title: A reversibly switching surface.
abstract: 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.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology (MIT), 45 Carleton Street, Cambridge, MA 02139, USA.
authors.forename: Joerg
authors.initials: J
authors.lastname: Lahann
authors.forename: Samir
authors.initials: S
authors.lastname: Mitragotri
authors.forename: Thanh-Nga
authors.initials: TN
authors.lastname: Tran
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kaido
authors.forename: Jagannathan
authors.initials: J
authors.lastname: Sundaram
authors.forename: Insung S
authors.initials: IS
authors.lastname: Choi
authors.forename: Saskia
authors.initials: S
authors.lastname: Hoffer
authors.forename: Gabor A
authors.initials: GA
authors.lastname: Somorjai
authors.forename: Robert
authors.initials: R
authors.lastname: Langer
mesh_terms: D000327:Adsorption; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004560:Electricity; D004563:Electrochemistry; D004952:Esters; D006046:Gold; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008968:Molecular Conformation; D015394:Molecular Structure; D010169:Palmitic Acids / Q000737:chemistry*; D013057:Spectrum Analysis; D013499:Surface Properties; D013816:Thermodynamics; D017155:Wettability
chemical_list: C470761:(16-mercapto)hexadecanoic acid (2-chlorophenyl)diphenylmethyl ester; C450319:16-mercaptohexadecanoic acid; D004952:Esters; D010169:Palmitic Acids; D006046:Gold