Projects / Programmes
Properties and Stability of Solutions of Charged Nanoparticles
| Code |
Science |
Field |
Subfield |
| 1.04.01 |
Natural sciences and mathematics |
Chemistry |
Phyisical chemistry |
| Code |
Science |
Field |
| P400 |
Natural sciences and mathematics |
Physical chemistry |
polyelectrolytes, colloids, proteins, solutions, Coulomb interaction, phase separation, short-range interactions, statistical thermodynamics, computer simulations, integral equations
Researchers (4)
Organisations (1)
Abstract
Solutions of surfactant micelles, globular proteins, microemulsions and suspensions of charged colloids (polyelectrolytes), constitute a rapidly expanding area of science. The interest is stimulated by the many applications these substances have in industry, as also by their important role in biological processes. Although in such systems the Coulomb interaction may most often be the dominant interaction, it is not the only one that governs the properties of these systems. Systems of biological relevance are quite complex; in addition to the aqueous polyelectrolyte-electrolyte mixture, large concentrations of neutral macromolecules are often present in solution. Toward better theoretical understanding of polyelectrolyte solutions, this proposal addresses a range of questions including a) instability and phase separation in solutions of like-charged macroions caused by strong correlations between counterions in the solution. In contrast to well established theories, which predict purely repulsive interaction between macroions, novel theoretical and experimental findings report existence of the effective attraction between macroions under certain conditions. It is of great interest to establish how the phase stability of these systems is affected by the parameters like the macroion charge, valency of counterions, a dielectric constant of the solvent, a temperature, and others. In this project we propose to use both the Monte Carlo computer simulation method and integral equation based modern statistical mechanical theories to study properties and range of stability of a highly asymmetric electrolyte model. b) studies of a model protein with a short-range directional attraction between macroions. In this contribution we propose to study the model for protein solution which accounts for both, the Coulomb long-range interaction, and for the dimerization of protein molecules in solution. The theoretical results, based on new N,P,T computer simulations and integral equation theory, will be used to analyze our own osmotic pressure measurements, and also experimental data from the literature. c) investigations of the catalytic effect in polyelectrolyte solutions. In spite of great potential for various applications, this effect received little theoretical attention so far. In this part of the proposal we intend to apply several theoretical techniques to calculate the changes in the collision frequency among small ions as brought about by the addition of polyelectrolyte solution. d) development of more realistic models. The primitive models of polyelectrolyte solutions, used in most calculations so far, neglect the granularity of solvent, and ignore the dielectric discontinuity at the solvent-ion boundary. The latter effect give rise to repulsive interactions which affect the stability of the system. In this study we propose to examine critically the effect of these approximations.
