Graphene as a high-performance additive: the importance of fine dispersion for corrosion protection in coatings

Abstract This study demonstrates a practical route to integrate commercially available graphene into corrosion-protective coatings. Emphasis is placed on processing conditions that govern dispersion quality, and a ready-to-use, letdown graphene intermediate is formulated for solvent- and waterborne systems to minimize in-plant dispersion. Processing windows for graphene loading, dispersant level, and dispersion energy are established. Deagglomeration and dispersion stability are quantified by laser diffraction particle size analysis and supported by SEM and Raman spectroscopy. Corrosion performance is evaluated by salt spray testing and electrochemical impedance spectroscopy. Clear processing–structure–performance relationships are identified. Well-dispersed graphene at an optimized dispersant level enhances barrier performance and corrosion resistance, whereas insufficient deagglomeration or nonoptimal dispersant dosage can negate benefits and even diminish protection. Excessive dispersant contents reduce film integrity, effectively offsetting graphene’s advantage. High-surface-area grades can be challenging due to elevated dispersant demand. Overall, achieving a narrow particle size distribution and maintaining dispersion stability are critical for effective use of graphene in coatings.