Oil‐Impregnated Nanoporous Oxide Layer for Corrosion Protection with Self‐Healing

Abstract

The major drawback of current passivation techniques for preventing corrosion is the lack of ability to withstand any external damages or local defects. In this study, oil‐impregnated nanoporous anodic aluminum oxide (AAO) layers are investigated to overcome such limitations and thus advance corrosion protection. By completely filling hydrophobized nanopores with oil via a solvent exchange method, a highly water‐repellent surface that prevents the penetration of corrosive media into the AAO layer and hence the corrosion of aluminum is achieved. The impregnation of oil into the hydrophobic nanoporous AAO layer enhances the corrosion resistance of an AAO layer by two and four orders of magnitude compared to that of a hydrophobic (i.e., air‐entrained) and a bare (hydrophilic) AAO, respectively. In the presence of local defects, the oil impregnated within the hydrophobic nanoporous AAO layer naturally permeates into the defects and ultimately inhibits the exposure of the aluminum surface to corrosive media. Whereas the corrosion current density of the air‐entrained hydrophobic AAO layer increases by more than 30 times after cracks, that of the oil‐impregnated AAO layer increases by no more than 4 times, showing superior anticorrosion property even after there are cracks, owing to the effective self‐healing capability.

Anti- and De-Icing Behaviors of Superhydrophobic Fabrics

“…Superhydrophobic materials and surfaces [1][2][3][4] have attracted great interest because of their extreme water-repellent surface property for many potential applications including self-cleaning [5][6][7], hydrodynamic friction reduction [8][9][10], anti-icing [11][12][13][14], anticorrosion [15][16][17][18], biotechnology [19][20][21], thermal systems [22][23][24][25], and micro-and nanodevices [26][27][28]. In particular, previous works on the use of superhydrophobic surfaces as anti-icing coatings have demonstrated that superhydrophobic surfaces have the capability to reduce or even prevent the accumulation and formation of snow and ice on hard solid surfaces [11][12][13][14].…”

Emerging Applications of Bioinspired Slippery Surfaces in Biomedical Fields

“…Targeting at high mechanical durability, various metals, such as stainless steel and aluminum have also been utilized as substrates for LISS by using different surface roughening strategies. Particularly, tungsten oxide films have been deposited on steels by electrodeposition, followed by surface modification and lubrication to obtain LISS, which represents so far the most durable coating substrates for LISS.…”

Slippery Liquid-infused Porous Surface Fabricated on Aluminum Maintains Stable Corrosion Resistance at Elevated Temperatures

“…Slippery liquid infused porous surface (SLIPS): 15 After anodization and modification with PFDS, fluorocarbon lubricant (Krytox GPL107) was infused onto the porous surface of aluminum with a solvent exchange method. The prepared aluminum sheet with porous Al 2 O 3 structures was immersed in ethanol, after 10 min, the sample was immediately immersed in Vertrel XF for 10 min, and then the sample was immersed in fluorocarbon lubricant for 20 min.…”

“…When the fluorocarbon lubricant was infused into the rough surface with solvent exchange method, the rough surface of adonic aluminum oxide acted as a reservoir to ensnare the fluorinated lubricant to form a smooth, transparent and static SLIPS on the aluminum substrate. 15 Fig. 4 shows the water CA of a water droplet on SLIPS, owing to the low surface energy of fluorinated lubricant oil, the water CA of the sample increased from 70°to 120°.…”