Trapping analytes with carbon nanotubes sponges

Carbon nanotubes sponges are three dimensional structures formed by the random self-assembly of these nanostructures during their synthesis. They are produced by the classical chemical vapor deposition method simply using special catalysts like ferrocene. The structure of an sponge can be observed in Figure 1A which shows a scanning electron micrograph of the bulk material. A closer view (Figure 1B) reveals how the nanostructures are interconnected(1). The sponges are characterized by a high superficial area (up to 100 m2/g), high porosity (derived from the 3D structure) and low density. From the chemical point of view they are superhydrophobic, property that has been exploited in some applications, such as the recovery of oil from water or the treatment of environmental waters.

Figure 1. SEM micrographs of carbon nanotubes sponges at two magnifications. Reproduced from reference 1

Researchers from the Shandong Academy of Sciences and the Wuhan University of Technology have evaluated the potential of this material in sample treatment under the solid phase extraction (SPE) format. For this purpose, the sponge is introduced in a typical SPE cartridge for sample processing. The determination of polychlorinated biphenyls (PCBs) in environmental waters has been selected as model analytical problem to demonstrate the potential of the material.(2)

The comparison of the extraction performance of the sponges with other sorbents is relevant. The sponges provide better results (the enhancement factor depends on the analyte under consideration) than single single-walled or multi-walled carbon nanotubes. This good results can be ascribed to the 3D network of the sponges that favors the processing of high volume of samples (100 mL).

This is a brief excerpt for encouraging our followers to read the article. Besides, two additional links devoted to describe the nature of this material can be found at the end of this post. (1, 3)

References

(1) Applications of three-dimensional carbon nanotube networks. Link to the article

(2) Carbon nanotube sponges as a solid-phase extraction adsorbent for the enrichment and determination of polychlorinated biphenyls at trace levels in environmental water samples. Link to the article

(3) Nanotube sponge soaks up oil again and again.Link to the article

Special acknowledgements to: Beilstein Journal of Nanotechnology. This open access journal permits unrestricted use, distribution, and reproduction in any medium, of its material. Figure 1 has been reproduced from one article which is also referenced in this post (1).