Interaction of copper-containing preservatives with wood. Part 1. Mechanism of the interaction of copper with cellulose

In the present work. the stare of the copper ions absorbed by cellulose fro m aqueous solutions with different pH values has been studied by electron s pin resonance (ESR), X-ray photoelectron spectroscopy (XPS) and energy-disp ersive X-ray analysis (EDXA) methods, It has been shown that the curve of c opper sorption has a S-like shape characteristic for weak acid sorbents. At all pH values in ESR-spectra, an anisotropic Cu(II)-signal is registered. At pH >4, the anisotropy of ESR-spectra decreases. At pH = 10, complexes co nnected by exchange interactions and diamagnetic clusters are formed. After the leaching of specimens, the ESR-signal practically disappeared. The dec rease of the copper content in cellulose did not correlate with the change of the integral intensity of the spectra. The changes in ESR-spectra of cop per-containing cellulose after leaching were explained by the formation of the Cu(II) diamagnetic clusters.