In-situ chemical grafting of aminophenyl and RGD peptide on an equimolar high-entropy HfNbTaTiZr alloy: electrochemical behavior and surface characterization
摘要
The in-situ chemical grafting conditions of aminophenyl on an equimolar high-entropy HfNbTaTiZr alloy were optimized using an experimental design strategy. A fluorescent ArgGlyAsp peptide molecule was also synthesized and mounted on the grafted aryl group layer as a preliminary investigation toward further alloy biofunctionalization. The chemical composition, anti-corrosion performance and thickness of the aminophenyl/peptide layers were analyzed by X-ray photoelectron spectroscopy (XPS), electrochemistry and transmission electron microscopy (TEM) coupled with energy diseprsive spectrometry (EDS). The grafted aminophenyl and aminophenyl + peptide layers were both inhomogeneous with thicknesses varying between ~ 35 nm and ~ 400 nm and ~ 300 nm and ~ 1250 nm, respectively. The grafted layers did not improve the corrosion potential of the alloy, while compared to the bare alloy, the measured impedance values and anodic current densities of the treated alloys were found to be larger and lower, respectively. Finally, this article presents the first high-resolution microscopic images of a deposited diazonium-based/peptide coating on a solid surface.