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.