摘要
We report a large-scale surface with continuously varying wettability induced by ordered gradient nanostructures.The gradient pattern is generated from nonuniform interference lithography by utilizing the Gaussian-shaped intensity distribution of two coherent laser beams.We also develop a facile fabrication method to directly transfer a photoresist pattern into an ultraviolet(UV)-cured high-strength replication molding material,which eliminates the need for high-cost reactive ion etching and e-beam evaporation during the mold fabrication process.This facile mold is then used for the reproducible production of surfaces with gradient wettability using thermal-nanoimprint lithography(NIL).In addition,the wetting behavior of water droplets on the surface with the gradient nanostructures and therefore gradient wettability is investigated.A hybrid wetting model is proposed and theoretically captures the contact angle measurement results,shedding light on the wetting behavior of a liquid on structures patterned at the nanoscale.
基金
This work was partially supported by the General Research Fund of the Research Grants Council of the Hong Kong Special Administrative Region(Award Numbers 17207419 and 17246116)。
