Preparation Of Core-Shell/Janus Particles By Ratrp/2-Disp

The anisotropy of Janus particles in the structure, composition, surface properties and other aspects makes them a broad application prospect in many areas such as coatings, optical information and biomedicine. Monodisperse photosensitive core-shell particles are functional microspheres with optical reactivity, and they can be further functionalized under certain light.In this paper, two-stage dispersion polymerization combined with RATRP was exploited to prepare monodisperse core-shell or Janus polymeric particles. Firstly, an appropriate reaction media of the mixture of ethylene glycol and water (5/5) were determined to keep stability of system during polymerization. Secondly, after the sensitive nucleation stage and polymerization of St had been carried out for3h, RATRP reagents (CuBr2and ligand), and photosensitive monomers (BPMA and/or DBPMA) were added, and monodisperse core-shell microparticles were formed. With the addition of DVB, THF or toluene in the2ed step of polymerization, Janus particles were achieved in one pot, while stability of system and monodispersity of particles were maintained. Influences of amounts of DVB, THF or toluene, reaction temperature on the formation of Janus particles were investigated, and the results indicated that their morphology and size could be controlled by the above parameters. Lastly, by controlling the adding amounts of DVB in the2ed step and/or the beginning time of the2ed step, we successfully prepared the Janus particles all the same. And we discussed the influence on the morphology of the prepared microspheres when the RATRP reagents were changed to AIBN or APS.