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In this paper, high-throughput sequencing technology was adopted to visualize the microbial communities on the surfaces of two types of carbon steel immersed in Sea Area Ⅰ. The results showed that different microbial communities were formed on different carbon steel surfaces, in which the genus with the highest abundance on the surface of Q235 was Escherichia–Shigella, while anaerobic Desulfovibrio on the surface of 921a was the most abundant, and the dominant genus varied with the depth of the rust layer. In addition, the distribution of sulfate-reducing bacteria (SRB) on the surface of Q235 submerged in Sea Area Ⅱ was compared with the sulfate-reducing bacteria's distribution in Sea Area Ⅰ, using the environmental factors correlation analysis. The results showed that the concentrations of Ca2+, Na+, K+, Mg2+, and Al3+ were positively correlated with the distribution of SRB, while the concentrations of Cu2+, Zn2+, SO42−, Cl−, NO3−, and organic carbon were negatively correlated with it. Furthermore, there was a highly significant correlation between each geochemical factor and Desulfotomaculum (p < 0.01). [ABSTRACT FROM AUTHOR]

This paper introduces a technique of preparing core-shell nanofibers on the surface of Q235 carbon steel by electrospinning, which was compounded with organic epoxy resin to form composite coating (PAN-NFs/BTA/EP). The electrospinning process were optimized to obtain the desired uniformly and continuously nanofibers. The composited coating owned better mechanical properties with high tensile strength and good crack-pursuit ability in contrast with pure epoxy resin. The electrochemical impedance of the composite coating/metal system was increased by two orders of magnitude. After salt-spray test, the corrosion degree of the composite coating/metal system with BTA was slighter than that without BTA, which may be attribute to the chelate of BTA with Fe substrate. And the molecular dynamics simulation proved the chelate effect and also verified that BTA had the blocking effect from water erosion. • The fabricated core-shell nanofiber had good dispersity and high uniformity. • The mechanical properties of composited coating were enhanced by nanofibers. • Molecular dynamic models confirmed the barrier performance of healing agent. • The anticorrosive performance of the composite coating was improved. Maintaining or even improving the anti-corrosion performance of coatings while enhancing their mechanical properties is an active research area. Here, polyacrylonitrile nanofibers (PAN-NFs) filled with benzotriazole (BTA) as an inhibitor were created via a coaxial electrospinning technique and directly deposited on a metal surface. The epoxy resin was then covered to form composited coatings. The as-prepared coatings revealed better mechanical properties and high protective ability than unprocessed coatings. The PAN-NFs/BTA system offered long-term sealing function when the coatings were damaged. Molecular dynamic models were then employed to further confirm that the healing agent releasing from the composite coating could prevent Fe substrate from eroding by water molecules. [ABSTRACT FROM AUTHOR]