In situ fabrication and infrared emissivity properties of oriented LDHs films on Al substrates

The fabrication of film materials with controlled structure and desired morphology offers the ability to control the infrared radiation properties. Here we report the controlled fabrication of oriented layered double hydroxides (LDHs) films on Al substrates and examine their infrared radiation (8–14 μm) characteristics. A series of LDHs films with gradients in morphologies were prepared by tuning the hydrothermal temperatures and times. Morphological and structural evolution of the as-prepared LDHs films was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that the LDHs films exhibit rough surfaces composed of platelet-like LDHs microcrystals. It is revealed that the longer reaction times are favorable for the formation of regular LDHs sheets. The infrared emissivity properties of the LDHs films are studied, and the results demonstrated that the surface structures of the films strongly influence its infrared radiation properties. The infrared emissivity of LDHs films can be controlled by controlling the hydrothermal time. Because of the controlled morphological and tunable structure of LDHs sheets, the as-fabricated LDHs films possess morphology-dependent infrared emissivity properties, which have promising application in low infrared emissivity materials and thermal control materials.