Lahann Joerg, Mitragotri Samir, Tran Thanh-Nga, Kaido Hiroki, Sundaram Jagannathan, Choi Insung S, Hoffer Saskia, Somorjai Gabor A, Langer Robert
Department of Chemical Engineering, Massachusetts Institute of Technology (MIT), 45 Carleton Street, Cambridge, MA 02139, USA.
Science. 2003 Jan 17;299(5605):371-4. doi: 10.1126/science.1078933.
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.
我们报道了一种表面的设计，这种表面能够响应电势而呈现出界面性质（如润湿性）的动态变化。润湿行为的改变是由表面受限的单层分子在亲水性和适度疏水性状态之间进行构象转变引起的。通过和频振动光谱在分子水平以及通过接触角测量在宏观水平上证实了可逆的构象转变。这种类型的表面设计能够将分子水平的构象转变放大为表面性质的宏观变化，而不改变表面的化学特性。这种可逆切换表面可能会在界面工程领域带来前所未有的机遇。
