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Title: Atomic force microscopy evidence of citrate displacement by 4-mercaptopyridine on gold in aqueous solution
Authors: Zhang, Hua
He, Hui-Xin
Wang, Jian
Liu, Zhong-Fan
Keywords: DRNTU::Engineering::Materials
Issue Date: 2000
Source: Zhang, H., He, H. X., Wang, J., & Liu, Z. F. (2000). Atomic force microscopy evidence of citrate displacement by 4-mercaptopyridine on gold in aqueous solution. Langmuir, 16(10), 4554-4557.
Series/Report no.: Langmuir
Abstract: The displacement adsorption process of 4-mercaptopyridine (4-MP) on trisodium citrate preadsorbed gold surface in aqueous solution was studied using atomic force microscopy (AFM). The measurement was done by monitoring the interaction force between a gold-coated AFM tip and a gold substrate, both presaturated by trisodium citrate. The addition of 4-MP was found to result in a remarkable change of tip−substrate adhesion force, which showed a gradual increase and finally reached a maximum. Using the chemical force titration technique, we estimated the surface pK1/2 of thus-formed 4-MP displacement film and compared with pure 4-MP self-assembled monolayer (SAM) formed on gold in ethanol solution. Our results indicate that the 4-MP molecules are more strongly adsorbed on gold than citrate anions, mostly via Au−S bonding, forming a less dense and mixed displacement film. The displacement adsorption kinetics seems very fast and it takes only ca. 2 min to establish more than 50% surface coverage of 4-MP molecules.
ISSN: 0743-7463
DOI: 10.1021/la9904657
Rights: © 2000 American Chemical Society.
Fulltext Permission: none
Fulltext Availability: No Fulltext
Appears in Collections:MSE Journal Articles


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