Studies of the mechanism of chromated-copper preservative. Fixation using electron spin resonance

IRG/WP 92-3701

K Yamamoto, J N R Ruddick

Two softwoods and one hardwood species were treated with chromium trioxide, copper sulphate, chromated-copper wood preservative (CCA). The treated wood samples were analyzed during fixation by electron spin resonance (ESR). ESR spectra indicated that more than one Cr(V) species was generated from Cr(VI) soon after CCA treatment. The Cr(V) signal became strong within increased several hours followed by the gradual decay of Cr(V) accompanying with generation of single broad Cr(III) species. Cr(V) signal still remained at least up to six months after the treatment. ESR spectral parameters from Cu(II) signal consisted of a quadruplet at lower field with a unresolved absorption of higher field, suggesting a evidence of a dX²-Y² ground state of Cu2+ ions bound in inner-sphare complexes with "O4" ("O6") ligands arranged in square planar cordination (distorted octahedral) cordination. Cu(II) signal did not change significantly during fixation.


Keywords: FIXATION; MECHANISM OF FIXATION; CCA; CHROMIUM TRIOXIDE; COPPER SULPHATE; CC; ESR; Cr(III); Cr(V); Cr(VI); Cu(II); CRYPTOMERIA JAPONICA; ANTHOCEPHALUS CADAMBA; TSUGA HETEROPHYLLA

Conference: 92-05-10/15 Harrogate, England, UK


Download document (599 kb)
free for the members of IRG. Available if purchased.

Purchase this document