Construction of highly hydrophobic and fast endothermic surfaces using candle soot and nano-TiO2.

This work combines hydrophobic and heat-absorbing materials to solve the problem of water and frost resistance in industrial and domestic scenarios in harsh environments. Here, highly hydrophobic and fast endothermic (HHFE) surfaces were prepared by applying candle soot (nanocarbon) as the template, slides as the carrier and nano-TiO₂ as a backbone and a connecting layer. The resulting HHFE surface exhibited a coral-like porous structure, which is beneficial to hydrophobic performance. The contact angle between the water droplet and the glass with the HHFE coating was about 120°, thus implying that the prepared HHFE surface with a TiO₂ skeleton layer has excellent hydrophobicity. The hydrophobic mechanism of the HHFE surface can be explained by the Cassie–Baxter model. Infrared thermography and thermometry were used to record the thermal capacity and heat-absorbing rate of the HHFE surface. The temperature of the glass covered with the HHFE coating rose from 16°C to 38°C within 5 minutes, which is 46.2% higher in capacity and 2.2 times faster in rate than ordinary glass under the same solar irradiation. The resulting HHFE thin film consists of nanocarbon materials, and nano-TiO₂ particles were hydrophobic and good heat absorbers. They have great potential for anti-freezing and water-proofing applications, especially in harsh environments. [ABSTRACT FROM AUTHOR]