scholarly journals Exploring the effects of approach velocity on depletion force and coalescence in oil-in-water emulsions

RSC Advances ◽  
2021 ◽  
Vol 11 (15) ◽  
pp. 8730-8740
Author(s):  
Ola Aarøen ◽  
Enrico Riccardi ◽  
Marit Sletmoen
Keyword(s):  
Optical Tweezers ◽  
Coalescence Time ◽  
System Parameters ◽  
Oil In Water ◽  
Depletion Force ◽  
Approach Velocity

Presented here are ways of producing unstable emulsions and use these in optical tweezers studies to determine the effects of system parameters on droplet depletion force and coalescence time.

scholarly journals A model of bubble coalescence in the presence of a nonionic surfactant with a low bubble approach velocity

2021 ◽  
Author(s):  
Yuelin Wang ◽  
Huahai Zhang ◽  
Tiefeng Wang
Keyword(s):  
Nonionic Surfactant ◽  
Surfactant Concentration ◽  
Bubble Coalescence ◽  
Bulk Concentration ◽  
High Concentration ◽  
Coalescence Time ◽  
Approach Velocity ◽  
Marangoni Stress ◽  
High Concentrations ◽  
High Concentration Range

A bubble coalescence model for a solution with a nonionic surfactant and with a small bubble approach velocity was developed, in which the mechanism of how coalescence is hindered by Marangoni stress was quantitatively analyzed. The bubble coalescence time calculated for ethanol-water and MIBC-water systems were in good agreement with experimental data. At low surfactant concentrations, the Marangoni stress and bubble coalescence time increased with bulk concentration increase. Conversely, in the high concentration range, the Marangoni stress and coalescence time decreased with bulk concentration. Numerical results showed that the nonlinear relationship between coalescence time and surfactant concentration is determined by the mass transport flux between the film and its interface, which tends to diminish the spatial concentration variation of the interface, i.e., it acts as a “damper”. This damping effect increases with increased surfactant concentration, therefore decreasing the coalescence time at high concentrations.

Stability and interaction forces of oil-in-water emulsions as observed by optical tweezers – a proof-of-concept study

RSC Advances ◽  
2014 ◽  
Vol 4 (94) ◽  
pp. 52220-52229 ◽  
Author(s):  
Julie Nilsen-Nygaard ◽  
Marit Sletmoen ◽  
Kurt Ingar Draget
Keyword(s):  
Optical Tweezers ◽  
Proof Of Concept ◽  
Interaction Forces ◽  
Concept Study ◽  
Emulsion Droplets ◽  
Oil In Water

This proof-of-concept study documents the suitability of optical tweezers in studies aiming at revealing the forces acting between emulsion droplets.

scholarly journals SORTING OF MESOSCOPIC PARTICLES DRIVEN THROUGH PERIODIC POTENTIAL LANDSCAPES

2006 ◽  
Vol 20 (23) ◽  
pp. 1427-1442 ◽  
Author(s):  
A. M. LACASTA ◽  
M. KHOURY ◽  
J. M. SANCHO ◽  
KATJA LINDENBERG
Keyword(s):  
Particle Size ◽  
Numerical Simulations ◽  
Optical Tweezers ◽  
Colloidal Particles ◽  
Periodic Potential ◽  
Materials Science ◽  
Periodic Array ◽  
System Parameters ◽  
Unified View ◽  
Particle Characteristic

Sorting of colloidal particles of different sizes is of importance in the transport and delivery of such particles in biological, materials science, and other technological contexts. A successful methodology involves the flow of a mixture of particles over designer surfaces presenting a periodic array of traps (optical tweezers) or microfabricated obstacles. The trajectories of the particles over these surfaces deviate from the direction of flow as the particles are attracted (traps) or repelled (obstacles) by the features of the landscape. The deviation of the particles from that of the flow depends on particle size (or on some other particle characteristic) and hence the particles can be sorted according to trajectory direction. On the basis of extensive numerical simulations, we present a unified view of these methodologies and discuss the effects of system parameters such as the magnitude and direction of the flow on the sorting efficacy.

Models of Cataclysmic Variables from Photometric and Spectroscopic Data

1979 ◽  
Vol 46 ◽  
pp. 65-74 ◽  
Author(s):  
A.C. Fabian ◽  
J.E. Pringle ◽  
J.A.J. Whelan ◽  
J.A. Bailey
Keyword(s):  
Spectroscopic Data ◽  
Cataclysmic Variables ◽  
System Parameters ◽  
Dwarf Nova ◽  
Spectroscopic Observations ◽  
Photometric And Spectroscopic Observations

Abstract.Recent photometric and spectroscopic observations of the dwarf nova system Z Cha are discussed. Methods for constraining the system parameters are applied and the disc emissivity is deduced as a function of radius. Indications are found that the disc shrinks in size with increasing time after outburst.

Defining the trapping limits of holographical optical tweezers

2004 ◽  
Vol 51 (3) ◽  
pp. 409-414 ◽  
Author(s):  
P. Jordan ◽  
J. Leach ◽  
M. J. Padgett ◽  
J. Cooper ◽  
G. Sinclair
Keyword(s):  
Optical Tweezers

Some Factors Influencing Metabolism and Distribution of Fibrinogen in Man and Rabbits

1977 ◽  
Vol 37 (02) ◽  
pp. 243-252
Author(s):  
Yi-Hsiang Chen ◽  
E. B Reeve
Keyword(s):  
Plasma Fibrinogen ◽  
Synthesis Rate ◽  
Fibrinogen Concentration ◽  
Fractional Catabolic Rate ◽  
System Parameters ◽  
Catabolic Rate ◽  
Simultaneous Decrease ◽  
Normal Males ◽  
Healthy Females ◽  
Made In

SummaryTo shed some light on the homeostatic regulation of plasma fibrinogen, metabolic studies were made in healthy females, and in normal, thyroidectomized, and thyroxine-treated rabbits. In females, compared with normal males, plasma fibrinogen concentration, plasma and interstitial fibrinogen decreased consequent to an increased fractional catabolic rate and a normal fibrinogen synthesis rate. The interstitial/plasma fibrinogen ratio remained unchanged. In normal rabbits, with increasing body weight fractional catabolic rate and catabolic rate decreased, while fibrinogen concentration and plasma fibrinogen remained constant owing to a simultaneous decrease in fibrinogen synthesis. In addition, fractional transcapillary transfer rate and transcapillary flux also decreased resulting in a shrinkage of interstitial fibrinogen. Thyroidectomy and thyroxine-injection markedly altered fibrinogen metabolism: thyroid hormone accelerated fibrinogen catabolism but also stimulated synthesis. The net result was an increase in plasma fibrinogen and fibrinogen concentration. The interstitial/plasma fibrinogen ratio decreased in thyroxine-treated, and increased in thyroidectomized animals. This study defines the variations of the fibrinogen system parameters in these physiologic and pathologic conditions, and illustrates some patterns of alterations in fibrinogen metabolism.

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