Benzimidazodone–metal complex and reduced graphene oxide composite pigments: preparation, characterization, and application in electrospinning

Benzimidazolone–metal complex pigments are widely used in various industrial fields owing to their comprehensive chromatograms, good color performance, excellent durability, and moderate cost. To expand their applications to flexible conductive materials, the conductivities of these pigments must be increased to make them compatible with the electrospinning technique. In this study, benzimidazolone–metal complex pigments with various chelating metals were prepared and combined with reduced graphene oxide (rGO) to form rGO composite pigments. The performance of various metal chelated pigments was compared, and the results showed that the pigment with Ni as the chelated metal had the highest crystallinity and thermal stability. The molecular geometries of the complexes were optimized at the DSD-PBEP86 level of the density functional theory. Nylon fiber membranes with or without rGO composite pigments were prepared via electrospinning, and the conductivity, surface morphology and mechanical properties of the fiber membranes were analyzed. The fiber membrane with rGO composite pigments demonstrated a maximum electrical conductivity of 21.7 S cm ⁻¹ . The average fiber diameter of the membranes decreased from 779 to 150 nm after the addition of rGO composite pigments, and the corresponding Young’s modulus increased from 21.1 to 91.7 MPa. The experimental results indicated that adding rGO composite pigments to electrospun nylon could produce flexible composite fiber membranes with high conductivity and excellent mechanical properties.