Optimising surface morphology for enhanced radiative properties in thermal energy-efficient materials

Abstract

Environmental concerns related to heat-absorbing materials in the construction industry can be effectively addressed by optimising the reflectivity of incoming sunlight and thermal emissivity of materials. These radiative properties are closely tied to the surface morphology characteristics of building materials, making superficial topography a critical factor in determining their thermal and energy performance. In our research, we performed reflectance analysis in the UV-Vis-NIR-MIR region and conducted FT-IR analysis to assess the colour and reflectance behaviour of the samples, along with surface morphology and topography investigations. The data collected were utilised in a statistical study to analyse the relationship between superficial topography and thermo-optical characteristics. Our findings underscore the significant impact of surface morphology as a secondary factor influencing radiative properties. Specifically, our results indicate that large-scale components influence mid-infrared absorbance, while surface roughness is crucial in determining solar reflectance properties. Notably, an increase in roughness consistently leads to a reduction in near-infrared and visible reflectance properties by up to 17% and 8%, respectively, with no noticeable effect in the UV region. In conclusion, our research demonstrates the potential for customising and optimising surface properties to reduce energy consumption for cooling purposes and alleviate the urban heat island effect.