Article
Polymer Science
Turash Haque Pial, Mihirkumar Prajapati, Bhargav Sai Chava, Harnoor Singh Sachar, Siddhartha Das
Summary: The response of polyelectrolytes to applied electric fields depends on their charge density. Highly charged polyelectrolytes exhibit a bending-driven reduction in brush height, while weakly charged polyelectrolytes experience a tilt-driven reduction.
Article
Chemistry, Physical
Yoshiki Ishii, Nobuyuki Matubayasi, Hitoshi Washizu
Summary: This study improves the prediction accuracy of ionic conductivity in ionic liquids and self-assembled ionic liquid crystals by using nonpolarizable force fields and self-consistent modeling scheme combined with density functional theory. It is found that the interaction between ionic groups plays a crucial role in maintaining the bicontinuous nanosegregation of ionic nanochannels in self-assembled nanostructures.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Polymer Science
Chan-En Fang, Yi-Chen Tsai, Christoph Scheurer, Chi-Cheng Chiu
Summary: This study reparametrized the molecular force field of PEO to improve the accuracy of density, thermal expansion coefficient, and dielectric constant calculations, which is crucial for simulating polymer electrolytes. The reparametrization method was also applied to the PEO/LiTFSI SPE system and significantly improved the kinetics of Li+ transport. The proposed OPLS(R) force field can benefit future simulation studies of SPE systems.
Article
Biochemistry & Molecular Biology
Alexei Nikitin, Vladimir Chekhov
Summary: The introduction of an additional interaction site next to nitrogen atoms greatly improves model quality with minimal impact on calculation speed. The proposed force field allows accurate prediction of heats of evaporation for compounds under investigation.
JOURNAL OF MOLECULAR MODELING
(2021)
Article
Chemistry, Physical
Jose Enrique Vazquez-Cervantes, G. Andres Cisneros
Summary: A new efficient parametrization approach for the polarizable ionic liquid potential AMOEBA-IL is proposed and applied to develop parameters for imidazolium-based cations. The approach involves the development of parameters for fragments that can be transferred to generate new molecules. The parameters are obtained using the AMOEBA-IL parametrization approach, including the use of Gaussian electrostatic model-distributed multipoles for the permanent multipoles and approximation of the van der Waals parameters using quantum mechanics energy decomposition analysis data. Molecular dynamics simulations were conducted to validate the new parametrized cations by comparing selected thermodynamic and transport properties with experimental data.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Gary Yu, Mark Richard Wilson
Summary: This study investigates the properties of the liquid crystal dimer CB7CB through molecular dynamics simulations. The results show that CB7CB exhibits a twist-bend nematic phase and has statistical achirality but can adopt chiral conformers with no preference for a specific handedness. Furthermore, the study reveals that the molecular shape and bend angle play important roles in determining the ability of a dimer to exhibit the twist-bend nematic phase.
Article
Chemistry, Physical
Devin M. Mulvey, Kenneth D. Jordan
Summary: The polarization model presented accurately describes the dipole polarizabilities of small hydrocarbons and reproduces the classical image potential of an infinite conducting sheet in graphene nanoflakes.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Devin M. Mulvey, Kenneth D. Jordan
Summary: We propose a polarization model that incorporates fluctuating charges and inducible dipoles to accurately describe dipole polarizabilities of hydrocarbons and reproduce the classical image potential of a conducting sheet. Applying this model to the hexagonal carbon nanoflake C-60000, we obtain excellent agreement with the image potential and induced charge distribution of a conducting sheet. Including inducible dipole terms, the model predicts an image plane of z(im) = 1.3334 a(0), consistent with prior estimates for graphene. We also find that the fluctuating charge model reproduces classical electrostatics for two charges placed on opposite sides of C-60000, indicating that an atomically thin molecule or extended system does not fully screen their interaction.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Yan M. H. Goncalves, Sadra Kashefolgheta, Marina P. Oliveira, Philippe H. Hunenberger, Bruno A. C. Horta
Summary: This article presents a new algorithm named LLS-SC for the simultaneous optimization of torsional and third-neighbor interaction parameters. The algorithm relies on fitting relative conformational energies against quantum-mechanical values and utilizes a self-consistent procedure involving linear least-squares regression and geometry optimization.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2022)
Article
Chemistry, Physical
Zherui Chen, Yanghui Li, Cong Chen, Xiang Sun, Weiguo Liu
Summary: The study reveals that asphalt aggregation primarily depends on pi-pi interaction, and with increasing surfactant coverage, larger aggregates are easier to form. Moreover, increasing the concentration of surfactant is not the best solution to resolve pipeline blockage issues, as it is essential to fully utilize the anti-agglomerant effect of asphalt itself.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Multidisciplinary Sciences
Li Wang, Jinlong He, Mohammad Heiranian, Hanqing Fan, Lianfa Song, Ying Li, Menachem Elimelech
Summary: We used NEMD simulations and permeation experiments to investigate the mechanism of water transport in RO membranes. The simulations showed that water transport is driven by a pressure gradient, contradicting the traditional solution-diffusion model. We also observed that water molecules form clusters and move through transiently connected pores. Permeation experiments with different solvents further revealed that solvent permeance depends on membrane pore size, solvent molecule size, and viscosity, which is inconsistent with the solution-diffusion model.
Article
Chemistry, Physical
Yang Ge, Xueping Wang, Qiang Zhu, Yuqin Yang, Hao Dong, Jing Ma
Summary: This study proposes a machine learning-guided adaptive parametrization method that develops a mixed atomic and coarse-grained model to precisely regulate the peptide self-assembly. The method significantly reduces computational costs while maintaining qualitative agreement with observed morphologies in experiments.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Xianwei Wang, Yiying Wang, Man Guo, Xuechao Wang, Yang Li, John Z. H. Zhang
Summary: The EEC model shows promising performance in accurately describing electrostatic interactions (EIs) of hydrogen bonds in proteins, as well as reproducing the QM/MM-calculated EIs in water solvent. Additionally, the EEC model can closely reproduce the oxygen-oxygen radial distribution function and density of water, similar to TIP4P-like empirical water models.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Materials Science, Multidisciplinary
Kristian Poll, Mark T. Sims
Summary: Partially-fluorinated mesogens exhibit de Vries behavior similar to non-fluorinated mesogens. The relationships between the fluorinated and hydrocarbon sub-layers suggest mutual offsetting effects. The consistent results with non-fluorinated mesogens indicate there is still much to learn about the molecular organization within these systems.
MATERIALS ADVANCES
(2022)
Article
Biochemical Research Methods
Li-Nan Lu, Cui Liu, Zhong-Zhi Yang, Dong-Xia Zhao
Summary: This study developed bonded and non-bonded models based on the ABEEM polarizable force field to study the coordination of enzyme-MFX-TSAs. The parameters of the models were determined through energy minimizations and molecular dynamics simulations. The results demonstrated the correctness, rationality, and transferability of the new parameters, providing a refined tool for studying the catalytic mechanism of phosphoryl transfer enzymes.
JOURNAL OF MOLECULAR GRAPHICS & MODELLING
(2022)