Greening perfluorocarbon based nanoemulsions by direct membrane emulsification: Comparative studies with ultrasound emulsification

• Published in: Journal of cleaner production Vol. 357; p. 131966
• Main Authors: Syed, Usman Taqui, Dias, Ana M.A., de Sousa, Hermínio C., Crespo, Joao, Brazinha, Carla
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10.07.2022
• Subjects: Direct membrane emulsification; Emulsion properties; Energy expenditure; Nanoemulsions; Perfluorodecalin; Ultrasound emulsification; Energy expenditure; Nanoemulsions; Emulsion properties; Perfluorodecalin; Ultrasound emulsification; Direct membrane emulsification
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2022.131966

A systematic experimental methodology was employed to produce oil-in-water (O/W) nanoemulsions by direct membrane emulsification while exploring first-ever studies on using polymeric membranes. Perfluorodecalin (PFD) constituted the dispersed phase and the continuous phase was an aqueous solution of two surfactants, Tween 80 and (1H,1H,2H,2H-perfluorooctyl)phosphocholine (FC8). This work aimed to formulate monomodal PFD-based nanoemulsions having a narrow-sized distribution with mean droplet sizes of around 150 nm or below, suitable for biomedical applications. Relevant processing conditions of membrane emulsification were optimised, and a monomodal emulsion of 103.4 ± 2.6 nm was achieved using an isoporous Nuclepore track-etched 30 nm nominal pore diameter membrane. In comparison to the reported ultrasound emulsification studies with the same colloidal system, direct membrane emulsification offered several advantages, such as electrokinetically stable nanoemulsions with a 40% reduction in the emulsion droplet sizes. Additionally, 36 times lower molar concentration of optimised surfactants’ composition were sufficient. Besides, interfacial tensions between the oil and aqueous phases were determined to explain the observed emulsion droplet sizes. Lastly, a critical analysis to determine energy expenditure and energy requirement to create nanoemulsion surface area, favourably indicates that the membrane-based process ensures a 99.5% reduction of energy expenditure to produce the same surface area. [Display omitted] •Direct membrane emulsification (DME) is advantageous over ultrasound emulsification.•97.2% decrease in optimised amount of surfactants required to produce nanoemulsions.•Energy needed is 215 times lower to produce 1 m2 of nanoemulsion surface area.•First-ever studies to produce O/W nanoemulsions with polymeric membranes by DME.•Isopores are crucial in membrane emulsification to produce monomodal nanodroplets.