(691f) Electrostatics At the Oil-Water Interface: Effect of Image Force and Dipole Field
Our work proposes two widely neglected electrostatic effects for the current understanding of Pickering emulsions via investigating the emulsification with charged latex particles. The emulsification results firstly suggest the effect of repulsive image force across the interface on the formation of Pickering emulsions via hindering the adsorption of particle to the oil-water interface, and secondly suggest the effect of self energy of particle- counterion on the contact angle of particle at the oil-water interface and concomitant emulsion type. Centering on these two arguments, the subsequent study attempts to support our claims with exploring the behavior of particle near and at the oil-water interface. Experimental observations of the deformation of oil-water interface as approaching to the particle indicate preliminarily the effect of repulsive image force. Also, the real contact angle of particle at the oil-water interface (counterpart to the macroscopic measured contact angle) measured by gel trapping method combined with AFM provides some evidences for effects of the particle-dipole. All these improved fundamental understandings will hopefully benefit the industrial application of Pickering emulsions and the development of novel emulsion –template materials.