Preparation of Water-In-Oil Emulsions Using Hydrophobic Microporous Hollow Fibers

Abstract

The preparation of fine and monodispersed water-in-oil (w/o) emulsions by utilizing hydrophobic polypropylene hollow fibers with 0.4 µm pores was investigated in this work. The experiments have been carried out using demineralized water as the disperse phase, mineral oil Velocite 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 water droplets in the resulting emulsions and the droplet size distribution strongly depended on the disperse phase content, the transmembrane pressure difference and the emulsifier concentration. The stable emulsions with a very narrow droplet size distribution and the mean droplet size lower than 0.27 μm were produced using 10 wt% PGPR 90 at the pressure difference below 30 kPa.

Stabilne monodisperzne emulzije vode u mineralnom ulju su dobijene propustanjem vode pod pritiskom kroz mikropore polipropilenskih supljih vlakana u kontinualnu fazu koja je recirkulisala unutar vlakana. Fluks disperzne faze kroz membranu u prisustvu kontinualne faze unutar vlakana je 3-4 puta manji od fluksa koji se dobija kada se i unutar vlakana nalazi voda, sto ukazuje da je pri emulgovanju vrlo veliki procenat pora blokiran uljem i kao takav ne ucestvuje u permeaciji vode kroz membranu. Srednja velicina emulgovanih kapi raste sa porastom transmembranske razlike pritisaka a opada sa porastom koncentracije emulgatora (poliglicerol-poliricinoleata). Ako se emulgovanje vrsi pri razlici pritisaka manjoj od 30 kPa i pri koncentraciji emulgatora od 10 mas% mogu se dobiti emulzije sa vrlo uskom raspodelom velicina emulgovanih kapi i srednjom velicinom kapi manjom od 0,27 urn.