title: Multiparametric characterization of nonelectroactive self-assembled monolayers during their formation.
abstract: The formation of nonelectroactive self-assembled monolayers (SAMs) at the electrode/electrolyte interface was characterized with simultaneous impedance, gravimetric, and direct current measurements. In the presence of specifically adsorbing inorganic ions, this provides key information about the formation of SAMs. Gravimetric measurements allow an estimation of the adsorbate surface coverage; and completion of the assembly process can then be monitored in real-time. Electrochemical impedance spectroscopy measurements play a multifunctional role: they enable elucidation of the physical models of the interface, provide the information about the effective capacitance of SAMs thus probing the dielectric properties of the adsorbed layers, and evaluate the ability of charged electrolyte components to approach the electrode surface through the SAM (using adsorbing/desorbing SO4(2-) as an electroactive probe). The latter is important to assess the extent of defects in the formed organic layers. Finally, monitoring the direct current during SAM formation together with the collected gravimetric data can give additional important information about the process. A series of n-mercaptoalcohols with different hydrocarbon chain length adsorbing at Au electrodes was used as the model object to evaluate the proposed approach.
authors.affiliation: Institute of Organic Chemistry and Biochemistry and Gilead Sciences Research Center, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague, Czech Republic.
authors.forename: Malte
authors.initials: M
authors.lastname: Kokoschka
authors.forename: John B
authors.initials: JB
authors.lastname: Henry
authors.forename: Aliaksandr S
authors.initials: AS
authors.lastname: Bandarenka
mesh_terms: D000327:Adsorption; D000438:Alcohols / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006838:Hydrocarbons / Q000737:chemistry*; D008958:Models, Molecular; D013431:Sulfates / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000438:Alcohols; D004573:Electrolytes; D006838:Hydrocarbons; D013431:Sulfates; D006046:Gold