ABSTRACT
In this work we have studied the diffusion of some typical microbe metabolic gases through building moisture barrier foils. The objective of this research is to achieve basic building physical information about diffusion in order to design the repairs of microbiological damage in buildings.
These gaseous test chemicals were chosen so that the effects of the size of molecules as well as the effects of their other properties could be studied upon the rate of diffusion.
Low concentrations of gaseous volatile organic compounds (VOC) were introduced into the β-diffusion chamber and were let to diffuse freely into the α-chamber. Gas samples from both chambers were collected and the samples were analyzed by the means of automatic thermal desorption gas chromatographic mass spectrometer. The values found as function of time to VOC-concentrations in both chambers were then applied to the calculation of the diffusion coefficients.
The results show that even at very low concentrations the gases used in this study tended to diffuse through polyethene (PE) foils and the diffusion is observed to be significant. The rates of the diffusion coefficients seem to depend both on the size and on the type of the diffusive compound. On the other hand the diffusion through polyethylene foil laminated with thin layer of polyamide (PE/PA) is almost non-existent.
