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Search Publications by: Alexandros Chremos (Fed)

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Displaying 1 - 24 of 24

Development of SAFT-based coarse-grained models of carbon dioxide and nitrogen

March 21, 2025
Author(s)
Alexandros Chremos, William P. Krekelberg, Harold Hatch, Daniel Siderius, Nathan Mahynski, Vincent Shen
We develop coarse-grained models for carbon dioxide (CO2 ) and nitrogen (N2 ) that capture the vapor-liquid equilibria of their single components and their binary mixtures over a wide range of temperatures and pressures. To achieve this, we used an

The Concentration Dependence of the Size and Symmetry of a Bottlebrush Polymer in a Good Solvent

August 7, 2020
Author(s)
Daniel F. Sunday, Alexandros Chremos, Tyler B. Martin, Alice B. Chang, Adam B. Burns, Robert H. Grubbs
Bottlebrush polymers consist of a linear backbone with densely grafted sidechains which impact the rigidity of the molecule. The persistence length of the bottlebrush backbone in solution is influenced by both the intrinsic structure of the polymer and by

Dynamic Heterogeneity and Collective Motion in Star Polymer Melts

February 4, 2020
Author(s)
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 segmental dynamics of star polymers via molecular dynamics simulations and contrast the

Superionic UO2: A Model Anharmonic Crystalline Material

May 7, 2019
Author(s)
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 attribute making these materials useful in diverse applications. Superionic crystalline materials

Hidden Hyperuniformity in Bottlebrush Polymer Melts

December 21, 2018
Author(s)
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 temperature. These findings open a venue for a practical design of hyperuniform polymeric materials for

Competitive solvation effects in polyelectrolyte solutions

August 1, 2018
Author(s)
Alexandros Chremos, Jack F. Douglas
An understanding of the solution properties and phase behavior of natural and synthetic polyelectrolytes requires an understanding of the competitive association of water (“hydration”) and ion association to the polymer backbone and the consequences of

Polyelectrolyte association and solvation

July 10, 2018
Author(s)
Alexandros Chremos, Jack F. Douglas
There has been significant interest in the tendency of highly charged particles having the same charge to form dynamic clusters in solution, but an accepted theoretical framework that can account for this ubiquitous phenomenon has been slow to develop. The

Influence of Ion Solvation on the Properties of Electrolyte Solutions

April 3, 2018
Author(s)
Marat Andreev, Juan J. DePablo, Alexandros Chremos, Jack F. Douglas
It is widely appreciated that the addition of salts to water leads to significant changes in the thermodynamic and dynamic properties of these aqueous solutions, which have great significance in biology and manufacturing applications. However, no

Free Surface Relaxations of Star-Shaped Polymer Films

November 28, 2017
Author(s)
Alexandros Chremos, Bradley R. Frieberg, Emmanouil Glynos, Kyle Johnson, Hengxi Yang, Suresh Narayanan, Peter F. Green, Georgios Sakellariou
X-ray photon correlation spectroscopy (XPCS) studies show that the viscosities of thin film linear chain polymers at temperatures sufficiently high above the bulk glass transition temperature Tg bulk are equal to the bulk zero shear viscosities. The free

Influence of polymer architecture on diffusion in polymers melts

August 2, 2017
Author(s)
Alexandros Chremos, Cheol Jeong, Jack F. Douglas
Recent simulations have indicated that the thermodynamic properties and the glassy dynamics of polymer melts are strongly influenced by average molecular shape, as quantified by the radius of gyration tensor of the polymer molecules, and that average

Self-Assembly of Polymer-Grafted Nanoparticles in Solvent-free Conditions

October 31, 2016
Author(s)
Alexandros Chremos, Jack F. Douglas
The grafting of polymer chains onto the surface of spherical nanoparticles leads to a hybrid type of fluid that exhibits properties of both particle suspensions and melts of star polymers – these properties being controlled by the relative dimensions of

Computer-Aided Molecular Design and Selection of CO2 Capture Solvents Based on Thermodynamics, Reactivity and Sustainability

August 10, 2016
Author(s)
Alexandros Chremos, Athanasios Papadopoulos, Sara Badr, Esther Forte, Theodoros Zarogiannis, Panos Seferlis, Stavros Papadokonstantakis, Amparo Galindo, George Jackson, Claire Adjiman
The identification of improved carbon dioxide (CO2) capture solvents remains a challenge due to the vast number of potentially-suitable molecules. We propose an optimization-based computer- aided molecular design (CAMD) method to identify and select, from

When does a branched polymer becomes a particle?

September 17, 2015
Author(s)
Alexandros Chremos, Jack F. Douglas
Melts with topologically distinct molecular structures are investigated by molecular dynamics simulation. We determine the mean polymer size and shape, and glass transition temperature for each molecular topology. Both in terms of structure and dynamics
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