화학공학소재연구정보센터
Chemical Engineering Research & Design, Vol.126, 286-296, 2017
Microfiltration of oil in water (O/W) emulsions: Effect of membrane microstructure and surface properties
In this work, oil in water (O/W) emulsions prepared with a natural emulsifier and different oil phase concentrations were processed by using Anodisc, cellulose acetate (CA), polyester/nylon, silicon nitride microsieves and polycarbonate track etched (PCTE) membranes of different pore sizes (0.22-0.8 mu m). The effect of membrane characteristics on properties of the emulsions was assessed by droplet size distribution, xi-potential and pH. Results suggest that membrane hydrophilicity is critical to avoid breaking during microfiltration of O/W emulsions. Partial or total retention of oil droplets from concentrated emulsions (10-30% oil) occurred with all 0.22 mu m membranes, except with the 0.26 mu m microsieves. PCTE membrane (uniform straight pores) performance was function of the adropiet/dpare ratio, i.e. (a) if (d) over bar (droplet)/d(pore) < 1, emulsions fully filtered, (b) if 1.0 < (d) over bar (droplet)/d(pore) <= 1.5, partial breaking of larger droplets occurs and (c) if (d) over bar (droplet)/d(pore) >= 2, retention and probably coalescence of larger drops led to fouling and total pore blockage. Performance of CA membranes (inter-connected pores) was rather related to the oil concentration and the number of droplets found in the emulsion. Breaking into the pores and coalescence onto the 0.22 mu m CA membrane surface started when processing a 5% oil emulsion with estimated concentration of >= 2.42 x 10(12) oil droplets/mL. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.