspheres decrease with the reducing of pH and its solubility in hydrochloric acid becomes worse as the time grows. The main driving force is electrostatic force between PGA and CS, which is supported by alternating zeta potentials. The hollow microcapsules with uniform size and good dispersity shows successful loading of model drug rhodamine, water-soluble drugs