Effects of Anion Coadsorption on the Self-Assembly of 11-Acryloylamino Undecanoic Acid on an Au(111) Electrode
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide 11-acryloylamino undecanoic acid (AAUA) is a versatile polymerizable surfactant that has been applied to coat medical devices, and these applications can benefit from a fundamental understanding of its interaction with a metal substrate. Cyclic voltammetry and in situ scanning tunneling microscopy (STM) were used to examine the adsorption configuration of AAUA molecules on an ordered Au(111) electrode and their mutual interactions, as AAUA was adsorbed from a methanol dosing solution. In addition to the van der Waals force between the aliphatic groups, the hydrogen bonding between the carboxylic acid and acrylamide groups was also important to guide the spatial arrangement of AAUA admolecules on the Au electrode. The −COOH group of AAUA admolecule likely dissociated in neutral media to −COO –, which formed hydrogen bonds with H 2 PO 4 – in phosphate buffer solution (PBS). This interaction between the AAUA admolecules and ions in the electrolyte resulted in different electrochemical characteristics observed in phosphate buffer solution (PBS) and potassium sulfate (K 2 SO 4 ). Molecular-resolution STM imaging revealed distinctly different AAUA spatial structures on the Au electrode in PBS and K 2 SO 4 . Shifting the potential positively to 0.5 V (versus Ag/AgCl) led to lifting of the reconstructed Au(111) to the (1 × 1) phase and the dissolution of the ordered AAUA film, suggesting that the orientation of the AAUA admolecule was altered. The ordered AAUA adlayer could be partially recovered by shifting the potential negatively.
Source: ACS Omega
Authors: Yi-Ting Huang, Jia-Yin Chen, Chiao-An Hsieh, Yamuna Ezhumalai, Chun-Jen Huang, Shuehlin Yau
Institutions: National Central University, Chung Yuan Christian University
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,935
Award: G7914562328
OpenAlex ID: W4402402354