University of Notre Dame
Haimeng Wang successfully defended his PhD thesis “Molecular Dynamics Simulations of Molten Salts: Force Field Evaluation and Development” today. He was the first person in the group to work on molten salts, and was a key element of the modeling and simulation team of our EFRC “Molten Salts in Extreme Environments (MSEE)”. Haimeng is moving on to take a postdoc position at Argonne National Lab. Congratulations, Haimeng!
We are excited to welcome five new PhD students to the group. They are: Barnabas Agbodekhe (BS University of Benin; MS Imperial College, London); Montana Carlozo (BS Rowan University); Yinke Jiang (BS. Dalian Univ. Tech); Daniel Kim (BSE, Calvin University); and Cole Strickling (BS Oklahoma State). Welcome!
We said goodbye this month to Dr. Ryan DeFever, who has taken a job as a data science researchers at Phillips66 in Bartlesville, OK. Best wishes, Ryan. We will miss you!
Congratulations to Garrett Tow, who successfully defended his thesis and graduated with his PhD this May. Garrett plans to take a computational research position with the Army Research Lab this summer. Well done!
Ryan DeFever, as part of the NSF-funded MoSDeF team, has developed a complete Python interface to Cassandra that enables rapid setup of Cassandra simulations. The tools help build the systems, assign atom types and force field parameters, and launch the job. The result is more reproducible results that are well documented and reliable. You can check out the tools at https://github.com/MaginnGroup/mosdef_cassandra
A paper describing the tools was published in the Journal of Computational Chemistry https://onlinelibrary.wiley.com/doi/10.1002/jcc.26544
Working with the BEES team at Case Western, Derrick Poe co-authored a recent paper entitled “A Nitroxide Containing Organic Molecule in a Deep Eutectic Solvent for Flow Battery Applications” (Journal of the Electrochemical Society, 2021, 168, 020527, https://doi.org/10.1149/1945-7111/abe28a). In this work, experimental and computational studies were carried out to investigate the nitroxide radical redox organic molecule, 2-phenyl-4,4,5,5-tetrame-thylimidazoline-1-oxyl-3-oxide (PTIO) in a deep eutectic solvent consisting of 1 1:4 molar mixture of choline chloride and ethylene glycol. Molecular modeling was performed to investigate the relative stability of PTIO as compared to the previously studied 4-hydroxy-TEMPO (4HT). It was found that the oxoammonium cation 4HT+ exhibits a noticeably larger nucleophilic reactive cloud as compared to PTIO+, indicating a higher reactivity.
Happy to announce that a Perspective paper was just published in the AIChE Journal entitled “Open‐source molecular modeling software in chemical engineering focusing on the Molecular Simulation Design Framework”. This paper describes work the MoSDeF team did in developing methods to improve the reliability and accuracy of molecular simulation software. Congratulations to Ryan DeFever, who played a huge role in this work!
Three new graduate students joined the group this year. Ning Wang (B.S. Polymer Materials and Engineering, Beijing University of Chemical Technology, M.S. Materials Science and Engineering, University of Pennsylvania), Fernando Carmoda (B.S. Chemical Engineering, University of Puerto Rico at Mayaguez), and Dinis Abranches (BSc and MSc in Chemical Engineering, University of Aveiro, Portugal). Welcome!
A recent paper from our group, in collaboration with Luciano Costa’s group at Fluminense Federal University (Brazil) and Burcu Gurkan’s group at Case Western Reserve University, has been featured by the Joint Center for Energy Storage Research (JCESR).
In this paper, our team used Raman spectroscopy and molecular dynamics (MD) simulations to study the structural and dynamical changes in the solvation shell surrounding Li+ in a ternary electrolyte is composed of a mixture of two ionic liquids (ILs), n-methyl-n-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([PYR13][TFSI]) and 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCA]), and a lithium bis(trifluoromethanesulfonyl)imide ([Li][TFSI]) salt (0–1 M). The local structure of Li+ in this eutectic was found to be heterogeneous and preferentially solvated by [DCA]. The Raman and MD analyses suggest a wide distribution of solvation. The computations showed increased ion pair lifetime for Li+ –[DCA] and decreased lifetimes for Li+–[TFSI] in the ternary mixture with the increase in the [Li][TFSI] concentration. These results show that the solvation and transport properties of charge carriers in ILs can be modified via the presence of multiple ions with varying degree of coordination, which provides an approach to impact the performance in electrochemical processes.
Garett Tow’s paper on simulating the orthorhombic phase of ammonium perchlorate has been published (Garrett M. Tow and Edward J. Maginn, “Evaluating physical properties of the orthorhombic crystal phase of ammonium perchlorate using a class II force field”, Journal of Chemical Physics, 2018, 149, 244502.
In this paper, we show how a class II force field can adequately capture the structural, thermodynamic and spectroscopic properties of ammonium perchlorate.
