Nanocharacterization techniques for investigating the durability of wood coatings

Nanocharacterization techniques such as nanoindentation and atomic force microscopy were used to investigate the exterior durability of waterborne coatings improved with inorganic nanosized UV-absorbers. Nanocomposite coatings for exterior uses of wood were formulated with different type of nanoparticles and their performance was evaluated trough artificial aging. Nanoindentation in continuous stiffness mode was used to demonstrate the changes of hardness and Young’s modulus of the coatings after accelerated weathering. The degradation mechanism of the surface coatings was investigated with atomic force microscopy that has provided valuable information on the morphological and microstructural changes of the surface coatings with the artificial aging. Additionally, the glass transition temperature and optical appearance changes were reported. The results obtained have shown that the nanoindentation technique in conjunction with atomic force microscopy can be satisfactorily used for durability investigation and service life prediction of nanocomposite coatings for wood.     

Themodynamic Approach to Diffusion-Controlled Epitaxial Silicon Deposition in Flow System from SiCl4 + H2 Mixtures

Treatment of diffusion-controlled chemical vapour deposition (CDV) usually neglects supersaturation at the gas-solid interface, which is the basic condition for crystal growth. A new approach based on metastable equilibria and on the concept of activity, taking into account departure from equilibrium has been given and applied to the system resulting from SiCl₄ + H₂ mixtures. The control of activity at the gas-solid interface should provide a method of controlling the morphology and perfection of CVD films.     

Morphology and Linear Viscoelasticity of Poly[ethylene‐co‐(1‐octene)]/Layered Silicate Nanocomposites

Poly[ethylene‐co‐(1‐octene)] nanocomposites with different microstructures were prepared with two kinds of organoclay by melt intercalation. X‐ray diffraction and transmission electron microscopy were used to characterize the morphology of the composites. Linear storage moduli of the composites in the melt state were found to increase greatly with increasing the extent of dispersion of silicate layers and showed an obvious sensitivity to the morphologies of the composites.