A three-dimensional network-structured self-healing anticorrosion coating with high barrier properties and significant benzotriazole loading capacity developed using cellulose nanocrystals and graphene oxide
摘要
Graphene-based nanomaterials encapsulated with corrosion inhibitors are promising materials for realizing smart coatings with self-repairing properties. However, the low loadings of corrosion inhibitors and cumbersome synthesis processes remain urgent problems for practical applications. In this paper, we present a novel 3D network structure designed to enhance the corrosion inhibitor loading via a combination of 3D network formation and self-polymerization of dopamine. The method utilizes cellulose nanocrystals (CNCs) as templates to support graphene oxide nanosheets through a one-step process. Due to their high aspect ratio, CNCs can effectively anchor and extend the 2D graphene sheets, significantly improving the dispersion of the nanocomposites and the loading capacity of the corrosion inhibitor benzotriazole (BTA). Meanwhile, dopamine promotes the adsorption of BTA on GO and CNCs through self-polymerization, enhancing the durability and anticorrosive properties of the aqueous resins. The EIS results show that the impedance modulus of the smart coatings reaches 2.1 × 108 Ω cm2 after 14 days of immersion, two orders of magnitude higher than that of conventional epoxy coatings. The loading capacity of BTA/PDA was determined to be 24 wt%. In addition, the coating specimens exhibited very few surface corrosion products and air bubbles after 7 days of saltwater immersion, further confirming their excellent corrosion protection performance. We believe that this work will significantly contribute to extending the service life of various anticorrosion coatings.