Department of Chemistry, Simon Fraser University , Burnaby, British Columbia V5A 1S6, Canada.
Key Laboratory of Advanced Transducers and Intelligent Control Systems (Ministry of Education and Shanxi Province), College of Physics and Optoelectronics, Taiyuan University of Technology , Taiyuan, Shanxi 030024, P. R. China.
ACS Appl Mater Interfaces. 2017 Nov 15;9(45):39728-39735. doi: 10.1021/acsami.7b08957. Epub 2017 Oct 5.
Off-the-shelf laboratory filter paper of different pore sizes and thicknesses can be modified with fluorine-free organosilanes to be superhydrophobic, patternable, and ready for quantitative assay applications. In particular, we have demonstrated that the cellulose filter paper treated with a binary hexane solution of short (methyltrichlorosilane) and long (octadecyltrichlorosilane) organosilanes exhibits remarkably high water contact angles (>150°) and low wetting hysteresis (∼10°). Beyond the optimized ratio between the two organosilanes, we have discovered that the thickness rather than the pore size dictates the resulting superhydrophobicity. Scanning electron microscopy images showed that silanization does not damage the cellulose microfibers; instead, they are coated with uniform, particulate nanostructures, which should contribute to the observed surface properties. The modified filter paper is chemically stable and mechanically durable; it can be readily patterned with UV/ozone treatment to create hydrophilic regions to prepare chemical assays for colorimetric pH and nitrite detections.
不同孔径和厚度的现成实验室滤纸可以用无氟有机硅烷改性为超疏水、可图案化且可用于定量分析应用的材料。具体来说，我们已经证明，用短（甲基三氯硅烷）和长（十八烷基三氯硅烷）有机硅烷的混合正己烷溶液处理的纤维素滤纸表现出极高的水接触角（>150°）和低的润湿滞后（∼10°）。在两种有机硅烷的优化比例之外，我们发现厚度而不是孔径决定了最终的超疏水性。扫描电子显微镜图像表明，硅烷化不会损坏纤维素微纤维；相反，它们被均匀的、颗粒状的纳米结构所覆盖，这应该有助于解释所观察到的表面性质。改性滤纸化学稳定性和机械耐久性好；它可以通过 UV/臭氧处理很容易地进行图案化，以创建亲水区域，从而准备用于比色 pH 值和亚硝酸盐检测的化学分析。
