Control surface wettability with nanoparticles from phase-change materials

Thewetting state ofsurfaces can be controlled physically from the highlyhydrophobic tohydrophilic states using the amorphous-to-crystallinephase transition of Ge2Sb2Te5 (GST) nanoparticles as surfactant. Indeed, contact angle measurements show that by increasing thesurface coverage of the amorphous nanoparticles the contact angle increases to high values ∼140°, close to the superhydrophobic limit. However, for crystallized nanoparticle assemblies after thermal annealing, the contact angle decreases down to ∼40° (significantly lower than that of the bare substrate) leading to an increasedhydrophilicity. Moreover, the wettability changes are also manifested on the capillaryadhesion forces by being stronger for the crystallized GST state.

Source: Applied Physics Letters - December 6, 2016 Category: Physics Authors: G. H. ten Brink, P. J. van het Hof, B. Chen, M. Sedighi, B. J. Kooi and G. Palasantzas Source Type: research