Surface activity of Janus particles adsorbed at fluid–fluid interfaces: Theoretical and experimental aspects

• Published in: Advances in colloid and interface science Vol. 233; pp. 240 - 254
• Main Authors: Fernandez-Rodriguez, Miguel Angel, Rodriguez-Valverde, Miguel Angel, Cabrerizo-Vilchez, Miguel Angel, Hidalgo-Alvarez, Roque
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-07-2016
• Subjects: Colloids; Emulsions; Fluids; Fluid–fluid interfaces; Foams; Janus particles; Nanoparticles; Particle-laden interfaces; Pendant drop tensiometry; Stabilization; Surface and interfacial activity; Surface chemistry; Particle-laden interfaces; Surface and interfacial activity; Janus particles; Fluid–fluid interfaces; Pendant drop tensiometry
• ISSN: 0001-8686; 1873-3727
• DOI: 10.1016/j.cis.2015.06.002

Since de Gennes coined in 1992 the term Janus particle (JP), there has been a continued effort to develop this field. The purpose of this review is to present the most relevant theoretical and experimental results obtained so far on the surface activity of amphiphilic JPs at fluid interfaces. The surface activity of JPs at fluid–fluid interfaces can be experimentally determined using two different methods: the classical Langmuir balance or the pendant drop tensiometry. The second method requires much less amount of sample than the first one, but it has also some experimental limitations. In all cases collected here the JPs exhibited a higher surface or interfacial activity than the corresponding homogeneous particles. This reveals the significant advantage of JPs for the stabilization of emulsions and foams.
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•Janus particles exhibit surface activity at fluid–fluid interfaces.•Physical properties of Janus particle-laden interfaces are studied.•Shape and wettability of Janus particles affect their arrangement at fluid–fluid interfaces.•Surface activity of Janus particles is explored using pendant drop tensiometry.