Biomimetics leading to liquid-infused surface based on vertical dendritic Co matrix: A barrier to inhibit bioadhesion and microbiologically induced corrosion

Abstract

Inspired by natural plant Nepenthes pitcher, liquid infused surface (LIS) imparts opportunities in material protection fields. In this report, LIS is realized via compositing superhydrophobic cobalt dendrite matrix and silicone oil phase. Firstly, metallic cobalt dendrite is electrodeposited onto Cu substrate. With oxidation, the dendrite is covered by oxide layer on external surface. Further deposition with mussel-inspired polydopamine and dodecanethiol obtains superhydrophobic/superoleophilic dendrite matrix. The infusion of oil phase achieves LIS, which shows high abiotic corrosion inhibition by characterization using scanning Kelvin probe (SKP), electrochemical impedance spectroscopy (EIS) and polarization curve technique. After immersion in seawater for 30 d, |Z|0.01Hz maintains the value of 1.08 × 108 Ω cm2, which is still four orders of magnitude larger than that of bare Cu. Moreover, LIS performs a prominent role to decrease sulfate-reducing bacteria (SRB) attachment on metal surface, which is the precondition leading to microbiologically induced corrosion (MIC), the composite deterioration from both bioactivity of the organisms and corrosion. The attachment density of SRB on LIS after immersion for 3 d and 6 d is approximately three and two orders of magnitude smaller than that of bare Cu. Therefore, by decreasing bioadhesion, the corrosion current density of Cu covered by LIS in SRB medium has drastically decreased, suggesting the promising role for MIC inhibition application.