Transfer and adsorption of surfactants to an expanding oil water interface during membrane emulsification
Author
Summary, in English
uses a microporous membrane operated in cross-flow. The continuous phase is pumped along the membrane and sweeps
away dispersed phase droplets forming from pore openings as shown in Figure 1. The key feature of the membrane
emulsification process, which sets it apart from conventional emulsification technologies, is that the size distribution of the
resulting droplets is primarily governed by the choice of membrane and not by the development of turbulent drop break up
[1]. The main advantages of membrane emulsification are the possibility to produce droplets of a defined size with a narrow
size distribution, low shear stress, the potential for lower energy
consumption, and simplicity of design [2].
The interfacial tension and applied dispersed phase pressure
determine the flow rate through the microporous membrane. As a
droplet is pressed into the continuous phase, a new interface is
created and surfactant molecules act at this surface to reduce the
tension over time. Membrane emulsification differs from
conventional emulsification processes in that the droplet
formation time is of the same order of magnitude as the dynamic
interfacial tension of common food emulsifiers [3]. The effect of
emulsifiers is further complicated by the fact that droplet
deformation and adsorption at the interface are coupled, thus
both the rate at which deformation and detachment forces act, as
well as how fast surfactants adsorb to the growing interfacial
area become relevant over the time scales involved.
The objectives of this work were to describe the diffusion controlled adsorption of surfactants at the oil water interface, and
secondly to model the flow of the dispersed phase through a pore and subsequent surface expansion rate as the drop grows
into the continuous phase.
away dispersed phase droplets forming from pore openings as shown in Figure 1. The key feature of the membrane
emulsification process, which sets it apart from conventional emulsification technologies, is that the size distribution of the
resulting droplets is primarily governed by the choice of membrane and not by the development of turbulent drop break up
[1]. The main advantages of membrane emulsification are the possibility to produce droplets of a defined size with a narrow
size distribution, low shear stress, the potential for lower energy
consumption, and simplicity of design [2].
The interfacial tension and applied dispersed phase pressure
determine the flow rate through the microporous membrane. As a
droplet is pressed into the continuous phase, a new interface is
created and surfactant molecules act at this surface to reduce the
tension over time. Membrane emulsification differs from
conventional emulsification processes in that the droplet
formation time is of the same order of magnitude as the dynamic
interfacial tension of common food emulsifiers [3]. The effect of
emulsifiers is further complicated by the fact that droplet
deformation and adsorption at the interface are coupled, thus
both the rate at which deformation and detachment forces act, as
well as how fast surfactants adsorb to the growing interfacial
area become relevant over the time scales involved.
The objectives of this work were to describe the diffusion controlled adsorption of surfactants at the oil water interface, and
secondly to model the flow of the dispersed phase through a pore and subsequent surface expansion rate as the drop grows
into the continuous phase.
Department/s
- Department of Food Technology, Engineering and Nutrition
Publishing year
2003
Language
English
Pages
68-71
Publication/Series
SIK Proceedings
Volume
162
Full text
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Document type
Conference paper
Publisher
SIK - Svenska Livsmedelsinstitutet
Topic
- Food Engineering
Status
Published