Preparation and Characterization of a Multifunctional Super-Hydrophobic Composite Coating with Ultra-low Near-Infrared Reflectivity and Dark Green Color
摘要
A super-hydrophobic composite coating with ultra-low near-infrared (NIR) reflectivity and dark green color characteristics was fabricated using graphene as the laser-absorbing filler, phthalocyanine green and polyurethane-based medium yellow color paste as the coloring pigments, nano-SiO2 as the surface roughness-regulating filler, and PDMS as the binder matrix, respectively. The effects of total pigment and filler content, mass ratio of nano-SiO2 to pigment-filler, mass ratio of graphene to phthalocyanine green, and mass ratio of medium yellow color paste to phthalocyanine green on the coating’s color, 1.06 μm NIR reflectivity, water contact angle (WCA), and mechanical properties were systematically investigated. The results show that when the total pigment and filler content is 40 wt.%, and the mass ratio of nano-SiO2 to pigment-filler is 4:6, the coating exhibits a WCA of 154° and a 1.06 μm NIR reflectivity of 11.9%. By optimizing the graphene to phthalocyanine green ratio (1:12) and medium yellow color paste to phthalocyanine green ratio (7:3), the coating color matches the dark green standard in GJB795A, approaching the color number of DG0546. Under these conditions, the coating maintains a WCA of 151°, a low 1.06 μm NIR reflectivity of 9.0%, and excellent mechanical properties: adhesion strength (grade 2), flexibility (2 mm), and impact resistance (50 kg × cm). These properties satisfy the requirements for super-hydrophobic laser and visible light compatible stealth coating, demonstrating broad application prospects in multi-spectrum compatible stealth coatings for land-based equipment.