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Emulsions undergoing phase transition: Effect of emulsifier type and concentration
Parinaz Ataeian1, Lucig Aroyan2, Waleed Parwez2
1Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue, Waterloo, ON N2L 3G1, Canada; Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Journal of Colloid and Interface Science
|March 11, 2022
Summary
Cellulose nanocrystals (CNCs) effectively stabilize paraffin wax Pickering emulsions during temperature-induced phase transitions, outperforming sodium dodecyl sulfate (SDS). CNCs offer superior stability and require lower concentrations for effective emulsion stabilization.
Area of Science:
- Colloid and Surface Science
- Materials Science
- Nanotechnology
Background:
- Pickering emulsions offer enhanced stability compared to conventional emulsions.
- Understanding the role of stabilizers during oil phase transitions is crucial for industrial applications.
- Cellulose nanocrystals (CNCs) are emerging as sustainable and effective Pickering stabilizers.
Purpose of the Study:
- To investigate the efficacy of CNCs in stabilizing paraffin wax Pickering emulsions during temperature-induced phase transitions.
- To compare the performance of CNCs with a conventional surfactant, sodium dodecyl sulfate (SDS).
- To develop a new model for the relationship between droplet size and emulsifier content.
Main Methods:
- Preparation and characterization of paraffin wax Pickering emulsions using CNCs and SDS.
- Differential scanning calorimetry (DSC) to analyze phase transitions.
- Temperature sweep viscosity measurements and rheological amplitude sweep analysis.
- Droplet size analysis and modeling.
Main Results:
- CNC-stabilized emulsions exhibited superior stability compared to SDS-stabilized emulsions, especially after paraffin wax solidification.
- The minimum CNC concentration required for stabilization was lower than that of SDS.
- Droplet size in CNC systems remained unaffected by temperature variations.
- Higher emulsifier surface coverage enhanced the deformation resistance of crystallized droplets, improving emulsion stability.
Conclusions:
- CNCs are highly effective stabilizers for Pickering emulsions undergoing phase transitions.
- CNC-stabilized emulsions demonstrate remarkable stability and robustness against temperature fluctuations.
- The findings suggest CNCs as a promising alternative to conventional surfactants for demanding emulsion applications.
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