Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Alexandros Chremos (Fed)
NIST scientist
Research Interests
Polyelectrolytes and counter-ions
Synthetic and biological polymers (e.g., DNA and proteins) are challenging to model due to the formation of dynamic layers of associated water and counter-ion particles in the proximity of the polyelectrolyte. The associating species predominantly influence the dynamics of these polyelectrolytes in these layers. This association phenomenon and the coupling to the polymer dynamics are poorly understood. Molecular dynamics of the bead-spring model and an explicit solvent are used to develop quantitative metrologies for quantifying these complex interactions between the polyelectrolytes and these dynamic layers of associating particles.
Impact of Molecular Shape on Dense Polymeric Materials
We investigate the role of molecular shape in thermodynamics and in the dynamics of dense fluids. Towards understanding the impact of molecular shape, ZENO is applied to compute shape-related characteristics, including the hydrodynamic radius and sphericity, and molecular dynamics simulations with a bead-spring model are used to investigate the thermodynamical and dynamical behavior of distinct molecular topologies such as linear chains, stars, and rings.