Changes in DRIFT spectra of wood irradiated by UV laser as a function of energy

We investigate the energy dependence of the UV laser irradiation on DRIFT spectra of wood. Changes in the spectra have been studied with 248.5 nm wavelength of UV laser radiation. To monitor the energy dependence, a different number of laser impulses were directed towards the sample's surface. It can be concluded that several chemical processes contribute to the effect of the UV laser radiation. The processes depend on several factors one of which is the amount of absorbed energy. The characteristics of wood species can be observed mainly at low energy irradiation in the changes of spectra since these characteristics disappear with increased energy, the absorption's changes have become more and more uniform. Recording the spectra of treated sample, the spectra show the degree of the surface's instantaneous degradation. The differences among the observed changes in spectra may originate from both the diversity of the original spectra (the features of wood species and surface properties) and the stage of degradation's degree of sample. Changes in absorption become less pronounced with increasing energy. (c) 2005 Elsevier B.V. All rights reserved.