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Fluid Dynamics Seminar


Monday, Feb. 7, 2011, 4:00 PM
Cullimore, Room 611
New Jersey Institute of Technology

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Manipulation of particles trapped at fluid-liquid interfaces


Pushpendra Singh

 

Department of Mechanical and Industrial Engineering, New Jersey Institute of Technology



Abstract

 

The behavior of particles trapped at fluid-liquid interfaces has come under intense scrutiny in recent years because of their importance in a wide range of applications, such as self-assembly of micron to nano sized particles leading to the formation of novel nano structured materials, the stabilization of emulsions. In this talk I will summarize the current state of understanding of the mechanisms that are important in determining the distribution of particles on fluid-liquid interfaces. Specifically, when particles come in contact with an interface they first disperse and cause particles already trapped on the interface to move away. The initial dispersion, which can be explosive for small particles on the surface of mobile liquids like water, is due to the fact that the capillary force pulls particles into the interface causing them to accelerate to a relatively large velocity. The motion of a particle in the direction normal to the interface gives rise to a secondary lateral flow on the interface away from the particle which causes other particles on the interface to move away. I will also discuss two recently developed techniques that use externally applied electric fields to manipulate the distribution of particles on interfaces.