Article
Physics, Fluids & Plasmas
Baruch Meerson
Summary: Random acceleration is a fundamental stochastic process encountered in many applications. In this study, the authors evaluate the tail of the distribution Pn(A|L) of a functional I[x(t)] using the optimal fluctuation method. They show that the tail has a universal essential singularity, which is calculated analytically for n = 0, 1, and 2 and numerically for other values of n. The results agree with previous findings for the first-passage time distribution.
Article
Polymer Science
Seung Heum Jeong, Soowon Cho, Chunggi Baig
Summary: This study presents a detailed analysis of the scaling behavior of chain rotation dynamics in shear flow for melt and dilute linear polymer systems. The results show that dilute systems with hydrodynamic interaction (HI) and excluded volume (EV) effects exhibit two distinct scaling behaviors of chain rotation time between the intermediate and strong flow regimes. In contrast, free-draining dilute polymer systems display a simpler single-scaling behavior throughout the intermediate-to-strong flow regimes. The combined HI and EV effects weaken the structural change of polymer chains and enhance chain rotation dynamics by disturbing chain stretch and alignment to the flow direction. The presence of intermolecular interactions between chains in melt systems leads to two distinct scaling behaviors of chain rotation time as well. The overall scaling behavior of chain rotation is determined by the kinematically stable angular regions near the flow direction, while the kinematically unstable angular regions exhibit affine chain rotation dynamics. This study provides important insights into the understanding of chain rotation dynamics in shear flow.
Review
Polymer Science
Yumi Matsumiya, Hiroshi Watanabe
Summary: The rheological behavior of polymeric liquids was traditionally believed to be universally determined by a few time-independent molecular parameters, but recent studies have shown non-universality under extensional flow conditions. A key concept is the reduction of segmental friction of highly oriented/stretched polymer chains, which changes with the chemical structure of the polymer and solvent as well as the polymer concentration.
PROGRESS IN POLYMER SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Jian Yang, Youngjae Kim, Il Sohn
Summary: The high-temperature thermal conductivity of CaO-Al2O3-B2O3 melts was measured and discussed in relation to changes in melt structure. It was found that the addition of CaO or B2O3 affected the thermal conductivity of the melts by altering the structure.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Mechanics
Manfred H. Wagner, Esmaeil Narimissa, Qian Huang
Summary: The study extends the criterion for brittle fracture of entangled polymer liquids by considering the effects of finite chain extensibility and polymer concentration. Experimental data and models support the finding that crack initiation originates from the rupture of C-C bonds, leading to the fracture of polymer chains and crack propagation.
JOURNAL OF RHEOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Sophia Y. Chan, Mayank Jhalaria, Yucheng Huang, Ruipeng Li, Brian C. Benicewicz, Christopher J. Durning, Thi Vo, Sanat K. Kumar
Summary: Polymer-grafted nanoparticle membranes show unexpected gas transport enhancements, but the structural origins of this behavior are unclear. This study measured and interpreted data on grafted nanoparticles and found that as the graft molecular weight increases, the gas transport enhancement decreases.
Review
Polymer Science
Jordan Ochs, Carlo Andrea Pagnacco, Fabienne Barroso-Bujans
Summary: Cyclic polymers, with their circular structure and lack of chain ends, exhibit unique properties and potential applications. However, the preparation of high-purity cyclic polymers in large quantities remains challenging and requires continuous development of synthetic methods and techniques.
PROGRESS IN POLYMER SCIENCE
(2022)
Article
Polymer Science
Argyrios Karatrantos, Jettawat Khantaveramongkol, Martin Kroeger
Summary: This study investigates the structure and diffusion of ionic poly(dimethylsiloxane) (PDMS) melts with negatively charged bromide counterions. The density of the melts increases with charge density, and the counterions are condensed to the cationic part of end-functionalized PDMS chains, resulting in a slow diffusion. Temperature has a weak effect on the counterion structure and leads to an Arrhenius type of behavior for the counterion diffusion coefficient. The charge density of PDMS chains enhances counterion diffusion but hinders PDMS chain dynamics.
Article
Polymer Science
Jehyeok Choi, Kwang Soo Cho, Mi Kyung Kwon
Summary: The relaxation spectrum of unentangled polymer solution is derived using the self-similarity approach, but this method does not work for entangled polymeric fluids. This paper confirms the universality of the exponent in the polymer melt spectrum by employing a new regression algorithm.
Article
Engineering, Environmental
Jiankai Ge, Baron Peters
Summary: Various heterogeneous catalysts are being developed for plastic recycling, most of which operate in viscous polymer melts. The external mass transfer effects in these melts can inhibit the supply of co-reactants and the diffusion of long chain products away from the catalyst after each cut. This can unintentionally confer processivity to catalyst operation.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
I. V. Brekotkin, N. F. Fatkullin, K. Lindt, C. Mattea, S. Stapf
Summary: This article introduces the spatial displacements of spins and their impact on the DQ Hamiltonian in a double-quantum nuclear magnetic resonance pulse sequence. It provides a simple expression for estimating and controlling the contributions to the initial rise of the DQ build-up function by varying experimental parameters. The application of polymers is also discussed.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Polymer Science
Ignacio Martin-Fabiani, Stavros X. Drakopoulos, Giuseppe Forte, Sylvain Prevost, Ingo Hoffmann, Sara Ronca
Summary: The study using neutron spin echo spectroscopy revealed that graphene oxide hinders chain dynamics in polyethylene melt. The proposed model allows for measurement of adsorbed and free polymer fractions, as well as the thickness of the adsorbed layer. The experiments provided evidence at the nanoscopic level of graphene oxide hindering entanglement formation in the polymer melt.
Article
Chemistry, Physical
Kumar J. B. Ghosh, Sabre Kais, Dudley R. Herschbach
Summary: This study presents a geometric picture of electron-electron correlations using the dimensional scaling approach and quantifies correlations through entanglement. The results indicate the feasibility of using the geometrical picture to obtain an upper bound on electron-electron correlations at the large-D limit and at D = 3.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Review
Polymer Science
Andrey V. V. Subbotin, Alexander Ya. Malkin, Valery G. Kulichikhin
Summary: This review focuses on the role of elasticity in the shearing and extension flow modes of polymeric viscoelastic liquids. Experimental data analysis reveals that energy losses in these flows are determined by the Deborah and Weissenberg numbers. These criteria not only govern the abnormally high entrance effects and mechanical losses in short capillaries, but also determine the threshold for flow instability caused by the liquid-to-solid transition. Additionally, the Weissenberg number determines whether deformation occurs as flow or elastic strain in extension. The stability of a free jet in extension depends on both the viscoelastic properties of the polymeric substance and external driving forces, such as gravity and surface tension. An analysis of different force combinations on the shape of the stretched jet is presented. The concept of the role of elasticity in the deformation of polymeric liquids is crucial for polymer processing.
Article
Polymer Science
Katalee Jariyavidyanont, Andreas Janke, Muhammad Tariq, Maria Laura Di Lorenzo, Christoph Schick, Rene Androsch
Summary: By conducting self-seed crystallization experiments, this study quantified the different thermal stabilities of pointlike and shishlike crystallization precursors of polyamide 11, coexisting in the same sample. Despite their similar thermal stabilities, these precursors exhibit distinctly different nucleation efficacies, with shishlike precursors leading to faster crystallization due to various factors such as their larger size and more perfect chain conformation.
Review
Polymer Science
Takahiro Sakaue
Article
Chemistry, Physical
Takahiro Sakaue, Takuya Saito
Article
Chemistry, Physical
T. Sakaue, J. -C. Walter, E. Carlon, C. Vanderzande
Article
Physics, Condensed Matter
Takahiro Sakaue
JOURNAL OF PHYSICS-CONDENSED MATTER
(2018)
Article
Chemistry, Physical
E. Carlon, H. Orland, T. Sakaue, C. Vanderzande
JOURNAL OF PHYSICAL CHEMISTRY B
(2018)
Article
Chemistry, Physical
Takahiro Sakaue
Article
Chemistry, Applied
Takahiro Sakaue
REACTIVE & FUNCTIONAL POLYMERS
(2019)
Article
Polymer Science
Takuya Saito, Takahiro Sakaue
Article
Polymer Science
Davide Michieletto, Takahiro Sakaue
Summary: The study introduces a novel dynamical entanglement analysis (DEA) method to extract spatiotemporal entanglement structures from pairwise displacement correlation of entangled chains. Applying DEA to molecular dynamics simulations reveals a strong and unexpected cooperative dynamics between entangled chains, providing previously unnoticed insights into the dynamics of generic entangled polymers. The method is proposed to be useful in analyzing the dynamical evolution of entanglements in generic polymeric systems like blends and composites.
Article
Biochemistry & Molecular Biology
Tetsuya Yamamoto, Takahiro Sakaue, Helmut Schiessel
Summary: Enhancers are DNA sequences located far from target genes, and studies show that the contact probability between promoters and transcription machineries in condensates increases with longer linker DNA lengths when the loop extrusion process is active.
NUCLEIC ACIDS RESEARCH
(2021)
Article
Biology
Rakesh Das, Takahiro Sakaue, G. Shivashankar, Jacques Prost, Tetsuya Hiraiwa, Naama Barkai
Summary: This study constructs a polymer physics model based on the mechanistic scheme of Topoisomerase-II to investigate its effect on the spatial organization of interphase chromatin. The simulations show that Topoisomerase-II can phase separate chromatin into eu- and heterochromatic regions, with a wall-like organization of the euchromatic regions. The ability of the euchromatic regions to cross each other, induced by the enzymatic activity of Topoisomerase-II, leads to this phase separation. The model is extended to a bidisperse setting, and the characteristic features of enzymatic activity-driven phase separation are observed. These findings highlight the critical role of enzymatic activity in chromatin organization.
Article
Chemistry, Physical
Yair Augusto Gutierrez Fosado, Fabio Landuzzi, Takahiro Sakaue
Summary: The relaxation dynamics of DNA circular plasmids undergoing a local twist perturbation is studied using analytical theory and Molecular Dynamics simulations. The twist-bend coupling in the DNA double helix due to groove asymmetry is clearly observed. Differences in diffusion coefficient values and dynamics are found in scenarios with and without this coupling, and can be explained by the existence of three distinctive time scales. Time scale separation allows the deduction of an effective diffusion equation with a diffusion coefficient influenced by twist-bend coupling.
Article
Chemistry, Physical
Michele Caraglio, Takahiro Sakaue, Enrico Carlon
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2020)
Article
Physics, Fluids & Plasmas
Yumino Hayase, Takahiro Sakaue, Hiizu Nakanishi
Article
Physics, Fluids & Plasmas
Takuya Saito, Takahiro Sakaue
