Studies:

• B.S., Chemistry, University of Patras, 1977.
  
• Ph.D., Chemical Engineering, University of Patras, 1987. 

Current Focus of Research:

Synthesis of model polymers.
Polymers with well-defined architecture, low degree of compositional heterogeneity and narrow molecular weight distribution are designed and synthesized by "living" polymerization techniques. Novel star-shaped macromolecules of various architectures such as star homopolymers (new monomers) (A_n) heteroarm star copolymers (A_nB_n), star block copolymers [(AB)_n] and functionalized star polymers [A_n-core-f_n, A_n-core-(B-F)_n, core-(B-f)] have been synthesized by anionic polymerization under inert atmosphere (Argon). Other type of block copolymers such as telechelic polyelectrolytes, heterotelechelic polyelectrolytes and stimuli responsive macromolecules have been the subject of our research efforts the recent years.

Association phenomena of block copolymers in solution
Block copolymers self assemble in the presence of a selective solvent, i.e. good for one block and poor for the other, forming stable micelles of a variety of structures. Polymer micelles seem to have important technological applications because various materials can be solubilized in them. Our efforts focus on the investigation of micellization phenomena arising from amphiphilic block copolymers of complex architectures such as heteroarm star copolymers (A_nB_n) and triblock copolymers of the type ABA and ABC for which the solvent is selective for the B blocks. We have shown that the macromolecular architecture is a very important factor affecting strongly the micellar characteristics. Recently more complex micellar structures (onion type) have been observed, exhibited in aqueous solutions of heteroarm star polyelectrolyte / diblock copolymer mixtures.

Physical Gels
In many technologies, controlling viscosity at different shear rates is essential to achieving good performance. Examples include various water-born coatings and paints, cosmetics and chemically enhanced oil recovery. A useful strategy for enhanced control of rheology in aqueous systems is to use the so-called associative polymers, which form transient networks through hydrophobic interactions. We are recently investigating new type of such polymers named telechelic (ABA) and /or heterotechelic (ABC) polyelectrolytes. The novelty in this case is, that the hydrophilic part is a fully charged and therefore extended macromolecular chain, end-capped with hydrophobic short blocks. These kinds of polymers are associated in aqueous solutions forming reversible transient networks responsible for the formation of strong physical gels. For example a polystyrene-poly(sodium acrylate)-polystyrene triblock copolymer aqueous solution exhibits viscosity seven orders of magnitude higher than that of water in 1 wt.% concentration.

Last Revised: 09/11/2005 13:22

Selected Publications