Laboratorio de Estudios Cristalográficos, IACT (CSIC-UGR) , Avda. de las Palmeras, 4, 18100 Armilla, Granada, Spain.
Langmuir. 2013 Oct 15;29(41):12628-32. doi: 10.1021/la402735k. Epub 2013 Oct 3.
We monitor the dissolution of arrayed picoliter-size sessile microdroplets of the aqueous phase in oil, generated using a recently developed fluidic device. Initial pinning of the microdroplet perimeter leads to a nearly constant contact diameter, thus contraction proceeds via microdroplet (micrometer-diameter) height and contact angle reductions. This confirms that picoliter microdroplets contraction or dissolution due to the selective diffusion of water in oil has comparable dynamics with microliter droplet evaporation in air. We observe a constant microdroplet dissolution rate in different aqueous solutions. The application of this simple model to solvent-diffusion-driven crystallization experiments in confined volumes, for instance, would allow us to determine precisely the concentration in the microdroplet during an experiment and particularly at nucleation.
我们监测了使用最近开发的流体装置产生的油中排列的皮升级贴壁微液滴的水相的溶解情况。微液滴周边的初始固定导致接触直径几乎保持不变，因此收缩是通过微液滴（微米级直径）高度和接触角的减小来进行的。这证实了由于水在油中的选择性扩散导致皮升级微液滴的收缩或溶解与空气中的微升级液滴蒸发具有相当的动力学。我们观察到在不同的水溶液中微液滴的溶解速率保持不变。将这种简单的模型应用于受限体积中的溶剂扩散驱动结晶实验，例如，可以使我们在实验过程中特别是在成核时精确地确定微液滴中的浓度。
