Zhang Fengxiang, Low Hong Yee
Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602.
Langmuir. 2007 Jul 3;23(14):7793-8. doi: 10.1021/la700293y. Epub 2007 Jun 1.
A series of two-level hierarchical structures on polystyrene (PS) and poly(methyl methacrylate) (PMMA) were fabricated using sequential nanoimprinting lithography (NIL). The hierarchical structures consist of micrometer and sub-micrometer scale grating imprinted with varying orientations. Through water contact angle measurements, these surface hierarchical structures showed a wide range of anisotropic wettabilities on PMMA and PS, with PMMA having an anisotropic wettability from 6 degrees to 54 degrees and PS having an anisotropic wettability from 8 degrees to 32 degrees. At the same time, the water contact angle of PMMA and PS can be tuned to nearly 120 degrees without modifying the surface chemistry. A tunable anisotropic wettability is beneficial for applications where controlling the direction of liquid flow is important, such as in microfluidic devices.
利用顺序纳米压印光刻技术（NIL）在聚苯乙烯（PS）和聚甲基丙烯酸甲酯（PMMA）上制备了一系列两级分层结构。这些分层结构由具有不同取向的微米级和亚微米级光栅组成。通过测量水接触角，这些表面分层结构在PMMA和PS上表现出广泛的各向异性润湿性，其中PMMA的各向异性润湿性为6度至54度，PS的各向异性润湿性为8度至32度。同时，在不改变表面化学性质的情况下，PMMA和PS的水接触角可调节至近120度。可调谐的各向异性润湿性对于控制液体流动方向很重要的应用（如微流控装置）是有益的。
