Double Immobilized Superhydrophobic and Lubricated Slippery Surface with Antibacterial and Antifouling Properties

A "double immobilized" superhydrophobic and lubricated slippery surface was prepared by simultaneously immobilizing lubricating oil and bactericide molecules. The coordination function of metal organic frameworks (MOFs) was utilized to immobilize trimesic acid, a fungicide, as a ligand of the MOF by the cathodic electrodeposition technique. Aminated silicone oil was used as a lubricating oil and was immobilized to the superhydrophobic MOF film by the curing reaction with isocyanates. This technique is a facile strategy to conductive substrates for fabricating superhydrophobic and lubricated slippery surfaces with satisfactory antibacterial and antifouling properties.

Preparation of Superhydrophobic Film on Ti Substrate and Its Anticorrosion Property

Superhydrophobic films were fabricated on a titanium substrate with or without anodizing by using a self-assembling method. Firstly, the pretreatments of mechanical polishing/anodizing or mechanical polishing only were conducted, respectively. Subsequently, the preparation of polydopamine film layer, deposition of nano-silver particles, and post modification of 1H,1H,2H,2H-perfluorodecanethiol were performed on the surface of the pretreated substrate. The surface morphologies, compositions, wettability, and corrosion resistance of the films were investigated with scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), water contact angle measurements, and electrochemical tests, respectively. Meanwhile, the effect of the deposition time in the silver nitrate solution on the hydrophobicity of the specimen surface was investigated. The result showed that with the increase of deposition time, the hydrophobic property enhanced gradually. The surface deposited for 7 h exhibited an optimum hydrophobic effect, which was characterized with a large water contact angle (WCA) of 154°, and the surface was rather rough and covered by a relatively uniform layer of micro-nano silver particles. The excellent hydrophobicity was attributed to a rough stratified microstructure along with the low surface energy. The electrochemical measurements showed that the existence of the superhydrophobic film can effectively enhance the corrosion resistance of Ti samples.

Simple and cost-effective fabrication of highly flexible, transparent superhydrophobic films with hierarchical surface design

Optical transparency and mechanical flexibility are both of great importance for significantly expanding the applicability of superhydrophobic surfaces. Such features make it possible for functional surfaces to be applied to various glass-based products with different curvatures. In this work, we report on the simple and potentially cost-effective fabrication of highly flexible and transparent superhydrophobic films based on hierarchical surface design. The hierarchical surface morphology was easily fabricated by the simple transfer of a porous alumina membrane to the top surface of UV-imprinted polymeric micropillar arrays and subsequent chemical treatments. Through optimization of the hierarchical surface design, the resultant superhydrophobic films showed superior surface wetting properties (with a static contact angle of >170° and contact angle hysteresis of <3.5°) in the Cassie-Baxter wetting regime, considerable dynamic water repellency (with perfect bouncing of a water droplet dropped from an impact height of 30 mm), and good optical transparency (>82% at 550 nm wavelength). The superhydrophobic films were also experimentally found to be robust without significant degradation in the superhydrophobicity, even under repetitive bending and pressing for up to 2000 cycles. Finally, the practical usability of the proposed superhydorphobic films was clearly demonstrated by examining the antiwetting performance in real time while pouring water on the film and submerging the film in water.