Carbon Vesicles: A Symmetry-Breaking Strategy for Wide-Band and Solvent-Processable Ultrablack Coating Materials

摘要

Solvent-processable ultrablack materials have obvious application convenience in many situations, such as absorbing coatings on large and complex surfaces. However, developing solvent-processable ultrablack materials with high light-absorption performance and wide absorption band remains a great challenge. In this article, carbon vesicles (CVs) are fabricated for solvent-processable ultrablack coating. The fabrication process involves a templated co-condensation of silica and resorcinol formaldehyde resin (RF resin), followed by carbonization and template removal. The resultant structure shows a very thin inner layer, a rough outer layer, as well as a nano-porous interlayer. This structure introduces randomness and breaks the spherical symmetry of the common carbon hollow spheres. As a result, structural color due to inner-particle interference is avoided. In addition, the as-fabricated CVs show a wide-band low reflectance because of its low carbon filling ratio and nanoscale scatterer size. The lowest reflectance reaches approximate to 0.10% at 360 nm, making it the darkest solvent-processable ultrablack material ever reported. The symmetry-breaking strategy presented here provides an efficient way for the design of solvent-processable ultrablack materials.