期刊
SMALL
卷 8, 期 17, 页码 2704-2714出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/smll.201200445
关键词
microbubbles; microdroplets; microfluidics; perfluorocarbons; phase transitions
类别
资金
- Ontario Institute for Cancer Research
- FY07 Department of Defense Breast Cancer Research Program Concept Award [BC075873]
- Ontario Research Fund-Research Excellence Program
Microfluidics (MFs) can produce monodisperse droplets with precise size control. However, the synthesis of monodisperse droplets much smaller than the minimum feature size of the microfluidic device (MFD) remains challenging, thus limiting the production of submicrometer droplets. To overcome the minimum micrometer-scale droplet sizes that can be generated using typical MFDs, the droplet material is heated above its boiling point (bp), and then MFs is used to produce monodisperse micrometer-scale bubbles (MBs) that are easily formed in the size regime where standard MFDs have excellent size control. After MBs are formed, they are cooled, condensing into dramatically smaller droplets that are beyond the size limit achievable using the original MFD, with a size decrease corresponding to the density difference between the gas and liquid phases of the droplet material. Herein, it is shown experimentally that monodisperse, submicrometer droplets of predictable sizes can be condensed from a monodisperse population of MBs as generated by MFs. Using perfluoropentane (PFP) as a representative solvent due to its low bp (29.2 degrees C), it is demonstrated that monodisperse PFP MBs can be produced at MFD temperatures >3.6 degrees C above the bp of PFP over a wide range of sizes (i.e., diameters from 2 to 200 mu m). Independent of initial size, the generated MBs shrink rapidly in size from about 3 to 0 degrees C above the bp of PFP, corresponding to a phase change from gas to liquid, after which they shrink more slowly to form fully condensed droplets with diameters 5.0 +/- 0.1 times smaller than the initial size of the MBs, even in the submicrometer size regime. This new method is versatile and flexible, and may be applied to any type of low-bp solvent for the manufacture of different submicrometer droplets for which precisely controlled dimensions are required.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据