|
Keywords
|
Polypyrrole, membranes, nano-sized, DMF,
methyl amine, gas sensor
|
|
Abstract
|
Some selective gas sensors based on nano-sized
polypyrrole (PPy) fiber surrounded with polytetrafluoroethylene
(teflon) and polypropylene membranes (PPy-m) were
constructed. Two membranes, including polytetrafluoroethylene
and polypropylene membranes, were used to surround
polypyrrole fibers. Polypyrrole fiber (PPy-f) samples have been
prepared by polymerization of pyrrole on the surfaces of the
polyester and polytetrafluoroethylene fibers in the presence of
an oxidizing agent at solution and vapor phase. The morphology
of the resulting PPy on the polyester and polytetrafluoroethylene
fibers was analyzed by scanning electron microscopy. The
effects of the used membrane type and a substrate type of
fiber on the conductivity and response patterns of the PPy-m
as a gas sensor to the different gasses were studied. The
PPy-m gas sensors demonstrated fast response time (<1 s).
The sensitivity of the PPy-m gas sensor for various volatile
organic compounds was also reported. The PPy-polyester-teflon
membrane exhibits a good selectivity to the methylamine and
could also be successfully applied as a highly selective sensor for
detection of methylamine (DL = 100 ng). The linearity of the
calibration curve was observed in the range of 0.5–60 μg. The
PPy-polyester-polypropylene exhibits a good selectivity to the
dimethylformamide (DMF). The detection limit of this sensor
for DMF is 0.6 μg. The linearity of the calibration curve was
observed in the range of 4–100 μg.
|