characterization of water-in-oil emulsions produced with microporous hollow polypropylene fibers

The preparation of fine and monodispersed water-in-oil (W/O) emulsions by utilizing hydrophobic hollow polypropylene fibers with 0.4 mm pores was investigated in this work. The experiments were carried out using demineralized water as the disperse phase, mineral oil Velocite No. 3 as the continuous phase, and polyglycerol polyricinoleate (PGPR 90) in the concentration range of 2.5 – 10 wt % as the oil-soluble emulsifier. The size of the water droplets in the prepared emulsions and the droplet size distribution strongly depend on the content of the disperse phase, the transmembrane pressure difference, and the emulsifier concentration. Stable emulsions with a very narrow droplet size distribution and a mean droplet diameter lower than 0.27 µm were produced using 10 wt % PGPR 90 at a pressure difference below 30 kPa.