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.
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