Article
Physics, Fluids & Plasmas
Roberto Benzi, Thibaut Divoux, Catherine Barentin, Sebastien Manneville, Mauro Sbragaglia, Federico Toschi
Summary: Yield stress fluids display a dual nature where they exhibit solid or liquid properties depending on the imposed stress, with a transition characterized by stress overshoot and subsequent relaxation. The complex spatiotemporal dynamics of shear-induced yielding in YSFs can be summarized into short-term response and stress relaxation stages.
Article
Chemistry, Physical
Bin Cheng, Zhichao Jiang, Jingfa Yang, Jiang Zhao
Summary: The study focuses on the activation of fast rotational motion of single fluorescent probe molecules inside a polymer thin film near its glass transition temperature by residual stress. The kinetic energy of the probes shows a monotonic increase with stress strength and exhibits a rough linear dependence at low stress levels. The activation effect is localized and diminishes above the glass transition temperature.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Physics, Fluids & Plasmas
Keerti Chauhan, Ankit Singh
Summary: Using Langevin dynamics simulations, we investigated the kinetics of collapse transition in free and pinned polymers. Pinning the central monomer has negligible effects on the kinetics, while pinning other monomers causes a delay in the process. The total collapse time scales with the polymer length and is maximum when an end monomer is pinned. The average cluster size of pinned polymers shows two time regimes and deviates from that of free polymers.
Article
Physics, Fluids & Plasmas
Hrishikesh Kalita, Parvej Khan, Sumana Dutta
Summary: This study demonstrates the synchronization of coupled rotors, specifically two spiral waves, using diffusion as the coupling mechanism. The frequency and phase synchronization of the spiral waves can be modified by pinning them to unexcitable obstacles. Experimental results show different types of phase synchronization depending on the difference in characteristic frequencies of the rotors. The time required for synchronization and the phase lag between the rotors can be influenced by the relative size of the pinning obstacles and the distance between the rotors.
Article
Physics, Multidisciplinary
Roberto Benzi, Thibaut Divoux, Catherine Barentin, Sebastien Manneville, Mauro Sbragaglia, Federico Toschi
Summary: Soft Glassy Materials (SGM) are dense amorphous assemblies of colloidal particles with diverse shapes, elasticity, and interactions, giving them solid-like properties at rest. They are widely used in modern engineering fields such as additive manufacturing, semi-solid flow cells, dip coating, and adhesive locomotion, and often undergo a solid-to-liquid transition induced by shear. In this article, we propose a continuum model based on a spatially resolved fluidity approach to explain shear-induced yielding in SGMs. Our model captures quantitatively the key features of complex flows in SGMs, including the rate dependence of stress overshoot, transient shear-banded flows, and scaling laws for fluidization times.
Article
Materials Science, Multidisciplinary
Rhodri Mansell, Yifan Zhou, Kassius Kohvakka, See-Chen Ying, Ken R. Elder, Enzo Granato, Tapio Ala-Nissila, Sebastiaan Van Dijken
Summary: This study demonstrates the formation of a weakly pinned skyrmion liquid in a magnetic heterostructure, and evaluates the dependence of skyrmion dynamics on the skyrmion size and density. The diffusion of skyrmions is found to be largest in dense liquids with small skyrmions. These findings are important for the design of probabilistic computing devices.
Article
Engineering, Chemical
Bennett D. Marshall, Ronita Mathias, Ryan P. Lively, Benjamin A. McCool
Summary: The study introduces a modified approach to self-consistently calculate the glassy polymer density of a solvent swollen polymer, which has profound implications on both theoretical and practical aspects. This is achieved through a new perturbation theory, validating the new approach against sorption data in several glassy polymers.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Materials Science, Multidisciplinary
Panpan Zhu, Ji Lin, Rui Xiao, Haofei Zhou
Summary: This work investigates the stress responses of pre-deformed glassy polymers using coarse-grained molecular dynamics simulations. The competition between intra-chain deformation and inter-chain friction is found to govern yielding and strain hardening. A mean-field shear transformation zone model is developed based on the physical mechanisms revealed by the simulations, which successfully captures the observed mechanical responses.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Physics, Condensed Matter
Anh D. Phan
Summary: The study proposes a theoretical framework for the dynamics of bulk isotropic hard-sphere systems in the presence of randomly pinned particles and applies it to supercooled water. It reveals that as the fraction of pinned particles increases, the local caging constraint becomes stronger, and the long-range collective relaxation is screened by immobile obstacles, resulting in different responses of local and cooperative motions.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
Yueran Wang, Peter Harrowell
Summary: The non-slip constraint between a particle and a wall is implemented using the rough sphere model in the microscopic collision dynamics. We investigate the effects of translation-rotation coupling of a rough sphere confined between two parallel planar walls and find that shearing the walls past each other preferentially transfers energy to the rotational degree of freedom and leads to bounded oscillation of the confined particle's energy.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
S. P. Acharya, A. Mukherjee, M. S. Janaki
Summary: This study explores the dynamics of (2+1)-dimensional nonlinear dust-ion acoustic waves in a low temperature plasma environment in the low Earth orbital region with charged space debris particles. The research reveals exact dust-ion acoustic solitary wave solutions and their bending phenomena in different planes, as well as a family of exact pinned accelerated solitary wave solutions. These solutions demonstrate how the shape of the debris function changes during propagation and may be valuable in modeling experimental data.
Article
Chemistry, Physical
Daniele Coslovich, Robert L. Jack, Joris Paret
Summary: This study uses unsupervised learning methods to characterize the disordered microscopic structure of supercooled liquids and glasses. Dimensionality reduction is performed on smooth structural descriptors, and the ability of the method to capture the essential structural features of glassy binary mixtures is assessed. The results indicate that some mixtures have well-defined locally favored structures and are reflected in bimodal distributions of structural variables identified through dimensionality reduction.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Polymer Science
Gaoyuan Wang, Annette Zippelius, Marcus Mueller
Summary: Cross-linking is a versatile strategy to stabilize the structure and control the dynamics of polymers. This study systematically investigates the phase behavior of randomly cross-linked diblock copolymer melts and reveals the significant influence of the preparation state on the phase diagram.
Article
Physics, Fluids & Plasmas
Tuhin Subhra Das, Dan Wilson
Summary: In this study, a strategy for unpinning cardiac fibrillation is proposed using phase analysis and optimal control. Synchronization of pinned spiral waves on heterogeneous obstacles is achieved using a time-varying external voltage gradient, and unpinning is performed simultaneously at appropriate stimulation moments. Numerical validation demonstrates the feasibility of this strategy.
Article
Physics, Applied
Yuri Dikansky, Anna G. Ispiryan, Igor M. Arefyev, Andrey S. Drozdov, Arthur R. Zakinyan
Summary: This study investigates ferrofluids with a dispersion medium that crystallizes with decreasing temperature. The temperature dependence of the dynamic magnetic susceptibility of these ferrofluids was measured. In comparison, similar susceptibility dependence of ferrofluids with a dispersion medium that does not form a crystalline structure when solidified by cooling is presented. It is demonstrated that the formation of regions of high particle concentration during the crystallization process is the cause for a jump in colloid magnetic susceptibility. This conclusion refutes the previously existing opinion regarding the cause of the susceptibility jump in ferrofluids.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Multidisciplinary
Anh D. Phan, Alessio Zaccone, Vu D. Lam, Katsunori Wakabayashi
Summary: The theoretical study predicts compression-induced rejuvenation and strain hardening in metallic glasses, mainly controlled by local cage dynamics. External pressure restricts dynamical constraints and slows down atomic mobility, inducing a rejuvenated metastable state at a higher energy. Consequently, compressed metallic glasses can rejuvenate and exhibit reversible relaxation, leading to strain hardening in mechanical deformation experiments. The theoretical predictions are in good agreement with experimental observations.
PHYSICAL REVIEW LETTERS
(2021)
Article
Polymer Science
Anh D. Phan, Nguyen K. Ngan, Nam B. Le, Le T. M. Thanh
Summary: In this study, the physical properties of ternidazole, glycerol, and probucol under pressure-induced activation volume and dynamic decoupling were theoretically investigated. The study found that pressure affects the molecular dynamics of materials and decouples the structural relaxation time of compressed systems from their uncompressed value. The decoupling exponent and activation volume are intercorrelated and linked to the differential activation free energy, providing explanations for results in previous experiments and simulations.
MACROMOLECULAR THEORY AND SIMULATIONS
(2022)
Article
Materials Science, Multidisciplinary
Nguyen K. Ngan, Anh D. Phan, Alessio Zaccone
Summary: The temperature dependence of reversible structural relaxation time and diffusion constant of metallic glasses under pressure is investigated in theory. External compression not only alters the glass dynamics, but also leads to the formation of a metastable state and a higher-energy state. The relaxation times in this two-state system are faster than the relaxation time without considering barrier recrossing.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2021)
Article
Multidisciplinary Sciences
Asieh Ghanekarade, Anh D. Phan, Kenneth S. Schweizer, David S. Simmons
Summary: This study investigates the influence of nanoscale confinement on the dynamics and glass transition temperature of nano-liquids. By combining molecular dynamics simulations and the ECNLE theory, the research reveals the dynamical features in films of different thicknesses, as well as the alterations in the structural relaxation process induced by interface-nucleated gradients and finite size effects.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Physical
Anh D. Phan
Summary: This work develops a new theoretical model to investigate the glassy dynamics in metallic glass thin films. The study finds that the thickness of the films has a significant impact on the spatial gradient of structural relaxation time and glass transition temperature. Moreover, reducing the film thickness enhances the dynamic coupling between two surfaces and makes the gradient of the glass transition temperature more uniform. These findings are important for understanding the properties of metallic glass thin films.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Materials Science, Multidisciplinary
Anh D. Phan, Nguyen K. Ngan, Do T. Nga, Nam B. Le, Chu Viet Ha
Summary: A theoretical approach is proposed to quantitatively determine the photothermally driven enhancement of molecular mobility of graphene-indomethacin mixtures under infrared laser irradiation. The temperature gradients of the bulk drug with different concentrations of graphene plasmons are calculated, from which the temperature dependence of structural molecular relaxation and diffusion of indomethacin is determined and the significant enhancement of drug mobility through the heating process is found out.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2022)
Article
Chemistry, Physical
Tran Dinh Cuong, Anh D. Phan
Summary: This study utilizes a theoretical model and numerical analysis to reveal the evolution of vacancies during heating. The results indicate that anharmonic effects have a significant impact on the Gibbs energy of vacancy formation.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
D. N. Dung, Anh D. Phan, Toan T. Nguyen, Vu D. Lam
Summary: The study introduces a theoretical model to investigate intermolecular electrostatic interactions between a virus and a substrate. The model considers the impact of electric potentials surrounding the virus and fiber, and it is applied to coronavirus or SARS-CoV-2 cases with quantitatively consistent numerical results. Findings show the significance of fiber potential on virus surface charge and the substantial decrease of electrostatic interaction with increasing separation distance.
Article
Polymer Science
Luis A. Miccio, Claudia Borredon, Ulises Casado, Anh D. Phan, Gustavo A. Schwartz
Summary: The analysis of structural relaxation dynamics of polymers provides insights into their mechanical properties, which are important for determining a material's suitability for practical applications. However, obtaining the relaxation time through experimental processes after polymer synthesis is time-consuming. In this study, we propose a method that combines artificial neural networks and the elastically collective nonlinear Langevin equation (ECNLE) to estimate the temperature dependence of the main structural relaxation time of polymers based solely on the chemical structure of the monomer.
Article
Physics, Condensed Matter
Anh D. Phan
Summary: The study proposes a theoretical framework for the dynamics of bulk isotropic hard-sphere systems in the presence of randomly pinned particles and applies it to supercooled water. It reveals that as the fraction of pinned particles increases, the local caging constraint becomes stronger, and the long-range collective relaxation is screened by immobile obstacles, resulting in different responses of local and cooperative motions.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Materials Science, Ceramics
Nguyen Minh Hieu, Cao Van Phuoc, Cao Viet Anh, Nguyen Manh Hung, Anh D. Phan, Nguyen Duc Chinh, Sutripto Majumder, Pham Thanh Huy, Jong- Ryul Jeong, Junghyo Nah, Dojin Kim
Summary: In this research, Bi2O3 nanoparticles/SWCNT nanohybrids were synthesized using a simple chemical procedure to construct a room temperature acetone gas sensor that can tolerate humidity. The morphological structure properties of the nanohybrids were analyzed using X-ray diffraction, transmission electron microscopy, and other surface area measurements. The effect of humidity was investigated through resistance and conductivity measurements, and the nanohybrids demonstrated a stable and linear response to acetone under increasing humidity conditions (0-90%), outperforming pure Bi2O3 and pure SWCNTs.
CERAMICS INTERNATIONAL
(2023)
Article
Physics, Multidisciplinary
Asieh Ghanekarade, Anh D. Phan, Kenneth S. Schweizer, David S. Simmons
Summary: Large-system molecular dynamics simulations reveal long-range tails of interface-driven gradients of the glass transition temperature in glass-forming polymer films, suggesting a combined local caging and long-range collective elasticity origin of relaxation and vitrification. The spatial gradients of the glass transition temperature and structural relaxation time near an interface provide signatures of relaxation in bulk glass-forming liquids. Thick glass-forming polymer films with one vapour interface exhibited two distinct regimes in the gradients of the glass transition temperature and relaxation time: a medium-ranged, large-amplitude exponential gradient, followed by a long-range tail described by an inverse power law. These findings support a coupled spatially local-nonlocal mechanism of relaxation and vitrification in both bulk and broken-symmetry films.
Article
Materials Science, Multidisciplinary
Do T. Nga, Anh D. Phan, Thudsaphungthong Julie, Nam B. Le, Chu Viet Ha
Summary: We theoretically investigate the photothermal heating of ultra-flexible metamaterials consisting of TiN nanoparticles randomly mixed in polydimethylsiloxane (PDMS). Due to the plasmonic properties of TiN nanoparticles, incident light is fully absorbed in the broadband range of 300-3000 nm, generating heat within the metamaterials. Our predicted temperature rise as a function of time under irradiation of an 808 nm near-infrared laser agrees well with recent experimental data. The temperature rise varies non-monotonically with the concentration of TiN nanoparticles due to the opposing effects of enhanced thermal conductivity and absorbed energy on the heating process.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Tran Dinh Cuong, Anh D. D. Phan
Summary: This study provides a concise quantum statistical method to solve the phase diagram problem of beryllium and reveals the correlation among symmetric characteristics, vibrational excitations, and physical stabilities. In addition, we modify the work-heat equivalence principle to quickly obtain the high-pressure melting curve. Lastly, we investigate the behavior of beryllium under shock compression, which is advantageous for designing inertial confinement fusion experiments.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Tran Dinh Cuong, Nguyen Quang Hoc, Nguyen Duc Trung, Nguyen Thi Thao, Anh D. Phan
Summary: In this study, an efficient approach is proposed to investigate the solid-liquid transition of iron under extreme conditions. The statistical moment method and work-heat equivalence principle are used to explain experimental and ab initio results.