Comparison of Bonds Existing Between C₆₀ Fullerene and Polyamide Molecules in Various Nanocomposite Materials

Abstract

Fullerene–polymer composites may find applications in different areas, particularly, in membrane technology. The formation of bonds between molecules of C₆₀ fullerene and poly(phenylene isophtalamide) (PA) in PA-C₆₀ composites was investigated. Powder-like PA-C₆₀ mixtures, ultrafiltration membranes and nonporous thin films were studied by extracting C₆₀ from the samples with various solvents. It was found that two types of fullerene coexist in the studied composites: the free (easily extractable) fullerene and the bound molecules. The percentage of extractable C₆₀ in a given sample depends on sample composition and the method used for obtaining this nanocomposite material. An important factor in increasing the C₆₀-PA bond strength is the duration of the material formation procedure. The quantitative processing of digital photographs of membranes, scanning electron microscopy (SEM), and electron spectroscopy for chemical analysis (ESCA) data showed that the free C₆₀ is mainly located close to the active membrane surface. The bound C₆₀ molecules are distributed throughout the membranes and films.

Keywords:

• poly(phenylene isophtalamide)
• fullerene C₆₀
• nanocomposites
• polymer membranes
• SEM

Acknowledgements

The authors are grateful to Dr. G. Polotskaya for the preparation of composite materials and valuable discussions.