ADSORPTION OF WATER ON COPPER, NICKEL, AND IRON

In atmospheric corrosion of copper, nickel and iron, adsorption of wat er affects corrosion rates. Knowledge of water adsorption and metal ox yhydroxide formation is important in understanding the atmospheric cor rosion process. The quartz-crystal microbalance (QCM) technique was us ed to measure mass changes of copper, nickel, and iron at 0% to 100% r elative humidity (RH) and 7 degrees C to 90 degrees C under nitrogen ( N-2) and air environments. Less water was adsorbed on copper, nickel a nd iron that formed oxides than on gold, me amount of water adsorption was similar on copper, nickel, and iron under N-2 and air carrier gas es. Shapes of isotherms suggested physical adsorption, capillary conde nsation. and pore filling occurred on all metals and were more signifi cant at higher temperatures, Adsorption isotherms were Type III and Ty pe IV according to the Brunauer-Emmett-Teller (BET) classification.