Abstract
The risk assessment, exposure and understanding of the release of embedded carbon nanotubes (CNTs) and carbon nanofibers (CNFs) from commercial high performance composites during machining processes are yet to be fully evaluated and quantified. In this study, CNTs and CNFs were dispersed in epoxy matrix through calendaring process to form nanocomposites. The automated drilling was carried out in a specially designed drilling chamber that allowed elimination of background noise from the measurements. Emission measurements were taken using condensed particle counter (CPC), scanning mobility particle sizer (SMPS) and DMS50 Fast Particulate Size Spectrometer. In comparison to the neat epoxy, the study results revealed that the nano-filled samples produced an increase of 102% and 227% for the EP/CNF and EP/CNT sample respectively in average particle number concentration emission. The particle mass concentration indicated that the EP/CNT and EP/CNF samples released demands a vital new perspective on CNTs and CNFs embedded within nanocomposite materials to be considered and evaluated for occupational exposure assessment. Importantly, the increased concentration observed at 10 nm aerosol particle sizes measurements strongly suggest that there are independent CNTs being released at this range.
| Original language | English |
|---|---|
| Pages (from-to) | 57-66 |
| Number of pages | 10 |
| Journal | Journal of Hazardous Materials |
| Volume | 340 |
| DOIs | |
| Publication status | Published - 15 Oct 2017 |
Keywords
- Nanoparticle release
- Carbon nanotubes
- Carbon nanofibers
- Drilling emissions
Project and Funding Information
- Funding Info
- The work is funded by and part of the European Commission_x000D_ Life project named Simulation of the release of nanomaterials_x000D_ from consumer products for environmental exposure assessment_x000D_ (SIRENA, Pr. No. LIFE 11 ENV/ES/596). We are also thankful to the_x000D_ funding by QualityNano Project through Transnational Access (TA_x000D_ Application VITO-TAF-382 and VITO-TAF-500) under the European_x000D_ Commission, Grant Agreement No: INFRA-2010-262163 for the_x000D_ access and use of the facilities at the Flemish Institute for Technological_x000D_ Research (VITO). The authors would like to acknowledge_x000D_ K. Tirez and R. Persoons at Vito for their XRF and SEM support._x000D_ Kristof Starost is also thankful for partial funding by the School of_x000D_ Engineering for his studentship.