Material surface wettability characterization

Abstract

Material surface wettability is of importance to investigate since the applicability of a certain material depends heavily on the surface wettability. With traditional sessile drop contact angle methods, due to the inherent constraint of droplet volume, one is not able to distinguish the relative contribution of morphology or chemistry related factors results in difference of contact angle for the same material pair. Here in this thesis, we employed a newly developed AFM-based force spectroscopy technique to investigate the nanoscale material surface interaction forces to determine how a given surface interacts with liquids, specifically water. We start from sample material graphite to study the wettability transition and also to correlate macroscopic measurements with nanoscopic measurements. Graphene is also investigated for understanding the intrinsic wettability. Furthermore, we applied the technique to a more complicated system like biomaterial (fish scales) to explore the competence of our method. In addition, insight in the development of an advance AFM approach (bimodal AFM) for the detection of chemistry heterogeneity on material surfaces is provided. Both theoretical discussion and experiment verification details are presented. Finally, we examined our newly developed AFM technique on three different samples and the nanoscopic results were in accordance with macroscopic measurements.

Date of Award	May 2015
Original language	American English
Supervisor	Matteo Chiesa (Supervisor)