Fig 1.
XFM map of the copper and iron concentrations showing the µXANES scan locations in the "control" (★) and "corrosion" (+) regions for MCQ treated wood in contact with a steel fastener for 1 year; the normalized X-ray absorption coefficient is provided for each group at the bottom of the figure.
(Note, the lines presented represent the mean μ(E) at each energy for all locations sampled). The signal at 8983 eV (vertical line) is proportional to the amount of Cu+ in the sample, see “Calculation of Copper Oxidation States”.
Table 1.
Preservatives examined in this study along with their composition and total retention.
Fig 2.
(a) Cu+ and Cu++ standards used to evaluate oxidation states in the study. (b) Difference spectra. The vertical line is at 8983eV and is the energy used to determine the fraction of Cu+ in the unknown samples.
Fig 3.
(a) XANES spectra of the preservative systems examined 1-day after treatment compared to the CuCO3 standard. (b) Difference spectra between the normalized μ(E) data and the CuCO3 standard; the vertical line is at 8983 eV and used to calculate Ex in Eq 1.
Fig 4.
XANES patterns for three preservative systems as a function of time.
The left column presents the normalized X-ray absorption coefficient; data are vertically offset for clarity. The right column presents difference spectra where the CuCO3 data have been subtracted from the data in the left column. From top to bottom the preservatives are chromated copper arsenate (CCA), copper azole (CA), and micronized copper azole (MCA). For MCA measurements the line shaded as “1w” was taken after 5 days and no measurement was taken at 1 month. The vertical line is at 8983 eV and used to calculate Ex in Eq 1.
Fig 5.
Difference spectra between the normalized μ(E) data and the CuCO3 standard after a 1 year field exposure test; the vertical line is at 8983 eV and used to calculate Ex in Eq 1.
Fig 6.
Difference spectra where the normalized X-ray absorbance of CuCO3 was subtracted from that collected from wood in contact with steel fasteners in a 1-year exposure test [6].
Red curves were collected as part of the current study and the blue curves (labeled “µXANES”) were collected in a previous study [26]. The vertical line is at 8983 eV and used to calculate Ex in Eq 1.
Fig 7.
Difference spectra where the normalized X-ray absorbance of CuCO3 was subtracted from that collected from wood in contact with hot-dip galvanized (zinc coated) fasteners in a 1-year exposure test [6].
Red curves were collected as part of the current study and the blue curves (labeled “µXANES”) were collected in a previous study [26]. The vertical line is at 8983 eV and used to calculate Ex in Eq 1.