**4. Conclusions**

(a) (b)

(c)

**Figure 4.** Changes in relative electrical resistance of nonwoven fabrics subject to toluene vapours at 200 ppm: a) 98%

(a) (b)

(c)

**Figure 5.** Changes in relative electrical resistance of nonwoven fabrics subject to benzene vapours at 200 ppm: a) 98%

PLA 4060D/2% MWCNT, b) 97% PEO/3% MWCNT, c) carbon (precursor 15% PAN/85% DMSO)

PLA 4060D/2% MWCNT, b) 97% PEO/3% MWCNT, c) carbon (precursor 15% PAN/85% DMSO)

272 Non-woven Fabrics

This paper has shown the possibility of using nonwoven fabrics as sensors to detect organic vapours. The results show that electrospinning and melt blowing for nonwoven fabric formation comprising a composite system made of a polymer matrix reinforced with MWCNT (98% PLA 4060D/2% MWCNT, 97% PEO/3% MWCNT) can be used to produce nonwoven fabrics whose resistance changes under the influence of solvent vapours. This is equally true of submicron carbon fibres made from a precursor using a 15% PAN/85% DMSO solution. All three nonwoven fabrics revealed an electrical response on contact with methanol, acetone, benzene and toluene vapours at a concentration of 200 ppm. Samples in direct contact with vapours show high sensitivity and very short response times, no longer than 20 seconds after exposure.

Nonwoven sensors show good electrical conductivity and, in the presence of vapours, they change their resistance. Such sensors are very light as a result of their high porosity. This also provides them with high sensory capacity. They show high sensitivity for substances that are widely used in industry and/or are highly toxic. What is more, sensors produced in this way can be easily shaped and adapted to the surface on which they are to be placed.
