Design,Preparation And Properties Of Ultra-black Nanocomposite Films

Due to the excellent light absorption properties,ultra-black materials have potential applications in the fields of optical instruments,space detection,etc.So far,mechanically robust and broadband planar blackbodies applied for coating are still limited,herein,this thesis focuses on the design,preparation and characterizations of nanocomposite blackbody materials.Blackbody films have been prepared by different strategies and their high-efficiency light absorption properties and the high-strength mechanical properties were studied.The results can be summarized as the following two parts:1.Considering the good optical properties of the mother-of-pearl layered structure film and the excellent light absorption properties of carbon nanotube materials,we dispersed them into a network of biological macromolecules to prepare organic-inorganic nanocomposite materials.MMT-PVA-CNTs blackbody films were prepared by vacuum filtration assembly process.The optical and mechanical properties of MMT-PVA-CNTs films were systematically studied.The results show that the MMT-PVA-CNTs composite film shows extremely low reflectance in the entire solar spectral range,which can effectively improve the broadband absorbance to have a higher optimal solar absorption rate as 96.9%.At the same time,this series of composite materials exhibit excellent flexibility and mechanical strength.In this work,compared with the reported nano-structures such as nano-columns or nano-cones,the layered microstructure can also improve the absorption of incident light,providing a new idea for the design of blackbody materials in the future.2.Considering the excellent light trapping performance of micro-nano structure arrays and the excellent mechanical properties of polyurethane elastomers,we have developed a series of black polyurethanes that are easy for nano-imprinting or in-situ replication.First,a mild polycondensation reaction is used to copolymerize the azobenzene dye with light absorption properties into the polyurethane main chain,and block with acrylate units to synthesize a new type of polymerizable black polyurethane film.The structure and properties of polyurethane were characterized by infrared,DSC,ultraviolet spectroscopy,etc.,which proved the successful preparation of light-absorbing elastomer.Subsequently,using the nano-pillar and nano-cone porous alumina AAO as templates,the embossing and replicating of this type of polyurethane elastomer and the corresponding absorbance were preliminary studied.