Interfacial aspects of water drop formation at micro-engineered orifices

Research output: Contribution to journalArticleAcademicpeer-review

37 Citations (Scopus)

Abstract

The formation of emulsions with micro-engineered silicon based arrays of micro-orifices is a relatively new technique. Until now, only the preparation of oil-in-water emulsions was studied due to the hydrophilic nature of silicon. This work evaluates the emulsification of water into n-hexadecane with hydrophobized arrays of micro-orifices. We have studied the drop formation rate, the number of active pores and the drop size. In contrast to conventional macroporous membranes used for membrane emulsification, we observed high dispersed phase fluxes up to 4600 L h−1 m−2 bar−1 while all pores being active at applied pressures below 2 times the critical pressure. The drop diameter was independent from the applied pressure difference. We observed a pressure dependent lag time between drop formations at low emulsification pressures. The lag time is related to the rate of surfactant diffusion to the water–oil interface causing a reduction of the interfacial tension. A significant influence of the used hydrophobization agents, perfluorinated octyltrichlorosilane (FOTS) and octyltrichlorosilane (OTS), was found for the resulting drop sizes and the number of active pores.
Original languageUndefined
Pages (from-to)460-469
JournalJournal of colloid and interface science
Volume312
Issue number2
DOIs
Publication statusPublished - 2007

Keywords

  • METIS-243802
  • IR-58127

Cite this

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title = "Interfacial aspects of water drop formation at micro-engineered orifices",
abstract = "The formation of emulsions with micro-engineered silicon based arrays of micro-orifices is a relatively new technique. Until now, only the preparation of oil-in-water emulsions was studied due to the hydrophilic nature of silicon. This work evaluates the emulsification of water into n-hexadecane with hydrophobized arrays of micro-orifices. We have studied the drop formation rate, the number of active pores and the drop size. In contrast to conventional macroporous membranes used for membrane emulsification, we observed high dispersed phase fluxes up to 4600 L h−1 m−2 bar−1 while all pores being active at applied pressures below 2 times the critical pressure. The drop diameter was independent from the applied pressure difference. We observed a pressure dependent lag time between drop formations at low emulsification pressures. The lag time is related to the rate of surfactant diffusion to the water–oil interface causing a reduction of the interfacial tension. A significant influence of the used hydrophobization agents, perfluorinated octyltrichlorosilane (FOTS) and octyltrichlorosilane (OTS), was found for the resulting drop sizes and the number of active pores.",
keywords = "METIS-243802, IR-58127",
author = "M.J. Geerken and Lammertink, {Rob G.H.} and Matthias Wessling",
year = "2007",
doi = "10.1016/j.jcis.2007.03.074",
language = "Undefined",
volume = "312",
pages = "460--469",
journal = "Journal of colloid and interface science",
issn = "0021-9797",
publisher = "Academic Press Inc.",
number = "2",

}

Interfacial aspects of water drop formation at micro-engineered orifices. / Geerken, M.J.; Lammertink, Rob G.H.; Wessling, Matthias.

In: Journal of colloid and interface science, Vol. 312, No. 2, 2007, p. 460-469.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Interfacial aspects of water drop formation at micro-engineered orifices

AU - Geerken, M.J.

AU - Lammertink, Rob G.H.

AU - Wessling, Matthias

PY - 2007

Y1 - 2007

N2 - The formation of emulsions with micro-engineered silicon based arrays of micro-orifices is a relatively new technique. Until now, only the preparation of oil-in-water emulsions was studied due to the hydrophilic nature of silicon. This work evaluates the emulsification of water into n-hexadecane with hydrophobized arrays of micro-orifices. We have studied the drop formation rate, the number of active pores and the drop size. In contrast to conventional macroporous membranes used for membrane emulsification, we observed high dispersed phase fluxes up to 4600 L h−1 m−2 bar−1 while all pores being active at applied pressures below 2 times the critical pressure. The drop diameter was independent from the applied pressure difference. We observed a pressure dependent lag time between drop formations at low emulsification pressures. The lag time is related to the rate of surfactant diffusion to the water–oil interface causing a reduction of the interfacial tension. A significant influence of the used hydrophobization agents, perfluorinated octyltrichlorosilane (FOTS) and octyltrichlorosilane (OTS), was found for the resulting drop sizes and the number of active pores.

AB - The formation of emulsions with micro-engineered silicon based arrays of micro-orifices is a relatively new technique. Until now, only the preparation of oil-in-water emulsions was studied due to the hydrophilic nature of silicon. This work evaluates the emulsification of water into n-hexadecane with hydrophobized arrays of micro-orifices. We have studied the drop formation rate, the number of active pores and the drop size. In contrast to conventional macroporous membranes used for membrane emulsification, we observed high dispersed phase fluxes up to 4600 L h−1 m−2 bar−1 while all pores being active at applied pressures below 2 times the critical pressure. The drop diameter was independent from the applied pressure difference. We observed a pressure dependent lag time between drop formations at low emulsification pressures. The lag time is related to the rate of surfactant diffusion to the water–oil interface causing a reduction of the interfacial tension. A significant influence of the used hydrophobization agents, perfluorinated octyltrichlorosilane (FOTS) and octyltrichlorosilane (OTS), was found for the resulting drop sizes and the number of active pores.

KW - METIS-243802

KW - IR-58127

U2 - 10.1016/j.jcis.2007.03.074

DO - 10.1016/j.jcis.2007.03.074

M3 - Article

VL - 312

SP - 460

EP - 469

JO - Journal of colloid and interface science

JF - Journal of colloid and interface science

SN - 0021-9797

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