22 citations · 83 across the 23 of their papers we have counts for
25 papers
A unified description of flow-induced scission of wormlike micelles under shear and extensional flows
Yusuke Koide, Takato Ishida, Takashi Uneyama +1
We investigate flow-induced scission of wormlike micelles under different flow kinematics using dissipative particle dynamics simulations of surfactant solutions in shear, uniaxial…
Stress Drops Associated with Surface Crack Formation in Photo-aged Polypropylene during Three-Point Bending
Kazuya Haremaki, Yusuke Koide, Takashi Uneyama +2
Using three-point bending, this study investigates surface-crack formation in photo-aged polypropylene (PP) that has a depth-dependent aging gradient. PP undergoes embrittlement un…
A Generalized Mechanical Model for the Cycle Rank Dependence of Stretch at Break in Phantom Chain Star Polymer Networks
Yuichi Masubuchi, Takato Ishida, Takashi Uneyama
A simple mechanical model was recently proposed to explain the universality of stretch at break (λ_b) as a function of cycle-rank density (ξ) in phantom-chain network simulations […
Statistics of rupture in phantom chain network simulations
Yuichi Masubuchi, Takato Ishida, Takashi Uneyama
Phantom chain simulations have shown that the mean rupture properties of star polymer networks collapse onto master curves against the cycle rank density . This study revisits t…
Effect of flow kinematics on extensional viscosity of dilute polymer solutions
Yusuke Koide, Takato Ishida, Takashi Uneyama +1
We investigate the effect of flow kinematics on the extensional viscosity of dilute polymer solutions by conducting dissipative particle dynamics simulations under uniaxial, planar…
Coarse-Grained Molecular Dynamics Simulations of Oxidative Aging and Stabilization in Polymer Melts with Primary Antioxidants: Effects of Antioxidant Concentration and Molecular Architecture
Takato Ishida, Emmanuel Richaud
Industrial polymeric materials often rely on antioxidants to achieve long-term reliability. Previous studies have frequently discussed the stabilization effect in the presence of m…
Relation between extensional viscosity and polymer conformation in dilute polymer solutions
Yusuke Koide, Takato Ishida, Takashi Uneyama +1
We investigate extensional viscosity and polymer conformation in dilute polymer solutions under uniaxial extensional flow using dissipative particle dynamics simulations. At high e…
A Review on Molecular Simulations for the Rupture of Polymer Networks
Yuichi Masubuchi, Takato Ishida, Yusuke Koide +1
Molecular simulations provide a powerful means to unravel the complex relationships between network architecture and the mechanical response of polymer networks, with a particular…
Influence of Stretching Boundary Conditions on Fracture in Phantom Star Polymer Networks: From Volume to Cross-sectional Area Conservation
Yuichi Masubuchi, Takato Ishida, Yusuke Koide +1
This study systematically investigates the effect of stretching boundary conditions, ranging from conservation of cross-sectional area to conservation of volume, on the rupture beh…
Steady-state extensional viscosity of wormlike micellar solutions via dissipative particle dynamics simulations
Yusuke Koide, Takato Ishida, Takashi Uneyama +1
We investigate the steady-state extensional viscosity of wormlike micellar solutions using dissipative particle dynamics simulations. As the extension rate increases, the steady-st…
Direct observation of the compression behavior of polystyrene microbeads in a diamond anvil cell
Haruto Moriguchi, Ken Niwa, Masashi Hasegawa +4
The pressure dependence of the bulk modulus of glassy polystyrene (PS) was measured in the relatively high-pressure regime, up to 6 GPa, at ambient temperature. For the measurement…
Effects of Stirring Time on Formation of Microplastics Fragmented from Photo-aged Polypropylene
Kazuya Haremaki, Takumitsu Kida, Yusuke Koide +3
This paper examines the evolution of microplastic (MP) size distributions fragmented from photo-aged polypropylene (PP) in stirred water. PP specimens fragmented into MPs with thei…
Nonmonotonic concentration dependence of the self-diffusion coefficient of surfactants in wormlike micellar solutions
Yusuke Koide, Takato Ishida, Takashi Uneyama +1
We investigate the concentration dependence of surfactant diffusion in wormlike micellar solutions using dissipative particle dynamics simulations. The simulations show that the se…
Coarse-Grained Molecular Dynamics Simulations for Oxidative Aging of Polymers under Various O2 Concentration
Takato Ishida, Kazuya Haremaki, Yusuke Koide +2
Modeling of polymer oxidative aging has been actively studied since the 1990s. Insights from these studies suggest that the transport of oxygen and radicals significantly influence…
Brownian simulations for fracture of star polymer phantom networks
Yuichi Masubuchi, Yusuke Koide, Takato Ishida +1
Based on a recent simulation study [Masubuchi et al., Macromolecules, 56, 9359 (2023)], the cycle rank plays a significant role in determining the fracture characteristics of netwo…
Reverse non-equilibrium molecular dynamics simulations of a melt of Kremer-Grest type model under fast shear
Tatsuma Oishi, Yusuke Koide, Takato Ishida +3
Although the reverse non-equilibrium molecular dynamics (RNEMD) simulation method has been widely employed, the range of applicability is yet to be discussed. In this study, for th…
Phantom chain simulations for fracture of star polymer networks with various strand densities
Yuichi Masubuchi, Takato Ishida, Yusuke Koide +1
Despite many attempts, the relation between fracture and structure of polymer networks is yet to be clarified. For this problem, a recent study for phantom chain simulations [Macro…
Dissipative particle dynamics simulation plus slip-springs for entangled polymers with various slip-spring densities
Yuichi Masubuchi, Hong-Xia Guo, Fan Wang +5
Slip-spring models are valuable tools for simulating entangled polymers, bridging the gap between bead-spring models with excluded volume and network models with presumed reptation…
Modeling for heterogeneous oxidative aging of polymers using coarse-grained molecular dynamics
Takato Ishida, Yuya Doi, Takashi Uneyama +1
This study presents a coarse-grained molecular dynamics simulation model to investigate the process of oxidative aging in polymers. The chemical aging effect is attributed to the a…
Phantom-Chain Simulations for the Effect of Node Functionality on the Fracture of Star-Polymer Networks
Yuichi Masubuchi, Yuya Doi, Takato Ishida +5
The influence of node functionality (f) on the fracture of polymer networks remains unclear. While many studies have focused on multi-functional nodes with f>4, recent research sug…
Gas Diffusion in Cement Pastes: An Analysis using a Fluctuating Diffusivity Model
Fumiaki Nakai, Takato Ishida
This work propose an application of the concept of fluctuating diffusivity to the diffusion of gas molecules in cementitious materials, particularly through a two-state fluctuating…
Extension of Moving Particle Simulation including rotational degrees of freedom for dilute fiber suspension
Keigo Enomoto, Takato Ishida, Yuya Doi +2
We develop a novel Moving Particle Simulation (MPS) method to accurately reproduce the motion of fibers floating in sheared liquids. In conventional MPS schemes, if a fiber suspend…
Increase in rod diffusivity emerges even in Markovian nature
Fumiaki Nakai, Martin Kröger, Takato Ishida +3
Rod-shaped particles embedded in certain matrices have been reported to exhibit an increase in their center of mass diffusivity upon increasing the matrix density. This increase ha…
Fluctuating Diffusivity Emerges even in Binary Gas Mixtures
Fumiaki Nakai, Yuichi Masubuchi, Yuya Doi +2
Diffusivity in some soft matter and biological systems changes with time, called the fluctuating diffusivity. In this work, we propose a novel origin for fluctuating diffusivity ba…