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A Reversibly Switching Surface

2003; American Association for the Advancement of Science; Volume: 299; Issue: 5605 Linguagem: Inglês

10.1126/science.1078933

1095-9203

Joerg Lahann, Samir Mitragotri, Thanh-Nga Tran, Hiroki Kaido, Jagannathan Sundaram, Insung S. Choi, Saskia Hoffer, Gábor A. Somorjai, Róbert Langer,

Surface Chemistry and Catalysis

We report the design of surfaces that exhibit dynamic changes in interfacial properties, such as wettability, in response to an electrical potential. The change in wetting behavior was caused by surface-confined, single-layered molecules undergoing conformational transitions between a hydrophilic and a moderately hydrophobic state. Reversible conformational transitions were confirmed at a molecular level with the use of sum-frequency generation spectroscopy and at a macroscopic level with the use of contact angle measurements. This type of surface design enables amplification of molecular-level conformational transitions to macroscopic changes in surface properties without altering the chemical identity of the surface. Such reversibly switching surfaces may open previously unknown opportunities in interfacial engineering.