Our group is interested in complex unconventional
organic and polymer synthesis, new concepts, reactions and mechanisms.
Areas of research include radical polymerizations, polycondensations,
liquid crystals, auxetic materials, self assembly and nanostructures.
Molecular weight and polydispersity control in living radical
polymerization (LRP) is based on the persistent radical effect
(PRE). Persistent radicals are not involved in homodimerization
reactions or addition to the double bond, and maintain radical
concentration at low levels via their reversible endcapping
with the growing chain. This process decreases the rate of both
propagation and termination, but dramatically suppresses the
second order (bimolecular) termination reaction. Various carbon
or oxygen centered radicals (nitroxides, addition fragmentation
derivatives) and metaloradicals (Cu, Ni, Fe, Ru complexes) are
usually employed in LRP. We are exploring novel organic and
inorganic systems capable of accomplishing LRP. One goal is
the design, synthesis and characterization of catalysts capable
of dual or multiple mechanism-polymerizations. Other research
directions include the use of unusual substrates for the initiation
of living polymerizations, as well as the LRP of monomers that
generate very reactive radicals. Radical polycondensation is
another topic of interest. It is believed that these reactions
alone, or in conjunction with other polymerizations, have a
lot of potential in the synthesis of complex structures with
remarkable properties. Controlled polymerizations of this type
will be targeted via proper monomer/catalyst design. Also of
interest are the design, synthesis and characterization of novel
architecturally complex, functional and well defined macromolecular
structures, via precision polymer synthesis. Examples include
polyelectrolytes, conductive polymers, liquid crystals and auxetic
materials.
