The wettability of the surface of hydrophilic cotton fabrics was modified using a one-step protocol with tannic acid (TA) to provide its excess catechol groups to be grafted with 1-eicosanamine at pH 8.5 and room temperature with catalysts CuSO/HO. The modification over the synthesis conditions revised the contact angles of water and diiodomethane droplets from 132.68 ± 0.49° to 143.95 ± 0.80° and from 100.08°±1.42° to 82.96 ± 1.38°, respectively. The corresponding dispersive of the so-yielded cotton surface ranged from 8.6 to 16.0 mJ/m, and the polar components ranged from 0.08 to 2.7 mJ/m, much lower than polytetrafluoroethylene. The modified cotton fabrics are omniphobic and can repel water and commercial oil products. The absorption tests revealed that the modified cotton fabrics absorbed 1.10 g hexane/g cotton by contacting hexane (top)-water (bottom) layers and absorbed 1.26 g hexane/g cotton by contacting water first for 30 s, then hexane for another 30 s. The modified fabrics reveal good absorption reusability as hexane absorbent is even pre-saturated with water. This conclusion is also valid for commercial unleaded gasoline #95 and diesel. A parametric study revealed that the added catalysts and prolonged reaction time would enhance the hydrophobicity of the surface. These modified cotton fabrics can absorb oil from water and oil spills. Mechanisms corresponding to this observation are discussed.

中文翻译：

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单宁酸/1-二十胺接枝层改性油水分离棉织物


使用单宁酸 (TA) 一步法改性亲水性棉织物表面的润湿性，以提供其过量的儿茶酚基团，并在 pH 8.5 和室温下用 CuSO4/H2O 催化剂与 1-二十胺接枝。合成条件的修改将水和二碘甲烷液滴的接触角分别从132.68±0.49°修改为143.95±0.80°和从100.08°±1.42°修改为82.96±1.38°。所得棉表面相应色散范围为8.6～16.0 mJ/m，极性成分范围为0.08～2.7 mJ/m，远低于聚四氟乙烯。改性棉织物具有万能性，可以排斥水和商业油品。吸收测试表明，改性棉织物通过己烷（顶部）-水（底部）层接触吸收1.10 g己烷/g棉花，并且通过先接触水30 s，然后再接触己烷30 s吸收1.26 g己烷/g棉花。 。改性织物表现出良好的吸收可重复使用性，因为己烷吸收剂甚至用水预先饱和。这一结论对于商业无铅汽油 #95 和柴油也有效。参数研究表明，添加的催化剂和延长的反应时间会增强表面的疏水性。这些改性棉织物可以吸收水和漏油中的油。讨论了与这一观察结果相对应的机制。