(213c) Sustainable Production of Nanoemulsions By Membrane Emulsification for Biomedical and Bioprocessing Applications

In the quest for replacing toxic, volatile and harsh solvents, and to abide by the principles of green and sustainable chemistry and engineering, various functional solvents have been introduced in the last two decades. The synthesis of perfluorocarbons and hydrophobic analogues of ionic liquids (ILs) and deep eutectic solvents (DESs) are some of the examples employing hydrophobic designer solvents. However, in order to potentiate bio-based applications wherein polar media is usually encountered, the low solubility of these hydrophobic solvents in water was tackled in this work by dispersing them as nanoemulsions¹.

Membrane emulsification was introduced in the end of the last century as an energy-efficient method to produce microemulsions. In the current study, various approaches of membrane emulsification processes were re-visited and re-established to sustainably produce nanoemulsions. Perfluorodecalin-in-water nanoemulsions with enhanced stability and energetics were formulated by ‘direct membrane emulsification’ using isoporous polymeric membranes. The high viscosity of ILs was addressed by employing ‘premix membrane emulsification’ to formulate IL-in-water nanoemulsions for enhanced CO₂ capture. Lastly, the unique observation of self-assembly of DES enabled the formulation of hydrophobic DES-in-water nanoemulsions with enhanced antimicrobial activities by ‘membrane-assisted nanoemulsification’ using laser drilled microengineered metallic membranes².

References

1. Syed et al. (2021). Studies on the formation and stability of perfluorodecalin nanoemulsions by ultrasound emulsification using novel surfactant systems. Colloids Surf., A. 616: 126315.
2. Syed et al. (2020). Microengineered membranes for sustainable production of hydrophobic deep eutectic solvent-based nanoemulsions by membrane emulsification for enhanced antimicrobial activity. ACS Sustainable Chem. Eng. 8: 16526-16536.

Acknowledgements

Executive Agency for Education, Audiovisual & Culture (EACEA) of the European Commission is acknowledged for the scholarship grant of Erasmus Mundus Doctorate in Membrane Engineering (EUDIME) program to Usman Syed. This work is also supported by the Associate Laboratory for Green Chemistry - LAQV which is financed by national funds from FCT/MCTES (UIDB/50006/2020).