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Adsorption of shape-anisotropic and porous particles at the air–water and the decane–water interface studied by the gel trapping technique

Horozov, Tommy S.; Sharp, Emma L.; Al-Shehri, Hamza; Horozov, Tommy; Stoyanov, Simeon D.; Paunov, Vesselin N.

Authors

Tommy S. Horozov

Emma L. Sharp

Hamza Al-Shehri

Simeon D. Stoyanov

Abstract

We have studied the attachment and orientation of anisotropic and porous microparticles at liquid surfaces by using the gel trapping technique (GTT). This technique involves spreading of the microparticles of interest at the liquid interface, subsequent setting of the aqueous phase to a hydrogel thus "arresting" the particle positions at the liquid surface, and further replication of the hydrogel surface with curable polydymethilsiloxane (PDMS). The advantage of the GTT comes from the possibility to look at the PDMS replica with scanning electron microscopy (SEM) or atomic force microscopy (AFM), which allows even sub-micrometer particles to be studied at the air-water and the oil-water interface. Here we report our results on the adsorption of non-spherical anisotropic particles at liquid surfaces using the GTT. Although the GTT was originally designed to measure three-phase contact angles of spherical colloid particles, here we used this technique to reveal the orientation of a variety of shape-anisotropic and porous microparticles of practical interest at both the air-water and decane-water interfaces. We show results on typical attachment and orientation of needle-like (aragonite), rhombohedra-like (calcite) microcrystals, ethyl cellulose micro-rods, as well as highly porous hydrophilic and hydrophobic silica microparticles at these liquid interfaces. The results are important for understanding the adsorption behaviour of shape-anisotropic particles as well as porous microparticles which are used in industrial formulations as fillers, foam stabilisers and emulsifiers. © 2014 The Royal Society of Chemistry.

Journal Article Type Article
Publication Date 2014
Journal RSC advances
Print ISSN 2046-2069
Electronic ISSN 2046-2069
Publisher Royal Society of Chemistry
Peer Reviewed Peer Reviewed
Volume 4
Issue 5
Pages 2205-2213
Institution Citation Sharp, E. L., Al-Shehri, H., Horozov, T., Stoyanov, S. D., & Paunov, V. N. (2014). Adsorption of shape-anisotropic and porous particles at the air–water and the decane–water interface studied by the gel trapping technique. RSC advances, 4(5), 2205-2213. https://doi.org/10.1039/c3ra44563a
DOI https://doi.org/10.1039/c3ra44563a
Keywords Gel trapping technique; Adsorption; Shape-anisotropic microparticles; Porous microparticles; Decane–water interface; Air–water interface
Publisher URL http://pubs.rsc.org/en/Content/ArticleLanding/2014/RA/c3ra44563a#!divAbstract
Copyright Statement Creative Commons Attribution 3.0 Unported Licence
Additional Information Copy of article first published in: RSC advances, 2014, issue 4