Magnetic resonance imaging of copper corrosion

[摘要] This research project studied the corrosion of copper in 0.5 M sodium chloride and 1.5 % w/v agar using magnetic resonance imaging (MRI).The imaging artefacts frequently associated with metals in the MRI were minimised in the copper corrosion system by aligning the copper strip in the cell parallel to the radio-frequency field of the spectrometer. T\(_1\) and T\(_2\) relaxation measurements of varying copper concentrations in 0.5 M sodium chloride and 1.5 % w/v agar show that the relaxation rate of proton water molecules increase with increasing copper concentration in the control samples. Diamagnetic contributions from other species apart from copper ions to the relaxivity of proton water molecules in the system were also observed. MRI was used to map spatial distribution and concentration of copper ions in electrolyte solution of sodium chloride for the first time. A time series of T\(_2\) maps of the system show reduction in spin-spin relaxation times during the corrosion process, which was attributed to increase in the concentration of copper ions in the electrolyte solution near the metal. Also, a time series of T\(_2\) maps revealed the spatial distribution of copper ions during the process of copper corrosion. The T\(_2\) concentration maps also showed how the concentration of copper ions increases as they are spatially distributed during the process. A time series of T\(_1\) maps does not show any significant variation in T\(_1\) times during the corrosion process. This was attributed to the corrosion products formed in the system.

[发布机构] University:University of Birmingham;Department:School of Chemistry

[关键词] Q Science;QD Chemistry