Particle emissions from laboratory activities involving carbon nanotubes

Abstract

This site study was conducted in a chemical laboratory to evaluate nanomaterial emissions from 20–30 nm diameter bundles of single-walled carbon nanotubes (CNTs) during product development activities. Direct-reading instruments were used to monitor the tasks in real time and airborne particles were collected using various methods to characterize released nanomaterials using electron microscopy and elemental carbon (EC) analyses. CNT clusters and a few high aspect ratio particles were identified as being released from some activities. The EC concentration at the source of probe sonication was found to be higher than other activities including weighing, mixing, centrifugation, coating and cutting. Various sampling methods all indicated different levels of CNTs from the activities, however, the sonication process was found to release the highest amounts of CNTs. It can be cautiously concluded that the task of probe sonication possibly released nanomaterials into the laboratory and posed a risk of surface contamination. Based on these results, the sonication of CNT suspension should be covered or conducted inside a ventilated enclosure with proper filtration or a glovebox to minimize the potential of exposure.

Interfacial rheology for the assessment of potential health effects of inhaled carbon nanomaterials at variable breathing conditions

“…γ m and Δσ m in Eqs. (5) and (6) denote the amplitudes of surface deformation and surface tension, respectively. For purely elastic response of the interface, the loss angle φ is zero, and, if the viscosity predominates, φ approaches π/2.…”

Evaluation of 1‐dimensional nanomaterials release during electrospinning and thermogravimetric analysis

“…In comparison, particle release in this study was lower compared with reported numbers for CNT sonication and spin coating of CNTs (1.04 and 1.78 μg m −3 , respectively). 29 The number-based measurement detected 1400 to 1600 # cm −3 which is an order of magnitude lower than the emissions reported during grilling with gas stove at minimum power (1.…”

“…It is worth noting that in surface contamination samples no trace of Cu NW was detected. This can be due to the fact the Cu NW synthesis is carried out through wet chemistry methods in closed‐cap bottles and mostly inside the fume hoods which significantly reduces the particle release and exposure potential 29 …”

“…There are numerous papers that have studied the potential release of MWCNTs in the workplace. 19,[26][27][28][29] In comparison, studies that have investigated the release of metal nanowires and works on electrospun polymeric fibers are very scarce. 17 Overall, results have shown that parameters such as nanomaterial size, type, and even surface chemistry can affect the potential release of 1D nanomaterials in the environment.…”

“…EC analysis of the filter placed in the booth during electrospinning of PVP/MWCNT/Cu-NW an average face velocity of 80 to 120 ft min −1 29. Also, the surfaces in the laboratory need to be clean regularly with wet and soupy rags.…”