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arXiv · 0910.3159

Stretching Folding Instability and Nanoemulsions

Chon U. Chan·Claus-Dieter Ohl
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Abstract

Here we show a folding-stretching instability in a microfluidic flow focusing device using silicon oil (100cSt) and water. The fluid dynamics video demonstrates an oscillating thread of oil focused by two co-flowing streams of water. We show several high-speed sequences of these oscillations with 30,000 frames/s. Once the thread is decelerated in a slower moving pool downstream an instability sets in and water-in-oil droplets are formed. We reveal the details of the pinch-off with 500,000 frames/s. The pinch-off is so repeatable that complex droplet patterns emerge. Some of droplets are below the resolution limit, thus smaller than 1 micrometer in diameter.

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Chon U. Chan, Claus-Dieter Ohl. 2009-10-16. Stretching Folding Instability and Nanoemulsions. https://arxiv.org/abs/0910.3159

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