Fungal durability of polyaniline modified wood and the impact of a low pulsed electric field

• Anti-fungal effect of polyaniline and a pulsed electric field is examined.
• Polyaniline is homogeneously polymerized in the wood samples.
• Both systems alone and in combination reduce the degradation of wood samples.
• pH is reduced by the treatment, which effects negatively the fungal degradation.
• Conductivity of treated wood is influenced by leaching and fungal exposure.

New wood protection technologies should be effective against biodeterioration and at the same time minimize environmental impact. The present study investigates the effect of polyaniline modification of wood and the effect of a pulsed electric field on fungal protection. The effect of fungi and a pulsed electric field on the conductivity of the modified wood was also measured.It was found that it is possible to polymerize polyaniline particles in-situ homogeneously throughout the wood specimens. The polyaniline particles themselves were not found to be anti-fungal, however when in contact with water they affected the pH drastically and inhibited fungal growth. The wood treatment with polyaniline and the connection to a pulsed electric field were found to be effective in protecting the wood from deterioration when exposed to Postia placenta. The unmodified samples that were connected to a pulsed electric field lost under 10 wt% due to fungal degradation. The combination of polyaniline treatment with the connection to a pulsed electric field showed a slight synergistic effect which resulted in less weight loss due to fungal degradation. However, a more brittle wood structure was observed.Leached and fungal exposed samples showed a significant drop in the conductivity, indicating that the network has broken down slightly.