Journal
JOURNAL OF COLLOID AND INTERFACE SCIENCE
Volume 580, Issue -, Pages 630-637Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.jcis.2020.06.106
Keywords
Emulsion; Destabilization; Particle; Surfactant; Interface; Coalescence
Categories
Funding
- Natural Sciences and Engineering Research Council of Canada (NSERC)
Ask authors/readers for more resources
Hypothesis: Micron and nano-scale particles are increasingly used to stabilize water-in-oil (W/O) emulsions. Though remarkably stable, the resulting emulsions can be broken by adding low molecular weight surfactants that modify the wettability of the interfacially-adsorbed particles. Experiments: W/O emulsions were prepared using lipophilic crystals of the monoglyceride glycerol monostearate (GMS), followed by addition of sorbitan monooleate (SMO) at concentrations below and above its critical micelle concentration (CMC). Systematic measurements of interfacial tension and three-phase contact angles, as well as characterization of emulsion sedimentation and microstructure, were used to assess GMS crystal wettability and emulsion destabilization. Findings: GMS crystals formed shells around the dispersed droplets, resulting in emulsions stable against breakdown under quiescent conditions. With SMO concentrations added below CMC, emulsion stability was not significantly affected. At SMO concentrations above CMC, the integrity of the crystalline shell was markedly affected. Notably, the GMS crystals transitioned from preferential oil-wet to water-wet behavior, eventually leading to their diffusion into the droplets. Therefore, in-situ modification of particle wettability at the oil-water interface was responsible for emulsion breakdown. Findings from this study may provide a pathway for the design of particle-stabilized W/0 emulsions with controllable breakdown properties for applications such as tailored release of aqueous bioactive compounds. (C) 2020 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available