Stable and biocompatible slippery lubricant-infused anode-oxidated titanium nanotube surfaces via a grafted polydimethylsiloxane brush

Abstract

Slippery lubricant-infused porous surfaces (SLIPS) are endowed with good pressure stability, self-repairing performance and omniphobic property due to the fluid lubricant layer. However, the problem that the lubricant is easily desorbed due to the poor fixation effect of the surface limits its wide range of applications. The functions will be diminished over time due to the depletion of the lubricant layer. Herein, the stability of the lubricant layer was enhanced by optimizing the structure and enhancing the interaction force between the substrate and the lubricant. Polydimethylsiloxane (PDMS) was grafted onto the surface of the titanium dioxide nanotube array with a regular morphology prepared by an anodizing method under ultraviolet irradiation, and the residual silicone oil was used as the lubricant, which endows the surface with a very low sliding angle of about 0.4°. On the one hand, the closed-cell and high-aspect-ratio titanium dioxide nanotube structure provides strong capillary force to improve the stability of the lubricant layer. On the other hand, the grafted polydimethylsiloxane molecular brush layer has good compatibility with the residual lubricant, providing strong intermolecular interaction force and further improving the stability of the lubricant layer. Therefore, the stable lubricant-infused surface can repel all kinds of liquids (water, hot water, organic liquids, etc.), and has good underwater (room temperature and 90 °C) stability, shear resistance, UV stability, high temperature stability, etc. In addition, the surface has excellent anti-fouling and anti-corrosion properties, which is also of great significance for practical applications.