Center for High Technology Materials and Department of Electrical and Computer Engineering, University of New Mexico, 1313 Goddard, SE, Albuquerque, New Mexico 87106, USA.
Langmuir. 2010 Feb 16;26(4):2700-6. doi: 10.1021/la904505n.
The use of simple plasma treatments and polymer deposition to tailor the anisotropic wetting properties of one-dimensional (1D) submicrometer-scale grooved surfaces, fabricated using interferometric lithography in photoresist polymer films, is reported. Strongly anisotropic wetting phenomena are observed for as-prepared 1D grooved surfaces for both positive and negative photoresists. Low-pressure plasma treatments with different gas compositions (e.g., CHF(3), CF(4), O(2)) are employed to tailor the anisotropic wetting properties from strongly anisotropic and hydrophobic to hydrophobic with very high contact angle and superhydrophilic with a smaller degree of wetting anisotropy and without changing the structural anisotropy. The change of the surface wetting properties for these 1D patterned surfaces is attributed to a change in surface chemical composition, monitored using XPS. In addition, the initial anisotropic wetting properties on 1D patterned samples could be modified by coating plasma treated samples with a thin layer of polymer. We also demonstrated that the wetting properties of 1D grooved surfaces in a Si substrate could be tuned with similar plasma treatments. The ability to tailor anisotropic wetting on 1D patterned surfaces will find many applications in microfluidic devices, lab-on-a-chip systems, microreactors, and self-cleaning surfaces.
本文报道了一种通过简单的等离子体处理和聚合物沉积来调整一维（1D）亚微米尺度沟槽表面各向异性润湿性的方法，该沟槽表面是通过干涉光刻在光致抗蚀剂聚合物薄膜中制造的。对于正性和负性光致抗蚀剂制备的 1D 沟槽表面，都观察到了强烈的各向异性润湿现象。采用不同气体成分（如 CHF(3)、CF(4)、O(2)）的低压等离子体处理来调整各向异性润湿性，从强烈各向异性和疏水性调整为疏水性，接触角非常高，超亲水性的各向异性润湿程度较小，且不改变结构各向异性。这些 1D 图案化表面的表面润湿性变化归因于表面化学成分的变化，通过 XPS 进行监测。此外，通过在等离子体处理后的样品上涂覆一层聚合物，可以改变 1D 图案化样品的初始各向异性润湿性能。我们还证明，通过类似的等离子体处理，可以调整 Si 衬底中 1D 沟槽表面的润湿性。在 1D 图案化表面上调整各向异性润湿性的能力将在微流控器件、芯片实验室系统、微反应器和自清洁表面等方面有广泛的应用。
