Article
Chemistry, Physical
Zhao Wang
Summary: This study used molecular dynamics simulations to investigate the physisorption behavior of hydrocarbon molecules on a covalent graphene-nanotube hybrid nanostructure. The results showed that the adsorbed molecules could diffuse into the nanotubes without external driving forces, due to variations in binding energy. Interestingly, the molecules remained trapped within the tubes even at room temperature, thanks to a gate effect observed at the neck region, overcoming the typical hindrance from concentration gradients. This passive mass transport and retention mechanism has implications for gas molecule storage and separation.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Multidisciplinary
Kalipada Koner, Susobhan Das, Shibani Mohata, Nghia Tuan Duong, Yusuke Nishiyama, Sharath Kandambeth, Suvendu Karak, C. Malla Reddy, Rahul Banerjee
Summary: Covalent organic nanotubes (CONTs) are one-dimensional porous frameworks constructed via dynamic covalent chemistry. Flexible and robust self-standing fabric has been successfully constructed using selected building blocks. The fabric has been characterized and its formation mechanism has been established. The synthesized fabric exhibits high mechanical strength and time-dependent elastic recovery.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Engineering, Mechanical
Seunghwa Yang
Summary: In this study, the impact of covalent grafting between CNTs and a PET matrix on the interface, interphase, and elasticity of the nanocomposite was investigated. The results show that covalent grafting can improve the transverse modulus and shear modulus of the nanocomposite. Additionally, the elastic modulus of the interphase is always higher than that of the neat PET matrix.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Chemistry, Physical
Pei Feng, Ye Kong, Li Yu, Anjie Min, Sheng Yang, Cijun Shuai
Summary: By modifying graphene oxide with APTES, the uniform dispersion of GO in PGA scaffold and improved interfacial bonding between the two materials were achieved, leading to enhanced mechanical properties and thermal stability of the scaffold.
SURFACES AND INTERFACES
(2021)
Article
Nanoscience & Nanotechnology
Junyao Zhang, Dapeng Liu, Qingqing Ou, Yang Lu, Jia Huang
Summary: A photonic synaptic transistor based on porphyrin-graphene covalent hybrids has been developed and successfully simulates essential biological functions. The synaptic plasticity and learning efficiency can be regulated by adjusting parameters. This method operates at a low voltage and shows great prospects in neuromorphic devices.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Qiangqiang Sun, Yong Zhao, Kwing-So Choi, Xianghui Hou, Xuerui Mao
Summary: Molecular dynamics simulations were conducted to investigate the physics of ice adhesion, and proposed graphene and carbon nanotube junctions can significantly reduce ice adhesion stresses on different substrates. This work sheds light on the design of icephobic wall surfaces and development of de-icing techniques.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Changxia Li, Patrick Guggenberger, Seung Won Han, Wei-Lu Ding, Freddy Kleitz
Summary: Covalent organic frameworks (COFs) have great potential as adsorbents due to their tailorable functionalities, low density, and high porosity. Constructing ultrathin COFs can increase the exposure of active sites to targeted molecules and enhance the adsorption capacity through a three-dimensional macroporous structure and well-exposed adsorption sites.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Liyuan Han, Caixiang Xiao, Qiang Song, Xuemin Yin, Wei Li, Kezhi Li, Yunyu Li
Summary: In this study, the mechanical properties of carbon nanotube (CNT)-reinforced carbon/carbon (C/C) composites were enhanced by seamlessly growing graphene nanosheets (GN) on the surface of CNT. The growth of GN improved stress transfer efficiency and effectively stiffened the interface, resulting in a significant increase in interlaminar shearing strength of the composite material.
Article
Chemistry, Multidisciplinary
Kaijie Ni, Ruiqi Xu, Rui Wang, Ming Guo, Yanyang Chen, Yuming Zhao
Summary: A novel interpenetrating polymer network (IPN) hydrogel has been developed as an effective and non-selective adsorbent for antibiotic pollutants in water. The hydrogel, made of carbon nanotube (CNTs), graphene oxide (GO), and urea-modified sodium alginate (SA), showed excellent adsorption capacity for tetracycline and good reusability. The hydrogel also exhibited efficient adsorptive performance for neomycin and erythromycin.
Article
Engineering, Chemical
Mehdi Ghasemi, Mohammad Khedri, Mohsen Didandeh, Mojtaba Taheri, Ebrahim Ghasemy, Reza Maleki, Ho Kyong Shon, Amir Razmjou
Summary: This study used computational techniques to assess the adsorption affinity of three regenerable covalent organic frameworks (COFs) for the removal of six different pharmaceutical pollutants. It found that the COFs showed promising potential as efficient adsorbents for the removal of these pollutants.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Zhiya Wang, Jingfeng Li, Shiyin Liu, Gaofeng Shao, Xiaojia Zhao
Summary: In this study, a new strategy was proposed to achieve the hybridization of COF and graphene through in situ polymerization, and high performance was demonstrated in electrocatalytic applications, showing potential for practical use.
Article
Nanoscience & Nanotechnology
Zongwei Guo, Zhao Wang, Jiajun Ma, Lin Jin, Yuhui Ao
Summary: Introducing two-dimensional nanoreinforced materials on the surface of carbon fibers is a promising strategy to overcome their chemical inertness. In this study, graphene oxide functionalized MXene was used to produce intercalated reinforcement materials with robust Ti-O-C covalent bonds, resulting in a more ordered and compact brick-and-mortar structure on the carbon fiber surface. The optimal carbon fiber composites achieved high strength and toughness with enhanced interlaminar shear and flexural strengths, expanding their applications.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Physical
Lulu Lyu, Jeongmin Kang, Kwang-dong Seong, Chae Won Kim, Jiho Lim, Yuanzhe Piao
Summary: By constructing a three-dimensional conductive graphene-carbon nanotube hydrogel network on nickel foam, this study has successfully improved the redox reaction kinetics and ionic electronic conductivity of ternary transition metal compounds, leading to high capacity, favorable rate performance, and cycling stability.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Tianyan Xu, Jinwu Jiang
Summary: In this study, the configuration of the graphene/carbon nanotube/graphene (GCG) van der Waals heterostructure is investigated through molecular dynamics simulations. A mechanical model based on the competition between bending energy and adhesion energy is successfully used to interpret the results. The findings show that the graphene layers compress the nanotube's cross-section into an ellipse, and the eccentricity increases with the nanotube's diameter. A concise expression for the relationship between eccentricity and nanotube diameter is obtained. These findings are valuable for further understanding the physical and mechanical properties of the GCG structure.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Polymer Science
Di Cui, Wei Xie, Shuran Zhang, Nan Jiang, Yanhong Xu, Zhongmin Su
Summary: A series of a-rGO@TD-COF hybrid materials were synthesized by growing a 2D TAPT-DHTA-COF with hydrogen bonds on the surface of aniline-functionalized graphene oxide. The energy storage performance of these materials was studied and it was found that a-rGO@TD-COF-4 showed significantly improved specific capacitance and energy density, demonstrating a synergistic effect between COFs and a-rGO.
Article
Chemistry, Applied
Sima Majidi, Hamid Erfan-Niya, Jafar Azamat, Soroush Ziaei, Eduardo R. Cruz-Chu, Jens Honore Walther
Summary: The global demand for clean and potable water is increasing due to population growth and pollution. Water contamination is a global problem that needs to be investigated for proper strategies to improve water quality and reduce water scarcity. Membrane technologies for water purification show promising results. This review discusses the use of molecular dynamics (MD) simulations to evaluate the performance of membrane-based water purification systems. The article also provides insights into recent developments and limitations of MD simulations in wastewater treatment using membranes.
SEPARATION AND PURIFICATION REVIEWS
(2023)
Article
Physics, Multidisciplinary
Ming-Jun Li, Lina Yang, Deng Wang, Si-Yi Wang, Jing-Nan Tang, Yi Jiang, Jie Chen
Summary: Traditional methods cannot non-destructively and quickly detect the internal structure of pavements, so it is important to accurately and quickly predict the mechanical properties of layered pavements. In recent years, machine learning has shown great superiority in solving nonlinear problems. This paper proposes a method based on random forest regression to predict the maximum deflection and damage factor of layered pavements under instantaneous large impact using the deflection basin parameters obtained from falling weight deflection testing. The prediction results have high consistency with finite element simulation results, indicating the potential of this method in non-destructive evaluation of pavement structure.
Article
Biochemical Research Methods
Sima Majidi, Hamid Erfan-Niya, Jafar Azamat, Eduardo R. Cruz-Chu, Jens Honore Walther
Summary: In this study, molecular dynamics simulation is used to investigate the effectiveness of graphdiyne nanosheet in separating nitrate ions from water. The results show that the fine regulation of hydrostatic pressure allows for efficient water flow and high water permeability, making graphdiyne a suitable membrane for nitrate separation.
JOURNAL OF MOLECULAR GRAPHICS & MODELLING
(2023)
Article
Chemistry, Physical
Elton Oyarzua, Jens H. H. Walther, Harvey A. A. Zambrano
Summary: The study introduces a graphene-based thermal nanopump that can produce controlled and continuous liquid flow in nanoslit channels by utilizing thermal gradients. Large-scale molecular dynamics simulations were conducted to investigate the performance of this thermal nanopump. The results show that water flow rates increase due to larger ripple fluctuations on the graphene layers as higher thermal gradients are applied, and the efficiency of the pump can be enhanced by modifying the wettability of the channel walls.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Biophysics
Lucas Amoudruz, Athena Economides, Georgios Arampatzis, Petros Koumoutsakos
Summary: In this study, a data-driven approach is employed to quantify the stress-free state shape and visco-elastic properties of red blood cells (RBCs) for the first time. A transferable RBC model is introduced based on these quantifications, and its effectiveness is demonstrated through accurate predictions of blood flows under unseen experimental conditions.
BIOPHYSICAL JOURNAL
(2023)
Article
Materials Science, Multidisciplinary
Wei-Jun Ren, Shuang Lu, Cui-Qian Yu, Jia He, Jie Chen
Summary: The carbon honeycomb structure has both high in-plane thermal conductivity and high axial thermal conductivity, which is robust to structural disorder. This study suggests that the carbon honeycomb structure has unique advantages to serve as a thermal management material.
Article
Engineering, Chemical
Seyed Heydar Rajaee Shooshtari, Jens Honore Walther, Chuang Wen
Summary: This paper presents a novel approach using computational fluid dynamics (CFD) and genetic algorithm to provide new equations for normal shock waves. The proposed model shows more accurate predictions for shock position compared to the traditional theoretical model. It can be used as an accurate and efficient tool for shock position prediction and nozzle design.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Physics, Multidisciplinary
Jian-Hui Jiang, Shuang Lu, Jie Chen
Summary: The rise of artificial microstructures has allowed for the modulation of various waves, including light, sound, and heat. In this study, we propose an atomic level triangular structure in single-layer graphene to achieve the phonon focusing effect. Our simulation results demonstrate that the height of the triangular structure can control multiple features related to the phonon focusing effect in the positive incident direction. Additionally, a distinct focusing pattern and enhanced energy transmission coefficient are observed in the reverse incident direction. Fourier transform analysis provides insights into the mode conversion physics of the phonon wave packet.
CHINESE PHYSICS LETTERS
(2023)
Article
Engineering, Multidisciplinary
Ivica Kicic, Pantelis R. Vlachas, Georgios Arampatzis, Michail Chatzimanolakis, Leonidas Guibas, Petros Koumoutsakos
Summary: Predictive simulations are crucial for various applications, but their accuracy relies on capturing effective system dynamics. Massively parallel simulations are expensive, while reduced order models have limitations. AdaLED is a novel framework that combines large-scale simulations and reduced order models to extract and forecast effective dynamics of multiscale systems. It employs autoencoders and probabilistic recurrent neural networks for fast and adaptable learning, achieving net speed-ups and detecting unseen dynamics regimes. AdaLED is a powerful tool for computationally expensive simulations.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Chemistry, Physical
Petr Karnakov, Sergey Litvinov, Petros Koumoutsakos
Summary: We introduce a potent computational method for solving inverse problems in fluid mechanics, which accelerates the convergence of gradient-based optimization methods for problems with parameters on a grid. By incorporating a multigrid decomposition technique, we achieve significant improvement in both computational efficiency and the avoidance of local minima. Our results demonstrate that this method, called mODIL, outperforms the popular Physics-Informed Neural Networks (PINNs) method in terms of computational cost, with three to five orders of magnitude lower cost in benchmark problems.
EUROPEAN PHYSICAL JOURNAL E
(2023)
Article
Energy & Fuels
Min Zhang, Jiun Cai Ong, Kar Mun Pang, Shijie Xu, Yan Zhang, Arash Nemati, Xue-Song Bai, Jens Honore Walther
Summary: The present study uses large eddy simulation to investigate combustion recession for the Engine Combustion Network Spray A flame under different ambient temperatures and injection pressures. The numerical results accurately capture the different combustion recession phenomena. The combustion recession is mainly controlled by the auto-ignition process at a higher ambient temperature, while at a lower ambient temperature, the local temperature within the fuel-rich region is not high enough to promote high-temperature ignition.
Article
Energy & Fuels
Arash Nemati, Jiun Cai Ong, Min Zhang, Jens Honore Walther
Summary: The auto-ignition process of micro-pilot diesel in premixed dual-fuel combustion was studied using large eddy simulation. It was found that the inhomogeneity in temperature has a more significant influence on the ignition delay time (IDT) than methane inhomogeneity. The inhomogeneity pockets of temperature advance the first-stage and second-stage ignition. This study is important for improving engine performance and reducing exhaust emissions.
Article
Mechanics
Diego Becerra, Andres Cordoba, Jens H. Walther, Harvey A. Zambrano
Summary: Through atomic-level simulations, it is found that graphene coating significantly enhances water flow in nanochannels compared to hexagonal boron nitride (hBN) coating. The natural undulations of graphene coating further enhance water flow.
Article
Materials Science, Multidisciplinary
Zhongwei Zhang, Yangyu Guo, Marc Bescond, Masahiro Nomura, Sebastian Volz, Jie Chen
Summary: In this paper, a theoretical model for exploring phonon coherence based on spectroscopy is proposed and validated using Brillouin light scattering data and molecular dynamic simulations. The model shows that confined modes exhibit wavelike behavior with a higher ratio of coherence time to lifetime. The spectroscopy data also demonstrates the dependence of phonon coherence on system size. The proposed model allows for reassessing conventional spectroscopy data to obtain coherence times, which are crucial for understanding and estimating phonon characteristics and heat transport in solids.
Article
Materials Science, Multidisciplinary
Cuiqian Yu, Shuyue Shan, Shuang Lu, Zhongwei Zhang, Jie Chen
Summary: Through molecular dynamics simulations, the fundamental characteristics of second sound are explored in a transient heat conduction modeling in single-layer and multilayer graphene and graphite. The results demonstrate that second sound can carry more heat energy and maintain for a longer lifetime than ballistic pulse. The effects of thickness and temperature on second sound propagation are also investigated.
