Preparation Of Photoreactive Polymer Particles And Their Surface Modification By Photografting

The surface properties of particles are very important. Partciles contain a variety of different groups on surface have wide applications in many fields, such as coatings, pharmaceuticals, diagnostics, biotechnology, printing ink and etc. The quantity of functional groups influences the activity of particles directly, however little results mentioned how to increase the amount of functional monomers.In this paper, monodisperse core-shell microspheres of polystyrene (PSt) contained photo-iniferter moieties were prepared firstly by a two-stage dispersion polymerization in which MAEDCA was charged into system after nucleation. Different add-methods and different dosage of monomer was studied to improve the content of DC groups on premise of monodisperse. It is advantageous to achieve narrowly distributed microspheres when a certain amount of mixture MAEDCA, St, AIBN, MeOH and H2O were introduced into system in the second stage of dispersion polymerization. Particles with hierarchical structure have recently attracted increasing attention because of their characteristics such as unique morphology, a higher specific surface area, high-surface roughness, and high-light scattering. Therefore, particle surface photo-grafting was taken under UV lamp, demonstrated that AM, MMA,9-vinylanthracene and HEMA were applicable.Morphology of PSt particles after grafting PAM was discussed. Particles with different morphologies were obtained by changing methanol/water ratio, stirring rate, and UV intensity. At last, non-unifrom grafting was carried to prepare asymmetric particles in pure methanol system, because UV intensity decreased and free rotation of particles was very difficult due to increasing viscosity in this condition.