Article
Physics, Multidisciplinary
Wilkin Woehler, Tanja Schilling
Summary: This study investigates crystal nucleation in suspensions of hard spheres and finds that there is a significant discrepancy between experimentally observed nucleation rates and numerically computed rates at low supersaturations. By proposing an interpretation of the experimental data as a combination of nucleation and crystal growth processes, the long-standing dispute about the differing rates may be resolved.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
Fabian A. Garcia Daza, Antonio M. Puertas, Alejandro Cuetos, Alessandro Patti
Summary: This study investigates particle tracking in soft materials using Dynamic Monte Carlo simulations and microrheology techniques. The effects of size and ordering on the system relaxation are evaluated under different structural properties. The results reveal that the size of the tracer and the background ordering have a direct influence on the observed microrheology phenomena.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Polymer Science
Vincenzo Calabrese, Stylianos Varchanis, Simon J. Haward, Amy Q. . Shen
Summary: Understanding the hydrodynamic alignment of colloidal rods in polymer solutions is crucial for producing structurally ordered materials. This study analyzes the alignment of colloidal rods suspended in polymer solutions and compares it to the case where additional colloidal rods provide crowding in a pure solvent. The dynamics of the polymer is found to govern the shear-induced alignment of colloidal rods, with the Weissenberg number as the control parameter for alignment. Additionally, it is shown that the alignment of colloidal rods follows a universal trend regardless of the crowding environment.
Article
Chemistry, Physical
Chengjie Luo, Liesbeth M. C. Janssen
Summary: This study investigates the generalized mode-coupling theory (GMCT) for sticky hard spheres, which expands the dynamics in higher-order density correlation functions to more accurately describe the glass transition point and complex glassy dynamics. Compared to traditional mode-coupling theory, GMCT is closer to empirical observations.
Article
Physics, Fluids & Plasmas
Alexander P. Antonov, Soeren Schweers, Artem Ryabov, Philipp Maass
Summary: We propose a simulation method for Brownian dynamics of hard rods in one dimension under arbitrary continuous external force fields. The method is based on event-driven procedures involving fragmentation and mergers of clusters formed by particles in contact. It can handle particle interactions in addition to hard-sphere exclusion, as long as the interaction forces are continuous functions of particle coordinates. Furthermore, we develop a treatment for sticky hard spheres using Baxter's contact interaction potential.
Article
Chemistry, Physical
Anja Kuhnhold, Paul van der Schoot
Summary: The internal structure of nematic droplets or tactoids formed by rod-like particles in a gas of spherical ghost particles is studied using Monte Carlo simulations. The size of the droplets strongly affects their shape and internal structure. An external quadrupolar alignment field makes the director field more uniform, but does not significantly increase the aspect ratio of the droplets.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Tor Sewring, Martin Trulsson
Summary: This computational study examines the ground state of suspensions of charged linear rods with monodisperse sizes at different densities and screening lengths. The study shows that closed-packed unidirectional configurations have the lowest energies in all cases. The researchers also identify metastable phases, such as heliconical structures, and conduct simulations to study the transition from isotropic to anisotropic order in dense suspensions of charged rods.
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
Yoshiharu Suzuki, Satoshi Takeya
Summary: Metastable forms of ice and their crystal growth are crucial in various areas. This study investigates the effects of solute on the crystal growth of ice in dilute solution and reveals the inhibitory effect of trehalose on ice crystal growth, which results in easier sublimation of ice.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Mechanics
K. Zhao, F. Pomes, B. Vowinckel, T. -J. Hsu, B. Bai, E. Meiburg
Summary: This study investigates the dynamics of cohesive particles in homogeneous isotropic turbulence, showing that weaker cohesive forces and larger turbulent shear result in smaller elongated flocs. Intermediate cohesive forces produce the largest flocs during the transient stage, while stronger cohesive forces yield larger flocs during equilibrium. Additionally, flocs tend to align with the strongest Lagrangian stretching direction, with smaller flocs aligning with the extensional strain direction.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
M. Schiodt, A. Hodzic, F. Evrard, M. Hausmann, B. Van Wachem, C. M. Velte
Summary: In this study, the analysis of the Lagrangian spectrum in particle-laden turbulence is extended from statistically stationary flows to temporally non-stationary flows using the technique of time-focalized proper orthogonal decomposition (POD). The temporal POD modes extracted from the dispersed phase are found to be useful for expanding both fluid and particle velocities. The POD Lagrangian spectrum of each phase can be computed from the same set of modal building blocks, allowing the evaluation of response functions in a POD frame of reference. A model for response functions in non-stationary flows is proposed, and the energies of the two phases are well approximated by simple analytical expressions dependent on the particle Stokes number. The analytical expressions closely resemble those derived through Fourier analysis of statistically stationary flows, suggesting the existence of an inherent spectral symmetry in particle-laden turbulence that spans across stationary/non-stationary flow states.
Article
Chemistry, Physical
J. Opdam, D. Guu, M. P. M. Schelling, D. G. A. L. Aarts, R. Tuinier, M. P. Lettinga
Summary: This study investigated the phase boundaries and interactions in aqueous mixtures containing colloidal rod-like fd-viruses and polystyrene spheres, revealing the importance of excluded volume interactions. Experimentally determined phase transitions showed good correspondence with theoretical predictions from free volume theory, highlighting the role of excluded volume of rod-like depletants in the system.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Ian Williams, Erdal C. Oguz, Hartmut Loewen, Wilson C. K. Poon, C. Patrick Royall
Summary: Colloids can be considered as big atoms and provide good models for atomic and molecular systems. Colloidal hard disks, serving as good models for 2D materials, have received relatively little attention in rheology despite being well-characterized in phase behavior. This study measures the shear rheology of quasi-hard-disk colloids in extreme confinement using a novel experimental setup and computer simulations. The results show that the rheological behavior of the confined system is similar to unconfined 2D and 3D hard particle systems, with the occurrence of dynamic yield stress and shear thinning.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
F. Orts, M. Maier, M. Fuchs, G. Ortega, E. M. Garzon, A. M. Puertas
Summary: The dynamics of a tracer particle in a bath of quasi-hard colloidal spheres is investigated using Langevin dynamics simulations and mode coupling theory. The study reveals that the size of the tracer particle has a significant impact on its motion, as well as on the dynamics of the bath particles.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Joeri Opdam, Poshika Gandhi, Anja Kuhnhold, Tanja Schilling, Remco Tuinier
Summary: In this paper, we study excluded volume interactions, free volume fraction available, and phase behavior in mixtures of hard spheres and hard rods. Comparing the results of free volume theory and Monte Carlo simulations, we find that the novel approach predicts free volume and phase stability accurately.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)