ELECTROPOLYMERISATION AND CHARACTERISATION OF DOPED-POLYPYRROLE AS HUMIDITY SENSOR
ABSTRACT: A new type of
sensing materials for humidity measurement has been developed based on
conducting polymer polypyrrole synthesised from pyrrole by adding some dopant
compounds, bromide and chloride, it is prepared by potentiodynamic-electropolymerisation
technique. Variation of dopant types and concentration has been carried out in
order to investigate the effect of this variation to the change of polymeric
conductivity when interacting with water vapour. Polypyrrole-Cl (Ppy-Cl) and
polypyrrole-Br (Ppy-Br) exhibit a good principal characteristic as sensor candidate
namely responding proportionally to humidly variation ranging 30% - 90%
relative humidity. Characterisation test for the sensor candidates has been
carried out for evaluating their linearity respond toward humidity, their
stability in certain period and their reproducibility in some tests. The
results show that Ppy-Cl and Ppy-Br showing good linearity respond with R value
in a range of 0.95 – 0.99. Their reproducibility and sensitivity were
relatively good, however their respond stability were only last in few days.
The stability probably is related to the stability of resulted polymeric
structure that very affected by synthesis process and dopant used. It is
necessary to extend the use of other dopant materials and changing the
synthesis process in order to improve sensor stability. In other hand it is
also necessary to characterise other performance characteristic of the sensor
namely response time, and interference effect of some volatile chemicals and
other gases.
Keywords: polypyrrole,
potentiodynamic, electropolymerisation, humidity sensor and conducting polymer
Author: Siswoyo, Trio F.
Nugroho, Zulfikar and Agus Subekti
Journal Code: jpkimiagg060027
