Application of the ESEM technique in wood research. Part II. Comparison of operational modes

An ESEM (Environmental Scanning Electron Microscopy) technique has been applied to wood objects. ESEM investigations were performed through several operational modes that offer various sets of environmental and imaging conditions. The comparison of ESEM micrographs with conventional SEM images revealed specific advantages and shortcomings of the ESEM technique in studies on genuine and painted wood objects. Merits of the application of ESEM technique for wood are related to the absence of preparation artifacts, such as sputtering irregularities or defects due to shrinkage in vacuum drying. Great ESEM advantage over high-vacuum SEM, such as conduction of dynamic experiments within the chamber, is illustrated with a sequence of condensation, freezing, and drying on a wood specimen. The wood imaging using ESEM proved inferior to that of c onventional SEM in terms of lower magnification, sharpness, and contrast. However, the article offers guidance for assessment of influential operating parameters and their selection for the optimization of the ESEM work with wood. It may result in micrographs of sufficient resolution, definition, and optical quality for study of wood structure on cellular and even intra-cellular level.