Explanipedia

Binding of Sulfates and Water to Monovalent Cations Open

Mark J. Stevens, Susan B. Rempe · 2024

The binding of the sulfate ligand group to monovalent cations in the presence of water is important for many systems. To understand the structure and energetics of sulfate complexes, we use density functional theory to study ethyl sulfate …

A New Theoretical Framework for Designing Ion Transport Pathways Open

Susan Rempe, Mark J. Stevens, Daniel L. Vigil, Cole D. Allen, Pengyu Ren · 2024

The rapid transport of specific ions through matter is critical to energy storage, membrane separations, and health. However, commercial materials resist ion transport, lack specificity, or both, making ion transport costly and ineffective…

Partial Solvation of Lithium Ions Enhances Conductivity in a Nanophase-Separated Polymer Electrolyte Open

Daniel L. Vigil, Benjamin T. Ferko, Anne Saumer, Stefan Mecking, Mark J. Stevens , et al. · 2024

In this study, we demonstrate that a multiblock lithium-ion-conducting polymer can be swollen with ethylene carbonate solvent to increase the conductivity relative to the dry polymer material by nearly 4 orders of magnitude. This increase …

Metadynamics simulations reveal mechanisms of Na+ and Ca2+ transport in two open states of the channelrhodopsin chimera, C1C2 Open

Lindsey Prignano, Mark J. Stevens, Juan M. Vanegas, Susan B. Rempe, Robert E. Dempski · 2024

Cation conducting channelrhodopsins (ChRs) are a popular tool used in optogenetics to control the activity of excitable cells and tissues using light. ChRs with altered ion selectivity are in high demand for use in different cell types and…

Force Fields for High Concentration Aqueous KOH Solutions and Zincate Ions Open

Amalie L. Frischknecht, Mark J. Stevens · 2024

Motivated by increasing interest in electrochemical devices that include highly alkaline electrolytes, we investigated two force fields for potassium hydroxide (KOH) at high concentrations in water. The "FNB" model uses the SPC/E water mod…

Simulations of swollen, self-assembled single-ion-conducting multiblock copolymers Open

Daniel L. Vigil, Amalie L. Frischknecht, Mark J. Stevens, Benjamin T. Ferko, Karen I. Winey · 2024

Dynamics and nano-rheology of interfacial water: general discussion Open

Susan Rempe, Mark J. Stevens · 2024

Anna T. Bui opened a discussion of the paper by Nikita Kavokine: Thank you for the interesting paper. Regarding transport properties under confinement, when we talk about confinement down to the Angstrom scale as you considered in your pap…

Binding of Li+ to Negatively Charged and Neutral Ligands in Polymer Electrolytes Open

Mark J. Stevens, Susan B. Rempe · 2023

Conceptually, single-ion polymer electrolytes (SIPE) with the anion bound to the polymer could solve major issues in Li-ion batteries, but their conductivity is too low. Experimentally, weakly interacting anionic groups have the best condu…

Molecular dynamics simulations of the dielectric constants of salt-free and salt-doped polar solvents Open

Cameron J. Shock, Mark J. Stevens, Amalie L. Frischknecht, Issei Nakamura · 2023

We develop a Stockmayer fluid model that accounts for the dielectric responses of polar solvents (water, MeOH, EtOH, acetone, 1-propanol, DMSO, and DMF) and NaCl solutions. These solvent molecules are represented by Lennard-Jones (LJ) sphe…

Explicit solvent machine-learned coarse-grained model of sodium polystyrene sulfonate to capture polymer structure and dynamics Open

Phillip A. Taylor, Mark J. Stevens · 2023

Accurate Calculation of Solvation Properties of Lithium Ions in Nonaqueous Solutions Open

Daniel L. Vigil, Mark J. Stevens, Amalie L. Frischknecht · 2023

We perform all-atom molecular dynamics simulations of lithium triflate in 1,2-dimethoxyethane using six different literature force fields. This system is representative of many experimental studies of lithium salts in solvents and polymers…

Insight into the K channel's selectivity from binding of K+, Na+ and water to N-methylacetamide Open

Mark J. Stevens, Susan B. Rempe · 2023

Binding site occupancy and the mechanism of K selectivity involve multiple K binding in multiple neighboring layers, or sites, of the K channel selectivity filter.

Tuning poly(N-isopropylacrylamide) surfactant phase behavior to access thermoresponsive micelle disassembly Open

Charles P. Easterling, Chester Kent Simocko, Manish Kumar Singh, Lauren J. Abbott, Zachary Romero , et al. · 2023

Exploiting Asynchronous Host-Parasitoid Emergence Distributions to Optimise Insecticide Applications and Protect Beneficial Insects– a Case Study Using the Citrus Gall Wasp Bruchophagus Fellis (Hymenoptera: Eurytomidae) Open

Jianhua Mo, Michael J. Furlong, Lisa L. Kirkland, Mark J. Stevens · 2023

Binding of carboxylate and water to monovalent cations Open

Mark J. Stevens, Susan B. Rempe · 2023

Water plays an important role in the binding of cations with carboxylates. DFT studies show n W = 2 waters combine with n A = 2 negatively-charged acetates to form the complexes with lowest free energies for Li, Na, and K ions in the gas p…

Neural Network for Principle of Least Action Open

Beibei Wang, Shane Jackson, Aiichiro Nakano, Ken‐ichi Nomura, Priya Vashishta , et al. · 2022

The principle of least action is the cornerstone of classical mechanics, theory of relativity, quantum mechanics, and thermodynamics. Here, we describe how a neural network (NN) learns to find the trajectory for a Lennard-Jones (LJ) system…

Overlap Concentration of Sodium Polystyrene Sulfonate in Solution. Open

Mark J. Stevens, Bryce Thurston, Gary S. Grest · 2022

The overlap concentration c* of sodium polystyrene\nsulfonate in water is calculated using multichain atomistic and coarse\ngrained (CG) simulations for a range of chain lengths. Fully atomistic\nmolecular dynamics simulations are c…

Coming Together Open

Kelly‐Ann Allen, Kathryn Riley, Annie Gowing, Michelle H. Lim, Christopher Boyle , et al. · 2022

Interdisciplinary collaboration is necessary for the progression and solution of many social problems we face in society. Many research areas in academia are criticised for being siloed, but this is not a criticism that can be easily level…

Overlap Concentration of Sodium Polystyrene Sulfonate in Solution Open

Bryce Thurston, Gary S. Grest, Mark J. Stevens · 2022

The overlap concentration c* of sodium polystyrene sulfonate in water is calculated using multichain atomistic and coarse grained (CG) simulations for a range of chain lengths. Fully atomistic molecular dynamics simulations are carr…

Carboxylate binding prefers two cations to one Open

Mark J. Stevens, Susan B. Rempe · 2022

The preferred optimal structure with 2 cations is favored over 1 cation in complexes of Li, Na, and K binding to carboxylates, providing an understanding of ionic cluster formation relevant for designing materials for rapid, selective ion …

Overlap Concentration in Salt-Free Polyelectrolyte Solutions Open

Jonathan A. Bollinger, Gary S. Grest, Mark J. Stevens, Michael Rubinstein · 2021

For strongly charged polyelectrolytes in salt-free solutions, we use molecular dynamics simulations of a coarse-grained bead-spring model to calculate overlap concentrations c* and chain structure for polymers containing N = 10 to 1600 mon…

Molecular Dynamics Simulations of Percolated Ionic Aggregates in PreciseSulfophenylated Polyethylene Polymers. Open

Bryce Thurston, Benjamin Paren, Justin G. Kennemur, Karen I. Winey, Mark J. Stevens , et al. · 2021

LAMMPS - a flexible simulation tool for particle-based materials modeling at the atomic, meso, and continuum scales Open

Aidan P. Thompson, Hasan Metin Aktulga, Richard A. Berger, Dan Bolintineanu, William M. Brown , et al. · 2021

Simulation of polymerization induced phase separation in model thermosets Open

Mark J. Stevens · 2021

Polymerization induced phase separation (PIPS) in a three component thermoset is studied using molecular dynamics simulations of a new coarse-grained thermoset model. The system includes two crosslinker molecules, which differ in their gla…

Fluorine-Free Precise Polymer Electrolyte for Efficient Proton Transport: Experiments and Simulations Open

Benjamin Paren, Bryce Thurston, Arjun Kanthawar, William J. Neary, Aaron Kendrick , et al. · 2021

Designing polymers with controlled nanoscale morphologies and scalable synthesis is of great interest in the development of fluorine-free materials for proton-exchange membranes in fuel cells. This study focuses on a precision polyethylene…

Structure and Dynamics of Hydrated Precise Sulfophenylated Polyethylene Polymers from Simulation. Open

Bryce Thurston, Benjamin Paren, Karen I. Winey, Mark J. Stevens, Amalie L. Frischknecht · 2021

Perceived COVID-19 risk is attenuated by ingroup trust: Evidence from three empirical studies Open

Tegan Cruwys, Mark J. Stevens, Jessica L. Donaldson, Diana Cárdenas, Michael J. Platow , et al. · 2021

Background: The social identity model of risk taking proposes that people take more risks with ingroup members because they trust them more. While this can be beneficial in some circumstances, in the context of the COVID-19 pandemic it has…

Percolated (yellow) and discrete (colored by size) clusters of ions in different types of ionic polymers. Open

Amalie L. Frischknecht, Mark J. Stevens · 2020

FY10 BES Bio Highlights. Open

Mark J. Stevens · 2020

Percolated Ionic Aggregate Morphologies and Decoupled Ion Transport in Precise Sulfonated Polymers Synthesized by Ring-Opening Metathesis Polymerization Open

Benjamin Paren, Bryce Thurston, William J. Neary, Aaron Kendrick, Justin G. Kennemur , et al. · 2020

Here, we describe a set of precise single-ion conducting polymers that form self-assembled percolated ionic aggregates in glassy polymer matrices and have decoupled transport of metal cations. These precise single-ion conductors (SICs), sy…

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