Enhancements in conductivity and thermal and conductive stabilities of electropolymerized polypyrrole with caprolactam-modified clay

In this study, a polypyrrole (PPy)/caprolactam-modified montmorillonite (MMT) clay composite was electropolymerized on a gold substrate. Basically, the nucleation and growth were instantaneous three-dimensional processes before and after nuclei overlapping for both pure PPy and the composite electropolymerizations. However, a distinguishable feature can be observed. The surface morphology of the resulting composite is denser and more compact. The composite demonstrates an extremely high oxidation level and oxidation degree of 0.41 and 0.59 revealed from the analyses of X-ray photoelectron spectroscopy (XPS) and surface-enhanced Raman scattering (SERS), respectively. The thermal stability of PPy is improved, as shown from thermogravimetric analysis (TGA), due to the modification of the incorporated clay. Also, the conductivity of the composite was significantly increased (∼12 times) and aging is depressed compared to that of pure PPy.