Nanocomposites and nanomaterials
Application of nanoparticles of metal oxides In wooden building materials
Lopatko L.S, PinchevskaO.O.
National University of Life and Environmental Sciences of Ukraine Heroyiv Oborony st., 15, Kyiv - 03041, Ukraine
E-mail:asp21-l.lopatko@it.nubip.edu.ua
Wood is a natural, environmentally friendly building material that accumulates carbon. Making products from it requires less energy. Despite its many benefits, wood is very sensitive to biological attacks and external factors. One of the ways to increase the service life of wood products is the use of nanoparticles, in particular alumina (Al2O3) and silica (SiO2), etc. Recently, the use of nanoparticles in the construction sector has become significantly more widespread. Reuse of nanoparticle concrete has shown its durability advantage and enhanced mechanical properties compared to fresh concrete. There is experience in the use of Al2O3 nanoparticles in the production of medium density fiberboard (MDF) by adding them to synthetic adhesives, which has improved mechanical and physical properties. The efficiency of using Al2O3 nanoparticles as a sorbent for removing residual formaldehyde from urea-formaldehyde resin has been proved.
Nanoparticles of colloidal solutions obtained by electro-spark treatment of the corresponding metals have a positive effect. The thus obtained particles with a size of 20–100 nm have a competitive advantage over powder forms because they use water as a base. Because most metals are good conductors of heat, nanoparticles increase the conductivity of wood-based materials, which reduces time holding pressure.
High Pressure Laminate (HPL) panels, which are used for facing public buildings and private homes, have become very popular among wood composites. HPL consists of 5-50 layers of kraft paper (core) saturated with phenol-formaldehyde (PF) adhesive, the top layer is made of decorative paper and covered with a finish saturated with melamine-formaldehyde (MF) adhesive. After build-up, these layers become a single rigid laminated sheet under the influence of high literature and pressure, and PF and MF adhesives undergo a series of crosslinking reactions, thus creating strong irreversible bonds between the adhesive matrix and the impregnated layers of paper.
Laminate manufacturers are looking to develop HPLs that include new and combined features to gain a competitive edge in national and international markets. The use of metal nanoparticles in their production will make the panels more resistant to external factors, strengthen the internal structure, reduce toxicity by binding unreacted formaldehyde and reduce production time.