scholarly journals Synergistic action of TiO2 particles and surfactants on the foamability and stabilization of aqueous foams

RSC Advances ◽  
2017 ◽  
Vol 7 (71) ◽  
pp. 44972-44978 ◽  
Author(s):  
Huiying Cao ◽  
Xuan Zhang ◽  
Baiyong Ding ◽  
Long Wang ◽  
Naiyan Lu
Keyword(s):  
Synergistic Effect ◽  
Synergistic Action ◽  
Water Interface ◽  
New Materials ◽  
Small Particles ◽  
Tio2 Particles ◽  
Aqueous Foams ◽  
Air Water Interface

Small particles can be activated via a synergistic effect with surfactants and adsorbed to the air–water interface to generate and stabilize foams, which has been applied extensively to develop new materials and techniques.

Critical role of nanocomposites at air–water interface: From aqueous foams to foam-based lightweight functional materials

2021 ◽  
Vol 416 ◽  
pp. 129121
Author(s):  
Kai Yu ◽  
Bin Li ◽  
Huagui Zhang ◽  
Zhentao Wang ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Critical Role ◽  
Functional Materials ◽  
Water Interface ◽  
Aqueous Foams ◽  
Air Water Interface

Dispersion of Particles on Liquid Surfaces

2011 ◽  
Author(s):  
Shriram B. Pillapakkam ◽  
Pushpendra Singh
Keyword(s):  
Numerical Simulation ◽  
Particle Size ◽  
Vertical Motion ◽  
Liquid Interface ◽  
Water Interface ◽  
Small Particles ◽  
Air Water Interface ◽  
Large Velocity ◽  
Simulation Results ◽  
Air Liquid Interface

In a recent study we have shown that when small particles, e.g., flour, pollen, glass, etc., contact an air-liquid interface, they disperse rapidly as if they were in an explosion. The rapid dispersion is due to the fact that the capillary force pulls particles into the interface causing them to accelerate to a large velocity. The vertical motion of a particle during its adsorption causes a radially-outward lateral (secondary) flow on the interface that causes nearby particles to move away. We present direct numerical simulation results for the adsorption of particles and show that the inertia of a particle plays an important role in its motion in the direction normal to a fluid-liquid interface. Although the importance of inertia diminishes with decreasing particle size, on an air-water interface the inertia continues to be important even when the size is as small as a few nanometers.

scholarly journals Foams Stabilized with Nanoparticles for Gas Well Deliquification

2014 ◽  
Vol 16 (2) ◽  
pp. 114-117 ◽  
Author(s):  
Ewa Knapik ◽  
Jerzy Stopa ◽  
Anna Marzec
Keyword(s):  
Ionic Surfactant ◽  
Water Interface ◽  
Interface Tension ◽  
Gas Well ◽  
Hydrophobically Modified ◽  
Aqueous Foams ◽  
Air Water Interface ◽  
Nanoparticles Concentration ◽  
The Stability ◽  
The Cost

Abstract This study examined the interaction of solid nanoparticles and anionic and non-ionic surfactant at an air–water interface. Aqueous foams stabilized by silica nanoparticles in water with different levels of salinity were studied in detail. The stability of solid/surfactant dispersion was evaluated visually. Nanoparticles content impact and concentration of surfactant on the foamability, deliquification of foams and structure of wet foams were studied. It was found that the foamability of dispersion depends either on the surfactant concentration or on the nanoparticles concentration. The adsorption of hydrophobically modified silica particles and surfactants reduces the air/water interface tension. The results of the examinations showed that the use of nanoparticles allows to increase the efficiency of brine unloading even up to 20%. Surfactant particle and nanosilica present synergistic action, use of 4 wt% of nanoparticles allows to reduce surfactant consumption up to half. The cost of the preparation of the proposed dispersion is slightly higher, about 5%, compared to the sole surfactant.

Modeling of Particles Dispersion on Liquid Surfaces

2010 ◽  
Author(s):  
Sathishkumar Gurupatham ◽  
Bhavin Dalal ◽  
Sai Nudurupati ◽  
Ian S. Fischer ◽  
Pushpendra Singh ◽  
...  
Keyword(s):  
Particle Size ◽  
High Frequency ◽  
Liquid Surface ◽  
Maximum Velocity ◽  
Capillary Forces ◽  
Viscous Drag ◽  
Water Interface ◽  
Small Particles ◽  
Air Water Interface ◽  
Large Velocity

When small particles (e.g., flour, pollen, etc.) come in contact with a liquid surface, they immediately disperse. The dispersion can occur so quickly that it appears explosive, especially for small particles on the surface of mobile liquids like water. This explosive-like dispersion is the consequence of capillary forces pulling particles into the interface causing them to accelerate to a relatively large velocity. The maximum velocity increases with decreasing particle size; for nanometer-sized particles (e.g., viruses and proteins), the velocity on an air-water interface can be as large as 47 m/s. We also show that particles oscillate at a relatively-high frequency about their floating equilibrium before coming to stop under viscous drag. The observed dispersion is a result of strong repulsive hydrodynamic forces that arise because of these oscillations.

scholarly journals General and robust covalently linked graphene oxide affinity grids for high-resolution cryo-EM

2019 ◽  
Author(s):  
Feng Wang ◽  
Yanxin Liu ◽  
Zanlin Yu ◽  
Sam Li ◽  
Yifan Cheng ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Polyethylene Glycol ◽  
High Resolution ◽  
Oxide Surface ◽  
Water Interface ◽  
Small Particles ◽  
Affinity Tag ◽  
Rapid Preparation ◽  
Air Water Interface ◽  
Covalently Linked

AbstractDespite their great potential to facilitate rapid preparation of quite impure samples, affinity grids have not yet been widely employed in single particle cryo-EM. Here, we chemically functionalize graphene oxide coated grids and use a highly specific covalent affinity tag system. Importantly, our polyethylene glycol spacer keeps particles away from the air-water interface and graphene oxide surface, protecting them from denaturation or aggregation and permits high-resolution reconstructions of small particles.

Sampling and analysis of the air-water interface with SEM and EDS of microlayers

1989 ◽  
Vol 47 ◽  
pp. 1004-1005
Author(s):  
Randall W. Smith ◽  
John Dash
Keyword(s):  
Heavy Metals ◽  
Surface Microlayer ◽  
Surface Films ◽  
Water Interface ◽  
Physical Processes ◽  
Infrared Spectroscopic Analysis ◽  
Eds Analysis ◽  
Air Water Interface ◽  
Significant Area ◽  
Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

Temperature Dependence of the Air/Water Interface Revealed by Polarization Sensitive Sum-Frequency Generation Spectroscopy

2018 ◽  
Author(s):  
Daniel R. Moberg ◽  
Shelby C. Straight ◽  
Francesco Paesani
Keyword(s):  
Temperature Dependence ◽  
Low Frequency ◽  
Potential Energy Function ◽  
Md Simulations ◽  
Sum Frequency Generation ◽  
Water Molecules ◽  
Water Interface ◽  
Sum Frequency ◽  
Air Water Interface ◽  
Frequency Generation

<div> <div> <div> <p>The temperature dependence of the vibrational sum-frequency generation (vSFG) spectra of the the air/water interface is investigated using many-body molecular dynamics (MB-MD) simulations performed with the MB-pol potential energy function. The total vSFG spectra calculated for different polarization combinations are then analyzed in terms of molecular auto-correlation and cross-correlation contributions. To provide molecular-level insights into interfacial hydrogen-bonding topologies, which give rise to specific spectroscopic features, the vSFG spectra are further investigated by separating contributions associated with water molecules donating 0, 1, or 2 hydrogen bonds to neighboring water molecules. This analysis suggests that the low frequency shoulder of the free OH peak which appears at ∼3600 cm−1 is primarily due to intermolecular couplings between both singly and doubly hydrogen-bonded molecules. </p> </div> </div> </div>

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