Enhancing the coating durability and electrical stability of fiber composites with SPEEK/PEDOT:PSS permanent coatings: A novel approach

This study focuses for the first time on the investigation of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) permanent coatings on composite surfaces to enhance the electrical and surface properties of fiber-reinforced composite materials, particularly those commonly used in the aerospace sector, such as Kevlar (R) (aramid), carbon (C), and glass fiber-reinforced composites. One significant challenge encountered is the weak adhesion property between PEDOT:PSS and the composite surface, which poses some difficulties in coating durability in harsh environmental conditions. The resulting material comprises a three-component structure, consisting of composite surface modifications, PEDOT:PSS coating, and sulfonated poly(ether ketone) (SPEEK) primer. To address the primary issues of adhesion, delamination, stability, and electrical conductivity, this study adopts a novel approach to improve the permanence of PEDOT:PSS coatings on composite surfaces by utilizing a SPEEK primer under ultraviolet (UV) light exposure, deionized (DI) water, saltwater, and acidic environments. Tape-peeling and cross-cut adhesion tape tests were employed to evaluate the coating durability, while optical microscopic observations, water contact angle (WCA), and Fourier-transform infrared (FTIR) spectroscopy analyses assess physical, chemical, and physicochemical property changes. Test results indicated that the SPEEK/ PEDOT:PSS-coated composite surfaces exhibited enhanced electrical conductivity, stability, and permanent adhesion properties. Overall, this study contributes to the development of next-generation materials for various industries (aviation, defense, energy, and manufacturing) by offering a promising solution to improve electrical, adhesion, and other surface properties in composite materials.