Crystal Comets: Dewetting During Emulsion Droplet Crystallization

Liquid oil emulsion droplets can violently dewet their own solid crystals during crystallization as a result of surfactant adsorption. The crystal shape formed is a function of the relative rates of dewetting and crystallization as controlled by surfactant adsorption, cooling rate, and lipid purity. For negligible dewetting rates, crystals nucleate and grow within the droplet. At similar crystallization and dewetting rates, the droplet is propelled around the continuous phase on a crystalline ‘comet tail’ much larger than the original droplet. Rapid dewetting causes the ejection of small discrete crystals across the droplet’s oil–water interface.

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Mineralization of water-in-oil emulsion droplets

MRS Proceedings ◽

10.1557/proc-847-ee3.5 ◽

2004 ◽

Vol 847 ◽

Cited By ~ 1

Author(s):

Giulia Fornasieri ◽

Stéphane Badaire ◽

Rénal Vasco Backov ◽

Philippe Poulin ◽

Cécile Zakri ◽

...

Keyword(s):

Continuous Phase ◽

Water Soluble ◽

Oil Emulsion ◽

Emulsion Droplets ◽

Emulsion Systems ◽

Oil Water ◽

Silica Precursor ◽

Concentration Threshold ◽

Water In Oil Emulsion ◽

Soluble Surfactant

Using reverse emulsion systems, we were able to trigger mineralization confined at an oil-water interface. In this process, the alcoxide silica precursor is dissolved in the oil continuous phase of the emulsion and diffuses through the bulk to the interface where it starts to hydrolyze and condense as soon as a certain concentration threshold is attained. The process takes place only in the presence of a water soluble surfactant inside the droplet. This surfactant leads to the presence of a controlled mesoporosity inside the silica shells. The obtained objects could be used in different encapsulation applications.

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BslA-stabilized emulsion droplets with designed microstructure

Interface Focus ◽

10.1098/rsfs.2016.0124 ◽

2017 ◽

Vol 7 (4) ◽

pp. 20160124 ◽

Cited By ~ 4

Author(s):

Keith M. Bromley ◽

Cait E. MacPhee

Keyword(s):

Structural Integrity ◽

Melting Process ◽

Continuous Phase ◽

Central Component ◽

Emulsion Droplet ◽

Emulsion Droplets ◽

Elastic Film ◽

Air Water Interface ◽

Droplet Morphology ◽

Spherical Droplets

Emulsions are a central component of many modern formulations in food, pharmaceuticals, agrichemicals and personal care products. The droplets in these formulations are limited to being spherical as a consequence of the interfacial tension between the dispersed phase and continuous phase. The ability to control emulsion droplet morphology and stabilize non-spherical droplets would enable the modification of emulsion properties such as stability, substrate binding, delivery rate and rheology. One way of controlling droplet microstructure is to apply an elastic film around the droplet to prevent it from relaxing into a sphere. We have previously shown that BslA, an interfacial protein produced by the bacterial genus Bacillus , forms an elastic film when exposed to an oil- or air–water interface. Here, we highlight BslA's ability to stabilize anisotropic emulsion droplets. First, we show that BslA is capable of arresting dynamic emulsification processes leading to emulsions with variable morphologies depending on the conditions and emulsification technique applied. We then show that frozen emulsion droplets can be manipulated to induce partial coalescence. The structure of the partially coalesced droplets is retained after melting, but only when there is sufficient free BslA in the continuous phase. That the fidelity of replication can be tuned by adjusting the amount of free BslA in solution suggests that freezing BslA-stabilized droplets disrupts the BslA film. Finally, we use BslA's ability to preserve emulsion droplet structural integrity throughout the melting process to design emulsion droplets with a chosen shape and size.

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Come Together: Molecular Details into the Synergistic Effects of Polymer–Surfactant Adsorption at the Oil/Water Interface

The Journal of Physical Chemistry B ◽

10.1021/acs.jpcb.8b05432 ◽

2018 ◽

Vol 122 (36) ◽

pp. 8582-8590 ◽

Cited By ~ 9

Author(s):

Brandon K. Schabes ◽

Rebecca M. Altman ◽

Geraldine L. Richmond

Keyword(s):

Synergistic Effects ◽

Surfactant Adsorption ◽

Water Interface ◽

Oil Water ◽

Polymer Surfactant

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Understanding the Different Steps of Surfactant Adsorption at the Oil–Water Interface with Second Harmonic Generation

The Journal of Physical Chemistry C ◽

10.1021/acs.jpcc.5b11278 ◽

2016 ◽

Vol 120 (12) ◽

pp. 6515-6523 ◽

Cited By ~ 25

Author(s):

Wei Wu ◽

Hui Fang ◽

Fangyuan Yang ◽

Shunli Chen ◽

Xuefeng Zhu ◽

...

Keyword(s):

Second Harmonic Generation ◽

Harmonic Generation ◽

Second Harmonic ◽

Surfactant Adsorption ◽

Water Interface ◽

Oil Water

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Behaviour of hybrid inside/out Janus nanotubes at an oil/water interface. A route to self-assembled nanofluidics?

Faraday Discussions ◽

10.1039/c6fd00034g ◽

2016 ◽

Vol 191 ◽

pp. 391-406 ◽

Cited By ~ 11

Author(s):

P. Picot ◽

O. Taché ◽

F. Malloggi ◽

T. Coradin ◽

A. Thill

Keyword(s):

Hydrophobic Surface ◽

Continuous Phase ◽

Internal Cavity ◽

Water Interface ◽

Natural Aluminosilicate ◽

Oil Water ◽

Self Assembled ◽

Oil Emulsions ◽

Chemical Groups ◽

Inside Out

Imogolites are natural aluminosilicate nanotubes that have a diameter of a few nanometers and can be several microns long. These nanotubes have different chemical groups on their internal (Si–OH) and external (Al–OH–Al) surfaces, that can be easily functionalised independently on both surfaces. Here we show that taking advantage of the particular shape and chemistry of imogolite, it is possible to prepare inside/out Janus nanotubes. Two kinds of symmetric Janus nanotubes are prepared: one with an external hydrophilic surface and an internal hydrophobic cavity (imo-CH3) and one with an external hydrophobic surface and a hydrophilic internal cavity (OPA-imo). The behaviour of such inside/out Janus nanotubes at oil/water interfaces is studied. The OPA-imo adsorbs strongly at the oil/water interface and is very efficient in stabilising water-in-oil emulsions through an arrested coalescence mechanism. Imo-CH3 also adsorbs at the oil/water interface. It stabilises oil-in-water emulsions by inducing slow oil-triggered modifications of the viscosity of the continuous phase. The possible transport of small molecules inside the imo-CH3 nanotubes is evidenced, opening up routes towards self-assembled nanofluidics.

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