Corrosion protection of Sunselect, a spectrally selective solar absorber coating, by (3-mercaptopropyl)trimethoxysilane

摘要: The formation of a protective layer from (3-mercaptopropyl)trimethoxysilane (MPTMS) on commercial Sunselect, cermet-based spectrally selective coating (Alanod, DE), was studied by non-electrochemical (infrared reflection–absorption—IR RA, X-ray photoelectron spectroscopy—XPS), electrochemical (cyclic voltammetry (CV) in the presence redox probe (Cd+2), and potentiodynamic (PD)) techniques. By simple immersion subsequent dip Sunselect substrate MPTMS sol, hydrolyzed precursor adsorbed substrate, forming imparting corrosion stability to salt spray chamber for at least 20 days, outperforming any other sol–gel used so far protection Sunselect. This attributed penetration into porous cermet structure through upper antireflective Sn-oxide layer, as shown XPS depth profile. Detailed analysis hydrolysis condensation reactions 29Si NMR IR spectroscopic techniques is reported. The most important finding observation that applied did not affect spectral selectivity, inferred solar absorptance increase 1% thermal emittance more than 2%.