Structural stability and variable dielectric constant in poly sodium 4-styrensulfonate intercalated graphite oxide

The structural stability and dielectric constant of poly sodium 4-styrensulfonate (PSS) intercalated graphite oxides (GOs) were investigated. We found that the interlayer distance of a PSS-treated graphite oxide increased by about 1 Å compared to that of the precursor graphite oxide. This increase in interlayer spacing was attributed to the intercalation of a monolayer of planar PSS into the graphite oxide interlayers facilitated by a π-π interaction between the aromatic rings of the graphite oxide and PSS. The PSS-intercalated graphite oxide had a higher structural stability than the pristine graphite oxide during thermal treatment because of the high melting point of PSS. Furthermore, the dielectric constant of the PSS-intercalated graphite oxide increased significantly at temperatures between 20 and 100 °C, and both of the GO and PSS-GO samples had dielectric constants that varied as a function of temperature due to their hydrophilicity.