X-ray photoelectron spectroscopy study of red oak- (Quercus rubra), black cherry- (Prunus serotina) and red pine- (Pinus resinosa) extracted wood surfaces

The X-ray photoelectron spectroscopy (XPS) study of black cherry (Prunus serotina), red oak Quercus rubra), and red pine (Pinus resinosa) wood samples extracted with ethanol, ethanol - toluene, and water was conducted to evaluate chemical modifications occurring on the wood surface due to wood extractives, and derive possible implications for wood utilization. Results obtained indicate an increase in the O/C values following extraction treatments due to the partial removal of high carbon content extractives. The C 1s peaks indicated a decrease in the area of the C1 peak, known to originate from lignin and extractives following extraction. At the same time, a rise in the C-2 peak (mainly originating from cellulose and hemicelluloses) was observed, indicating that more cellulose was exposed on the wood surface following extraction. The O 1s peaks showed an increase in the O-1 peak originating from cellulose, therefore confirming the trend observed for C 1s peaks. These results suggest that extracted wood is more wettable because of the increased exposure of high-oxygen-content cellulose molecules, known to be more hydrophilic than lignin and high carbon content extractives. Copyright (c) 2005 John Wiley & Sons, Ltd.