| AVS 60th International Symposium and Exhibition | |
| Applied Surface Science | Monday Sessions |
| Session AS+BI-MoM |
| Session: | Organic Depth Profiling |
| Presenter: | G. Zorn, GE Global Research |
| Authors: | G. Zorn, GE Global Research M. Karadge, GE Global Research M.M. Morra, GE Global Research J. Davis, GE Power & Water C.C. Pierce, GE Power & Water J.I. Melzer, GE Power & Water |
| Correspondent: | Click to Email |
GE Power & Water GenGard technology is GE’s most advanced and effective water treatment technology for open recirculating cooling systems. It can be applied across a broad pH spectrum and provide superior results, even under the most stressed system conditions. The patented GenGard technology includes a new Stress Tolerant Polymer (STP) in combination with phosphate-based steel corrosion inhibitors. The GenGard technology, when used, develops complex multilayered structures that incorporate metal, ceramic and polymer, where the STP is designed to maintain phosphate-based corrosion inhibitors’ solubility. For optimal performance it is important to understand the structure, morphology and composition of different layers. However, characterizing these nano scale films is very challenging, as they can be sensitive to preparation technique and damage. Moreover, surface roughness and homogeneity of the layers should be considered.
This work is focused on the ToF SIMS study of the multilayered structures formed by the GenGard technology, with an emphasis on the STP analysis and its distribution within the inhibition layers. ToF-SIMS is capable of high detection sensitivity (ppb), very high surface specificity (analysis of the top 1-3 surface layers during date acquisition, high mass resolution (∆m/m greater than 8000 ), and is able to detect high mass molecular fragments associated with the STP. ToF SIMS allows rapid data collection while analyzing through multilayers, and provides high interfacial resolution during a depth profile measurement.
ToF SIMS depth profiling of the structures formed by the GenGard technology showed a calcium phosphate / iron oxide two layer structures on the base metal. This structure was further confirmed by Transmission Electron Microscopy (TEM) equipped with Energy Dispersive X-Ray Spectrometer (EDS). The STP that is added in ppm levels was identified in the ToF-SIMS by three high mass NaxSyOz fragments at m/z=229,245 and 261 amu. In order to eliminate the possibility that these fragments are associated with surface contamination, Ion Chromatography (IC) was performed. After identifying the STP characteristic tags, ToF SIMS depth profiling of the inhibition layers allows showing that the STP is incorporated within the entire inhibition layers at the initial steps (after 7 days) but later it starts to migrate to the surfaces of these films as they grow with time. This ToF SIMS study combined with TEM and IC provides a detailed picture of the complex structures and compositions as well as the kinetic behavior of the inhibition films formed by the GenGard technology.