Surface initiated polymerization from nanoparticle surfaces

The synthesis, characterization, and development of new nanoparticle materials have both scientific and technological significance. Surface initiated polymerization (SIP) from nano-particle surfaces involves the growth of end-tethered polymer brushes where the length or thickness can be more than twice the radius of gyration (Rg) compared to a free polymer in solution. Different mechanisms are possible on a variety of initiators, reaction conditions, monomers, and nanoparticles. Important differences to solution and bulk polymerization can be observed where the nanonparticles with grafted initiators behave as macroinittors. In turn, the development of these materials will allow the preparation of thermodynamically and kinetically stable nanocomposites and colloids. Through the careful use of surface sensitive spectroscopic and microscopic techniques, much has been gained from the direct and in-situ analysis of grafted polymers on the nanoparticles with regards to the kinetics and mechanism of the polymerization process. Parallels can be drawn to SIP on flat surfaces where surface sensitive spectroscopic and microscopic measurements are complementary to analysis methods for colloidal particles. Thus, this review surveys the different polymerization mechanisms and procedures towards forming core-shell types of hybrid inorganic-organic polymer nanoscale materials.