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báo cáo hóa học:" Effective surface oxidation of polymer replica molds for nanoimprint lithography"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Effective surface oxidation of polymer replica molds for nanoimprint lithography | Ryu et al. Nanoscale Research Letters 2012 7 39 http www.nanoscalereslett.eom content 7 1 39 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Effective surface oxidation of polymer replica molds for nanoimprint lithography Ilhwan Ryu Dajung Hong and Sanggyu Yim Abstract In nanoimprint lithography a surface oxidation process is needed to produce an effective poly dimethylsiloxane coating that can be used as an anti-adhesive surface of template molds. However the conventional photooxidation technique or acidic oxidative treatment cannot be easily applied to polymer molds with nanostructures since surface etching by UV radiation or strong acids significantly damages the surface nanostructures in a short space of time. In this study we developed a basic oxidative treatment method and consequently an effective generation of hydroxyl groups on a nanostructured surface of polymer replica molds. The surface morphologies and water contact angles of the polymer molds indicate that this new method is relatively nondestructive and more efficient than conventional oxidation treatments. Introduction Recently nanoimprint lithography NIL has attracted increasing attention as a facile technique for patterning polymer nanostructures 1-3 . The principle of NIL is very simple and described in detail elsewhere 1 . A hard mold with nanoscale surface-relief features is pressed onto a polymer cast at controlled temperature and pressure which creates replica patterns on the polymer surface. Mold materials normally used for NIL include silicon silicon dioxide silicon nitride or metals such as nickel and the surface nanostructures are typically fabricated using various lithographic electrochemical and etching techniques 1 4-6 . While these conventional inorganic molds are thermally and mechanically stable 7 they often easily break due to their stiffness when pressed or removed. The large mismatch of thermal expansion between stiff inorganic molds and polymeric .