Effect of high-voltage electric field on formaldehyde diffusion within building materials

• High-voltage electric field was used to test formaldehyde diffusion within building materials.
• Formaldehyde diffusion within building materials was affected by high-voltage electric field.
• High-voltage electric field processing opens up a potential method for formaldehyde reduction in man-made boards.

An experimental study concerning the diffusion of formaldehyde within building material in different high-voltage electric fields was conducted. Formaldehyde concentration was tested under electric field intensities of 0, 33.3, 66.6 and 100 kV/m. The Capsule Concentration Footprint Method (CCFM) was proposed to analyse the resulting experimental data. It was found that both equilibrium concentration and emission rate increased under greater electric field intensity. In addition, the experimental data indicated that high-voltage electric fields have a significant effect on partition coefficient, little effect on initial concentration and nearly no influence on diffusion coefficient. The partition coefficient decreased remarkably, while initial concentrations increased slowly due to the increasing electric field intensity. A formula was obtained to explain the relationship between partition coefficient and electric field intensity. A simulation of the adsorption between the formaldehyde and building material was conducted to illustrate the decrease in adsorption potential due to the greater electric field intensity, which helps to understand the principle established by the experimental data. The results of this study confirmed the feasibility of a new method for the reduction of formaldehyde in the man-made boards.