A5006037161- Membrane Separation Technologies
- Advanced Sensor and Energy Harvesting Materials
- Adhesion, Friction, and Surface Interactions
- Advanced Materials and Mechanics
- Membrane-based Ion Separation Techniques
- Surface Modification and Superhydrophobicity
- Fuel Cells and Related Materials
- Force Microscopy Techniques and Applications
- Polymer Surface Interaction Studies
- Liquid Crystal Research Advancements
- Nanofabrication and Lithography Techniques
- Nanopore and Nanochannel Transport Studies
- Membrane Separation and Gas Transport
- Material Dynamics and Properties
- Hydrogels: synthesis, properties, applications
- Polymer crystallization and properties
- Remote Sensing and LiDAR Applications
- Conducting polymers and applications
- Textile materials and evaluations
- Advanced Surface Polishing Techniques
- High-Velocity Impact and Material Behavior
- Energetic Materials and Combustion
- Photonic Crystals and Applications
- Advanced Polymer Synthesis and Characterization
- Modular Robots and Swarm Intelligence
National Institute of Standards and Technology
2015-2024
Material Measurement Laboratory
2017-2024
Stanford University
2024
National Institute of Standards
2011-2020
University of Sarjanawiyata Tamansiswa
2020
University of Auckland
2012-2015
Korea Institute of Science and Technology
2013
Korea University
2013
Rice University
2013
Harvard University
2013
There is a significant medical need for tough biodegradable polymer adhesives that can adapt to or recover from various mechanical deformations while remaining strongly attached the underlying tissue. We approached this problem by using poly(glycerol-co-sebacate acrylate) and modifying surface mimic nanotopography of gecko feet, which allows attachment vertical surfaces. Translation existing gecko-inspired applications complex, as multiple parameters must be optimized, including:...
A novel and highly scalable approach to generating a reusable, "smart" polymer adhesive based on surface wrinkling is presented. The patterning the film combination of swelling lateral confinement. control adhesion, or adhesion utilizes mechanism contact line splitting. This enhancement controlled by wrinkle wavelength, which tuned degree
A new approach to fabricating microlens arrays (see figure and cover) based on the confinement of surface wrinkles a soft polymer is presented. The dimensions arrangement microlenses are controlled by degree lateral material properties wrinkled regions. This allows for nonplanar patterning with array form biomimetic compound lens.
Molecular layer-by-layer (mLbL) assembled thin-film composite membranes fabricated by alternating deposition of reactive monomers on porous supports exhibit both improved salt rejection and enhanced water flux compared to traditional reverse osmosis prepared interfacial polymerization. Additionally, the well-controlled structures achieved mLbL further lead antifouling performance. As a service our authors readers, this journal provides supporting information supplied authors. Such materials...
Abstract The field of visual computing is rapidly advancing due to the emergence generative artificial intelligence (AI), which unlocks unprecedented capabilities for generation, editing, and reconstruction images, videos, 3D scenes. In these domains, diffusion models are AI architecture choice. Within last year alone, literature on diffusion‐based tools applications has seen exponential growth relevant papers published across computer graphics, vision, communities with new works appearing...
The elastic moduli of polythiophenes, regioregular poly(3-hexylthiophene) (P3HT) and poly-(2,5-bis(3-alkylthiophene-2-yl)thieno[3,2-b]thiophene) (pBTTT), are compared to their field effect mobility showing a proportional trend. the films measured using buckling-based metrology, is determined from electrical characteristics bottom contact thin film transistors. Moreover, crack onset strain pBTTT shown be less than 2.5%, whereas that P3HT greater 150%. These results show increased long-range...
We introduce a new methodology to produce aligned, or patterned, surface wrinkles on soft elastomer sans topography. The buckles orient through the manipulation of local stress distributions, which we control by defining specific regions differences in elastic moduli material.
Abstract Polymer gels are remarkable materials with physical structures that can adapt significantly and quite rapidly changes in the local environment, such as temperature, light intensity, electrochemistry, mechanical force. An interesting phenomenon observed certain polymer gel systems is mechanochromism – a change color due to deformation. Mechanochromic photonic periodically structured engineered stopband be tuned by forces reflect specific colors. These have potential mechanochromic...
Independent control of the extrinsic and intrinsic properties polyamide (PA) selective layer is essential for designing thin-film composite (TFC) membranes with performance characteristics required water purification applications besides seawater desalination. Current commercial TFC fabricated via well-established interfacial polymerization (IP) approach yield materials that are far from ideal because their thickness, surface roughness, polymer chemistry, network structure cannot be...
In this work, we present the Poroelastic Relaxation Indentation (PRI) testing approach for quantifying mechanical and transport properties of thin layers poly(ethylene glycol) hydrogels with thicknesses on order 200 μm. Specifically, PRI characterizes poroelastic relaxation in by indenting material at fixed depth measuring contact area-dependent load process as a function time. With aid linear theory developed or geometrically confined swollen polymer networks, demonstrate that can quantify...
A mechanochromic sensor based on a block copolymer photonic gel is presented. This material provides simple yet quantitative means to measure the local stress of an interface via color change by making advantageous use band gap properties and mechanical compliance one-dimensional periodic microstructure hydrophobic block-hydrophilic polyelectrolyte gel. Detailed facts importance specialist readers are published as ”Supporting Information”. Such documents peer-reviewed, but not copy-edited or...
We present a nonconventional membrane surface modification approach that utilizes topography to manipulate the tribology of foulant accumulation on water desalination membranes via imprinting submicron titanium dioxide (TiO2) pillar patterns onto molecularly structured, flat surface. This versatile overcomes constraint conventional relying interfacial polymerization inevitably leads formation ill-defined topography. Compared nonpatterned membranes, patterned showed significantly improved...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Yuhang Hu, Edwin P. Chan, Joost J. Vlassak, Zhigang Suo; Poroelastic relaxation indentation of thin layers gels. Appl. Phys. 15 October 2011; 110 (8): 086103. https://doi.org/10.1063/1.3647758 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar...
To fully explore bottlebrush polymer networks as potential model materials, a robust and versatile synthetic platform is required. Ring-opening metathesis polymerization highly controlled, rapid, functional group tolerant technique that has been used extensively for generation but to this point not synthesize networks. We polymerized mononorbornene macromonomer dinorbornene cross-linker (both poly(n-butyl acrylate)) with Grubbs' third-generation catalyst achieve in turn demonstrated control...
The fracture behavior of glassy polymers is strongly coupled to molecular parameters such as entanglement density well extrinsic strain rate and test temperature. Here we use laser-induced projectile impact testing (LIPIT) study the extreme (≈107 s–1) puncture free-standing polycarbonate (PC) thin films. We demonstrate that changes PC mass degree plasticization can lead substantial in specific energy. relate these alteration polymer determines underlying failure mechanism size deformation zone.
We present a new wrinkling-based measurement technique for quantifying the viscoelastic properties of confined polymer thin films. This approach utilizes real-time laser-light scattering to observe kinetics thermally-induced surface wrinkling, which evolves isothermally as function annealing time. Specifically, wrinkling is induced by applying thermal stress polystyrene film that sandwiched between silicon substrate and an aluminium superstrate. By following time evolution wrinkle wavelength...
The viscoelastic properties of polymer thin films can have a significant impact on the performance in many small-scale devices. In this work, we use phenomenon based thermally induced instability, termed thermal wrinkling, to measure polystyrene as function geometric confinement via changes film thickness. With application appropriate buckling mechanics model for incompressible and geometrically confined films, estimate stress-relaxation modulus by measuring time-evolved wrinkle wavelength...
We present the design of an automated spin-coater that facilitates fabrication polymer films based on molecular layer-by-layer (mLbL) assembly. Specifically, we demonstrate synthesis ultrathin crosslinked fully-aromatic polyamide (PA) are chemically identical to membranes used in water desalination applications as measured by X-ray photoelectron spectroscopy. reflectivity measurements indicate mLbL assembly creates with a constant film growth rate and minimal roughness compared traditional...
Charge carrier mobilities in conjugated semicrystalline polymers depend on morphological parameters such as crystallinity, crystal orientation, and connectivity between ordered regions. Despite recent progress the development of conducting polymers, complex interplay aforementioned their impact charge transport is not fully understood. By varying casting solvents thermal annealing, we have systematically modulated crystallization poly(3-hexylthiophene-2,5-diyl) (P3HT)...