Orientation of Ultrathin α-ZrP Nanosheets in Aqueous Epoxy Resin for Anticorrosive Coatings

Two-dimensional layered materials have attracted wide attention owing to their many desirable properties. In particular, its outstanding barrier properties can effectively improve the impermeability of organic polymer coatings. However, the barrier properties of the coating depend to a large extent on the dispersion and orientation of the nanosheets in the coating. Here, monoamine-capped poly(etheramine) is inserted into the synthesized α-zirconium phosphate (α-ZrP) to obtain water-dispersible nanosheets with regular shapes and controllable thicknesses. In addition, the effects of the orientation (random and parallel) of α-ZrP nanosheets on the permeability and corrosion resistance of waterborne epoxy coatings have been systematically studied, and the results are in good agreement with the theoretical model. Compared with the pure coating, the impedance of the coating with high aspect ratio nanosheets and the coating with high aspect ratio nanosheets arranged in parallel increased by 83.5 and 221.7 times, respectively, after immersion for 60 days. This provides a strategy and theoretical basis for the two-dimensional nanosheet to improve the long-term service of anticorrosion coatings.