Chemical Instability-Induced Wettability Patterns on Superhydrophobic Surfaces.

Chemical instability of liquid-repellent surfaces is one of the nontrivial hurdles that hinders their real-world applications. Although much effort has been made to prepare chemically durable liquid-repellent surfaces, little attention has been paid to exploit the instability for versatile use. Herein, we propose to create hydrophilic patterns on a superhydrophobic surface by taking advantage of its chemical instability induced by acid solution treatment.

Droplet impacting on pillared hydrophobic surfaces with different solid fractions.

Hypothesis: The solid fraction of the substrate is expected to influence the bouncing behavior of an impinging droplet, thereby affecting spreading and contact time. Hence, it should be possible to alter the velocity and pressure distribution of impacting droplet, and also affect the impact velocity for droplet penetration right upon impact.

Simulations: We systematically investigate the impact dynamics of water droplets on pillared hydrophobic surfaces with different solid fractions using phase-field simulations.

Robust and durable liquid-repellent surfaces.

Liquid-repellent surfaces, such as superhydrophobic surfaces, superoleophobic surfaces, and slippery liquid-infused surfaces, have drawn keen research interest from the communities engaged in chemical synthesis, interfacial chemistry, surface engineering, bionic manufacturing and micro-nano machining. This is due to their great potential applications in liquid-proofing, self-cleaning, chemical resistance, anti-icing, water/oil remediation, biomedicine, However, poor robustness and durability that notably hinders the real-world applications of such surfaces remains their Achilles heel. The past few years have witnessed rapidly increasing publications that address the robustness and durability of liquid-repellent surfaces, and many breakthroughs have been achieved.

Maskless Hydrophilic Patterning of the Superhydrophobic Aluminum Surface by an Atmospheric Pressure Microplasma Jet for Water Adhesion Controlling.

Superhydrophobic surfaces with hydrophilic patterns have great application potential in various fields, such as microfluidic systems and water harvesting. However, many reported preparation methods involve complicated devices and/or masks, making fabrication of these patterned surfaces time-consuming and inefficient. Here, we propose a highly efficient, simple, and maskless microplasma jet (MPJ) treatment method to prepare hydrophilic patterns such as dots, lines, and curves on superhydrophobic aluminum substrates.

Transforming a Simple Commercial Glue into Highly Robust Superhydrophobic Surfaces via Aerosol-Assisted Chemical Vapor Deposition.

Robust superhydrophobic surfaces were synthesized as composites of the widely commercially available adhesives epoxy resin (EP) and polydimethylsiloxane (PDMS). The EP layer provided a strongly adhered micro/nanoscale structure on the substrates, while the PDMS was used as a post-treatment to lower the surface energy. In this study, the depositions of EP films were taken at a range of temperatures, deposition times, and substrates via aerosol-assisted chemical vapor deposition (AACVD).

Stability of plasma treated superhydrophobic surfaces under different ambient conditions.

Plasma hydrophilizing of superhydrophobic substrates has become an important area of research, for example, superhydrophobic-(super)hydrophilic patterned surfaces have significant practical applications such as lab-on-chip systems, cell adhesion, and control of liquid transport. However, the stability of plasma-induced hydrophilicity is always considered as a key issue since the wettability tends to revert back to the untreated state (i.e.

Underwater Spontaneous Pumpless Transportation of Nonpolar Organic Liquids on Extreme Wettability Patterns.

Spontaneous pumpless transportation (SPT) of liquids has generated tremendous demands in microfluidic systems and advanced devices. However, the transportation of nonpolar organic liquids on open platforms underwater remains a challenge because most existing SPT systems are only designed for use in air. Here, we report a surface-tension-driven SPT system to transport various nonpolar organic liquids using underwater extreme wettability patterns.