Fabrication of Multiscale Surface-Chemical Gradients by Means of Photocatalytic Lithography

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• 作者：Nicolas Blondiaux ; Stefan Zü ; rcher ; Martha Liley ; Nicholas D. Spencer
• 刊名：Langmuir
• 出版年：2007
• 出版时间：March 27, 2007
• 年：2007
• 卷：23
• 期：7
• 页码：3489 - 3494
• 全文大小：268K
• 年卷期：v.23,no.7(March 27, 2007)
• ISSN：1520-5827

文摘

We describe a new method for the fabrication of surface-chemical gradients. A film of titanium dioxide is broughtinto close proximity to a uniformly monolayer-covered surface and exposed to UV light to produce oxygen radicals.The use of a gradated grayscale mask between the UV source and the TiO₂ allows the production of surface-chemicalgradients via oxidation of the monolayer. The technique is demonstrated on gold surfaces bearing alkanethiol SAMs.Oxidation and subsequent replacement of the oxidized thiols has been used to produce surface-chemical gradientswith lengths on the submillimeter to centimeter scales. The oxidation, removal, and replacement of the thiols duringthe process have been demonstrated by means of XPS. This oxidative process may be applied to other surfacechemistries. Similarly, other shapes and slopes of gradients may be produced, depending on the photomask employed.