کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9595782 1507984 2005 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Surface morphology and wetting properties of surfaces coated with an amphiphilic diblock copolymer
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Surface morphology and wetting properties of surfaces coated with an amphiphilic diblock copolymer
چکیده انگلیسی
X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and dynamic wetting measurements with the Wilhelmy plate method were used to characterize layers of three polystyrene-b-poly(acrylic acid) (PS-PAA) diblock copolymers (differing by their block lengths) created by dip coating or spin coating on glass and gold substrata. The copolymer layers were thick and continuous, whatever the substratum, with a preferred exposure of PS chains at the extreme surface for the copolymers with a small PS block. The surface roughness decreased as the PAA/PS block length ratio increased and was larger for dip-coated than for spin-coated layers. The dip-coated layers obtained with the copolymer with the large PAA block presented self-assembled nanostructures of worm-like type. Dynamic wetting measurements showed that the coated layers were able to reorganize, upon immersion-emersion in solution at different pH, due to the deprotonation and swelling of the PAA chains. This phenomenon was dependent on the block length and on the pH. A water contact angle typical of pure PS was obtained with the large PS block. A hydrophilic surface was obtained for the large PAA block after immersion at pH 11. In intermediate situations (large PAA block in water, large PS block at pH 11), the advancing contact angle was dependent on the time of contact with air subsequent to the preceding immersion. This demonstrates the possibility to modulate hydrophobicity-hydrophilicity switching and pH sensitivity of the coatings by the copolymer composition.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 575, Issues 1–2, 20 January 2005, Pages 125-135
نویسندگان
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