Grigori M. Sigalov, Ph.D. Scientific Page

Objective: Basic research and teaching oriented career in

• Polymer Physics and Mechanics
• Polymer Chemistry
• Phase Transitions and Critical Phenomena
• Thermodynamics and Statistical Mechanics
• Theory of Disordered Matter
• Nonlinear Dynamics

Research interests

• Digital Image Analysis methods for characterization of the stucture of mutliphase polymer blends. Processing conditions-morphology and material morphology-properties correlations.

• Kinetics of the phase decomposition and structure formation in polymer blends, in particular the theory of the cure-reaction induced microphase separation: nucleation-and-growth and spinodal decomposition mechanisms.

• Nonlinear dynamics and structural transformations in glass-like/Ising-like classical systems.

• Thermal and kinetic properties of glass-like classical systems of particles (in particular, Reichert-Schilling model) reducible to Ising model.

Major accomplishments

• A new DIA (digital image analysis) oriented method for the polymer blend morphology analysis was developed. The particles seen on SEM and TEM (scanning/transmission electron microscopy) pictures of the two-phase blends are considered as ellipses rather than circles, so that their asphericity and orientation may be dealt with.

• A new theory of cure reaction-induced microphase separation (CRIMPS) was developed. Models for nonequilibrium nucleation and growth of dispersed phase particles were proposed, and the particle size distribution for the final heterophase polymer material was analyzed.

• Analysis of kinetics of phase separation in a curing multicomponent system was performed. Expressions describing the phase separation trajectory were derived, and the first quantitative criterion which characterizes the extent of its deflection from the equilibrium was found.

• New probabilistic approach to the description of conformationally disordered polymer chain was developed. The new method allows to take into account the long-range intramolecular interaction. For the chains with finite interaction range a finite system of kinetic equations was derived exactly.