Article
Polymer Science
Katsumi Hagita, Takahiro Murashima, Hiroshi Jinnai
Summary: This study investigates the qualitative behavior of large rings embedded in crosslinked polymer networks through coarse-grained molecular dynamics simulation. The results show that the large rings interfere with the network structure and have an impact on the stress-strain curve. The study also confirms that these embedded rings can act as movable crosslinks and reinforce the network.
Article
Chemistry, Physical
Qixin Chen, Xixi Hu, Hua Guo, Daiqian Xie
Summary: Thermal rate coefficients and kinetic isotope effects for the H/D + O-3 -> OH/OD + O-2 reaction were calculated using advanced methods, with the RPMD approach showing better agreement with experimental data and potential to reduce uncertainty in recommended rate coefficients.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Anna Kristina Schnack-Petersen, Matyas Papai, Klaus Braagaard Moller
Summary: The photoisomerization reaction of azobenzene in both directions was investigated using the surface hopping procedure with forced jumps based on density functional theory. It was found that the cis to-trans isomerization proceeds stepwise, while the trans-to-cis isomerization occurs in one smooth step. The analysis revealed that two coupled modes must be considered for a fuller picture of the cis to-trans isomerization, while the trans-to-cis isomerization can be well described along only the CNNC dihedral angle. The study provides insights into the interpretation of experimental observations and shows a heavy functional dependency in the structures of the conical intersections (CIs) for both reactive and non-reactive trajectories.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2022)
Article
Chemistry, Physical
Giovanni Granucci, Giancarlo Padula
Summary: In this study, a computational investigation was conducted on the photoisomerization of SP to merocyanine, with optimized parameters of the semiempirical Hamiltonian and consideration of the impact of excited states on dynamics simulations. The results showed that the photoisomerization quantum yield depends on the electronic state initially populated.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Analytical
Takuya Mabuchi, Koki Nakajima, Takashi Tokumasu
Summary: Through molecular dynamics simulations, the study investigated the relationship between Li-ion transport and polymer morphology in polymer electrolytes for all-solid-state Li-ion batteries. The size and number of LiTFSI clusters were found to increase with increasing salt concentrations, leading to a decrease in ion diffusivity at high salt concentrations. Additionally, it was found that the intra-hopping rate and distance were higher in PEO compared to P(2EO-MO), resulting in higher diffusivity in PEO.
Article
Engineering, Multidisciplinary
Chao Ma, Yuxi Lei, Weiyin Li, Xuefeng Xiao, Han Han
Summary: The progress in technology and industry has led to environmental pollution, especially in the form of industrial wastewater containing pollutants like formaldehyde. This research used molecular dynamics simulation to study the interaction between polymers and formaldehyde. The findings suggest that polypropylene (PP) is the most effective polymer for eliminating formaldehyde.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2023)
Article
Polymer Science
Katsumi Hagita, Takahiro Murashima, Minami Ebe, Takuya Isono, Toshifumi Satoh
Summary: This study aims to create a tough polymer network material using rings as movable crosslinks and explores the preparation methods of materials in which linear chains penetrate rings and ring complexes. Through the correspondence between simulations and experiments, we found that the ring size is crucial for achieving novel mechanical properties. In addition, we introduced the concept of ring-bridge probability and investigated the dependence of trapping probability and ring-bridge probability on the ring size. By establishing a close correspondence between experimental and simulation results, we were able to predict the bridge and trapping probabilities of spiro-multicyclic polymers. The findings highlight the significant contribution of simulation-based prediction in the development of polymer network materials with ring-linear blends.
Article
Multidisciplinary Sciences
Stanislav Zalis, Jan Heyda, Filip Sebesta, Jay R. Winkler, Harry B. Gray, Antonin Vlcek
Summary: The study elucidates the mechanism of charge transport over long distances through hole hopping via tryptophan/tyrosine chains, with experimental and theoretical analyses revealing key factors influencing the process. Experimental kinetics investigations demonstrated the acceleration effect of closely spaced tryptophans on long-range electron transfer, while theoretical calculations identified crossings between sensitizer-localized and charge-separated states in excited-state trajectories.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Multidisciplinary Sciences
Sarah E. Biehn, Steffen Lindert
Summary: HRPF combined with mass spectrometry can reveal protein structure, while a dynamics-driven algorithm can enhance the accuracy of structure prediction.
NATURE COMMUNICATIONS
(2021)
Article
Polymer Science
Yaguang Sun, Kaiwei Wan, Wenhui Shen, Jianxin He, Tong Zhou, Hui Wang, Hua Yang, Xinghua Shi
Summary: Recycling and reprocessing of conventional thermosetting polymers have gained attention due to environmental concerns. This study focuses on covalent adaptable networks (CANs) which incorporate functional groups capable of reversible exchange reactions into polymer networks, altering the topology arrangement and achieving stress relaxation. The researchers developed a machine-learning force field to describe the exchange reactions of polyimine CANs and provided insights into reaction mechanisms and energy profiles through enhanced sampling methods.
Article
Chemistry, Physical
Matyas Papai, Xusong Li, Martin M. Nielsen, Klaus B. Moller
Summary: In this study, we investigated the nonadiabatic excited-state dynamics initiated from the 3p Rydberg states of trimethylamine (TMA) using computational methods. We found that the CAM-B3LYP functional provides high accuracy for describing Rydberg excited states. Our simulations revealed the crucial role of vibrational coherence and energy transfer from the planarisation mode for N-C bond activation and branching at intersections.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Jiale Shi, Michael J. Quevillon, Pedro H. Amorim Valenca, Jonathan K. Whitmer
Summary: A machine learning method is proposed to predict the adhesion ability between a model polymer's sequence and decorated surfaces, providing a new approach for the design of functional polymers.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Jingbai Li, Patrick Reiser, Benjamin R. Boswell, Andre Eberhard, Noah Z. Burns, Pascal Friederich, Steven A. Lopez
Summary: By utilizing neural networks to accelerate photodynamics simulations, it becomes possible to predict complex molecular structures and reaction processes in a short amount of time, achieving significant time savings compared to traditional multiconfigurational photodynamics simulations.
Article
Materials Science, Multidisciplinary
Zhen Sun, Sheng Li, Shijie Xie, Z. An
Summary: The paper discusses the surface hopping method based on the PPP Hamiltonian and CIS, and its application in studying the dynamics of a cis-polyacetylene chain. The inability to detect trivial crossings between excited states at time zero using traditional methods may lead to false results, which can be addressed by screening appropriate initial conditions. Additionally, the contribution of the Z matrix to nonadiabatic coupling terms and forces can be neglected to some extent, leading to significant computational cost savings.
Article
Biochemistry & Molecular Biology
Heng Zhang, Jiyong Zheng, Cunguo Lin, Shiling Yuan
Summary: Zwitterionic polymers exhibit excellent antifouling performance due to their strong hydration ability. This study investigates the surface hydration ability of three antifouling polymer membranes and explores the relationship between surface structure and antifouling performance. The results show that the distribution of electrostatic potential and the nature of anionic groups play crucial roles in determining the antifouling ability.