Laser Ablation and Chemical Oxidation Synergistically Induced Micro/Nano Re-entrant Structures for Super-Oleophobic Surface with Cassie State

Generally,re-entrant structures are a key part of fabricating superoleophobic surfaces,and this structure appears in almost all kinds of published research articles regarding superoleophobicity.However,the application of related fabrication methods is usually too complex and costly in real practice.In this paper,we present a simple method to generate micro-cauliflower structures,which work as re-entrant structures in microcone arrays,to promote the formation of superoleophobic surfaces.The heating process after alkali-assisted surface oxidation is the main reason for the appearance of a micro-ball structure,and the oxidation time can influence the size of the micro-ball.To the best of our knowledge,the influence of the heating process after alkali-assisted surface oxidation on the birth of the micro-ball structure is seldom researched.A low-surface-energy treatment was also analyzed in influencing the size of the re-entrant structure and its relative wettability.Droplets of 5μl of n-decane show contact angles of 155±1°on the as-prepared superoleophobic surface,and air pockets can be clearly seen underneath,indicating a stable Cassie contacting state and a promising application value in the near future.

Controlling DNA Bundle Size and Spatial Arrangement in Selfassembled Arrays on Superhydrophobic Surface

The use of superhydrophobic surfaces(SHSs) is now emerging as an attractive platform for the realization of one-dimensional(1D) nanostructures with potential applications in many nanotechnological and biotechnological fields.To this purpose, a strict control of the nanostructures size and their spatial arrangement is highly required. However, these parameters may be strongly dependent on the complex evaporation dynamics of the sessile droplet on the SHS. In this work, we investigated the effect of the evaporation dynamics on the size and the spatial arrangement of self-assembled 1D DNA bundles. Our results reveal that different arrangements and bundle size distributions may occur depending on droplet evaporation stage. These results contribute to elucidate the formation mechanism of 1D nanostructures on SHSs.

Peach skin effect:a quasi-superhydrophobic state with high adhesive force

The surface of a peach is known to exhibit spe- cial wettability and adhesion behaviors. We disclose that the peach surface is covered with long and short indumentums. The long indumentums are covered mainly with hydrophobic wax molecules, while the short indumentums are coated mostly with hydrophilic polysaccharides. Thus, the peach surface exhibits a quasi-superhydrophobic property and high adhesive force. A water droplet on the surface of a peach is a quasi-sphere, which is unable to roll off even when the peach is turned upside down. This is defined as the peach skin effect. We present that the quasi-superhydrophobic state with high adhesive force is attributed to the special coexisting Wenzel＇s and Cassie＇s state for water droplets, thus creating the strong interaction between the water droplet and surface.