Environmental mobility of carbon nanotubes


Environmental mobility of carbon nanotubes

Schymura, S.; Kulenkampff, J.; Franke, K.; Lippmann-Pipke, J.

The environmental mobility of nanoparticles is a key factor for the risk assessment of nanoparticle release into the environment. If the environmental conditions render the nanoparticles mobile, a risk beyond the very near field of the actual release has to be taken into account. However, the lack of suitable detection methods constitutes a severe setback for studies of these effects, especially in the low concentration range environmentally relevant and with a considerable background of the same element. This is particularly significant for the study of carbon based nanoparticles such as carbon nanotubes, as carbon-containing water constituents such as humic or fulvic acids are ubiquitous in many ground and surface waters.
We present the results of our studies using carbon nanotubes labelled with radioactive iodine isotopes, e.g. 124I, 125I, 131I. This allowed us to detect carbon nanotubes in the ng/L range, even against a background of mg/L of fulvic or humic acids. Experiments were conducted to investigate the transport behaviour of carbon nanotubes in dependence of the carbon nanotube type, their modification, the geomatrix material and grain size, and the water composition regarding the presence of natural organic matter and electrolytes. The radiolabelling enabled working with a typical amount of about 100 ng carbon nanotubes per experiment. Experiments using different surfactants allowed the distinguishing between different removal mechanisms.
Moreover, the labelling of carbon nanotubes with 124I, a positron emitter, allowed the use of positron emission tomography (PET) to record 4D data (3 spatial dimension plus time) of nanotube transport inside a column.

  • Lecture (Conference)
    International Conference on Safe production and use of nanomaterials, Nanosafe 2014, 18.-20.11.2014, Grenoble, France

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Publ.-Id: 20772