School of Energy and Environment, Zhongyuan University of Technology, Zhengzhou 450007, China.
J Colloid Interface Sci. 2010 Dec 15;352(2):580-4. doi: 10.1016/j.jcis.2010.08.062. Epub 2010 Aug 31.
Particle separation is an important topic in microfluidic field and has recently gained significant attention in sample preparations for biological and chemical studies. In this paper, a novel particle separation method was proposed. In this method, the particles were separated by the air-liquid interface in a microchannel. The motion of the air-liquid interface was controlled with a syringe pump. Depending on the air-liquid interface speed, the liquid film thickness and the viscous force on particles were changed and the particles were separated by sizes. We observed the separation of 1.01 μm particles from the larger particles when the air-liquid interface speed was less than 11 μm/s, and the separation of both 1.01 μm and 5.09 μm particles from the larger particles when the interface speed was between 11 μm/s and 120 μm/s. When the speed was higher than 120 μm/s, the drag force of the liquid flow generated by the advancing interface on particles was so strong that the flow removed all particles off from the bottom channel wall and there were no particles left behind the advancing interface.
粒子分离是微流控领域的一个重要课题，最近在生物和化学研究的样品制备中受到了广泛关注。本文提出了一种新的粒子分离方法。在该方法中，通过微通道中的气液界面实现粒子分离。通过注射器泵控制气液界面的运动。根据气液界面速度的不同，改变液体膜厚度和粒子上的粘性力，从而按尺寸分离粒子。当气液界面速度小于 11μm/s 时，我们观察到 1.01μm 粒子从较大粒子中分离出来，当界面速度在 11μm/s 至 120μm/s 之间时，我们观察到 1.01μm 和 5.09μm 粒子都从较大粒子中分离出来。当速度高于 120μm/s 时，前进界面产生的液体流动对粒子的阻力非常大，以至于流动将所有粒子从底部通道壁上冲走，前进界面后面没有留下任何粒子。
