关键词: 表面, 纳米粒子, 复合材料, 超疏水, 涂布, 纸基

Abstract:

This work aimed to fabricate a superhydrophobic surface on paper substrate by roller coating with modified micro/nano-TiO₂, and evaluate the robustness, self-cleanability and hydrophobic performance of the coating paper surface. First, TiO₂ particles in microns and nanometers were hydrophobic modified by 1H,1H,2H,2H-perfluorooctyltriethoxysilane (POTS) and γ-aminopropy- ltriethoxysilane. Then, the modified micro/nano TiO₂ particles were coated on paper substrate surface. The chemical compositions of modified micro/nano TiO₂ were analyzed by FTIR and the surface structure of coating paper was characterized by SEM. The superhydrophobicity, robustness and self-cleaning property of the coating surface were evaluated by water contact angle, abrasion testing and self-cleaning testing. FTIR analysis of modified TiO₂ showed that the multiple stretching vibration peaks of C—F bond appeared between 1000~1500cm^-1, indicating that POTS was bound to the surface of TiO₂ through chemical bonds and the hydrophobic modification of TiO₂ was successful. SEM analysis of coating paper surface indicated that TiO₂ particles with micron and nanometer size were evenly distributed on the surface of paper substrate. The coating paper was a rough surface with micro-nano structure similar to that of lotus leaf. Water contact angle and rolling angle of coating paper surface were 153°±1.5° and 3°±0.5°, respectively, so water droplet was spherical on the coating surface and easily fall off, showing that coating paper surface was excellent superhydrophobic property. After the coating paper was immersed in water for 7d, the contact angle did not change significantly, indicating that the coating had good hydrophobic stability. After 10 cycles of abrasion testing on the coating paper surface, water contact angle and rolling angle of coating paper surface were 150° and 9°, respectively. It indicated that the mechanical friction did not cause significant damage to the chemical composition and rough structure of the coating paper surface, and the robustness of superhydrophobic surface was very well. Furthermore, self-cleaning testing showed that the coating paper surface was good self-cleaning and anti-fouling performance. The preparation process of superhydrophobic surface was simple and easy to be industrialized, and provided a novel convenience approach to constructing super-hydrophobic surface with excellent comprehensive performance.

Key words: surface, nanoparticles, composites, superhydrophobic, coating, paper substrate