Determining Surface Energies of Nanoparticles from the Contact Angles Measured with the NanoTraPPED Method

Abstract

Extended Abstract Nanoparticle behaviour in bulk and interaction with the environment could be in part determined by their surface physicochemical properties, or surface functional groups. Characterization of the physicochemical state of the surface of nanoparticles can be important for predicting and understanding their bulk behaviour, in powders, such as dispersibility in water, or solvents, flowing ability, pelleting ability, aggregation, etc., which can be useful for many industries. In fundamental science, establishing a correlation between surface properties and nanoparticle bulk behaviour powders represents an ongoing challenge. One parameter that could give important insights into physicochemical state of the nanoparticles and their capability to interact with the environment through physical forces is the surface energy and its components. The magnitude of the surface energy can be interpreted as the ability of the surface to interact through physical forces. Surface energy can be broken down into components, such as polar, dispersive, hydrogen bonding, acid, base, etc., and their relative magnitude describes the preferred way, following the principles of independent action, through which a surface can interact with a solvent, an adsorbate, etc.[1]. For macroscopic surfaces, the surface energy components can be trivially determined by measuring the contact angles of several solvents and with the help of existing surface energy models, such as Owens-Wendt-Rabel-Kaelble OWRK (dispersive and polar), van Oss-Chaudhury-Good (OCG) (dispersive, acid and base); extended Fowkes