The highly stable pristine C60 fullerene aqueous colloid solution (C60FAS; purity > 99.5%, concentration 0.15 mg/ml) was prepared according to the method of [19 (link), 20 (link)]. Briefly, it is based on the transferring of C60 fullerenes from toluene to an aqueous phase with the help of ultrasonic treatment.
The atomic force microscopy (AFM) was performed to determine the size of C60 fullerene particles (their aggregates) in the aqueous solution. Measurements were done with the “Solver Pro M” system (NT-MDT Spectrum Instruments, Russia). A drop of investigated solution was transferred on the atomic-smooth substrate to deposit layers. Measurements were carried out after complete evaporation of the solvent. A freshly broken surface of mica (V-1 grade, SPI supplies, West Chester, PA, USA) was used as a substrate. Measurements were carried out in a semicontact (tapping) mode with AFM probes of the RTPESPA150 (Bruker, 6 N/m, 150 kHz) type.
We used the dynamic light scattering (DLS) and zeta potential measurements for ascertaining the hydrodynamic size and electrokinetic potential of the prepared C60FAS. The tested volume of C60FAS was 1.5 ml. Measurements were conducted on a Zetasizer Nano ZS90 (Malvern, Malvern, Worcestershire, UK) at 25°C. Results were evaluated using the Smoluchowski approximation, which is known to be rigorously valid only for spherical-like particles.
The atomic force microscopy (AFM) was performed to determine the size of C60 fullerene particles (their aggregates) in the aqueous solution. Measurements were done with the “Solver Pro M” system (NT-MDT Spectrum Instruments, Russia). A drop of investigated solution was transferred on the atomic-smooth substrate to deposit layers. Measurements were carried out after complete evaporation of the solvent. A freshly broken surface of mica (V-1 grade, SPI supplies, West Chester, PA, USA) was used as a substrate. Measurements were carried out in a semicontact (tapping) mode with AFM probes of the RTPESPA150 (Bruker, 6 N/m, 150 kHz) type.
We used the dynamic light scattering (DLS) and zeta potential measurements for ascertaining the hydrodynamic size and electrokinetic potential of the prepared C60FAS. The tested volume of C60FAS was 1.5 ml. Measurements were conducted on a Zetasizer Nano ZS90 (Malvern, Malvern, Worcestershire, UK) at 25°C. Results were evaluated using the Smoluchowski approximation, which is known to be rigorously valid only for spherical-like particles.