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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.


For a complete publication list, see:

Google Scholar Profile

Selected Publications

Hidden Hyperuniformity in Bottlebrush Polymer Melts

Alexandros Chremos, Jack F. Douglas
We show that the backbone chains of bottlebrush polymer melts exhibit a hidden hyperuniform packing over a wide temperature range above glass transition


Dynamic Heterogeneity and Collective Motion in Star Polymer Melts

Jack F. Douglas, Jinpeng Fan, Hamed Emamy, Francis W. Starr, Alexandros Chremos
While glass formation of linear chain polymers has been widely explored, comparatively little is known about glass formation in star polymer melts. We study the

Superionic UO2: A Model Anharmonic Crystalline Material

Jack F. Douglas, Hao Zhang, Xinyi Wang, Alexandros Chremos
Crystalline materials at elevated temperatures and pressures can exhibit properties more reminiscent of simple liquids than ideal crystalline materials, an
Created June 6, 2019, Updated September 15, 2023