Article
Chemistry, Physical
Giovanni Russo, Marco Lattuada
Summary: In this work, a method combining activated swelling and control of free radical polymerization is used to successfully prepare monodisperse non-spherical polymer particles with asymmetric Janus structure. The addition of inhibitors 4-methoxyphenol (MEHQ) and O2 during the polymerization process enables the control of particle shape, resulting in a variety of shapes with excellent monodispersity and reproducibility. Furthermore, the introduction of iron oxide nanocrystals within the polymer matrix adds superparamagnetic properties to these non-spherical polymer particles.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Engineering, Chemical
Prakhyat Hejmady, Lambert C. A. van Breemen, Patrick D. Anderson, Ruth Cardinaels
Summary: This study developed a simple method to transform rough powders into spherical polymer particles, and processing conditions can be tailored based on material characteristics. The roundness and size distribution of the particles can be validated and controlled in various ways.
Article
Mechanics
Richard Cobos, Aditya S. Khair
Summary: In this paper, a spectral element algorithm is developed to compute the electrophoretic velocity of a spherical, rigid, dielectric particle over a wide range of dimensionless surface charge density sigma. The results show that for moderately charged particles, the electrophoretic velocity is linear in beta when beta << 1, and its dependence on the delta = 1/(kappa * a*) agrees with Henry's formula. For highly charged particles in the thin-Debye-layer limit, the computations are in good agreement with recent experimental and asymptotic results.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Subhabrata Das, Joel Koplik, Ponisseril Somasundaran, Charles Maldarelli
Summary: This study examines the hydrodynamic interaction between identical spherical colloids on a planar gas/liquid interface, calculating drag coefficients based on separation distance and immersion depth. The results show that normalized coefficients increase with a decrease in separation, but remain bounded at contact, while coefficients for in-tandem motion decrease with decreasing separation, eventually collapsing to match the drag coefficient for two particles moving in tandem in an infinite medium.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Multidisciplinary
Masahide Sato
Summary: The study reveals that as the patch area of particles increases, the cluster structures formed transition from dimers to island-like clusters and ultimately to square lattice structures, with the formation of other polygonal clusters as well.
Article
Multidisciplinary Sciences
Sieun Choi, Shunji Kurosu, Yuta Mashiko, Takanobu Minakawa, Toru Maekawa
Summary: In this study, uniform spherical particles composed of carbon nanobelts and C-60 molecules were synthesized through self-assembly, and the method can be applied to create nano/micro structures/materials at room temperature.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
Samuel Lopez-Godoy, Pedro Diaz-Leyva, Anna Kozina
Summary: This review summarizes the current knowledge about the phase behavior of binary mixtures of spherical colloids with different inter-particle interactions, and compares experimental work with theoretical predictions. Several open questions are outlined in the conclusions.
ADVANCES IN COLLOID AND INTERFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Zhanglei Zhu, Youhua Jiang, Jaroslaw W. Drelich
Summary: This study measured the spreading and adhesion forces of liquid droplets on polyethylene terephthalate (PET) surfaces with different radii of curvature using a high-sensitivity microelectronic mechanical balance. The results showed that the curvature of the surface affects the extent of spreading and the maximum adhesion force of the droplets.
Article
Chemistry, Physical
Gannena K. S. Raghuram, Lalit Bansal, Saptarshi Basu, Aloke Kumar
Summary: This study experimentally investigates the concentration and molecular weight dependence of deposit patterns of polymer droplets on hydrophobic surfaces. The results show a transition from ring to non-ring patterns with increasing concentration, while decreasing the polymer molecular weight does not suppress the coffee ring formation. The findings provide insights for applications like inkjet printing, surface coatings, and biotechnology assays where tuning polymer deposit patterns is important.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Chemistry, Multidisciplinary
Ivany Romero-Sanchez, Ilian Pihlajamaa, Natasa Adzic, Laura E. Castellano, Emmanuel Stiakakis, Christos N. Likos, Marco Laurati
Summary: In this study, we investigate the effects of crowding on the conformations and assembly of confined, highly charged, and thick polyelectrolyte brushes. Particle tracking experiments and theoretical simulations reveal that aggregation and re-entrant ordering occur due to the combined effect of osmotic pressure and short-range attraction. The attraction is caused by blunt-end interactions between stretched DNA fragments of neighboring brushes.
Article
Chemistry, Multidisciplinary
Marco Lattuada, Kata Dorbic
Summary: This review provides a summary on the development of colloidal particles, with a focus on submicron particles. It discusses the methods applicable to these particles, their applications, and the advantages and drawbacks of different approaches.
Article
Polymer Science
Mark Clyde Staub, Shichen Yu, Christopher Yuren Li
Summary: This study reports the fabrication of polymer crystalsomes formed by 1D polymer crystals. P3HT crystalsomes were successfully prepared using a miniemulsion solution crystallization method, and their properties were examined through microscopy and diffraction experiments. The results reveal curvature-dependent structural, thermal, and electro-optical properties of P3HT crystalsomes.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Liangliang Zhu, Haozhi Yuan, Kai Wu, Xueru Wang, Gang Liu, Jun Sun, Xiangbiao Liao, Xi Chen
Summary: The study investigates a unique instability mechanism of buckle delamination in a closed thin film weakly bonded to spherical substrates, resulting in a periodic pattern of delaminated hexagonal dimples. This new discovery opens up new possibilities for surface microfabrication with controllable features.
Article
Chemistry, Analytical
Daniel W. Weisgerber, Makiko Hatori, Xiangpeng Li, Adam R. Abate
Summary: In this study, we demonstrated a droplet microfluidic method for fabricating polyhedral microparticles with controlled concavity. By manipulating pressure and particle rheology, we achieved diverse particle shapes and increased capture efficiency in particle-templated emulsification, leading to enhanced chemical and biological functionality of the microparticles.
ANALYTICAL CHEMISTRY
(2022)
Article
Polymer Science
Iurii Chubak, Stanard Mebwe Pachong, Kurt Kremer, Christos N. Likos, Jan Smrek
Summary: In this study, we investigated the active topological glass under spherical confinement to determine the critical exponents of the arrested conformations beyond the previous simulated chain lengths. We discovered a previously unresolved tank-treading dynamic mode of active segments along the ring contour and discussed possible connections of the conformational and dynamic features of the system to chromosomes enclosed in the nucleus of a living cell.
Article
Polymer Science
Aijie Han, Ralph H. Colby
Summary: The dynamics of polyelectrolyte solutions have been studied experimentally and theoretically, showing that at predicted entanglement concentrations, the response of the polyelectrolyte solutions appear unentangled. At higher concentrations in entangled solutions, the behavior of polyelectrolyte solutions resembles that of solutions of neutral polymers. Four methods for evaluating entanglement concentration have been compared, with results similar to those of neutral polymer solutions.
Review
Polymer Science
Daniele Parisi, Jiho Seo, Richard P. Schaake, Alicyn M. Rhoades, Ralph H. Colby
Summary: This study focuses on the shear-induced isotropic-nematic transition exhibited by PEEK melts, revealing a relationship between zero-shear viscosity and molecular weight. The shear-induced I-N transition is characterized by three distinct regimes in the flow curves, providing insights into this intriguing phenomenon.
PROGRESS IN POLYMER SCIENCE
(2021)
Article
Chemistry, Physical
Deyang Yu, Xiaona Pan, Joshua E. Bostwick, Curt J. Zanelotti, Linqin Mu, Ralph H. Colby, Feng Lin, Louis A. Madsen
Summary: Molecular ionic composites (MICs) are a new type of rigid gel electrolyte that combine fast ion transport with high thermal stability and mechanical strength. These MIC membranes demonstrate stable cycling performance over a wide temperature range, making them suitable for use as solid electrolytes in lithium metal batteries operating in various temperature environments.
ADVANCED ENERGY MATERIALS
(2021)
Article
Mechanics
Daniele Parisi, Aijie Han, Jiho Seo, Ralph H. Colby
Summary: The study focused on the rheological response of isotactic polypropylene (iPP) melts, specifically looking at edge fracture and its correlation with zero-shear viscosity. Different experimental setups were used to measure properties like first normal stress difference and flow curves, providing valuable data for developing and testing molecular models. Viscosity of strongly polydisperse iPPs was found to scale with the -0.7 power of shear rate, while primary normal stress difference scaled with the square root of shear rate, revealing insights into the shear thinning behavior of iPPs.
JOURNAL OF RHEOLOGY
(2021)
Article
Polymer Science
Anton Mordvinkin, Diana Doehler, Wolfgang H. Binder, Ralph H. Colby, Kay Saalwaechter
Summary: The study found that star-shaped molecules form more time-stable networks with larger and somewhat more distantly arranged aggregates compared to their linear counterparts. Using stickers providing less hydrogen bonds speeds up terminal flow significantly.
Editorial Material
Mechanics
Ralph H. Colby
JOURNAL OF RHEOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Joshua E. Bostwick, Curt J. Zanelotti, Deyang Yu, Nicholas F. Pietra, Teague A. Williams, Louis A. Madsen, Ralph H. Colby
Summary: Molecular ionic composites (MICs) are a new class of solid electrolytes that combine ionic liquids (ILs) and a rigid-rod double helical polyelectrolyte, showing excellent mechanical properties and high ionic conductivities. The broad range of moduli and high tensile to shear modulus ratio in MICs are attributed to the distribution of PBDT chains and strong ionic interactions between IL ions and PBDT chains.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Abigail M. Fenton, Renxuan Xie, Melissa P. Aplan, Youngmin Lee, Michael G. Gill, Ryan Fair, Fabian Kempe, Michael Sommer, Chad R. Snyder, Enrique D. Gomez, Ralph H. Colby
Summary: The relationship between Kuhn length, Kuhn monomer volume, and plateau modulus for flexible polymers has a gap in experimental data. Conjugated polymers with a combination of backbone and side chains are ideal materials to study this crossover region. We have shown that certain polymers with aromatic backbones populate a large part of this gap and exhibit nematic ordering.
ACS CENTRAL SCIENCE
(2022)
Article
Polymer Science
Aijie Han, Veera Venkata Shravan Uppala, Daniele Parisi, Christy George, Benjamin J. Dixon, Camila Denise Ayala, Xiuli Li, Louis A. Madsen, Ralph H. Colby
Summary: Chain dynamics in the semidilute unentangled regime can be used to determine the molecular weight of polyelectrolytes. Four methods, including measurements of correlation length, specific viscosity, relaxation time, and diffusion coefficient, enable determination of the number density of chains. Different narrow dispersity cesium polystyrene sulfonate solutions in various solvents were studied to test these methods. The weight-average molecular weight can be obtained by combining viscosity and correlation length, while the number-average molecular weight can be reliably determined by combining diffusion coefficient and correlation length in water. Glycerol slows relaxation dynamics and the shear rate dependence of viscosity provides reliable relaxation time for higher molecular weight chains. The terminal modulus correlates with the ratio of weight-average molecular weight to the product of z-average and z + 1 average molecular weight.
Article
Chemistry, Physical
Bolton Tran, Yusheng Cai, Michael J. Janik, Scott T. Milner
Summary: The thermodynamics of hydrogen bonds in aqueous and acidic solutions have a significant impact on the kinetics and thermodynamics of acid reaction chemistry. This study utilizes a multiscale approach combining density functional theory (DFT) and classical molecular dynamics (MD) to model the thermodynamics of hydrogen bonds in acidic solutions. The results validate the accuracy of the DFT/MD approach in predicting hydrogen bond free energies in solution and suggest its promising application in modeling hydrogen bonding and proton transfer thermodynamics in condensed phases.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Mechanics
Daniele Parisi, Colin D. Ditillo, Aijie Han, Seth Lindberg, Mark W. Hamersky, Ralph H. Colby
Summary: In this study, intrinsic viscosity and flow curve measurements on industrial poly(vinyl alcohol) samples in water and DMSO were reported. The aqueous solutions exhibited features of associative polymers, while chain-chain associations were prevented in DMSO. Comparing solutions in both solvents at the same concentration allowed for the measurement of time delay due to associations.
JOURNAL OF RHEOLOGY
(2022)
Article
Chemistry, Physical
Ritwick Kali, Wezi D. Mkandawire, Scott T. Milner
Summary: This study investigates the impact of PAP pore diameter on water mobility and ion rejection using atomistic molecular dynamics simulations, and identifies the limiting PAP geometry that has the highest water permeability while still rejecting ions.
MOLECULAR SYSTEMS DESIGN & ENGINEERING
(2023)
Article
Thermodynamics
Xiaoshi Zhang, Jason D. Alexander, Jiho Seo, Anne M. Gohn, Matthew J. Behary, Richard P. Schaake, Ralph H. Colby, Alicyn M. Rhoades
Summary: The interior structure of PEEK composite pellets was reconstructed using ultra-high-resolution X-ray computed tomography (XCT), and different slicing methods were analyzed. For samples with thickness less than 50μm, PEEK samples sliced perpendicular to the fiber flow direction showed good filler homogeneity and lower coefficient of variation compared to samples sliced along the fiber flow direction. This conclusion was supported by further studies on the crystallization kinetics of PEEK and its composites.
THERMOCHIMICA ACTA
(2023)
Article
Engineering, Chemical
Ritwick Kali, Scott T. Milner
Summary: Ion exchange membranes have nanostructured pore space that facilitates ion and water transport. This study investigates the pore structure and transport properties of polystyrene-polymethylbutylene block copolymer membranes. The water content in the membrane affects the pore structure and diffusivity significantly.
JOURNAL OF MEMBRANE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Wenwen Mei, Deyang Yu, Christy George, Louis A. Madsen, Robert J. Hickey, Ralph H. Colby
Summary: Maximizing ion conduction in single-ion-conducting ionomers is crucial for energy-related technologies. Understanding the impact of anion chemical composition on ion conduction emphasizes the necessity of minimizing ion aggregation through the rational choice of anion chemical composition.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
