化工学报 ›› 2016, Vol. 67 ›› Issue (2): 469-475.DOI: 10.11949/j.issn.0438-1157.20151273

• 流体力学与传递现象 • 上一篇    下一篇

微通道内纳米颗粒对液滴聚并的影响规律

王凯, 易诗婷, 周倩倩, 骆广生   

  1. 清华大学化学工程联合国家重点实验室, 北京 100084
  • 收稿日期:2015-08-07 修回日期:2015-09-16 出版日期:2016-02-05 发布日期:2016-02-05
  • 通讯作者: 王凯
  • 基金资助:

    国家自然科学基金项目(91334201,U1302271);全国优秀博士学位论文作者专项资金项目(FANEDD201349);化学工程联合国家重点实验室自主课题(SKL-ChE-12T02)。

Effect of nano-particles on droplet coalescence in microchannel device

WANG Kai, YI Shiting, ZHOU Qianqian, LUO Guangsheng   

  1. State Key Laboratory of Chemical Engineering, Tsinghua University, Beijing 100084, China
  • Received:2015-08-07 Revised:2015-09-16 Online:2016-02-05 Published:2016-02-05
  • Supported by:

    supported by the National Natural Science Foundation of China (91334201, U1302271), the Foundation for the Author of National Excellent Doctoral Dissertation of China (FANEDD 201349) and the State Key Laboratory of Chemical Engineering (SKL-ChE-12T02).

摘要:

Pickering 乳液是纳米颗粒稳定的液液两相体系,微流控技术是制备单分散Pickering 乳液的有效方法,而含有纳米颗粒体系在微通道内的液滴聚并规律是该实施方法的关键科学问题之一。以正辛醇为连续相,水为分散相,研究了六边形扩大微通道内液滴碰撞过程,发现了液滴聚并、碰撞不聚并和不相互接触3 种流动状态,研究了流量、颗粒浓度和颗粒亲疏水性对于液滴聚并率的影响规律,分析了颗粒在液膜排空过程中的作用机理。

关键词: Pickering 乳液, 微流体, 微通道, 聚并

Abstract:

Pickering emulsion is a liquid/liquid system stabilized by nano-particles. Microfluidic technology is an important method for preparing monodispersed Pickering emulsions. The droplet coalescence rule for the working system containing nano-particles is a core scientific issue for proceeding this new method. Using n-octanol and water as the continuous and dispersed phases respectively, the droplet collision processes in a broadening microchannel with a hexagon shape were investigated. Three typical flows (droplet coalescence, contact without coalescence and contactless) were confirmed. The effects of flow rate, nano-particle concentration and wetting property of nano-particles on the droplet coalescence percentage were studied. In addition, the working mechanism of nano-particles in the liquid film drainage processes were analyzed.

Key words: Pickering emulsion, microfluidics, microchannel, coalescence

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