Structural and proactive safety aspects of oxidation debris from multiwalled carbon nanotubes

• Published in: Journal of hazardous materials Vol. 189; no. 1; pp. 391 - 396
• Main Authors: Stéfani, Diego, Paula, Amauri J., Vaz, Boniek G., Silva, Rodrigo A., Andrade, Nádia F., Justo, Giselle Z., Ferreira, Carmen V., Filho, Antonio G. Souza, Eberlin, Marcos N., Alves, Oswaldo L.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.05.2011; Elsevier
• Subjects: Alum Compounds; Aluminium sulphate; aluminum sulfate; Animals; Applied sciences; Carbon; Carbon - toxicity; Carbon nanotubes; Cell Line; Chemical engineering; Cytotoxicity; Debris; dissolved organic carbon; drinking water; Drinking water and swimming-pool water. Desalination; Exact sciences and technology; fibroblasts; Fibroblasts - cytology; Fulvic acids; General purification processes; Humans; infrared spectroscopy; keratinocytes; Keratinocytes - cytology; Mass spectrometry; Mice; Multi wall carbon nanotubes; Nanotubes, Carbon - chemistry; Nanotubes, Carbon - toxicity; Oxidation; Oxygen - chemistry; Pollution; Reactors; Safety; sodium hydroxide; Toxicity Tests; Waste water; wastewater; wastewater treatment; Wastewaters; water purification; Water Purification - methods; Water quality; Water treatment and pollution; Carbon nanotubes; Cytotoxicity; Aluminium sulphate; Mass spectrometry; Fulvic acids; Human; Drinking water; Organic matter; Purification; Sulfates; Modeling; Nitric acid; Sewage treatment plant; Waste water; Dissolved organic carbon; Flocculation reagent; Functionalization; Flocculation; Water quality; Aromatic compound; Physicochemical purification; Oxidation; Safety; Debris
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2011.02.050

The removal of oxidation debris from the oxidized carbon nanotube surface with a NaOH treatment is a key step for an effective functionalization and quality improvement of the carbon nanotube samples. In this work, we show via infrared spectroscopy and ultrahigh resolution and accuracy mass spectrometry that oxidation debris obtained from HNO 3-treated multiwalled carbon nanotubes is a complex mixture of highly condensed aromatic oxygenated carbonaceous fragments. We have also evaluated their cytotoxicity by using BALB/c 3T3 mouse fibroblasts and HaCaT human keratinocytes as models. By knowing the negative aspects of dissolved organic carbon (DOC) to the water quality, we have demonstrated the removal of these carbon nanotube residues from the NaOH solution (wastewater) by using aluminium sulphate, which is a standard coagulant agent used in conventional drinking water purification and wastewater treatment plants. Our results contribute to elucidate the structural and proactive safety aspects of oxidation debris from oxidized carbon nanotubes towards a greener nanotechnology.