A reversibly switching surface.
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.
Lahann
Joerg
J
Department of Chemical Engineering, Massachusetts Institute of Technology (MIT), 45 Carleton Street, Cambridge, MA 02139, USA.
Mitragotri
Samir
S
Tran
Thanh-Nga
TN
Kaido
Hiroki
H
Sundaram
Jagannathan
J
Choi
Insung S
IS
Hoffer
Saskia
S
Somorjai
Gabor A
GA
Langer
Robert
R
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
C470761:(16-mercapto)hexadecanoic acid (2-chlorophenyl)diphenylmethyl ester; C450319:16-mercaptohexadecanoic acid; D004952:Esters; D010169:Palmitic Acids; D006046:Gold