Surface modification and characterization of impregnated paper

• Published in: Applied surface science 2012-03, Vol.258 (10), p.4678-4686
• Main Authors: Wang, Shaoxia, Mahlberg, Riitta, Kaukoniemi, Otto-Ville, Nikkola, Juha, Mannila, Juha, Jämsä, Saila, Ritschkoff, Anne-Christine, Peltonen, Jouko
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Impregnated paper; Physics; Sol–gel coating; Surface chemistry; Surface energy; Surface morphology; Water repellence
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2012.01.060

► We developed two silane-based nano-hybrid coatings to improve the water repellence of PF (phenolic resin) impregnated paper. ► We characterized the surface structure and chemistry of the sol–gel coatings on impregnated paper. ► We found the wettability and surface energy of impregnated paper were clearly reduced by the applied coatings. Two organic–inorganic hybrid sol–gel coatings were developed in order to modify the surface energy and moisture behaviour of the commercial impregnated paper. The surface characteristics of the paper samples were studied by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectroscopy (ToF-SIMS). It was found that the applied sol–gel coatings as well as the curing process changed the surface structural and chemical properties of the impregnated paper. The chemical bonding between the hydroxyl groups present on paper surface and silanol groups from sol–gel coatings was confirmed by the FTIR spectra. The measured surface energies divided into polar and dispersive components indicated that the coating B resulted in less polar surface than did the coating A which was more polar than the reference (the impregnated paper with water and heat treatment). Coating B brought about the lowest total surface energy. It was obtained that the water repellence of the impregnated paper was improved by both coatings and the curing process.