Selective droplet coalescence using microfluidic systems
Selective droplet coalescence using microfluidic systems
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DOI：
10.1039/c2lc40121e
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发表时间：
2012-01-01
期刊：
影响因子：
6.1
通讯作者：
Griffiths, Andrew D.
中科院分区：
文献类型：
--
作者：
Mazutis, Linas;Griffiths, Andrew D.
我们报告了一种微流体方法，它允许选择性和受控的1：1，2：1或3：1液滴融合。当第二液滴的γ <16%时，具有> 98%的界面表面活性剂覆盖率γ的表面活性剂稳定的液滴将与第二液滴自发融合。然而，当第二液滴的Gamma类似于66%时，两个液滴将不会融合，除非它们先前已经接触了临界时间τ。因此，控制在时间τ内接触的液滴的数量允许精确控制融合液滴的数量。我们已经证明了有效的（聚结的液滴比例p（c）1.0，n > 1000）和选择性的1：1、2：1或3：1液滴融合（正确融合的液滴比例p（s）> 0.99，n > 1000）。在这个制度中的聚结是由流体动力学流动引起的界面分离，并在不同的Ca数和使用不同的分散相，连续相和表面活性剂是有效的。然而，当第二液滴的伽马接近96%时，不再观察到聚结。基于液滴的微流控系统，其中每个液滴作为一个独立的微反应器的功能，被证明是一个有前途的工具，在生物学和化学的超高通量的广泛应用。向预形成的液滴中添加新试剂对许多这些应用至关重要，我们相信这里描述的系统是一种简单灵活的方法，也是研究界面稳定性现象的新工具。
We report a microfluidic approach, which allows selective and controlled 1 : 1, 2 : 1 or 3 : 1 droplet fusion. A surfactant-stabilized droplet with an interfacial surfactant coverage, Gamma, of > 98% will fuse spontaneously with a second droplet when Gamma of the latter droplet is < 16%. However, when Gamma of the second droplet is similar to 66%, the two droplets will not fuse, unless they have previously been brought into contact for critical time tau. Therefore, controlling the number of droplets in contact for time tau allows precise control over the number of fused droplets. We have demonstrated efficient (proportion of droplets coalesced p(c) 1.0, n > 1000) and selective 1 : 1, 2 : 1 or 3 : 1 droplet fusion (proportion of correctly fused droplets p(s) > 0.99, n > 1000). Coalescence in this regime is induced by hydrodynamic flow causing interface separation and is efficient at different Ca numbers and using different dispersed phases, continuous phases and surfactants. However, when Gamma of the second droplet is similar to 96% coalescence is no longer observed. Droplet-based microfluidic systems, in which each droplet functions as an independent microreactor, are proving a promising tool for a wide range of ultrahigh-throughput applications in biology and chemistry. The addition of new reagents to pre-formed droplets is critical to many of these applications and we believe the system described here is a simple and flexible method to do so, as well as a new tool to study interfacial stability phenomena.