Recent interest in the use of nanoparticles in emulsion stabilization, has driven increased efforts-to understarid how the diaracteristics of the particles influence the emulsion properties. While it is clear that the contact angle arid wettability must play significant roles in determining the type of emulsion formed, it is not straightforward to measure the contact angle of a nanopartide. In this paper, we compare multiple techniques for characterizing the water air contact angle of silica nanoparticles while systematically varying the hydrophobicity of the nanoparrides using sllanization. We then compare the performance of the particles in decarie/water emulsions. While the heat of immersion measured by microcalorimetry is found to provide the best method for discriminating between the wettability of the particles, the fraction of surface coveted by the slime groups was observed to affect the structure of the emulsion more profoundly than the differences in the contact angles of the particles. Furthermore, we find that the phase of initial dispersion is extremely influential in determining the resulting emulsion type and droplet size.