Xps Analysis Carbon Film On Phosphorus Deoxidized Copper Tube

The copper tubes of heat exchangers used in air conditioning and sanitation equipment have been reported to show type I pitting corrosion due to the synergistic effects of carbon film and water quality. To quantify the carbon film, the inner surfaces of the tubes after degreasing with acetone are dissolved with a mixture of nitric and hydrochloric acid to allow collection and analysis of the attached carbon. However, there are concerns about the difficulty and danger of the conventional procedure. Therefore, a simple method for quantifying carbon film is required. We reported a method for measuring the difference between the corrosion potentials on the inside with attached carbon film and outside with removed carbon film of copper tubes. However, data variation is observed in medium residual carbon, which is thought to be due to uneven carbon film. In this study, we examined the correlation between residual carbon and composition of surface for X-ray photoelectron spectroscopy (XPS) measurement. The results confirmed that the peak of C is increased and Cu 2p(3/2) decreased with increasing residual carbon. As the residual carbon and the integrated intensity at C is in the same way showed a linear relation, the residual carbon can be determined by the XPS measurement.