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
Physics, Multidisciplinary
Elena N. Govorun, Ruslan M. Shupanov, Sophia A. Pavlenko, Alexei R. Khokhlov
Summary: The paper discusses the use of conformation-dependent design of polymer sequences to control macromolecular self-assembly, considering different microphase-separated morphologies. It explores the application of this design in domains of different shapes through probability distributions and exponential asymptotes.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Polymer Science
Yexin Zheng, Mesfin Tsige, Shi-Qing Wang
Summary: In this study, molecular dynamics simulations were used to investigate the entanglement lockup phenomena in the uniaxial melt stretching of entangled polymer melts. The results revealed that under high strains, the entanglement network became increasingly tighter, leading to chain tension and the formation of network junctions. It was hypothesized that the interchain entanglement at junctions can lockup as long as certain conditions are met. This study provides insights into the mechanical properties of polymer materials.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Polymer Science
Heyi Liang, Kenji Yoshimoto, Masahiro Kitabata, Umi Yamamoto, Juan J. de Pablo
Summary: In this study, a multiscale simulation method is used to investigate the rheological properties of entangled Nylon 6 melts. The calculated results agree reasonably with experiments, showing the potential of this approach for designing polymeric materials based on purely molecular models.
JOURNAL OF POLYMER SCIENCE
(2022)
Article
Physics, Applied
Ji-Xuan Hou
Summary: In this paper, a coarse-graining method is presented to obtain the primitive chain from a polymer chain configuration in the entangled polymer melt by eliminating high-frequency Rouse modes. Theoretical demonstration shows that the tube step length is twice the tube diameter using this coarse-graining procedure. Additionally, a simple method to visualize the tube by adding high-frequency modes to the primitive chain is also provided.
MODERN PHYSICS LETTERS B
(2023)
Article
Chemistry, Physical
D. Nieto Simavilla, V Ramakrishnan, S. K. Smoukov, D. C. Venerus
Summary: Investigations on the diffusion of small molecules or particles in polymeric materials are important for various technologies and understanding polymer chain dynamics. This study focuses on systems where the probe size is comparable to or smaller than a characteristic length of the polymer chain. The research uses forced Rayleigh scattering to study the diffusion of a molecular probe in entangled polymer melts and finds that the diffusion coefficient is significantly larger than predicted by the Stokes-Einstein relation. Anomalous, non-Fickian diffusion is observed, where the measured diffusion coefficient can abruptly change.
Article
Mechanics
Oluseye Adeyemi, Shiping Zhu, Li Xi
Summary: The study explored the dynamics of bidisperse polymer melts and found that adding short chains can significantly accelerate the dynamics of long chains by lessening their extent of entanglement. The introduction of long chains hinders the motion of short chains, but does not qualitatively alter their dynamics, as unentangled short chains still follow classical Rouse dynamics even in a matrix containing entangled chains.
Article
Chemistry, Organic
Marcus J. Jellen, Xing Jiang, Stefan Benders, Alina Adams, Miguel A. Garcia-Garibay
Summary: Artificial molecular machines are expected to operate in environments where solvent behaviors dramatically change upon confinement into limited spaces, impacting molecules significantly. In this study, an amphidynamic metal-organic framework with barrierless rotators was demonstrated to operate as NMR sensors for solvent viscosity, showing that confined solvents have significantly higher viscosity values compared to bulk solvents. Relaxation times and activation energies for rotational dynamics of solvents in MOFs were also explored, revealing different behaviors compared to those in bulk solvents. Translational diffusion measurements of solvents in MOFs showed intermediate dynamics for the translational motion.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Polymer Science
Nilesh Patil
Summary: Rheology is fundamental in understanding polymer chain dynamics and plays a significant role in improving the processing and properties of polymer products. This review focuses on the influence of immiscible nanoparticles on the physical properties of polymers from a rheological perspective, specifically examining viscoelastic behaviors in linear flow and deformation. In-depth rheological analysis is crucial for verifying material properties and optimizing processing parameters on a larger scale.
POLYMER-PLASTICS TECHNOLOGY AND MATERIALS
(2023)
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
Polymer Science
Anna Dmochowska, Jorge Peixinho, Cyrille Sollogoub, Guillaume Miquelard-Garnier
Summary: We conducted a systematic study on the extensional rheology of multilayer films of immiscible polymer blends using multi-nanolayer coextrusion. By increasing the number of interfaces, we were able to quantify the interfacial response of the films. Our findings revealed that a model based on the summation of individual polymer contributions and the interfacial contribution accurately predicted the transient extensional viscosity at low strain rates, but underestimated the extra stress at higher strain rates. This extra contribution was attributed to an interphase modulus and followed a power law increase with strain rate.
Article
Polymer Science
Claire Schune, Marc Yonger, Mohamed Hanafi, Juergen Thiel, Laurent Guy, Thomas Chaussee, Francois Lequeux, Helene Montes, Emilie Verneuil
Summary: Nanometer-thick supported films of polymer melts spontaneously form and spread around deposited droplets. These films become dense and adopt a uniform thickness equal to twice the gyration radius of the free polymer. The phenomenon is not dependent on the polymer chemistry nor on the surface state and existing theoretical descriptions cannot reproduce the experimental result.
Article
Polymer Science
Fan Wang, Lu-Kun Feng, Ye-Di Li, Hong-Xia Guo
Summary: Dissipative particle dynamics (DPD) is a promising method for studying entangled polymers, but its applicability as a model for ideal chains and accurate description of entangled melts is not well understood. In this study, we comprehensively investigate the structure, dynamics, and linear viscoelasticity of a DPD entangled model system, specifically a semiflexible linear polymer melt. Our results show that the DPD model accurately predicts the monomer motion and relaxation behavior of entangled polymers, following the predictions of reptation theory. However, there are some limitations to the reptation theory, as evidenced by anomalous sub-diffusive motion and cross-correlation between chains. Overall, the semiflexible linear DPD model is able to capture the static and dynamic properties of entangled polymer melts.
CHINESE JOURNAL OF POLYMER SCIENCE
(2023)
Article
Chemistry, Physical
Ismail Karakurt, Gunay Basar, Paul Leiderer, Seyma Parlatan, Nihan Arapoglu
Summary: We studied the anomalous lateral diffusion process in thin tungsten trioxide films using optical methods. The diffusion starts at imperfections within the film shortly after H+ ion intercalation begins and progresses parallel to the film surface. We measured the mean square displacement of the diffusion front and calculated the instantaneous diffusion coefficient using its time-dependence. The observed large diffusion coefficients and depth dependence of film expansion can be explained by interfacial jobsharing diffusion of electrons and protons. Raman measurements revealed an additional strong band at 855 cm-1 after the lateral diffusion, indicating the irreversible nature of this process.
SURFACES AND INTERFACES
(2023)
Article
Polymer Science
Maximilian Piszko, Tobias Schaible, Christian Bonten, Andreas P. Froeba
Summary: This study demonstrates the applicability of dynamic light scattering for the characterization of molecular mass and thermal transport in mixtures consisting of a polymer melt and a blowing agent. The experimental uncertainties of the obtained diffusivities in the studied mixtures have a minimum value close to 3% and average around 13% for thermal diffusivity and 7.4% for mutual diffusivity.
Article
Chemistry, Physical
Younghoon Oh, Eun Sub Song, Bong June Sung
Summary: This study investigates how lipid-cholesterol interactions affect the spatial arrangement and dynamics of cholesterol in cell membranes. The rate of cholesterol flip-flop is found to be enhanced when lipids are less saturated or shorter, and in certain cases, a metastable state emerges in the center of the membrane for cholesterol to reside in, complicating cholesterol diffusion significantly.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Polymer Science
Junsoo Moon, Yoon Huh, Seonghwan Kim, Youngson Choe, Joona Bang
Summary: A core-shell structured bottlebrush copolymer (BBP) was designed as an epoxy toughening agent, improving the mechanical properties of epoxy resin. Compared to linear additives, BBP showed significant increases in adhesion strength and fracture toughness, with nanocavitation effect and void formation playing a key role in strengthening the modified epoxy resins.
CHINESE JOURNAL OF POLYMER SCIENCE
(2021)
Article
Chemistry, Physical
Jong Dae Jang, Moongi Bae, Changwoo Do, Soo-Hyung Choi, Joona Bang, Young Soo Han, Tae-Hwan Kim
Summary: This study demonstrates the formation of a highly ordered superlattice of gold nanoparticles in a 2D confined geometry using hydrophobic interactions in a polymer vesicle layer. The use of block copolymers as templates allows for control over the degree of freedom of the gold nanoparticles, resulting in a centered rectangular structure formation.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Min Sung Kim, Youngjin Kim, Han-Hyeong Choi, Woojin Jeon, Jong Hyuk Park, Joona Bang, Sang-Soo Lee
Summary: This study proposes a novel CRS memory using core-shell nanowires, demonstrating that electric field confinement from the structural characteristic enables efficient CRS performance, including high Ron/Roff ratio and low power consumption.
APPLIED MATERIALS TODAY
(2021)
Article
Polymer Science
Junsoo Moon, Yoon Huh, Youngson Choe, Joona Bang
Summary: The core-shell structured copolymer (CSP) consisting of a rubbery core and an epoxy-miscible shell was synthesized and used as additives in epoxy resin to improve mechanical properties. When CSP was used as additives, the adhesion strength of the epoxy resin increased by 160%, compared to only a 130% increase with linear copolymer (LP). This enhancement was attributed to the nanocavitation effect induced by the rubbery core and the uniform dispersion achieved by the epoxy-miscible shell.
Article
Chemistry, Physical
Nag-Young Kim, Junsoo Moon, Myeong-Hwa Ryou, Seung-Hyeok Kim, Jung-Hui Kim, Ju-Myung Kim, Joona Bang, Sang-Young Lee
Summary: Amphiphilic bottlebrush polymers (BBPs) designed as a new class of cathode binder material exhibit process compatibility, strong adhesive properties, and transition metal ion chelation capabilities, resulting in high-performance NCM811 cathodes with high mass loading.
ADVANCED ENERGY MATERIALS
(2022)
Article
Multidisciplinary Sciences
Chao Bao, Tae-Ho Kim, Amirhossein Hassanpoor Kalhori, Woo Soo Kim
Summary: Neuromorphic systems provide energy-saving in-memory computing compared with conventional processors. Here, we present a trained neuromorphic humanoid hand that mimics the reflex arc for quick response to complex spatiotemporal information.
Article
Medical Informatics
Margaret Chen-Mei Lin, Tae-Ho Kim, Woo Soo Kim, Ingrid Hakanson, Ali Hussein, Lillian Hung
Summary: Co-development of healthcare technology with users is crucial for producing user-friendly products and meeting patients' needs. This paper reports lessons learned from the development of a 3D printed origami ventilator prototype in response to the COVID-19 pandemic. The focus group discussions provided valuable insights into the challenges and practical tips for technology development, emphasizing the importance of multi-disciplinary collaboration and involving frontline clinicians.
HEALTH AND TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Taeil Kim, Amirhossein Hassanpoor Kalhori, Tae-Ho Kim, Chao Bao, Woo Soo Kim
Summary: A wireless pressure monitoring structure, based on a 3D-structured origami architecture, has been developed. The structure utilizes LC sensors and an antenna for wireless pressure sensing, allowing real-time monitoring of foot pressure in different postures. The sensitivity of the wireless pressure sensor is adjustable.
MICROSYSTEMS & NANOENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Chao Bao, Hadi Moeinnia, Tae-Ho Kim, Wonchul Lee, Woo Soo Kim
Summary: This article introduces a new method of 3D printing using a double-arm robot, combining paste-based direct ink writing and filament-based fused filament fabrication technologies, for the manufacturing of customized 3D structural electronics. The double-robot 3D printing system enables multi-directional curvilinear printing and enables electrical registration and vertical integration of multi-layered printed circuit boards, expanding design freedom and realization of 3D structural electronics.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Engineering, Electrical & Electronic
Haotian Su, Tae-Ho Kim, Hadi Moeinnia, Woo Soo Kim
Summary: This article develops an affordable customizable 3D-printed wristband for improved control of prostheses. It consists of serpentine dry electrodes, an EMG sensor, and a signal processing PCB to detect finger movements. The wristband demonstrates stability in EMG signal processing and offers improved signal detection compared to existing dry electrodes. The collected EMG signals reflect muscle movements and show potential in advancing prosthetic control systems.
IEEE SENSORS JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Younghoon Oh, Qiang Cui
Summary: In this study, a non-equilibrium transport mechanism for 6 nm diameter nanoparticles across lipid membranes is investigated. The simulations show that the transport efficiency is relatively insensitive to the fraction of reactive surface ligands, but the distribution pattern of different ligands on the nanoparticle surface has a notable impact on both insertion and ejection steps. This study provides a novel approach for designing efficient internalization of nanoparticles and offers guidelines for surface functionalization.
Article
Engineering, Electrical & Electronic
Tae-Ho Kim, Chao Bao, Ziniu Chen, Woo Soo Kim
Summary: In this study, a dry electrode inspired by origami and the suction mechanism of leeches was developed for reliable blood pressure monitoring. The electrode showed promising results in detecting ECG and photoplethysmography signals, demonstrating its potential for accurate blood pressure measurement.
NPJ FLEXIBLE ELECTRONICS
(2022)
Article
Physics, Fluids & Plasmas
Dong Jae Chun, Younghoon Oh, Bong June Sung
Summary: The dynamic heterogeneity and translation-rotation decoupling in glasses and supercooled liquids are closely related to the local structure development, with significant differences observed between 2D polydisperse colloids and 2D binary colloids. Tracers in 2D polydisperse colloids exhibit a shape-dependency parameter of the decoupling that grows with the dynamic correlation length, while tracers in 2D binary colloids do not show a similar correlation, highlighting the relationship between dynamic heterogeneity, translation-rotation decoupling, and local structure development in glasses.
Article
Chemistry, Multidisciplinary
Kyung-Seok Kang, Anthony Phan, Chisom Olikagu, Taeheon Lee, Douglas A. Loy, Minho Kwon, Hyun-jong Paik, Seung Jae Hong, Joona Bang, Wallace O. Parker, Monia Sciarra, Alberto R. Angelis, Jeffrey Pyun
Summary: A method for producing high-performance sulfur-based plastics with improved thermomechanical properties, elasticity and flame retardancy has been developed, involving the synthesis of sulfur-based segmented multi-block polyurethanes and thermoplastic elastomers. These materials incorporate a significant amount of sulfur and exhibit controlled tensile strength, elasticity, and enhanced flame retardancy compared to traditional thermoplastic polyurethanes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
