Study on the surface dissociation properties of 6-(10-mercaptodecaoxyl)quinoline self-assembled monolayer on gold by chemical force titration
Date of Issue1999
School of Materials Science and Engineering
Chemical force microscopy (CFM) was used to measure the adhesion force between quinolyl group (–Q)-terminated Au-coated tip and gold substrate (abbreviated as –Q/–Q) modified with self-assembled monolayers (SAMs) of 6-(10-mercaptodecaoxyl)quinoline (MDQ) in pH buffer solution. From the plot of adhesion force vs. pH value, which is called force titration curve, the pK1/2 of surface –Q group of MDQ SAM can be estimated to be 5.3, which corresponds to the pH value at the peak. By using the –OH group as a general probe, the similar pK1/2 value, estimated from the force titration curve of –OH/–Q and –Q/–OH, which also corresponds to the pH at the peak, is 5.2 and 5.4, respectively. From the conventional contact angle titration, pK1/2=5.9 was obtained. The difference of the obtained pK1/2 values arises from two different measurement methods and their measurement accuracies.
Materials Science and Engineering: C
© 1999 Elsevier Science S.A. This is the author created version of a work that has been peer reviewed and accepted for publication by Materials Science and Engineering C, Elsevier. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/S0928-4931(99)00046-6].