A5047303971- Polymer Surface Interaction Studies
- Polymer crystallization and properties
- Advanced Polymer Synthesis and Characterization
- Force Microscopy Techniques and Applications
- Material Dynamics and Properties
- Adhesion, Friction, and Surface Interactions
- Rheology and Fluid Dynamics Studies
- Surface Modification and Superhydrophobicity
- Advanced Materials and Mechanics
- Hydrogels: synthesis, properties, applications
- Polymer composites and self-healing
- Surfactants and Colloidal Systems
- Polymer Nanocomposites and Properties
- Block Copolymer Self-Assembly
- Cellular Mechanics and Interactions
- Additive Manufacturing and 3D Printing Technologies
- Advanced Sensor and Energy Harvesting Materials
- Blood properties and coagulation
- Carbon Nanotubes in Composites
- biodegradable polymer synthesis and properties
- Pickering emulsions and particle stabilization
- Composite Material Mechanics
- Fiber-reinforced polymer composites
- Electrostatics and Colloid Interactions
- Innovative Microfluidic and Catalytic Techniques Innovation
University of Chicago
2020-2024
John Wiley & Sons (United States)
2022
University of Akron
2016-2020
Queen Mary University of London
2008-2019
Fudan University
2016
Institute of Polymers
2016
National University of Singapore
2007
Active camouflage is widely recognized as a soft-tissue feature, and yet the ability to integrate adaptive coloration tissuelike mechanical properties into synthetic materials remains elusive. We provide solution this problem by uniting these functions in moldable elastomers through self-assembly of linear-bottlebrush-linear triblock copolymers. Microphase separation architecturally distinct blocks results physically cross-linked networks that display vibrant color, extreme softness, intense...
We use a combination of the coarse-grained molecular dynamics simulations and scaling analysis to study conformations bottlebrush comb-like polymers in melt. Our shows that crossover between comb regimes is controlled by crowding parameter, Φ, describing overlap neighboring macromolecules. In systems characterized sparse grafting side chains (Φ < 1), backbones belonging macromolecules interpenetrate. However, bottlebrushes with densely grafted ≥ interpenetration suppressed steric repulsion...
Softness and firmness are seemingly incompatible traits that synergize to create the unique soft-yet-firm tactility of living tissues pursued in soft robotics, wearable electronics, plastic surgery. This dichotomy is particularly pronounced such as fat known be both ultrasoft ultrafirm. However, synthetically replicating this mechanical response remains elusive since ubiquitously employed gels unable concurrently reproduce tissue firmness. We have addressed challenge through self-assembly...
A combination of scaling analysis and rheological experiments was used to study correlations between the entanglement plateau modulus grafting density graft polymers in a melt. Using crowding parameter Φ, which describes overlap side chains belonging neighboring macromolecules, we identified two classes polymers—combs bottlebrushes—that demonstrate distinct conformational behaviors. In comb systems, both backbones sparsely grafted are coiled that allow macromolecules (Φ < 1). bottlebrush...
Using a combination of the scaling analysis and molecular dynamics simulations, we study relationship between mechanical properties networks graft polymers their architecture. The elastic response such can be described by replacing brushlike strands with wormlike characterized effective Kuhn length which is controlled degree polymerization side chains nsc grafting density 1/ng. In framework this approach have established relationships network structural shear modulus G, extension ratio β,...
We have studied properties of comb-like and bottlebrush-like graft copolymers made chemically different backbones side chains in a melt. A diagram states for this class was calculated terms architectural parameters (degree polymerization the chains, nsc, number backbone bonds between grafting points ng) structural (backbone side-chain monomer projection lengths, excluded volumes, Kuhn lengths). apply concept crowding parameter, Φ, describing overlap neighboring macromolecules classification...
A type of copper-nanocluster-polymer composites is reported and showcased that their 3D nanolattices exhibit a superior combination high strength, toughness, deformability, resilience, damage-tolerance. Notably, the strength toughness ultralight in some cases surpass current best performers, including alumina, nickel, other ceramic or metallic lattices at low densities. Additionally, are super-resilient, crack-resistant, one-step printed under ambient condition which can be easily integrated...
ABA triblock copolymers composed of a poly(dimethylsiloxane) (PDMS) bottlebrush central block and linear poly(methyl methacrylate) (PMMA) terminal blocks self-assemble into physical network PDMS strands connected by PMMA spherical domains. A combination small- ultrasmall-angle X-ray scattering techniques was used to concurrently examine dimensions domains both in the bulk at PMMA-PDMS interface. In agreement with scaling model predictions, degrees polymerization backbone (nbb) (nA) correlate...
While chain branching generally promotes swelling of polymer networks, it also leads to nonlinear modulus increase with network expansion. To understand the effect branched architecture on swelling, we study comb-like and bottlebrush networks using a combination theoretical analysis, computer simulations, experiments. The equilibrium ratio such is shown be larger than that conventional linear as result two effects: architectural disentanglement strands amplification polymer–solvent...
Results of the coarse-grained molecular dynamics simulations are used to show that force balance analysis at triple-phase contact line formed an elastic substrate has include a quartet forces: three surface tensions (surface free energies) and per unit length. In case by droplet on is due deformation generated formation wetting ridge. The magnitude this fel proportional product ridge height h shear modulus G. Similar should be included in solid particle with substrate. For problem obtained...
Polyelectrolyte complexation plays an important role in materials science and biology. The internal structure of the resultant polyelectrolyte complex (PEC) phase dictates properties such as physical state, response to external stimuli, dynamics. Small-angle scattering experiments with X-rays neutrons have revealed structural similarities between PECs semidilute solutions neutral polymers, where total function exhibits Ornstein-Zernike form. In spite consensus among different theoretical...
Understanding of how surface properties could change upon deformation is paramount importance for controlling adhesion, friction, and lubrication soft polymeric materials (i.e., networks gels). Here, we use a combination the theoretical calculations coarse-grained molecular dynamics simulations to study stress dependence on in films made rigid networks. Simulations have shown that demonstrate both polymer melts elastic solids depending their deformation. In particular, at small film...
Gold nanomaterials (NMs), such as gold nanoparticles (NPs), nanoclusters (NCs), and nanosheets (NSs), attract great interest in many different fields of science technology, due to their distinct optical, catalytic conductive properties. Reports the biogenic formation colloids from complexes have also led an increased level attention biomineralization gold. However, few methods can be applied integrated generation multiform high purity NMs. Here, we report synthesis stable, water-soluble NPs,...
Monomer sequences in statistical (co)polyelectrolytes can be used to tune complex coacervation, including density and structure of the polymer-rich phase.
We use coarse-grained molecular dynamics simulations to establish correlations between peak position in the static structure factor S(q) of combs and bottlebrushes a melt their architectural parameters such as degree polymerization side chains nsc number backbone bonds ng side-chain grafting points. Analysis scattering function derived framework random phase approximation one obtained shows that comb regime with dilute chains, > nsc, wavenumber q* corresponding scales macromolecular ∝...
Electrostatic interactions in polymeric systems are responsible for a wide range of liquid–liquid phase transitions that importance biology and materials science. Such referred to as complex coacervation, recent studies have sought understand the underlying physics chemistry. Most theoretical simulation efforts date focused on oppositely charged linear polyelectrolytes, which adopt nearly ideal-coil conformations condensed phase. However, when one coacervate components is globular protein,...
Elastomer components fail at cyclic strain amplitudes much lower than their catastrophic tear strength as a result of cumulative fatigue crack growth. Cracks typically develop in regions high stress concentrations. In general, the rate growth is determined by shape component, and nature magnitude deformation imposed. Extensive earlier work has been done on prediction life components. However, reproducibility results was poor and, addition, there low degree accuracy. A fracture mechanics...
3-D printing is a revolutionary manufacturing technique which makes it possible to fabricate objects of any shape and size that are hard reproduce by traditional methods. We develop coarse-grained molecular dynamics simulation approach model the continuous liquid interface production (CLIP) technique. This utilizes polymerization cross-linking monomeric precursor UV light within thin layer while pulling cross-linked polymeric object out pool monomers. Simulations show quality printed...
Understanding the surface properties of polymer melts is crucial for designing new polymeric coatings, adhesives, and composites. Here, we study effect molecular architecture on interfacial tension graft linear polymers by dynamics simulations. In particular, elucidate degree polymerization side chains nsc their grafting density 1/ng polymer/vacuum interface, γG, interface between melts, γGL. For case our simulations confirm that a function fraction backbone ends fbe chain fse, γG = γ∞ –...