S056021 Light Scattering in a Shear Flow of Surfactant Solution Including Micro Oil Droplets

2011 ◽  
Vol 2011 (0) ◽  
pp. _S056021-1-_S056021-2
Author(s):  
Takashi KOSHIBA ◽  
Takehiro YAMAMOTO
Keyword(s):  
Light Scattering ◽  
Shear Flow ◽  
Surfactant Solution ◽  
Oil Droplets

Kinetics of flowing dispersions. X. Oscillations in optical properties of streaming suspensions of spheroids

1977 ◽  
Vol 55 (24) ◽  
pp. 4243-4256 ◽  
Author(s):  
A. Okagawa ◽  
S. G. Mason
Keyword(s):  
Light Scattering ◽  
Shear Flow ◽  
General Pattern ◽  
Relaxation Times ◽  
Simple Shear Flow ◽  
Scattering Coefficients ◽  
Human Red Blood Cells ◽  
Dielectric Particles ◽  
Dilute Suspensions ◽  
Orientation Distributions

Transients in angular light scattering and turbidity of dilute suspensions of nearly monodisperse spheroidal particles undergoing simple shear flow have been investigated by combining Rayleigh–Debye light scattering theory for single dielectric particles with fluid mechanical theory for the orientation distributions of particle assemblies in shear flow. Applying shear to an initially isotropic suspension causes the orientation distributions and thus the angular scattering coefficients to oscillate. Various geometrical arrangements are considered with a view to selecting those that will maximize such rheo-optical effects.By calculating the optical scattering cross section of a single particle, the turbidity of a suspension is obtained; like the scattering coefficient, it undergoes oscillations that are damped by (1) the inevitable spread in particle shape and volume in real systems, (2) shear-induced particle interactions, and (3) rotary Brownian motion. The rates of damping, expressed as relaxation times, are considered for the three mechanisms acting alone or in concert.Preliminary measurements of the turbidity of dilute suspensions of hardened human red blood cells confirm this general pattern of behavior. Apart from their intrinsic interest, such rheo-optical effects can be used to determine a number of useful properties of dispersions.

LIGHT SCATTERING TECHNIQUES FOR DISCRIMINATING BETWEEN OIL AND PARTICULATES IN CONTAMINATED WATER

1977 ◽  
Vol 1977 (1) ◽  
pp. 153-156 ◽  
Author(s):  
Bruce Friedman
Keyword(s):  
Particulate Matter ◽  
Light Scattering ◽  
Intensity Distribution ◽  
Scattered Light ◽  
Incident Light ◽  
Real Life ◽  
The State ◽  
Oil Droplets ◽  
State Of Polarization

ABSTRACT Light scattering techniques are used in several oil-in-water monitors, proposed or in existence. Particulate matter which may interfere with these monitors is also frequently found in oily wastes. An analysis is made of the potential of using measurements of the angular intensity distribution of scattered light in conjunction with determination of the state of polarization of the scattered light for discriminating between oil and particulates. The size conditions which apply to the oil droplets and particulates relative to the incident light allow the scattered light angular intensity distribution to be treated as a consequence of a combination of classical diffraction and of geometrical refraction and reflection. The state of polarization of the scattered light for oil droplets is investigated using expressions for the electric field which are approximations to the expressions of the Mie theory. For the particulate matter, the state of polarization is probed on the basis of light reflected from a plane. It is found that it would be difficult to discriminate between oil and particulates using measurements of the angular intensity distribution of scattered light even in conjunction with the determination of the state of polarization of the scattered light in a real life situation.

Self-Propelled Oil Droplets and Their Morphological Change to Giant Vesicles Induced by a Surfactant Solution at Low pH

Langmuir ◽  
2016 ◽  
Vol 32 (37) ◽  
pp. 9591-9597 ◽  
Author(s):  
Taisuke Banno ◽  
Yuki Tanaka ◽  
Kouichi Asakura ◽  
Taro Toyota
Keyword(s):  
Morphological Change ◽  
Surfactant Solution ◽  
Low Ph ◽  
Giant Vesicles ◽  
Oil Droplets

scholarly journals Photoinduced Collective Motion of Oil Droplets and Concurrent Pattern Formation in Surfactant Solution

2021 ◽  
Author(s):  
Tomoya Kojima ◽  
Hiroyuki Kitahata ◽  
Kouichi Asakura ◽  
Taisuke Banno
Keyword(s):  
Pattern Formation ◽  
Collective Motion ◽  
Surfactant Solution ◽  
Light Illumination ◽  
Artificial System ◽  
Oil Droplets ◽  
Uv Illumination ◽  
Azobenzene Moiety ◽  
Visible Light Illumination ◽  
Far From Equilibrium

Collective motion is ubiquitous in living systems. Although various biomimetic artificial systems have been constructed, there have been few studies reported on collective motion induced by the coupling of chemical reactions, diffusion and convection in a far-from-equilibrium state. In this study, we report an artificial system of oil droplets in a surfactant solution wherein the collective motion of multiple droplets and pattern formation occurred concurrently. Using photo-responsive surfactants with an azobenzene moiety, the assembly of droplets and the formation of circular patterns around the formed droplet clusters occurred under UV illumination, whereas the disassembly of droplets and disappearance of the patterns occurred under subsequent visible light illumination. The observed dynamics were induced by Marangoni flows based on the reversible photoisomerisation of azobenzene-containing surfactants. The phenomena were considered analogous to the bioconvection of microorganisms. These findings could be useful for understanding the mechanism of motion of life in terms of physicochemical aspects.<br>

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