Surface Roughness of Natural and Polished Synthetic Materials and Geologic Minerals

Abstract

To evaluate wettability of geologic minerals and rocks, surfaces, at first, are subjected to a polishing routine, which involves sequential polishing with coarse to fine grit paper. The polishing routine introduces a degree of ‘surface roughness’, which likely affects the surface wettability measurements. For example, engineered materials are designed by creating nano-scale textured surfaces, i.e., grooved surfaces, which transforms the wettability of a surface from hydrophilic to hydrophobic. How individual polishing routine on mineral and rock surfaces contribute to minerals surface roughness, and thus, its wettability is not well understood. In this study, we systematically polish mineral surface and quantify surface roughness by ‘Confocal Microscopy’. Later, these minerals are tested for their wettability by contact angle measurement of air-water system using a ‘Goniometer’. Our preliminary results show that polishing from coarse to fine size, which decreases the ‘surface roughness’, transforms the wettability of quartz and calcite minerals from intermediately low wetting to strongly wetting characteristics. Furthermore, we have been able to show control of surface cleanliness through a cleansing procedure, which has produced variance by tens of degrees.

AAPG Datapages/Search and Discovery Article #90373 © 2019 AAPG Eastern Section Meeting, Energy from the Heartland, Columbus, Ohio, October 12-16, 2019