Abstract Bifunctional hybrid silica sol-gel coatings were synthesized, which showed both increased light transmittance and water-repellence. The as-prepared coatings of variable thickness (100–175 nm) were found to have low refractive index (1.250–1.275), high porosity (36%–42%), and maximum light transmittance up to 99.8%. Water-repellence of the surface was due to high water contact angle (90°) and low contact angle hysteresis (1–2°). Ellipsometric porosimetry and transmission electron microscopy measurements confirmed the microporous structure of the coatings. A systematic investigation for studying the durability and the deterioration of optical and surface properties was studied during aqueous soaking tests at different pH. During these experiments atomic force microscopy showed that the morphology of the surface did not change. The changes in the wetting properties were also confirmed by surface free energy measurements and an increase of the polar component was observed. The optical properties could be regenerated completely or partially after the soaking via heat treatment at 400 °C. The light transmittance of the samples remained high after the soaking, most likely due to the swelling of the solid matrix. The light transmittance and the water-repellent properties of the coatings showed long-term stability up to a year of storage.

中文翻译：

---

微孔混合二氧化硅涂层的耐久性：光学和润湿特性

摘要 合成了兼具透光率和疏水性的双功能杂化硅溶胶-凝胶涂层。发现所制备的可变厚度 (100-175 nm) 涂层具有低折射率 (1.250-1.275)、高孔隙率 (36%-42%) 和高达 99.8% 的最大透光率。表面的防水性是由于高水接触角 (90°) 和低接触角滞后 (1-2°)。椭圆光度计和透射电子显微镜测量证实了涂层的微孔结构。在不同 pH 值的水性浸泡试验期间，对研究耐久性和光学和表面性能劣化的系统研究进行了研究。在这些实验中，原子力显微镜显示表面的形态没有改变。润湿性能的变化也通过表面自由能测量得到证实，并观察到极性成分的增加。在 400°C 下通过热处理浸泡后，光学性能可以完全或部分再生。浸泡后样品的透光率仍然很高，很可能是由于固体基质的膨胀。涂层的透光率和防水性能显示出长达一年的长期稳定性。最有可能是由于固体基质的膨胀。涂层的透光率和防水性能显示出长达一年的长期稳定性。最有可能是由于固体基质的膨胀。涂层的透光率和防水性能显示出长达一年的长期稳定性。