Surfactant-enhanced cellulose nanocrystal Pickering emulsions

Area of Science:

• Materials Science
• Colloid and Surface Science
• Nanotechnology

Background:

• Pickering emulsions offer unique properties but require careful stabilization.
• Cellulose nanocrystals (CNCs) are promising eco-friendly stabilizers for Pickering emulsions.
• Understanding surfactant-CNC interactions is crucial for tailoring emulsion performance.

Purpose of the Study:

• To investigate the impact of cationic surfactants (DMAB, CTAB) on anionic CNC properties.
• To elucidate the adsorption mechanisms and resulting CNC wettability changes.
• To correlate CNC surface modification with Pickering emulsion characteristics, including phase inversion.

Main Methods:

• Electrophoretic mobility, interfacial tension, and contact angle measurements.
• Confocal microscopy to visualize surfactant adsorption on CNCs.
• Preparation and characterization of CNC-stabilized Pickering emulsions.

Main Results:

• Surfactants adsorb onto CNCs, altering their hydrophobicity in a concentration-dependent manner.
• DMAB, a double-tailed surfactant, induced greater CNC hydrophobicity than single-tailed CTAB.
• Surfactant addition enhanced emulsion stability, reduced droplet size, and enabled tunable phase inversion.

Conclusions:

• Surfactant adsorption provides an effective route for in situ surface modification of CNCs.
• This surface modification allows precise control over CNC Pickering emulsion properties, including phase behavior.
• The findings open new avenues for utilizing CNCs in diverse liquid formulations and solid materials.