Lan Thi Phan Park, Sang Jin Moon, Myoung-Woon 2024-01-19T13:01:33Z 2024-01-19T13:01:33Z 2022-04-03 2022-01 0169-4332 https://pubs.kist.re.kr/handle/201004/115843 Two levels of nanostructures, consisting of slanted nanostructure and nanogroove, were fabricated on polymeric surface through a single step oxygen plasma processing with tuning incident angles. A polymeric sheet embedded with the SiO2 nanospheres was exposed to the oxygen plasma through Faraday cages to induce anisotropic etching. The nanopillars were slanted by changing the relative angle between plasma ions and polymer substrate from 10 to 80 degrees. The nanogrooves were also formed among the slanted nanopillars along the trajectory of plasma ions. Together with the nanogrooves, the slanted nanopillars enhanced unidirectional water spreading. The wetting behaviors, with gradual transformation through four stages with different degree of hydrophilicity (super-, strong, moderate, and mild hydrophilicity), were observed. The surface with moderate hydrophilicity showed strong asymmetric wetting for unidirectional water spreading, against the gravity force, at very high velocity (up to 1.5 similar to 4.17 mm/sec). This easy and simple fabrication method of slanted nanostructures could be utilized in a wide range of applications requiring long-lasting hydrophilicity with asymmetric wetting, such as, microfluidic, oil-water separation, water-harvesting, and biomedicines. English Elsevier BV Slanted nanostructures capped with SiO2 nanospheres for asymmetric hydrophilicity inducing rapid unidirectional water spreading Article 10.1016/j.apsusc.2021.151625 1 Applied Surface Science, v.573 Applied Surface Science 573 N scie scopus 000724787700001 2-s2.0-85117715023 Chemistry, Physical Materials Science, Coatings & Films Physics, Applied Physics, Condensed Matter Chemistry Materials Science Physics Article HYDROPHOBIC RECOVERY PERISTOME SURFACE SUPERHYDROPHOBICITY CRYSTALLINITY TRANSPORT MODEL Directional plasma etching Slanted nanostructures Asymmetric hydrophilicity Unidirectional water spreading