Article
Chemistry, Physical
N. N. Ren, P. F. Guan, K. L. Ngai
Summary: This study investigated the superposition of frequency dispersion of structural alpha relaxation at different temperature and pressure combinations, as well as the time dependence of faster processes like caged molecule dynamics and JG beta relaxation. Through molecular dynamics simulations, it was confirmed that this property holds for not only alpha relaxation but also caged dynamics and JG beta relaxation.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Liang Gao, Yang Sun, Hai-Bin Yu
Summary: The Johari-Goldstein secondary (0) relaxations are intrinsic features of supercooled liquids and glasses, and play a crucial role in several properties of glassy materials. This study demonstrates through atomistic simulations and percolation analysis that the mobile clusters are percolated at the occurrence of 0 relaxation in seven different glassy systems. The percolation transition shows the same temperature and time dependence with 0 relaxation, and emerges universally when about 10% of the atoms are mobile, with a dimension of approximately 2 for the system-spanning cluster. These findings contribute to the understanding of 0 relaxation in glasses.
Article
Multidisciplinary Sciences
Kumpei Shiraishi, Hideyuki Mizuno, Atsushi Ikeda
Summary: Supercooled liquids with complicated structural relaxation processes have been a long-standing problem in condensed matter physics. Previous experiments observed that relaxation dynamics in many molecular liquids separate into two distinct processes at low temperatures. This study uses molecular dynamics simulations to investigate the potential energy landscape and provides the first direct evidence of the topographic hierarchy that induces relaxation. The results contribute to a fundamental and comprehensive understanding of relaxation dynamics in supercooled liquids.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Physics, Fluids & Plasmas
K. L. Ngai
Summary: This study focuses on the research status and techniques related to JG beta relaxation in glass-forming materials. By combining TDI technique with dielectric and neutron scattering data analysis, it reveals that the JG beta relaxation is heterogeneous and comprises processes with different length scales, with processes of longer length scale having longer relaxation time. The study also finds that the primitive relaxation time of the coupling model falls within the distribution of the TDI q-dependent JG beta-relaxation times, which explains the experimental observations of the relationship between tau(beta) and tau(0) in various glass formers.
Article
Multidisciplinary Sciences
Michela Romanini, Roberto Macovez, Maria Barrio, Josep Lluis Tamarit
Summary: Temperature- and pressure-dependent dielectric spectroscopy and calorimetry techniques were used to characterize benzophenone and its ortho-bromobenzophenone derivative in the liquid and glass states. The study revealed the existence of a Johari-Goldstein relaxation in both compounds and identified the mechanism of intramolecular relaxation.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Physical
Federico Caporaletti, Simone Capaccioli, Dimitrios Bessas, Aleksander I. Chumakov, Alessandro Martinelli, Giulio Monaco
Summary: The JG relaxation is closely connected to the structural relaxation in supercooled liquids, and investigating its microscopic properties is crucial for understanding the glass-transition. In this study, we used time-domain interferometry to probe the microscopic density fluctuations of the van der Waals glass-former cumene. Our results show that the molecules involved in the JG relaxation undergo a restricted motion, leading to local cage-breaking events at the characteristic time-scale for molecular re-orientations.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Materials Science, Multidisciplinary
Qijing Sun, David M. Miskovic, Michael Ferry
Summary: This study investigated the impact of film thickness on the development of ultrastable metallic glasses, showing that controlling thickness can tune the thermophysical and mechanical properties of the material. Structural heterogeneity develops with film buildup, leading to variations in properties as the glass undergoes rejuvenation.
MATERIALS TODAY PHYSICS
(2021)
Article
Multidisciplinary Sciences
Misaki Ozawa, Yasutaka Iwashita, Walter Kob, Francesco Zamponi
Summary: A recent breakthrough in glass science involves the synthesis of ultrastable glasses using physical vapor deposition techniques. These glasses exhibit increased stability in terms of thermodynamics, kinetics, and mechanics, with significant implications for both fundamental research and practical applications. However, the current deposition technique is limited to specific types of glass-formers and can only produce thin film samples. In this study, a novel approach using random particle bonding is proposed to generate ultrastable glassy configurations in bulk materials. Computer simulations show the effectiveness of this method, which can be applied to various molecular and soft matter systems, offering great potential for the design of a wide range of ultrastable glasses.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Cecilia Herrero, Camille Scalliet, M. D. Ediger, Ludovic Berthier
Summary: The discovery of ultrastable glasses presents new challenges in understanding glassy systems. Recent experiments have studied the macroscopic devitrification of ultrastable glasses into liquids upon heating, but lacked microscopic resolution. By using molecular dynamics simulations, we analyze the kinetics of this transformation. Our study elucidates the nonequilibrium kinetics of glasses following a large temperature jump, which differs from both equilibrium relaxation and aging dynamics, and will guide future experimental studies.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Biochemistry & Molecular Biology
Antonio Tripodo, Francesco Puosi, Marco Malvaldi, Dino Leporini
Summary: Research indicates that analysis based on mutual information provides a deeper insight into the transport and relaxation properties of molecular and macromolecular glass formers. Near the glass transition, mutual information reveals different mobility and relaxation properties of particle clusters with filamentous or compact globular structures, especially in the context of dynamical heterogeneity and secondary Johari-Goldstein relaxation processes. Both dynamical heterogeneity and mutual information between orientation and bond displacement reach local maxima at the time scales of primary and JG secondary relaxation, indicating the involvement of rotation/translation coupling in the mechanistic explanation of both phenomena in (macro)molecular systems.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Polymer Science
Carlo Andrea Massa, Francesco Puosi, Dino Leporini
Summary: Extensive molecular-dynamics simulations were used to study a polymer model exhibiting heterogeneous Johari-Goldstein secondary relaxation. The time-temperature-pressure superposition of the primary relaxation was confirmed. The time scales of the primary and JG relaxations were found to be highly correlated, in agreement with the predictions of the Coupling Model. However, the exponent of the power law deviated from the expected value, potentially due to the specific relaxation process and the heterogeneity of the JG process.
Article
Polymer Science
Yuan-Biao Liu, Gao-Peng Shi, Guo-Zhang Wu
Summary: The study investigates the tuning of Johari-Goldstein β (β(JG)) relaxation in poly(n-alkyl methacrylate)s by adding various low-molecular-weight phenols, revealing the impact of different types of small molecules on the dynamic properties of polymers. Small molecules with small size and strong intermolecular hydrogen bond strength can significantly retard and suppress β(JG) relaxation, while those with a larger size and weak hydrogen bond strength enhance the separation between α and β(JG) relaxation.
CHINESE JOURNAL OF POLYMER SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
L. T. Zhang, Yun-Jiang Wang, Y. Yang, J. C. Qiao
Summary: In this study, the rejuvenation of metallic glasses through the training of the beta relaxation process is demonstrated. The transition from structural relaxation to rejuvenation is observed with increasing training frequency. Surprisingly, rejuvenation can be achieved at a relatively small cyclic strain of 0.2%. Rejuvenation increases relaxation enthalpy and promotes decoupling of the beta relaxation process and relaxation process. A cluster of beta relaxation time curves is formulated to describe energetic states between ultrastable and ultimately rejuvenated metallic glasses. Additionally, rejuvenation expands the distribution of the beta relaxation process, anelastic, and viscoplastic components during deformation.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Polymer Science
Herminio P. Diogo, Joaquim J. Moura Ramos
Summary: This study investigates the molecular mobility of poly (ether imide) across a wide temperature range using thermostimulated depolarization currents, covering the amorphous solid state, glass transition, and rubber state. Through analyzing different motional modes of the PEI glass transition, a comprehensive view of physical aging process was achieved. Additionally, a new mobility mode was identified below T-g and space charge motions were found in the rubber state.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Sofia Valenti, Luis Javier del Valle, Michela Romanini, Meritxell Mitjana, Jordi Puiggali, Josep Lluis Tamarit, Roberto Macovez
Summary: In this study, dispersions of a small-molecule drug in biodegradable polylactide were investigated using differential scanning calorimetry and broadband dielectric spectroscopy. The study reveals that the same small-molecule compound can have opposite effects on the mobility of a biopolymer depending on the preparation method, temperature, and polymer enantiomerism. The drug acts as an antiplasticizer for films but as a plasticizer for microfibres. Furthermore, the structural relaxation time of the samples is influenced by the chemical composition and morphology.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Multidisciplinary Sciences
Hai-Bin Yu, Ranko Richert, Konrad Samwer
Article
Chemistry, Physical
Hai-Bin Yu, Meng-Hao Yang, Yang Sun, Feng Zhang, Jian-Bo Liu, C. Z. Wang, K. M. Ho, Ranko Richert, Konrad Samwer
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2018)
Article
Chemistry, Physical
Si-Xu Peng, Cheng Zhang, Chong Yang, Ran Li, Tao Zhang, Lin Liu, Hai-Bin Yu, Konrad Samwer
JOURNAL OF CHEMICAL PHYSICS
(2019)
Article
Chemistry, Physical
Zhen-Ya Zhou, Hai-Long Peng, Hai-Bin Yu
JOURNAL OF CHEMICAL PHYSICS
(2019)
Article
Physics, Multidisciplinary
Yang Sun, Si-Xu Peng, Qun Yang, Feng Zhang, Meng-Hao Yang, Cai-Zhuang Wang, Kai-Ming Ho, Hai-Bin Yu
PHYSICAL REVIEW LETTERS
(2019)
Letter
Materials Science, Multidisciplinary
Qun Yang, Jing Huang, Xiao-Hui Qin, Fa-Xi Ge, Hai-Bin Yu
SCIENCE CHINA-MATERIALS
(2020)
Article
Multidisciplinary Sciences
Xu Peng, Yudong Cheng, Julian Pries, Shuai Wei, Hai-Bin Yu, Matthias Wuttig
Article
Multidisciplinary Sciences
Qun Yang, Si-Xu Peng, Zheng Wang, Hai-Bin Yu
NATIONAL SCIENCE REVIEW
(2020)
Article
Nanoscience & Nanotechnology
Chong Yang, Cheng Zhang, Zheng-Jie Chen, Yu Li, Wen-Yuan Yan, Hai-Bin Yu, Lin Liu
Summary: The study introduces a novel strategy to design efficient and reusable catalysts by incorporating Cu into a metallic glass-based catalyst and constructing three-dimensional hierarchical porous structures through laser 3D printing. The resulting catalysts show outstanding catalytic efficiency and exceptional reusability in degrading dyes.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Hao Zhang, Xinyi Wang, Hai-Bin Yu, Jack F. Douglas
Summary: The study investigates the fast beta- and Johari-Goldstein relaxation processes, along with the elastic scattering response of glass-forming liquids and the boson peak. These processes are found to be universal, even in glass-forming liquids with a fragile-strong transition. Heating leads to the growth of stringlets, resulting in an increase in relaxation process intensity and excitation softening.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Qun Yang, Chao-Qun Pei, Hai-Bin Yu, Tao Feng
Summary: Nanoglasses exhibit promoted beta-relaxation and enhanced microscale tensile plasticity compared to rapidly melt-quenched metallic glasses. The beta-relaxation is sensitive to the interfacial regions among grains in nanoglasses, showing a clear correlation between amorphous nanostructures and the beta-relaxation.
Article
Chemistry, Physical
Si-Xu Peng, Zheng Yin, Tao Zhang, Qun Yang, Hai-Bin Yu, Ming-Hua Zeng
Summary: This paper presents a new method for glass formation, utilizing mechanical vibration to facilitate the melting of metal-organic frameworks at lower temperatures and produce glass with unique properties. Experimental results show that the vibrated glass material exhibits a lower glass transition temperature, improved gas accessible porosity, and pronounced short-to-medium range structures compared to conventionally melt-quenched glass.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Liang Gao, Yang Sun, Hai-Bin Yu
Summary: The Johari-Goldstein secondary (0) relaxations are intrinsic features of supercooled liquids and glasses, and play a crucial role in several properties of glassy materials. This study demonstrates through atomistic simulations and percolation analysis that the mobile clusters are percolated at the occurrence of 0 relaxation in seven different glassy systems. The percolation transition shows the same temperature and time dependence with 0 relaxation, and emerges universally when about 10% of the atoms are mobile, with a dimension of approximately 2 for the system-spanning cluster. These findings contribute to the understanding of 0 relaxation in glasses.
Article
Materials Science, Multidisciplinary
Tao Zhang, Hui-Feng Zhao, Ke-Yan Wang, Zhen-Jie Chen, Li Li, Jing Peng, Xu Peng, Yong-Jiang Huang, Hai-Bin Yu
Summary: Even in their bulk forms, complex alloys like high-entropy alloys (HEAs) can be used as electrocatalysts for the oxygen evolution reaction (OER). The performance of HEAs is influenced by three crucial factors: homogeneous solid solution phase, surface reconstruction, and diversity of active intermediate species. These factors contribute to the potential industrial applications of bulk HEAs.