Preparation of Superhydrophobic P-TiO<sub>2</sub>-SiO<sub>2</sub>/HDTMS Self-Cleaning Coatings with UV-Aging Resistance by Acid Precipitation Method
The superhydrophobic coatings for outdoor use need to be exposed to sunlight for a long time; therefore, their UV-aging resistances are crucial in practical applications. In this study, the primary product of titanium dioxide (P-TiO<sub>2</sub>) was used as the raw material. Nano-silica...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-07-01
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| Series: | Nanomaterials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2079-4991/15/14/1127 |
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| Summary: | The superhydrophobic coatings for outdoor use need to be exposed to sunlight for a long time; therefore, their UV-aging resistances are crucial in practical applications. In this study, the primary product of titanium dioxide (P-TiO<sub>2</sub>) was used as the raw material. Nano-silica (SiO<sub>2</sub>) was coated onto the surface of P-TiO<sub>2</sub> by the acid precipitation method to prepare P-TiO<sub>2</sub>-SiO<sub>2</sub> composite particles. Then, they were modified and sprayed simply to obtain a superhydrophobic P-TiO<sub>2</sub>-SiO<sub>2</sub>/HDTMS coating. The results indicated that amorphous nano-SiO<sub>2</sub> was coated on the P-TiO<sub>2</sub> surface, forming a micro–nano binary structure, which was the essential structure to form superhydrophobic coatings. Additionally, the UV-aging property of P-TiO<sub>2</sub> was significantly enhanced after being coated with SiO<sub>2</sub>. After continuous UV irradiation for 30 days, the color difference (ΔE*) and yellowing index (Δb*) values of the coating prepared with P-TiO<sub>2</sub>-SiO<sub>2</sub> increased from 0 to 0.75 and 0.23, respectively. In contrast, the ΔE* and Δb* of the coating prepared with P-TiO<sub>2</sub> increased from 0 to 1.68 and 0.74, respectively. It was clear that the yellowing degree of the P-TiO<sub>2</sub>-SiO<sub>2</sub> coating was lower than that of P-TiO<sub>2</sub>, and its UV-aging resistance was significantly improved. After modification with HDTMS, the P-TiO<sub>2</sub>-SiO<sub>2</sub> coating formed a superhydrophobic P-TiO<sub>2</sub>-SiO<sub>2</sub>/HDTMS coating. The water contact angle (WCA) and water slide angle (WSA) on the surface of the coating were 154.9° and 1.3°, respectively. Furthermore, the coating demonstrated excellent UV-aging resistance. After continuous UV irradiation for 45 days, the WCA on the coating surface remained above 150°. Under the same conditions, the WCAs of the P-TiO<sub>2</sub>/HDTMS coating decreased from more than 150° to 15.3°. This indicated that the retention of surface hydrophobicity of the P-TiO<sub>2</sub>-SiO<sub>2</sub>/HDTMS coating was longer than that of P-TiO<sub>2</sub>/HDTMS, and the P-TiO<sub>2</sub>-SiO<sub>2</sub>/HDTMS coating’s UV-aging resistance was greater. The superhydrophobic P-TiO<sub>2</sub>-SiO<sub>2</sub>/HDTMS self-cleaning coating reported in this study exhibited outstanding UV-aging resistance, and it had the potential for long-term outdoor use. |
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| ISSN: | 2079-4991 |