Development of a Robust Slippery Liquid-Infused Porous Surface with Grafted Polymer Brushes and Its Anti-Biofouling Applications in Marine Engineering

It is difficult for any marine engineering equipment to avoid the impact of biofouling. Especially, for engineering equipment made of titanium with a high biocompatibility, biofouling is a thorny problem. The outstanding anti-biofouling properties of the slippery liquid-infused porous surfaces (SLIPSs) and the grafted polydimethylsiloxane (gPDMS) brush surfaces have attracted the attention of researchers. However, the durability and stability of the conventional SLIPSs and the wear resistance of gPDMS are insufficient and should be improved. In this work, PDMS molecule brushes were grafted onto a micro-arc oxidized porous surface infused with a lubricant (silicone oil) to develop a grafted SLIPS (gSLIPS) on a titanium alloy (TA2). The gPDMS molecule brushes have a stronger chemical affinity with silicone oil, which can preserve more lubricants to enhance the durability and stability of the SLIPS. Simultaneously, the infused lubricant in the micro-arc oxidized porous surface can improve the wear resistance of the grafted molecule brushes. Besides, the molecule brushes can further isolate the vulnerable titanium substrate from the biofouling microorganisms. By combining the advantages of the SLIPS and gPDMS, the gSLIPS has excellent stability, durability, and mechanical robustness. The gSLIPS possesses a better biofouling resistance than TA2 and gPDMS. For example, the coverage of Chlorella on the gSLIPS is 0.067% ± 0.022% after being immersed for 14 days, which reduces by 98.8 and 95.6% compared with those on TA2 and gPDMS, respectively. In addition, the gSLIPS also has excellent anti-protein property. Therefore, this method will help develop a more stable, durable, and mechanically robust super-slippery coating with excellent anti-biofouling performance, which has great potential for the extensive titanium applications in marine engineering.