Surface tension anomaly observed for chemically-modified Janus particles at the air/water interface

Sepideh Razavi; Laura M Hernandez; Alismari Read; Watson L Vargas; Ilona Kretzschmar

doi:10.1016/j.jcis.2019.09.084

Surface tension anomaly observed for chemically-modified Janus particles at the air/water interface

J Colloid Interface Sci. 2020 Jan 15:558:95-99. doi: 10.1016/j.jcis.2019.09.084. Epub 2019 Sep 23.

Authors

Sepideh Razavi¹, Laura M Hernandez², Alismari Read³, Watson L Vargas⁴, Ilona Kretzschmar⁵

Affiliations

¹ Chemical, Biological, and Materials Engineering, University of Oklahoma, Norman, OK 73019, USA. Electronic address: srazavi@ou.edu.
² Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada.
³ Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
⁴ MedicWare Solutions, Colombia.
⁵ Department of Chemical Engineering, City College of City University of New York, New York, NY 10031, USA. Electronic address: kretzschmar@ccny.cuny.edu.

PMID: 31585226
DOI: 10.1016/j.jcis.2019.09.084

Abstract

The behavior of Janus particles fabricated from core silica particles decorated with gold nanoparticles on one hemisphere is studied at the air/water interface. An unexpected reduction in the effective surface tension is observed in the presence of these chemically-modified Janus particles. Experiments on the interfacial behavior of a variety of control particles, including the physically-modified Janus particles made from the same core silica particles coated with a thin gold layer, do not exhibit significant surface tension effects. We hypothesize that the chemical modification of particles in form of a Janus structure is needed to alter the surface tension and attribute the surfactant-like behavior of these particles to the presence of immersion forces.