Abstract With the increasing consumption of vegetable oils, value-added recycling of spent bleaching earth (SBE) is of wide concern. Here, we report a simple and sustainable method for converting SBE containing palygorskite (PAL) to hybrid carbon materials (PAL/C) with a nanorod-like structure, which can then be used as building blocks for the preparation of durable and fluorine-free superhydrophobic coatings. The PAL/C composites were prepared by calcination of the SBE containing PAL in air. Then, the homogeneous suspensions in ethanol were prepared by hydrolytic condensation of n -hexadecyltrimethoxysilane onto the PAL/C nanorods. Superhydrophobic coatings can be readily prepared by spray-coating the suspensions onto substrates. The PAL/C composites and the superhydrophobic coatings were characterized using a variety of analytical techniques including scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Superhydrophobicity of the coatings depends upon their surface topography, which can be precisely regulated by the calcination temperature of SBE and the concentration of the PAL/C composites in the suspensions. The superhydrophobic coatings show high water contact angle and extremely low sliding angle of 1.2°. The superhydrophobic coatings also feature high mechanical, thermal and chemical durability. This is because the PAL/C nanorods are closely linked and encapsulated together by polysiloxane (POS) among them, forming a highly crosslinked network. We believe that this study will shed light on the value-added recycling of SBE and cost-effective preparation of bioinspired antiwetting coatings.

中文翻译：

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来自富含坡缕石的废漂白土的耐用无氟超疏水涂层

摘要 随着植物油消费量的增加，废漂白土（SBE）的增值回收受到广泛关注。在这里，我们报告了一种将含有 SBE 的坡缕石 (PAL) 转化为具有纳米棒状结构的混合碳材料 (PAL/C) 的简单且可持续的方法，然后可以将其用作制备耐用和无氟的基石超疏水涂层。PAL/C 复合材料是通过在空气中煅烧含有 PAL 的 SBE 制备的。然后，通过将正十六烷基三甲氧基硅烷水解缩合到 PAL/C 纳米棒上来制备乙醇中的均匀悬浮液。通过将悬浮液喷涂到基材上，可以很容易地制备超疏水涂层。PAL/C 复合材料和超疏水涂层使用多种分析技术进行表征，包括扫描电子显微镜、透射电子显微镜和 X 射线光电子能谱。涂层的超疏水性取决于它们的表面形貌，这可以通过 SBE 的煅烧温度和悬浮液中 PAL/C 复合材料的浓度来精确调节。超疏水涂层显示出高水接触角和 1.2° 的极低滑动角。超疏水涂层还具有高机械、热和化学耐久性。这是因为 PAL/C 纳米棒之间通过聚硅氧烷 (POS) 紧密连接并封装在一起，形成高度交联的网络。