Structural and optical properties of C₇₀ fullerenes in aqueous solution

Abstract

The simple method of preparation of highly stable and purified C₇₀ fullerene aqueous solution (C₇₀FAS) is proposed. The features of structural stabilization of C₇₀ fullerenes in an aqueous solution by studying their structural and optical properties using Raman, photoluminescence, infrared reflection-absorption, UV–VIS absorption, and dynamic light scattering spectroscopy methods were analyzed. The experimental results showed that the most likely mechanism for C₇₀ fullerenes stabilization in water is surface hydroxylation with covalent attachment of water hydroxyls to C₇₀ fullerene carbons. Raman and infrared absorption spectra of C₇₀FAS showed characteristic vibrational bands of C₇₀ fullerenes with a slight broadening and low-frequency shift of ∼1 cm⁻¹, indicating the attachment of water hydroxyls to the C₇₀ fullerene carbons. The photoluminescence spectra showed excitonic emission bands of C₇₀ molecules with intensity depending on their content. UV–VIS absorption spectra demonstrate the absorption bands typical for monomeric C₇₀ fullerene. Finally, the dynamic light scattering data confirmed that C₇₀FAS is a typical colloidal fluid containing both individual C₇₀ molecules and their nano aggregates up to 100 nm. These findings provide insights into the stabilization mechanism of C₇₀ fullerenes in water and may have implications for their potential application in nanobiotechnology.

Keywords:

• C₇₀ fullerene aqueous colloid solution
• chemical analysis
• Raman
• FTIR
• photoluminescence and UV-VIS spectroscopy
• dynamic light scattering
• zeta potential

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.