Novel oscillating membrane for production of W/O/W emulsion

Bing Wang (126120)

Goran Vladisavljevic (1253448)

Marijana M. Dragosavac (7127981)

Richard Holdich (1253271)

English

Loughborough University Institutional Repository

   This item was submitted to Loughborough’s Institutional Repository (https://dspace.lboro.ac.uk/) by the author and is made available under the following Creative Commons Licence conditions.      For the full text of this licence, please go to: http://creativecommons.org/licenses/by-nc-nd/2.5/  ICOM1755Novel oscillating membrane for production of W/O/W emulsionsMarijana M. Dragosavac1 *, Richard G. Holdich1 ,Goran T. Vladisavljević1 , Bing Wang11. Loughborough University, Department of Chemical Engineering, Loughborough, United KingdomConventional devices for preparing emulsions (high pressure, ultrasonic homogenisers, colloid mills, rotor–statorsystems, microfluidisers) apply more energy than needed for the production of monosized droplets, leading todroplets with a wide size distribution. Membrane emulsification is a dispersion process to produce a monosizedemulsion of one liquid phase (e.g. oil) in a second immiscible liquid phase (e.g. water) using low energy per unitvolume where the shear stress applied on the membrane surface mainly influences the droplet size [1]. Production oflarger oil droplets of controlled diameter is becoming increasingly popular. Those droplets after additional treatmentmay be applied in industries such as food and flavour encapsulation, controlled release depots under the skin,medical diagnostic particles, high value fillers, electronic ink capsules, ion exchange resins. A new techniquesupplied by Micropore Technologies Ltd. UK was introduced for generating the shear on the membrane surfaceproviding the possibility to generate larger droplets without risk of breakage [2].In this work oscillating membrane emulsification was used to produce water in oil in water emulsion (W/O/W). Suchemulsions can be used for encapsulation of water soluble compounds and their controlled release.Fig. 1 Image of produced droplets for condition f=70 Hz, A=0.4 mm corresponding to the maximal shear stress of 3Pa, oscillating membrane system, tubular membrane and surface of used membrane.The shear stress required for droplet detachment from the tubular membrane in the oscillating membraneemulsification (Fig. 1) can be altered by varying the frequency, or the amplitude of oscillation. The maximal shearstress is related to the frequency f and amplitude A of the oscillation by the equation [2]:(1)The oil phase in W/O/W emulsions was sunflower oil containing 10 wt% PGPR (polyglycerol polyricinoleate). Theinner aqueous phase was pure water and the continuous phase was 2 wt% Tween 20 (polyoxyethylene sorbitanmonolaurate). Low dispersed phase flux of 30 L m-2 h-1was maintained, in order to minimise any push-off force [3].In Fig. 2 influence of frequency and amplitude on median droplet size and droplet uniformity is presented (span wasused as a measure of droplets uniformity).Fig. 2 Influence of frequency and amplitude on median droplet diameter and span.The results shown here indicate that an oscillating membrane system is applicable for generating larger droplets ofW/O/W emulsion. Changing frequency or amplitude it is possible to produce droplets in the range between 50 and280 µm.An important advantage of the oscillating membrane technique is that it can easily be scaled up by providing a largermembrane area in the oscillating membrane assembly.

Novel oscillating membrane for production of W/O/W emulsions

https://repository.lboro.ac.uk/articles/Novel_oscillating_membrane_for_production_of_W_O_W_emulsions/9245429/files/16829282.pdf

Novel oscillating membrane for production of W/O/W emulsions

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