van der Waals interaction between internal aqueous droplets and the external aqueous phase in double emulsions

A mathematical model for analyzing the van der Waals interaction between the internal aqueous droplets (W(1)) and the external aqueous phase (W(2)) of double emulsions has been established. The effects of Hamaker constants of the materials forming the system, especially those of the two different ad...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 20(2004), 19 vom: 14. Sept., Seite 8391-7
1. Verfasser: Wen, Lixiong (VerfasserIn)
Weitere Verfasser: Cheng, Jing, Zou, Haikui, Zhang, Lei, Chen, Jianfeng, Papadopoulos, Kyriakos D
Format: Aufsatz
Sprache:English
Veröffentlicht: 2004
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Emulsions Water 059QF0KO0R
Beschreibung
Zusammenfassung:A mathematical model for analyzing the van der Waals interaction between the internal aqueous droplets (W(1)) and the external aqueous phase (W(2)) of double emulsions has been established. The effects of Hamaker constants of the materials forming the system, especially those of the two different adsorbed surfactant layers with uniform density (A(1) and A(2)), on the van der Waals interaction were investigated. The overall van der Waals interaction across the oil film is a combined result of four individual parts, that is, W(1)-W(2), A(1)-A(2), W(1)-A(1), and A(2)-W(2) van der Waals interaction, and it may be either attractive or repulsive depending on many factors. It was found that the overall van der Waals interaction is dominated by the W(1)-W(2) interaction at large separation distances between the W(1)/O and O/W(2) interfaces, while it is mostly determined by the A(1)-A(2) interaction when the two interfaces are extremely close. Specifically, in the cases when the value of the Hamaker constant of the oil phase is intermediate between those of W(1) and W(2) and there is a thick oil film separating the two interfaces, a weak repulsive overall van der Waals interaction will prevail. If the Hamaker constant of the oil phase is intermediate between those of A(1) and A(2) and the two interfaces are very close, the overall van der Waals interaction will be dominated by the strong repulsive A(1)-A(2) interaction. The repulsive van der Waals interaction at such cases helps stabilize the double emulsions
Beschreibung:Date Completed 13.06.2006
Date Revised 21.11.2013
published: Print
Citation Status MEDLINE
ISSN:1520-5827