Flame retardancy of wood coated by ZnO nanorod arrays via a hydrothermal method

Abstract

In the present paper, ZnO nanorod arrays (ZNAs) coating was covered onto wood surface via a hydrothermal method to improve wood flame retardancy. With the scanning electron microscopy, X-ray diffraction and energy disperses X-ray analysis characterisations, a wurtzite structured ZNAs with a length of ∼1·5 μm were densely coated onto the wood surface. Using the cone calorimetry technique, the significant difference in combustion parameters between the untreated and the ZNAs coated wood was observed. In comparison to the untreated wood, the time to ignition was increased about three times, and the burning time of ZNAs coated wood was extended by 55 s. Simultaneously, the heat release rate, total heat release, total smoke production and production of CO, CO₂ (COP, CO₂P) were significantly reduced. As a result, the thin ZNAs coating could be effectively acted as a protective layer for wood and convert wood from a flammable material into a non-flammable material.

Keywords:

• Flame retardancy
• ZnO nanorod arrays
• Wood
• Cone calorimetry
• Hydrothermal method

This work was supported by the Breeding Plan of Excellent Doctoral Dissertation of Northeast Forestry University (grant no. GRAP09), the Programme of Introducing Talents of Discipline to Universities of China (grant no. B08016).