A5075490337- Polymer Surface Interaction Studies
- Force Microscopy Techniques and Applications
- Advanced Polymer Synthesis and Characterization
- Hydrogels: synthesis, properties, applications
- Molecular Junctions and Nanostructures
- Dendrimers and Hyperbranched Polymers
- Advanced Materials and Mechanics
- Block Copolymer Self-Assembly
- Advanced Sensor and Energy Harvesting Materials
- Polymer composites and self-healing
- Surfactants and Colloidal Systems
- biodegradable polymer synthesis and properties
- Polymer crystallization and properties
- Nanofabrication and Lithography Techniques
- Surface Modification and Superhydrophobicity
- Luminescence and Fluorescent Materials
- Adhesion, Friction, and Surface Interactions
- Supramolecular Self-Assembly in Materials
- Polymer Nanocomposites and Properties
- Electrospun Nanofibers in Biomedical Applications
- Mechanical and Optical Resonators
- Lubricants and Their Additives
- Radioactive element chemistry and processing
- Cellular Mechanics and Interactions
- Synthetic Organic Chemistry Methods
University of North Carolina at Chapel Hill
2016-2025
Institute of Macromolecular Compounds
2005-2022
Communities In Schools of Orange County
2018-2021
University of North Carolina Health Care
2017-2021
A. N. Nesmeyanov Institute of Organoelement Compounds
2018-2019
Institute of Synthetic Polymeric Materials
1997-2018
Carnegie Mellon University
2001-2010
National and Kapodistrian University of Athens
2005-2008
Centre National de la Recherche Scientifique
2008
North Carolina Agricultural and Technical State University
2008
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication the EditorNEXTThe Synthesis of Densely Grafted Copolymers by Atom Transfer Radical PolymerizationKathryn L. Beers, Scott G. Gaynor, Krzysztof Matyjaszewski, Sergei S. Sheiko, and Martin MöllerView Author Information Department Chemistry, Mellon Institute, Carnegie University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213 University Ulm, Organishe Chemie III/ Makromolekulare Chemie, 89069 Germany Cite this:...
A new type of "rigid and tough" hydrogel with excellent elasticity is designed by dense clustering hydrogen bonds within a loose chemical network. The resultant exhibits good combination high modulus (28 MPa), toughness (9300 J m−3), extensibility (800%), tensile stress (2 MPa). Furthermore, the gel displays fatigue-resistance complete extremely fast recovery shape mechanical properties (3 min at 37 °C). As service to our authors readers, this journal provides supporting information supplied...
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...
“Ultra‐monomolecular” films of block copolymers , i.e., whose surface concentration is so low that the substrate cannot be covered homogeneously without affecting structure macromolecules very strongly, have been studied using tapping‐ and friction‐mode SFM. Two‐dimensional phase separation yielding an ordered pattern polystyrene poly‐2‐vinylpyridine domains observed. SFM shown to distinguish topological features also discriminate between chemically different components. The generated...
Brush macromolecules having poly(n-butyl acrylate-block-styrene) and poly(styrene-block-n-butyl acrylate) side chains have been synthesized by the "grafting from" approach using atom transfer radical polymerization (ATRP). The molecular weights of resulting polymers were characterized gel permeation chromatography (GPC) refractive index multiangle light scattering detection. block copolymer cleaved from backbone analyzed GPC, confirming synthesis well-defined brushes. Visualization...
Steric repulsion between grafted side chains inhibits interpenetration of bottlebrushes, transforming them into flexible filaments.
We present a general strategy for enabling reversible shape transformation in semicrystalline memory (SM) materials, which integrates three different SM behaviors: conventional one-way SM, two-way and SM. While (RSM) is observed upon heating cooling cycles, the RSM occurs only. Shape reversibility achieved through partial melting of crystalline scaffold secures temporary by leaving latent template recrystallization. This behavior neither mechanically nor structurally constrained, thereby...
Freestanding, single-component dielectric actuators are designed based on bottlebrush elastomers that enable giant reversible strokes at relatively low electric fields and altogether avoid preactuation mechanical manipulation. This materials design platform allows for independent tuning of actuator rigidity elasticity over broad ranges without changing chemical composition, which opens new opportunities in soft-matter robotics.
The current approach to regulating mechanical properties of elastomeric materials is predominately based on the exploratory mixing different polymers, solvents, and fillers—which both inflexible in application imprecise property control. Here we overview a new design that harnesses well-defined molecular codes independently controlled architectural parameters program grand variation "phenotypes". This design-by-architecture generates set universal correlations between architecture physical...
Injectable hydrogels are desired in many biomedical applications due to their minimally invasive deployment the body and ability introduce drugs. However, current injectables suffer from mechanical mismatch with tissue, fragility, water expulsion, high viscosity. To address these issues, we design brush-like macromolecules that concurrently provide softness, firmness, strength, fluidity, swellability. The synthesized linear-bottlebrush-linear (LBL) copolymers facilitate improved...
Abstract Mechanically robust and tough polymeric materials are in high demand for applications ranging from flexible electronics to aerospace. However, achieving both toughness strength polymers remains a significant challenge due their inherently contradictory nature. Here, universal strategy enhancing the of polymer blends using ligand‐modulated metal–organic framework (MOF) nanoparticles is presented, which engineered have adjustable hydrophilicity lipophilicity by varying types ratios...
Two macromonomers containing ethylene oxide (EO) segments with different degrees of polymerization (DPPEO = 5 and 23), capped by a methoxy methacrylate group (PEOMA), were polymerized atom transfer radical (ATRP) in organic solvents. In addition to the direct preparation densely grafted brush copolymers "grafting through" macromonomers, lower molecular weight PEOMA (MWav 300 g/mol, DPPEO 5) was also employed from" reaction using well-defined multifunctional macroinitiator...
The synthesis and structural analysis of a library containing 13 taper- conical-shaped self-assembling dendrons, 16 dendritic monomers, their corresponding polymers is reported. Fifteen these exhibit well-defined cylindrical shape produced by the self-assembly side groups that self-organizes in hexagonal columnar two-dimensional liquid crystalline lattice. retrosynthetic this lattice X-ray diffraction (XRD) showed diameter (60 to 41 Å) number repeat units forming cylinder cross-section (7...
We performed theoretical and experimental investigations of dilute solutions micelles neutral amorphous diblock copolymers in selective solvents. The ranges thermodynamic stability spherical, cylindrical, lamellar morphologies along with the equilibrium sizes aggregation numbers are calculated measured. For high molecular weight it is shown that sphere-to-cylinder transition as well precipitation associated cylinder-to-lamella occurs when aggregates have a crew-cut structure thickness corona...
High molar mass polymacromonomers based on methacryloyl end-functionalized oligo methacrylates (Mn = 2410 g/mol) adopt the conformation of wormlike cylindrical brushes. Comparison absolute mass, Mw, determined by static light scattering and contour length, Lw, molecules measured SFM in dry state revealed length per vinylic main chain monomer structure to be less than 0.1 nm, thus being much shorter maximum value 0.25 nm. In solution this shrinkage could quantified 0.071 nm Holtzer analysis...
A series of three-arm star densely grafted molecular brushes with poly(n-butyl acrylate) side chains were prepared by atom transfer radical polymerization (ATRP). The macroinitiators poly(2-bromopropionyloxyethyl methacrylate) ATRP 2-trimethylsilyloxyethyl methacrylate using trifunctional initiators 1,1,1-tris(4-(2-bromoisobutyryloxy)phenyl)ethane and different catalytic systems, i.e., a CuIX/dNbpy complex (X = Br, Cl) without CuIIX2 as deactivators, followed the subsequent esterification...