1:30 PM - 3:30 PM
▲ [25p-P03-7] Local Cross-Coupling Activity of Azide-terminated Self-Assembled Monolayers Investigated by Frequency Modulation Atomic Force Microscopy in Liquid
Keywords:soft material
Self-assembled monolayers with terminal azide (N3) and oligo(ethylene glycol) (OEG) units are promising interfacial structures for surface functionalization. The azide group serves as site for cross-coupling and the OEG unit is expected to provide non-specific adsorption resistance. Despite its many potential applications, such as in sensors and surface model construction, there are limited information particularly on the molecular-scale structures and local cross-coupling activities of N3-OEG-SAMs that are essential to understanding its surface properties and molecular design.
In this study, frequency modulation atomic force microscopy (FM-AFM) in liquid was employed to investigate the molecular-scale surface structures and the cross-coupling activity of azide-hexa(ethylene glycol)-terminated SAMs (N3-EG6-SAMs). Subnanometer-resolution surface structures were visualized in an aqueous solution using a laboratory-built FM-AFM instrument. The results showed N3-EG6-SAMs with well-ordered molecular arrangement, clean surface and its nanometer-scale defects. Moreover, copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction on N3-EG6-SAMs revealed additional island-shaped structures and fluctuating structures, which give information on the local cross-coupling activity of N3-EG6-SAMs. The FM-AFM investigation was able to provide molecular-scale information on surface structures and functionalization of N3-EG6-SAMs, which are important for interfacial molecular design of alkanethiol-based SAMs in many applications.
In this study, frequency modulation atomic force microscopy (FM-AFM) in liquid was employed to investigate the molecular-scale surface structures and the cross-coupling activity of azide-hexa(ethylene glycol)-terminated SAMs (N3-EG6-SAMs). Subnanometer-resolution surface structures were visualized in an aqueous solution using a laboratory-built FM-AFM instrument. The results showed N3-EG6-SAMs with well-ordered molecular arrangement, clean surface and its nanometer-scale defects. Moreover, copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction on N3-EG6-SAMs revealed additional island-shaped structures and fluctuating structures, which give information on the local cross-coupling activity of N3-EG6-SAMs. The FM-AFM investigation was able to provide molecular-scale information on surface structures and functionalization of N3-EG6-SAMs, which are important for interfacial molecular design of alkanethiol-based SAMs in many applications.