Polypyrrole was deposited in situ on the macroporous open-cell melamine sponge by the oxidation of pyrrole with iron(III) chloride. The oxidant was used in excess, and the reaction mixture after the polymerization thus contained both iron(II) and iron(III) chlorides.
These subsequently provided magnetite after treatment with ammonia solution. The conducting melamine/polypyrrole produced in the first step thus afforded melamine/polypyrrole/magnetite ferrosponge in the second.
The composite sponge was characterized with respect to molecular structure by FTIR spectroscopy. The dependence of conductivity on the sponge compression is provided and magnetic properties have also been determined.
The performance of sponge in electromagnetic radiation shielding in GHz region is demonstrated. While conducting polypyrrole afforded the radiation reflection, magnetite added the absorption component.