Abstract:

The large surface area of nanoparticles provides an appealing laboratory for the production and study of polymer brushes grown from those surfaces. Two logical starting points for this work due to the wealth of preexisting literature - are thiols on gold and silanes on silica and one might expect that the major difficulties in utilizing either system for this purpose had been overcome. Unfortunately several tools appropriate for gold nanoparticles are not effective for silica nanoparticles. Efforts in our laboratory have shown that the rate of initiation is sensitive to the structure of a layer of tethered initiators when polymerizations are initiated from particle surfaces. The results of this range from broadened molecular weight distributions to no polymerization at all. It is also desirable to make the polymerization chemistry independent of the nature of the substrate. Both of these issues can be addressed through manipulation of the surface coverage containing the tethered initiator.