Application of Laser-Induced Breakdown Spectroscopy (LIBS) as an Attempt to Determine Graphene Oxide Incorporation on Wood Surfaces

Wood modification with graphene oxide can give it unique features characteristic of other materials. However, the durability of the newly acquired features is of great importance. To better understand them, it is worth conducting an in-depth analysis of the structural changes that occur in wood under the influence of modification with graphene oxide. As part of the research, wood was impregnated with aqueous graphene oxide dispersion. Wood was impregnated using two methods: single vacuum and pressureless with ultrasound. Laser-assisted ionization spectroscopy (LIBS) was used to determine elements, mainly carbon, and to characterize differences in the elemental composition between the surface layers of wood impregnated with graphene oxide and native wood. Changes in the structure of polymers building wood tissue were analyzed using LIBS and FTIR spectrometry. The wood surface was also imaged using three microscopic techniques (stereomicroscope, confocal laser scanning microscope, and scanning electron microscopy). LIBS showed that graphene oxide was deposited on the surface of impregnated wood, and the intensity of carbon signals in wood impregnated with graphene oxide using vacuum and ultrasound differed. The content of carbon, magnesium, and oxygen elements in the surface layers of wood impregnated with graphene oxide using ultrasound was lower than in vacuum-impregnated wood. Analysis of FTIR spectra showed effective incorporation of graphene oxide into the surface layer of wood.