Article
Polymer Science
Marcus Mueller
Summary: This study investigates the structure and dynamics of loops and bridges in the lamellar phase of symmetric ABA triblock copolymers, revealing a linear correlation between bridge fraction and the average variance of the first Rouse mode. The system is proposed to be a mixture of noninteracting loops and bridges with a two-state Markov dynamics. Multichain simulations show an extremely long relaxation time, which can be accelerated using the heterogeneous multiscale method.
Article
Materials Science, Multidisciplinary
Olivier Simard, Philipp Werner
Summary: This paper presents the nonequilibrium implementation of the two-particle self-consistent (TPSC) approach, which has been demonstrated to provide a reliable and versatile description of interacting lattice systems. The method captures the effects of local and nonlocal correlations in two -and higher-dimensional systems and satisfies the Mermin-Wagner theorem. The authors demonstrate the performance of nonequilibrium TPSC through calculations of spin and charge response functions, as well as the evolution of effective temperatures in the two-dimensional Hubbard model.
Article
Chemistry, Physical
Yao Xuan, Kris T. Delaney, Hector D. Ceniceros, Glenn H. Fredrickson
Summary: This study presents a computational framework that combines deep learning with self-consistent field theory simulations to accelerate the exploration of parameter space for block copolymers. Several innovations and improvements are proposed, including the use of a Sobolev space-trained convolutional neural network to handle the dimension increase of monomer density fields and the introduction of a generative adversarial network (GAN) to predict saddle point density fields. The framework demonstrates its potential in accelerating the discovery of polymer nanostructures through the successful application to 2D cell size optimization.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
T. Oyama, Y. Nakamura, Y. Yamanaka
Summary: This study aims to construct a theoretical formulation of a nonequilibrium process for a Bose-Einstein condensate system associated with spontaneous symmetry breakdown. Thermo Field Dynamics is used for this purpose. The general forms of a 4 x 4 matrix transformation and an unperturbed Hamiltonian are described, followed by the calculation of the on-shell 4 x 4 matrix self-energy. By imposing the renormalization condition where the entire on-shell self-energy should vanish, sufficient independent equations are obtained to determine the parameters in an unperturbed Hamiltonian, including the quantum transport equations for normal and anomalous number distributions.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2022)
Article
Chemistry, Physical
Apostolos T. Lakkas, Aristotelis P. Sgouros, Constantinos J. Revelas, Doros N. Theodorou
Summary: Polymer/matrix nanocomposites have exceptional properties and promising applications in key industrial sectors. To ensure the best dispersion, nanoparticles are often stabilized by grafting polymer chains on their surface of the same chemical constitution as the matrix. A model is proposed to predict key structural and thermodynamic properties, exploring various regimes and extracting important quantities related to the distribution and configuration of polymer chains.
Article
Chemistry, Multidisciplinary
Emanuele Penocchio, Giulio Ragazzon
Summary: Molecular nonequilibrium systems have great potential for future nanotechnology, but their development is hindered by the lack of an informative representation. We extended the energy span model, an approach pertaining to catalytic networks, to provide an insightful visual representation of kinetic asymmetry in system dynamics. Our approach applies to both chemically and photochemically driven systems, ranging from unimolecular motors to simple self-assembly schemes. The obtained diagrams offer immediate access to information needed for guiding experiments and understanding the effects of design changes.
Review
Chemistry, Multidisciplinary
Lasith S. Kariyawasam, Mohammad Mosharraf Hossain, C. Scott Hartley
Summary: Biochemical systems use the energy of chemical fuels to operate out-of-equilibrium and perform critical functions. The formation of transient covalent bonds is a key tool in designing analogous reaction networks. Recent demonstrations of abiotic nonequilibrium systems using fuel chemistries have shown how different fuel reactions can impact a wide range of nonequilibrium behaviors, from self-assembly to the operation of molecular machines.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Materials Science, Multidisciplinary
Kazuya Hiraide, Yutaka Oya, Misato Suzuki, Mayu Muramatsu
Summary: This study proposes a framework for the inverse design of material structures based on macroscopic properties using deep learning models. The framework generates phase separation structures and predicts properties using deep learning models. The framework is able to suggest phase separation structures that possess desired macroscopic properties.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Physics, Condensed Matter
M. Georgiev, H. Chamati
Summary: A structured theoretical framework was developed to characterize the unusual behavior of the magnetic spectrum, magnetization and magnetic susceptibility of the molecular magnet Ni4Mo12, based on molecular orbital theory and multi-configurational self-consistent field method. The bilinear spin-like Hamiltonian with discrete coupling parameters was constructed to explain relevant spectroscopic magnetic excitations, magnetization and magnetic susceptibility. The method was demonstrated by computing the spectral properties of a spin-one magnetic dimer and could be applied to various magnetic units based on transition metals and rare Earth elements.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Computer Science, Interdisciplinary Applications
Michael F. Herbst, Antoine Levitt
Summary: In this study, a novel adaptive damping algorithm for self-consistent field (SCF) iterations in Kohn-Sham density-functional theory is proposed. The algorithm adjusts the damping in each SCF step using a backtracking line search based on a theoretically sound and accurate energy model. Unlike traditional SCF schemes, this algorithm is fully automatic and does not require user input for selecting the damping parameter. The algorithm is successfully applied to various challenging systems, including elongated supercells, surfaces, and transition-metal alloys.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Mingxue Gao, Yu Tian, Xiaoning Li, Yanxiang Gong, Manman Fang, Jie Yang, Zhen Li
Summary: The research on purely organic room-temperature phosphorescence (RTP) materials has gained great attention due to their wide range of potential applications. This study focuses on the self-doping effect on the RTP property by designing phenothiazine derivatives with two distinct molecular conformations and studying their RTP behaviors in different states.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Materials Science, Multidisciplinary
Alexander Duthie, Sthitadhi Roy, David E. Logan
Summary: We present a self-consistent theory of mobility edges in nearest-neighbor tight-binding chains with quasiperiodic potentials, discussing the boundaries between localized and extended states in these systems and demonstrating the agreement of the theory with known mobility edges through two model examples.
Article
Physics, Multidisciplinary
Alessio Maiezza, Juan Carlos Vasquez
Summary: We introduce the concept of dimensional reduction at high energies in the perturbative formulation of quantum field theory (QFT). Space and momentum integrations are modified by a weighting function, incorporating an effective mass energy associated with the dimensional reduction scale. The quantization of the theory within the canonical formalism leads to finiteness in perturbation theory, absence of renormalon ambiguities, and improved analytic behavior for infinitesimal coupling constant compared to standard QFT. The new approach reproduces known results at low energies. One key feature of this class of models is the coupling constant always reaches a fixed point in the ultraviolet (UV) region, making the models UV complete.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2023)
Article
Computer Science, Interdisciplinary Applications
Yao Xuan, Kris T. Delaney, Hector D. Ceniceros, Glenn H. Fredrickson
Summary: A new framework using data obtained from SCFT simulations and deep learning is introduced to accelerate the exploration of parameter space for block copolymers. The method focuses on learning an approximation to the effective Hamiltonian and predicting saddle density fields, while ensuring invariance under shifts and rotations. Data-enhancing techniques and appropriate regularization are used to achieve this invariance.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Panpan Zhu, Ji Lin, Rui Xiao, Haofei Zhou
Summary: This work investigates the stress responses of pre-deformed glassy polymers using coarse-grained molecular dynamics simulations. The competition between intra-chain deformation and inter-chain friction is found to govern yielding and strain hardening. A mean-field shear transformation zone model is developed based on the physical mechanisms revealed by the simulations, which successfully captures the observed mechanical responses.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Chemistry, Multidisciplinary
Veronica Chappa, Yuliya Smirnova, Karlo Komorowski, Marcus Mueller, Tim Salditt
Summary: This study quantifies the effects of size polydispersity, thermal fluctuations, and membrane asymmetry on small unilamellar vesicles' (SUVs) curved bilayer using simulated Small Angle X-ray Scattering (SAXS) curves. The factorization approximation of the scattering intensity holds even for small vesicle radii, but curvature-induced asymmetry in the electron-density profile can arise for very small vesicles. Thermal fluctuations and size polydispersity have distinguishable signatures in the SAXS intensity, with polydispersity affecting low-q features and thermal fluctuations predominantly affecting scattering at larger q.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2021)
Review
Chemistry, Multidisciplinary
Marcus Muller, Volker Abetz
Summary: This passage discusses the application of porous polymer and copolymer membranes for ultrafiltration and water purification, as well as the formation of isoporous membranes using block copolymers. Understanding the spatiotemporal structure evolution and the interplay of multiple nonequilibrium processes is essential for optimizing membrane performance and fabrication processes.
Article
Polymer Science
Wei Li, Pritam K. Jana, Alireza F. Behbahani, Georgios Kritikos, Ludwig Schneider, Patrycja Polinska, Craig Burkhart, Vagelis A. Harmandaris, Marcus Mueller, Manolis Doxastakis
Summary: A hierarchical triple-scale simulation methodology is applied to investigate the dynamics of cis-1,4 polyisoprene melts, showing good agreement with experimental data, especially for highly entangled polymer melts. The study provides parameter-free predictions on the dynamics of polymeric materials.
Article
Polymer Science
Marcus Mueller
Summary: This study investigates the structure and dynamics of loops and bridges in the lamellar phase of symmetric ABA triblock copolymers, revealing a linear correlation between bridge fraction and the average variance of the first Rouse mode. The system is proposed to be a mixture of noninteracting loops and bridges with a two-state Markov dynamics. Multichain simulations show an extremely long relaxation time, which can be accelerated using the heterogeneous multiscale method.
Article
Chemistry, Physical
Marcus Mueller
Summary: Using analytical considerations and particle-based simulations, this study investigates the relaxation of a density modulation in a polymer system without nonbonded interactions. The results demonstrate that shallow density modulations, prepared by different processes but with identical amplitudes and wavevectors, exhibit different nonexponential decay behaviors, challenging the assumption that density alone characterizes the polymer system configuration. Analytic descriptions within Linear-Response Theory (LRT) and the Rouse model are provided, showing quantitative agreement with the particle-based simulations.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Polymer Science
Cody T. Bezik, Joshua A. Mysona, Ludwig Schneider, Abelardo Ramirez-Hernandez, Marcus Mueller, Juan J. de Pablo
Summary: A new mesophase in binary blends of A-b-(BA')3 miktoarm star block copolymers and A homopolymers has been discovered, consisting of aperiodic discrete domains of A embedded in a continuous matrix of B. Molecular bridging dominates the mechanical behavior of the mesophase, outweighing the influence of microphase segregation. The application of shear leads to a closer structure resembling its speculated discrete nature.
Article
Polymer Science
Gaoyuan Wang, Marcus Mueller
Summary: This study investigates the interplay between elasticity and microphase separation in quasi-two-dimensional phantom networks formed by AB diblock copolymers. Computer simulations and phenomenological considerations show that network elasticity has a minor role in the system when the stretching is weak. As the stretching increases, the incompatibility for the order-disorder transition decreases, and a multigrain state with tilted lamellae is observed at intermediate stretching.
Article
Chemistry, Physical
David Steffen, Ludwig Schneider, Marcus Mueller, Joerg Rottler
Summary: This paper investigates the spatiotemporal autocorrelation of shear stress in a supercooled fluid close to the glass transition using molecular dynamics simulations. The results show anisotropic correlations and strongly damped oscillations at non-zero wavevectors. The experimental findings are in good quantitative agreement with a recently developed hydrodynamic theory.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Polymer Science
Gaoyuan Wang, Annette Zippelius, Marcus Mueller
Summary: Cross-linking is a versatile strategy to stabilize the structure and control the dynamics of polymers. This study systematically investigates the phase behavior of randomly cross-linked diblock copolymer melts and reveals the significant influence of the preparation state on the phase diagram.
Article
Polymer Science
Pritam Kumar Jana, Petra Bacova, Ludwig Schneider, Hideki Kobayashi, Kai-Uwe Hollborn, Patrycja Polinska, Craig Burkhart, Vagelis A. Harmandaris, Marcus Mueller
Summary: The theological properties of polymer composites depend on the interfacial interactions between solid fillers and a polymer fluid. This study presents a simulation strategy called the wall-spring thermostat, which uses transient bonds to mimic the interactions between the polymer and the solid surface. The density and lifetime of these transient bonds can be adjusted to control the single-chain and collective dynamics of the polymer at the surface. The simulation technique allows for the capture of dynamic heterogeneities at surfaces.
Article
Chemistry, Physical
Kai-Uwe Hollborn, Ludwig Schneider, Marcus Muller
Summary: Highly coarse-grained (hCG) linear polymer models, based on dissipative particle dynamics (DPD), allow for studying long time and length scales. This top-down strategy uses relevant interactions, such as molecular connectivity, and coarse-grained invariants, like the mean-squared end-to-end distance, to describe the equilibrium behavior of long, flexible macromolecules. However, describing the dynamics of long, entangled polymers is challenging because hCG models do not enforce the noncrossability of molecular backbones. One technique to mimic entanglements in hCG models is slip-springs, which has shown quantitative agreement with simulations, experiments, and theoretical predictions.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Polymer Science
Oliver Dreyer, Gregor Ibbeken, Ludwig Schneider, Niklas Blagojevic, Maryam Radjabian, Volker Abetz, Marcus Mueller
Summary: In this study, the self-assembly of asymmetric diblock copolymers during solvent evaporation was investigated using particle-based Monte Carlo simulations and continuum modeling. The effects of evaporation rate and solvent selectivity on structure formation, particularly the alignment of minority block cylinders, were examined. Comparing the two simulation techniques helped identify general trends with parameter variation and understand the role of single-chain dynamics, fluctuations, and additional model details.
Article
Chemistry, Physical
Felix Weissenfeld, Lucia Wesenberg, Masaki Nakahata, Marcus Mueller, Motomu Tanaka
Summary: The interactions between vesicle and substrate were investigated using simulation and experiment. Polyacrylic acid brushes with cysteine side chains were grafted onto planar lipid membranes. The addition of Cd2+ ions compacted the polymer brushes and influenced the adhesion of lipid vesicles. Wetting of the vesicles occurred at [CdCl2] = 0.25 mM. The shape and adhesion of vesicles were quantitatively evaluated, and simulations revealed that wetting sensitivity was dependent on the interaction range.
Article
Polymer Science
Niklas Blagojevic, Marcus Mueller
Summary: Using a particle-based model, a free-energy functional, and a lattice model, this study investigates the structure and motion of a grain boundary between two orthogonal grains in asymmetric block copolymers. The study reveals insights into transitions and correlations in space and time. By characterizing the system using a free-energy functional and calculating the minimum free-energy path, the study identifies a minimal set of transitions. The results are used to parametrize a lattice model and investigate grain-boundary motion by kinetic Monte Carlo simulation.
Article
Polymer Science
Xavier Chevalier, Cindy Gomes Correia, Gwenaelle Pound-Lana, Philippe Bezard, Matthieu Serege, Camille Petit-Etienne, Guillaume Gay, Gilles Cunge, Benjamin Cabannes-Boue, Celia Nicolet, Christophe Navarro, Ian Cayrefource, Marcus Mueller, Georges Hadziioannou, Ilias Iliopoulos, Guillaume Fleury, Marc Zelsmann
Summary: This detailed concept of patternable top-coats for directed self-assembly of high-chi block copolymers enables a crosslinking reaction triggered by thermal or photo-activation, facilitating controlled domain orientation in nanostructured BCP areas. The crosslinked nature of the material suppresses BCP dewetting and offers exceptional capabilities for constructing 3D stacks.
JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY
(2021)
