UCLA

This research investigates the potential for surface modifying pre-treatments to increase the surface roughness of calcareous stone in order to improve efficacy of hydrophobic protective treatments. The modification of intrinsic surface roughness is presented as an alternative to nanocomposite coatings which are currently being explored for multifunctional, superhydrophobic effects. Novel pre-treatment methods were developed and evaluated for their ability to modify surface roughness of calcite, marble and limestone samples through anisotropic dissolution and precipitation mechanisms. Surface modification achieved through pre-treatment was assessed using scanning electron microscopy (SEM). Hydrophobic treatments were applied to surface-modified samples and contact angle measurements were obtained. These contact angle measurements were compared to those achieved on unmodified surfaces receiving the same hydrophobic treatments. This research demonstrates the potential for pre-treatment methods to modify surface roughness and improve hydrophobicity for some substrates, and may provide an alternative method for achieving superhydrophobic, self-cleaning surfaces if further improved.