Stability of oil-in-water emulsions produced by membrane emulsification with microporous ceramic membranes

- Sunflower oil in water emulsions were prepared by membrane emulsification.
- 0.2 μm ceramic membranes yielded average droplet sizes from 2 to 11 μm.
- Effect of process parameters increases with membrane pore size.
- The emulsions obtained by membrane technique were stable up to 100 days.

Membrane emulsification has been drawing attention due to its many application possibilities. This study aimed to assess the preparation and stability of oil in water (O/W) emulsions by membrane emulsification technique. Microporous ceramic membranes with mean pore size 0.2 μm and 0.8 μm were used for producing sunflower oil in water emulsions, displaying mean droplet size ranging from 2.9 to 11.6 μm and from 4.8 to 16.2 μm, respectively. The effect of the oil concentration (10%-20%), surfactant concentration (1%-4%), tangential velocity (0.12 m s−1 to 0.24 m s−1), and feed pressure (100 kPa-300 kPa) on the process performance was investigated using an experimental design. All the parameters significantly influenced the mean droplet size, the droplet size distribution, and the emulsion stability. Depending on the emulsification conditions, monodisperse and polydisperse emulsions were obtained. The use of a membrane with 0.2 μm mean pore size led to better results than those obtained with a 0.8 μm membrane, since they yielded emulsions displaying smaller droplet size and narrower size distribution. The emulsions prepared using this membrane were stable up to 100 days.