Buckling of a monolayer of platelike particles trapped at a fluid-fluid interface
Two-dimensional nanomaterials, such as graphene and graphene oxide, are platelike particles with nanometric thickness. Understanding the behavior of these 2D nanoparticles at fluid interfaces is crucial for various applications. Corrugated films, produced by assembling nanosheets at the air-water interface, are used as high-performance electrode materials. However, the formation of these corrugated films through buckling instability remains poorly understood.
In collaboration with Hugo Perrin and under the supervision of Lorenzo Botto, PhD candidate Suriya Prakash developed a novel experimental setup to study the buckling of monolayers of platelike particles at fluid-fluid interfaces. The results show that the models developed for spherical particles are not suitable for describing the behavior of platelike particles at fluid interfaces. To overcome this limitation, the team developed a mathematical model to explain the buckling behavior of these monolayers with platelike particles. This work has been published in Physical Review E.
Abstract
Particles trapped at a fluid-fluid interface by capillary forces can form a monolayer that jams and buckles when subject to uniaxial compression. Here we investigate experimentally the buckling mechanics of monolayers of millimeter-sized rigid plates trapped at a planar fluid-fluid interface subject to uniaxial compression in a Langmuir trough. We quantified the buckling wavelength and the associated force on the trough barriers as a function of the degree of compression. To explain the observed buckling wavelength and forces in the two-dimensional (2D) monolayer, we consider a simplified system composed of a linear chain of platelike particles. The chain system enables us to build a theoretical model which is then compared to the 2D monolayer data. Both the experiments and analytical model show that the wavelength of buckling of a monolayer of platelike particles is of the order of the particle size, a different scaling from the one usually reported for monolayers of spheres. A simple model of buckling surface pressure is also proposed, and an analysis of the effect of the bending rigidity resulting from a small overlap between nanosheet particles is presented. These results can be applied to the modeling of the interfacial rheology and buckling dynamics of interfacial layers of 2D nanomaterials.
