The increasing discharge of oily wastewater and frequent oil spill accidents pose a great threat to our environment and cause a great waste of valuable resources. However, most existing methods to separate oily water often involve unique equipment and toxic chemicals that hinder their commercial applications. Inspired by the synergy of various additives in commercial paint, we proposed a strategy to fabricate a metal mesh for oil–water separation by using a bicomponent hydrogel paint. This paint consists of an undercoat and a topcoat. Owing to the exceptional adhesion and molecular recognition effect, the paint can show a high binding degree. In addition, the hydrogel paint can decouple polymerization from crosslinking due to the reversible hydrogen bond crosslinking of topcoat, resulting in a separation of labor between paint makers and paint users. The rough as-prepared metal mesh with hydrophilic hydrogel and micropapillaes result in an excellent underwater superhydrophobicity and low oil-adhesion characteristics. This mesh can display high stability and durability under various complex conditions and successfully remove water from various oil/water mixtures and exhibit a high separation efficiency (above 99%). We believe that even ordinary people without professional training can also prepare an efficient oil/water separation mesh easily through brushing the bicomponent hydrogel paint. Consequently, the bicomponent hydrogel paint could be an attractive commercial paint to fabricate oil/water separation mesh.
This study investigates the interlayer bonding mechanism between epoxy primers and polyurethane topcoats commonly used in marine coatings. Previous studies have focused on the physical bonding between the coatings, but this study focused on the theory of chemical bonding. Using E-44 and HP2000 as primers and MDI toluene solution to simulate a polyurethane topcoat, the changes in the molecular structure at the interface between the epoxy primer and the polyurethane topcoat after curing were revealed by sum-frequency vibrational spectroscopy (SFG) technique. The experiments showed that the hydroxyl (-OH) signals on the surface of the epoxy primer disappeared after contacting with the MDI solution, and the isocyanate (-NCO) and carbonyl (C=O) signals on the urethane topcoat were revealed, suggesting that a chemical reaction occurred between them. The results of SFG analysis were further supported by X-ray photoelectron spectroscopy, Raman spectroscopy, infrared spectroscopy and scanning electron microscopy. It was found that chemical bonding had a positive effect on the macroscopic properties of the coatings, indicating that the interlayer bonding between the primer and the topcoat could be significantly enhanced by chemical bonding, which provides new theoretical support for the interlayer bonding of the coating support system for marine environment.
危险品化学品经营许可证（带存储）