Ice formation can have catastrophic consequences for human activity on the ground and in air. Here we investigate water freezing delays untreated coated surfaces ranging from hydrophilic to superhydrophobic use these evaluate icephobicity. Supercooled microdroplets are inkjet-deposited coalesce until spontaneous of accumulated mass occurs. Surfaces with nanometer-scale roughness higher wettability display unexpectedly long delays, at least 1 order magnitude longer than typical larger...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMorphology of flame-generated soot as determined by thermophoretic samplingR. A. Dobbins and C. M. MegaridisCite this: Langmuir 1987, 3, 2, 254–259Publication Date (Print):March 1, 1987Publication History Published online1 May 2002Published inissue 1 March 1987https://pubs.acs.org/doi/10.1021/la00074a019https://doi.org/10.1021/la00074a019research-articleACS PublicationsRequest reuse permissionsArticle Views1819Altmetric-Citations422LEARN ABOUT...

In this paper an experimental and theoretical study of the deformation a spherical liquid droplet colliding with flat surface is presented. The model accounts for presence inertia, viscous, gravitation, tension, wetting effects, including phenomenon contact-angle hysteresis. Experiments impingement surfaces different wettability were performed. showed that maximum splat radius decreased as value advancing contact angle increased. effect impact velocity on spreading was more pronounced when...

Surface tension driven transport of liquids on open substrates offers an enabling tool for micro total analysis systems that are becoming increasingly popular low-cost biomedical diagnostic devices. The present study uses a facile wettability patterning method to produce microfluidic tracks - due their shape, surface texture and chemistry capable transporting wide range liquid volumes (~1-500 μL) on-chip, overcoming viscous other opposing forces (e.g., gravity) at the pertinent length...

Co-electrospinning is ideally suited for fabricating continuous fibers encasing materials within a polymer sleeve, but requires relatively complex coannular nozzles. A single-nozzle co-electrospinning technique demonstrated using blends of poly(methyl methacrylate) (PMMA)/polyacrylonitrile (PAN) solutions in dimethylformamide (DMF). The as-spun have outer diameters the range 0.5-5 microm and possess core-shell structure similar to that attained via relies on precipitation PMMA solution...

Dropwise condensation (DWC) heat transfer depends strongly on the maximum diameter (Dmax) of condensate droplets departing from condenser surface. This study presents a facile technique implemented to gain control Dmax in DWC within vapor/air atmospheres. We demonstrate how this approach can enhance corresponding rate by harnessing capillary forces removal examine various hydrophilic–superhydrophilic patterns, which, respectively, sustain and combine filmwise substrate. The material system...

Carbon nanotube (CNT) membranes hold the promise of extraordinary fast water transport for applications such as energy efficient filtration and molecular level drug delivery. However, experiments computations have reported flow rate enhancements over continuum hydrodynamics that contradict each other by orders magnitude. We perform large scale dynamics simulations emulating first time micrometer thick CNTs used in experiments. find enhancement rates are length dependent due to entrance exit...

Marine oil spills seriously endanger sea ecosystems and coastal environments, resulting in a loss of energy resources. Environmental economic demands emphasize the need for new methods effectively separating oil-water mixtures, while collecting content at same time. A surface-tension-driven, gravity-assisted, one-step, separation method is presented sustained filtration collection from floating spill. benchtop prototype device uses selective-wettability (superhydrophobic superoleophilic)...

Abstract Aluminum nitride (AlN), a versatile ceramic with high thermal conductivity, electrical resistivity, and coefficient of expansion compatible silicon, is well‐suited for direct‐to‐chip cooling applications electronics, implementation in wide bandgap semiconductors, high‐temperature heat exchangers. Despite multiple advantages, AlN's liquid‐cooling often hindered by surface‐degrading effects working‐fluid‐induced hydrolysis. Herein, scalable ‐but highly tunable‐ wettability engineering...

This article presents a theoretical study of the deformation spherical liquid droplet impinging upon flat surface. The accounts for presence surface tension during spreading process. model is solved numerically utilizing deforming finite elements and grid generation to simulate accurately large deformations, as well domain nonuniformities characteristic results document effects impact velocity, diameter, tension, material properties on fluid dynamics droplet. Two liquids with markedly...

Abstract The soot formed in a coannular ethene diffusion flame was extracted by thermophoretic sampling technique for examination transmission electron microscopy. A detailed analysis of the particle statistics samples is presented. Primary diameters range from 10 to 40 nm and their spatial variation within affords quantitative information on specific surface growth oxidation rates. moment ratio aggregate volume-equivalent (D63D30,) found be close values predicted self-preserving size...

The absorption, scattering, and differential scattering cross sections are presented for polydisperse aggregates of prescribed fractal dimension uniform primary particle size. These optical properties formulated in terms the diameter, appropriate moments discrete size distribution function, mean-square radius gyration. absorption compared with Rayleigh theory small limit results computational simulations Mountain Mulholland [ Langmuir4, 1321 ( 1988)] intermediate large aggregates. well...

Hydrothermal multiwall closed carbon nanotubes are shown to contain an encapsulated multiphase aqueous fluid, thus offering attractive test platform for unique in situ nanofluidic experiments the vacuum of a transmission electron microscope. The excellent wettability graphitic inner tube walls by liquid and mobility this nanotube channels observed. Complex interface dynamic behavior is induced means irradiation. Strong atomic-scale interactions between entrapped phase wetted terminated...

We present a method to fill 2−5-nm-diameter channels of closed multiwalled carbon nanotubes (MWNT) with an aqueous fluid and perform in situ high-resolution observations dynamic behavior this confined system. Transmission electron microscope (TEM) confirm the successful filling two types MWNTs reveal disordered gas/liquid interfaces contrasting smooth curved menisci visualized previously MWNT diameter above 10 nm. Electron energy loss spectroscopy (EELS) dispersive spectrometry (EDS)...

Cell differentiation, adhesion, and orientation are known to influence the functionality of both natural engineered tissues, such as articular cartilage. Several attempts have been devised regulate these important cellular behaviors, including application inexpensive but efficient electrospinning that can produce patterned extracellular matrix (ECM) features. Electrospun oriented polycaprolactone (PCL) scaffolds (500 or 3000 nm fiber diameter) were created, human mesenchymal stem cells...

An experimental study is presented on contact angle dynamics during spreading/recoiling of mm-sized water droplets impacting orthogonally various surfaces with data. Application hydrodynamic theory indicates that in the slow stage forced spreading slip length and microscopic should be line velocity dependent. The performs well kinematic (fast) spreading, which solid/liquid interactions are weak. molecular kinetic yields physically reasonable wetting parameters, which, however, vary impact...

This work examines the release of a model water-soluble compound from electrospun polymer nanofiber assemblies. Such attracts attention in relation to biomedical applications, such as controlled drug delivery. It is also important for stem cell attachment and differentiation on biocompatible scaffolds containing growth factors, which have been encapsulated by means electrospinning. Typically, mechanism has attributed solid-state diffusion fibers into surrounding aqueous bath. Under this...

Rapid advances in modern electronics place ever-accelerating demands on innovation towards more robust and versatile functional components. In the flexible domain, novel material solutions often involve creative uses of common materials to reduce cost, while maintaining uncompromised performance. Here we combine a commercially available paraffin wax-polyolefin thermoplastic blend (elastomer matrix binder) with bulk-produced carbon nanofibres (charge percolation network for electron...

Abstract A probe sampling technique. which is based on the phenomenon of thermophoresis, employed to study soot aggregate morphology within a emitting (smoking) coannular ethylene/air diffusion flame at atmospheric pressure. Primary particle diameters are obtained through electron microscope analysis aggregates collected from environment. These observations, when combined with laser diagnostic and velocity measurements performed by others, result in calculation specific surface growth rates,...

Deciduous trees shed their leaves each autumn to survive cold weather. A first step in this process causes the lose hydrophobic layer--a phenomenon that is hastened by pollution. Little known about physical details of raindrop-leaf interaction as hydrophobicity changed, yet these affect premature leaf loss and vulnerability rainstorms. The authors model dynamic response a raindrop an elastic cantilever beam, find surface can protect against impact better than hydrophilic one. These results...