2019/06/17 by Dan Daniel, Daniel, Dan, Alfred Yu Ting Chia +11 · 1 citation
Engineering · Materials Science · #Adhesion, Friction, and Surface Interactions #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Polymer Surface Interaction Studies #Soft Condensed Matter (cond-mat.soft) #Surface Modification and Superhydrophobicity
paper · pdf · doi:10.48550/arxiv.1906.09910
openalex publication_date 2019/06/17 · openalex created_date 2019/06/27 · openalex updated_date 2026/07/28
Recently, there has been much progress in the design and application of oil-repellent superoleophobic surfaces. Polyzwitterionic brush surfaces are of particular interest, because of their ability to repel oil under water, even in the absence of micro-/nano-structures. The origin of this underwater superoleophobicity is attributed to the presence of a stable water film beneath the oil droplet, but this had not been demonstrated experimentally. Here, using optical interferometric techniques, we show that an oil droplet effectively hydroplanes over a water film, whose thickness is between one hundred and hundreds of nanometres. In addition, using a custom-built Droplet Force Apparatus, we measured the friction and adhesion forces to be in the nN range for millimetric-sized droplets. These forces are much lower than for other classes of well-known liquid-repellent surfaces, including the lotus-effect and lubricant-infused surfaces, where the typical force is on the order of μN