Study on preparation, structure, and cooling properties of TiO2/acrylonitrile–styrene–acrylate terpolymer solar reflective nanocomposite

Abstract

AbstractPreparation, characterization, and cooling properties of TiO2 /acrylonitrile–styrene‐acrylate (ASA) terpolymer solar reflective nanocomposites with various contents of titanium dioxide (TiO2) nanoparticles were investigated. The formation of nanocomposites was monitored by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and contact angle measurements. The cooling features were characterized via ultraviolet–visible–near infrared (UV–vis–NIR) spectrophotometry and heat build‐up tests. FTIR spectra show the disappearance of the vinylic absorption peak at 1636 cm−1 of the modified TiO2 which signifies good chemical interaction between the poly (butyl acrylate) chains and the nanoparticles. DLS measurements revealed relative enlargement in the diameter of nanocomposite latex particles from 107 to 184 nm as the percentage of mineral nanoparticles increased. SEM and TEM analysis revealed the formation of a core‐shell morphology with an almost uniform distribution of nanoparticles in the polymer chains. Spectral properties details obtained using UV–vis–NIR spectrophotometry revealed that surface modification of TiO2 nanoparticles resulted in a more than 7% increase in solar transmittance compared to the raw form. Nevertheless, grafting a thermoplastic shell onto the acrylic core reduced the average solar transmittance from 81.92% to 55.32%. Incorporating TiO2 nanoparticles (up to 6 wt%) into the polymer matrix led to an 18.44% further decrease in solar transmittance compared to the neat ASA. Heat build‐up tests showed enhanced cooling of 10.2, 12.7°C, 13.4°C, and 14.2°C for 0, 2, 4, and 6 wt% of used nanoparticles, respectively.Highlights In situ nanocomposites were synthesized through mini‐emulsion polymerization. Chemical bonding formed between functionalized TiO2 and polymeric matrix. ASA/TiO2 nanocomposite shields >56% of NIR light and 63% of solar light. Nanocomposites reduced heat build‐up temperature by more than 14°C during indoor test.