Phase separation of gas-liquid and liquid-liquid microflows in microchips

Arata Aota, Kazuma Mawatari, Susumu Takahashi, Teruki Matsumoto, Kazuteru Kanda, Ryo Anraku, Akihide Hibara, Manabu Tokeshi, Takehiko Kitamori

Research output: Contribution to journalArticlepeer-review

33 Citations (Scopus)

Abstract

Phase separation of gas-liquid and liquid-liquid microflows in microchannels were examined and characterized by interfacial pressure balance. We considered the conditions of the phase separation, where the phase separation requires a single phase flow in each output of the microchannel. As the interfacial pressure, we considered the pressure difference between the two phases due to pressure loss in each phase and the Laplace pressure generated by the interfacial tension at the interface between the separated phases. When the pressure difference between the two phases is balanced by the Laplace pressure, the contact line between the two phases is static. Since the contact angle characterizing the Laplace pressure is restricted to values between the advancing and receding contact angles, the Laplace pressure has a limit. When the pressure difference between the two phases exceeds the limiting Laplace pressure, one of the phases leaks into the output channel of the other phase, and the phase separation fails. In order to experimentally verify this physical picture, microchips were used having a width of 215 μm and a depth of 34 μm for the liquid-liquid microflows, a width of 100 μm and a depth of 45 μm for the gas-liquid microflows. The experimental results of the liquid-liquid microflows agreed well with the model whilst that of the gas-liquid microflows did not agree with the model because of the compressive properties of the gas phase and evaporation of the liquid phase. The model is useful for general liquid-liquid microflows in continuous flow chemical processing.

Original languageEnglish
Pages (from-to)249-255
Number of pages7
JournalMicrochimica Acta
Volume164
Issue number3-4
DOIs
Publication statusPublished - 2009 Mar 1
Externally publishedYes

Keywords

  • Interface
  • Microchip
  • Microfluidics
  • Multiphase flow
  • Phase separation

ASJC Scopus subject areas

  • Analytical Chemistry

Fingerprint Dive into the research topics of 'Phase separation of gas-liquid and liquid-liquid microflows in microchips'. Together they form a unique fingerprint.

Cite this