Skin-mimetic assembly strategy for fabricating a transparent and highly anti-corrosive FSO-GO/epoxy nanocomposite coating

A transparent and anti-corrosive coating is of great importance for the protection of valuable articles, historical relics, and metal. However, there is a significant challenge due to the trade-off between high transparency and pleased anti-corrosive performance. The barrier function of skin, derived from the “brick and mortar” microstructure where hydrophobic corneocytes are parallelly embedded in lipids of the skin stratum corneum, offers an admirable concept to solve the problem. Herein, a novel bio-inspired assembly strategy is implemented to fabricate transparent and high-performance anti-corrosive epoxy nanocomposite coatings (Bio-MFICs), cooperating with superhydrophobic magnetic responsive graphene oxide nanosheets (FSO-GO) parallelly aligned in epoxy resin via magnetic-field-induced assembly and bridging structure further forming during curing process. The structure of Bio-MFICs is highly consistent with the “brick and mortar” structure of the skin stratum corneum, where FSO-GO nanosheets act as “corneocytes” and epoxy matrix acts as “lipids”. The subtle skin-mimetic structure contributes to the excellent anti-corrosive performance of Bio-MFICs because of the prolonged and blocked diffusion pathway of corrosive media. As a result, the resistance of Bio-MFIC- 3 (0.75 wt% filler content) remains 4.17×10 7  Ω·cm −2 , which is 43 times that of the pure epoxy coating, and the logarithm of breaking point frequency is quite low as −1.05 after immersion in 3.5 wt% NaCl solution for 28 days. Moreover, the transparency of the Bio-MFIC- 3 is highly close to that of the pure epoxy coating. This work provides an effective method of constructing transparent protective materials to reduce the loss of materials and achieve the goal of energy-saving and greenhouse gas emissions reduction.