Article
Materials Science, Multidisciplinary
Eva Zarkadoula, Ying Yang, Albina Borisevich, Easo George
Summary: Using molecular dynamics simulations, this study investigates the deformation-induced phase transition in an Fe-Ni alloy with and without precipitates. The results show that larger precipitates and smaller spacings hinder the phase transformation. These findings help interpret the experimental results and analyze the individual effects of precipitate size and spacing.
MATERIALS RESEARCH LETTERS
(2022)
Article
Chemistry, Physical
Nina Lorenz, Ishan Gupta, Thomas Palberg
Summary: We studied low-salt, binary aqueous suspensions of charged colloidal spheres with a size ratio of 0.57. The typical phase formed is a substitutional alloy with a body centered cubic structure. We also prepared the same samples using a different method which resulted in a complex sequence of gradients and a variety of microstructures. The observed crystallization processes are not volume-filling and the formed alloys are thermodynamically metastable without solid-fluid interfaces.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
J. Schwarz, P. Leiderer, T. Palberg
Summary: The study investigated bulk crystal nucleation rates in aqueous suspensions of charged spheres at low metastability, showing a correlation between crystal size distributions and electrolyte concentration. Parameterization of the results in terms of classical nucleation theory revealed unusually low interfacial free energies of the nucleus surfaces and nucleation barriers well below thermal energy. The presence of doublets introduced by the conditioning technique may be responsible for the observed phenomena of nucleation induced by small seeds.
Article
Chemistry, Multidisciplinary
Kohji Ohno, Tatsuya Hisatomi, Haruna Seo
Summary: Colloidal crystals are self-assembled systems suitable for studying crystallization. By synthesizing charged-polymer-brush-decorated core-shell hybrid particles through surface-initiated living radical polymerization, colloidal crystals were successfully constructed in an organic solvent.
Article
Materials Science, Multidisciplinary
Z. Z. Wei, X. Ma, C. B. Ke, X. P. Zhang
Summary: This study investigates the migration behavior of stepped FCC/BCC martensitic interfaces using molecular dynamics simulation. The results show that the stepped interfaces maintain a planar morphology and migrate at constant velocities due to the collective motion of disconnections. The migration velocities obtained are in good agreement with experimental measurements. The results provide insights into the interplay between interface structure and transformation process, which is crucial for understanding the atomic mechanism of martensitic transformations.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Chemistry, Physical
Xin Zhang, Wenliang Lu, Zun Liang, Yashen Wang, Songtai Lv, Hongtao Liang, Brian B. Laird, Yang Yang
Summary: In this study, a classical molecular-dynamics approach was used to investigate the collective dynamical properties of coexisting liquid phase at equilibrium body-centered cubic (BCC) Fe crystal-melt interfaces. An anisotropic speedup of the collective dynamics in all three BCC crystal-melt interfacial orientations was observed. The validity of time-dependent Ginzburg-Landau theory for solidification crystal-melt interface kinetic coefficients was revisited.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Yinsheng He, Jianbing Gao, Yizhu He, Keesam Shin
Summary: A new mechanism of martensitic transformation has been discovered, where the direct transformation of gamma (fcc) -> alpha ' (bcc) is possible in addition to the traditional gamma (fcc) -> epsilon (hcp) -> alpha ' (bcc) sequence. Atomic-scale observations using high-resolution transmission electron microscopy provided insights into the details of the transformation processes.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Chemistry, Physical
Bin Wu, Takuya Iwashita, Wei-Ren Chen
Summary: In this study, the electroviscous effects on shear rheology of highly charged silica particles were investigated. The system undergoes a glass transition as the salinity varies, and the steady shear viscosities follow critical scaling relations. Quantitative relationships between shear viscosity, stress, and salinity were established based on the scaling relations and common modeling equations.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Multidisciplinary
Emiko Mouri, Kei Kajiwara, Shuhei Kawasaki, Yusuke Shimizu, Hikaru Bando, Hideki Sakai, Teruyuki Nakato
Summary: This study reports the influence of aqueous clay colloids on the photoisomerization kinetics of anionic and cationic azobenzene molecules dissolved in the colloids. Under UV-light irradiation, the clay colloids decelerate the reaction, while under visible-light irradiation, they accelerate it. This expands the applicability of clay colloids as matrixes for functional organic species.
Article
Chemistry, Multidisciplinary
Xin Huang, Elizabeth Suit, Jinlong Zhu, Binghui Ge, Frauke Gerdes, Christian Klinke, Zhongwu Wang
Summary: Diffusion-mediated assembly of PbS nanocrystals in a confined antisolvent environment results in the growth of rhombic bcc supercrystals and triangle fcc supercrystals through burst nucleation, Ostwald ripening, and oriented attachment processes. The growth of rhombic bcc supercrystals is promoted by fast solvent diffusion and high-NC concentration, while the growth of triangle fcc supercrystals is accelerated by slow solvent diffusion and low-NC concentration. The successful designable growth of 3D fcc supercrystals provides principles for controlled fabrication of supercrystals with desired superlattices.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Wen-Liang Lu, Hong-Tao Liang, Xiang-Ming Ma, Zi-Feng Yuan, Xin Zhang, Zun Liang, Yang Yang
Summary: In this study, molecular dynamics simulations were used to investigate the equilibrium crystal-melt interface stresses in FCC and BCC structures. The characteristics of the interface stresses and their relationship with the interfacial free energies were analyzed. The effects of interatomic bonding on the shape and magnitude of the interface stress profiles were discussed through the examination of different crystal-melt interfaces in various materials. Additionally, the Irving-Kirkwood fine-grained algorithm was shown to outperform the per-particle virial stress algorithm in depicting microscopic pressure components and stresses near the crystal-melt interface.
SURFACES AND INTERFACES
(2022)
Article
Engineering, Chemical
Xiongtao Ji, Jingkang Wang, Ting Wang, Yunhai Huang, Bugui Zhao, Na Wang, Xin Huang, Hongxun Hao
Summary: In this study, the motion behavior of particles and its effect on colloidal stability were systematically studied and characterized at multiple stages and multiple scales through surface analysis of the nanocrystal, thermodynamic derivation, zeta potential measurements, and rheological studies. The interaction and motion behaviors of particles were further discussed through theoretical model calculations, and the destruction of the colloidal suspension was investigated and analyzed.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Physical
Giulia Fiorucci, Marjolein Dijkstra
Summary: The study investigates the out-of-equilibrium phase behavior of charged colloids under external oscillatory shear using non-equilibrium Brownian dynamics simulations. It reveals the formation of a twinned face-centered-cubic phase and a martensitic transition to a body-centered-cubic crystal in a specific range of maximum strain amplitude, along with the presence of a sliding layer phase and a string phase.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Miyu Ioka, Akiko Toyotama, Megumi Yamaguchi, Jun Nozawa, Satoshi Uda, Tohru Okuzono, Masamichi Yoshimura, Junpei Yamanaka
Summary: The addition of like-charged linear polyelectrolyte, sodium polyacrylate (NaPAA), formed non-close-packed colloidal crystals of negatively charged submicron-sized colloidal Au particles in aqueous dispersions, preventing particle aggregation. The NaPAA induced depletion attraction and reduced interparticle repulsion, while strong electrostatic repulsion prevented direct contact between particles. By drying the sample, the non-space-filling crystals transformed into closest packed crystals with enhanced Raman scattering intensity due to high hot-spot density.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Bin Li, Yong-Lei Wang, Guang Shi, Yangyang Gao, Xinghua Shi, Clifford E. Woodward, Jan Forsman
Summary: This study investigates systems containing oppositely charged colloidal particles under applied alternating current electric fields using overdamped Langevin dynamics simulations. The results show the formation of jammed bands perpendicular to the field direction under intermediate frequencies and lanes parallel with the field under low frequencies, depending on particle charges. The pathway for generating these bands follows a stepwise mechanism, with observations of intermediate bands in some systems. Additionally, the transition from jammed bands to lanes is found to occur at a critical value of pressure tensors parallel to the field direction, with stable steady states conforming to the principle of maximum entropy production.
