Article
Multidisciplinary Sciences
D. Michieletto, P. Neill, S. Weir, D. Evans, N. Crist, V. A. Martinez, R. M. Robertson-Anderson
Summary: The study demonstrates time-dependent rheology of DNA solutions via enzymatically-driven architectural alterations by restriction endonucleases. The rheological properties of the systems depend on the concentrations and properties of DNA and REs, showcasing tunable behaviors with potential applications in both industry and biology.
NATURE COMMUNICATIONS
(2022)
Article
Polymer Science
Giulia Amici, Michele Caraglio, Enzo Orlandini, Cristian Micheletti
Summary: In this study, catenated ring polymers confined inside channels and slits were investigated using Langevin dynamics simulations. It was found that catenation constraints generate a drag that couples the contour motion of the interlocked regions. The strength of this coupling decreases as the interlocking becomes tighter and shorter due to confinement, with the results having implications for linked biomolecules in experimental or biological confining conditions.
Article
Physics, Fluids & Plasmas
F. Sultanov, M. Sultanova, G. Falkovich, V Lebedev, Y. Liu, V Steinberg
Summary: Entropy of extension statistics can be used as a proper measure to identify and quantify the coil-stretch phase transition of polymer molecules in flow, showing strong fluctuations around this transition. Comparison with traditional linear or nonlinear models demonstrates the effectiveness of this new approach in characterization of the transition.
Article
Polymer Science
Tom Herschberg, Jan-Michael Y. Carrillo, Bobby G. Sumpter, Eleni Panagiotou, Rajeev Kumar
Summary: The study found that the topology of polymer chains significantly influences the order-disorder transition of AB diblock copolymer melts, with linear and ring chains remaining stretched while knot chains experience stretching and tightening in disordered melts.
Article
Chemistry, Physical
Dario Vincenzi
Summary: Research shows that internal friction does not change the critical Weissenberg number for the coil-stretch transition of polymers, but it does steepen the slope of the extension probability distribution, making the transition more pronounced.
Article
Chemistry, Multidisciplinary
Sho Takahashi, Shiki Yagai
Summary: This study demonstrates an example of thermodynamically controlled random supramolecular copolymerization. By forming six-membered hydrogen-bonded rosette intermediates, the random copolymerization of two monomers with distinct molecular structures is achieved. The experimental results reveal the homopolymerization of one monomer in the high-temperature region and the incorporation of the other monomer in the medium-temperature region to form supramolecular copolymers.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Multidisciplinary Sciences
Jan Smrek, Jonathan Garamella, Rae Robertson-Anderson, Davide Michieletto
Summary: The study reveals that larger supercoiling in dense supercoiled DNA increases the size of entangled plasmids and enhances DNA mobility. These findings suggest a way to tune DNA mobility via supercoiling, enabling topological control over the (micro)rheology of DNA-based complex fluids.
Article
Physics, Multidisciplinary
Rabih Mezher, Jack Arayro, Nicolas Hascoet, Francisco Chinesta
Summary: This study focuses on the discrete simulation of flow in concentrated suspensions encountered in forming processes involving reinforced polymers. It explores the statistical characterization of intense fiber interactions during flow induced orientation and their impact on fiber trajectories, revealing characteristic patterns based on flow conditions using topological data analysis. These patterns can be used for classification and modeling purposes in rheology and processing monitoring.
Article
Polymer Science
Takahiro Murashima, Katsumi Hagita, Toshihiro Kawakatsu
Summary: Coarse-grained molecular dynamics simulations were used to analyze blends of multicyclic and linear polymers under biaxial elongational flow. The blends exhibited an overshoot behavior in the normal stress difference, with multicyclic/linear blends showing a steeper overshoot compared to monocyclic/linear blends. The origin of the overshoot was found to be a topological transition mechanism in the multicyclic chains, which resulted in a drastic change in the stress of the rings.
Article
Materials Science, Multidisciplinary
Christopher M. Plummer, Noemie Gil, Pierre-Emmanuel Dufils, D. James Wilson, Catherine Lefay, Didier Gigmes, Yohann Guillaneuf
Summary: Incorporating heteroatoms into radical polymerization of commodity polymers can confer biodegradability, with thionolactones identified as promising co-monomers. Thionolactone monomers thCL and thin can perform radical ring-opening polymerization with less activated monomers, producing readily degradable copolymers. Thorough mechanistic investigations and polymerization experiments were conducted to understand the reactivity of the cyclic monomers and demonstrate the usefulness of thionolactones.
ACS APPLIED POLYMER MATERIALS
(2021)
Article
Polymer Science
Adam Linscott, Rene Zhu, Lauren Hong, Madison Castellanos, Svetlana Morozova
Summary: The effects of grafting density on the extensional flow properties of polymer solutions were studied. At low grafting densities, the added side chains counteract the losses in extensibility to the backbone, leading to an increase in relaxation time. At higher grafting densities, the extension of the backbone reduces the relaxation time. By characterizing the effects of graft density architecture on extensional flows, the breakup dynamics of elastic solutions can be finely tuned and controlled.
JOURNAL OF POLYMER SCIENCE
(2023)
Article
Chemistry, Physical
Iurii Chubak, Christos N. Likos, Jan Smrek
Summary: The study investigates effective interactions in dilute polydisperse ring polymer solutions, deducing the contributions of sterics, topology, and threading for differently sized rings. The research also quantifies the contribution of topological constraints for rings of different asymmetries in length, as well as compares changes in effective potentials when mutual ring threading is restricted. Threading depth distributions at different center-of-mass ring separations are also characterized.
Article
Mechanics
Martin Zatloukal, Jiri Drabek
Summary: The recently proposed frame-invariant Generalized Newtonian Fluid (GNF) constitutive equation has been modified in this work to provide uniaxial extensional viscosity at a high strain rate limit, and successfully tested against steady-state uniaxial extensional viscosity data for entangled polymer liquids. The modified GNF model was shown to outperform selected advanced viscoelastic constitutive equations in predicting steady uniaxial extensional viscosities under fast flow conditions, suggesting its potential for stable modeling of non-Newtonian polymer liquids in very fast steady-state flows.
Article
Mechanics
Andrea K. I. Hall, Thomas C. O'Connor, Molly K. McGath, Patricia McGuiggan
JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME
(2018)
Article
Materials Science, Multidisciplinary
Hai Dong, Zheliang Wang, Thomas C. O'Connor, Aurelie Azoug, Mark O. Robbins, Thao D. Nguyen
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2018)
Article
Physics, Multidisciplinary
Thomas C. O'Connor, Nicolas J. Alvarez, Mark O. Robbins
PHYSICAL REVIEW LETTERS
(2018)
Editorial Material
Physics, Multidisciplinary
Thomas C. O'Connor, Nicolas J. Alvarez, Mark O. Robbins
PHYSICAL REVIEW LETTERS
(2019)
Article
Polymer Science
Thomas C. O'Connor, Austin Hopkins, Mark O. Robbins
Article
Chemistry, Physical
Thomas C. O'Connor, Mark O. Robbins
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Polymer Science
Anine Borger, Wendi Wang, Thomas C. O'Connor, Ting Ge, Gary S. Grest, Grethe V. Jensen, Junyoung Ahn, Taihyun Chang, Ole Hassager, Kell Mortensen, Dimitris Vlassopoulos, Qian Huang
Article
Polymer Science
Jiuling Wang, Thomas C. O'Connor, Gary S. Grest, Yitong Zheng, Michael Rubinstein, Ting Ge
Summary: The diffusion of monomerically thin nanorods in polymer melts is affected by both chain length and entanglement, leading to varying diffusion coefficients in different directions with increasing rod length. The findings show a complex relationship between nanorod motion and polymer properties.
Article
Mechanics
Thomas C. O'Connor, Ting Ge, Gary S. Grest
Summary: This study extensively uses molecular simulations to investigate the equilibrium dynamics, entanglement topology, and nonlinear extensional rheology of symmetric ring-linear polymer blends. The topological analysis reveals a critical ring fraction where the composite entanglement network exhibits maximum constraints. The study also identifies an extensional stress overshoot phenomenon in uniaxial elongation flows, and explains its underlying mechanism.
JOURNAL OF RHEOLOGY
(2022)
Article
Physics, Multidisciplinary
Supun S. Mohottalalage, Manjula Senanayake, Joel T. Clemmer, Dvora Perahia, Gary S. Grest, Thomas O'Connor
Summary: The response to elongational flow is important in soft matter and has implications in various technologies. In this study, the effects of associating groups on the structure and dynamics of linear polymer melts under uniaxial elongation were investigated using molecular dynamics simulations.
Article
Physics, Multidisciplinary
Jiuling Wang, Thomas C. O'Connor, Gary S. Grest, Ting Ge
Summary: The stretchability of conventional polymeric materials is limited by entanglements between polymer chains. However, cross-linked ring polymers are significantly more stretchable than cross-linked linear polymers. The entanglements between ring polymers do not act as effective cross-links, resulting in increased stretchability determined by the maximum extension of polymer strands between cross-links.
PHYSICAL REVIEW LETTERS
(2022)
Article
Polymer Science
Supun S. Mohottalalage, Chathurika Kosgallana, Shalika Meedin, Thomas C. O'Connor, Gary S. Grest, Dvora Perahia
Summary: Ionizable polymers form dynamic networks controlled by ionic interactions and van der Waals forces. Molecular dynamics simulations of a model ionizable polymer provide insight into its nonlinear response. Increasing elongational flow rate leads to an initial elastic response, followed by strain hardening, stress overshoot, and eventually strain thinning. Flow-driven ionic assembly dynamics control the system's response.
Article
Polymer Science
Michael Q. Tu, Oleg Davydovich, Baicheng Mei, Piyush K. Singh, Gary S. Grest, Kenneth S. Schweizer, Thomas C. O'Connor, Charles M. Schroeder
Summary: In this work, the slow stress relaxation behavior of concentrated ring polymers is reported, which is caused by ring-ring interactions and ring packing structure. Topologically pure, high molecular weight ring polymers are prepared without linear chain contaminants. Experimental results are in good agreement with molecular dynamics simulations, which show non-power-law stress relaxation due to ring-ring interpenetrations. These findings provide a new understanding of ring polymer physics.
Article
Polymer Science
Gary S. Grest, Ting Ge, Steven J. Plimpton, Michael Rubinstein, Thomas C. O'Connor
Summary: Nonconcatenated ring polymers form compact conformations due to topological constraints, and mixing with linear polymers results in increased entropy. With increasing chain stiffness, the negative entropy mixing ratio also increases.