Field and Laboratory Measurements Related to Occupational and Consumer Exposures - Safety of Nanomaterials along Their Lifecycle - page 303

The absolute numbers of aerosol during high speed sanding are
clearly above clean-air background, and comparable to the
environmental background. Importantly, the numbers are not
signiicantly different between the nanomaterial-free comparison
material and the nanocomposite. In mass metrics, only larger
fragments with 10-200 mm diameters are generated. Free CNTs
were not observed: not by morphology, not by quantitative
surface chemistry, not in the quantitative size distribution.
Protrusions of CNTs on the polymer fragments were not
observed either in morphology or in surface chemistry

Golanski et al.
(2012)

Abrasion,
scratching,
mechanical
shocks, sanding

CNT composite High energy

released CNTs
only in the case
of bad
dispersion, only
release of SiO 2
in the case of
bad dispersion

PSD, PNC, TEM
EDX

Abrasion was performed on polycarbonate, epoxy, and PA11
polymers containing carbon nanotubes (CNT) up to 4%wt.
Release under mechanical shocks and hard abrasion was
observed but only when nanomaterials present a bad dispersion
of CNT within the epoxy matrix. Under the same conditions
no release was obtained from the same material presenting a
good dispersion. The CNT used in this study had an external
diameter of 12 nm and a mean length of 1 µm. Release from
paints under hard abrasion using a standard rotative taber tool
was observed from an intentionally non-optimized paint
containing SiO 2 nanoparticles up to 35%wt. The primary
diameter of the SiO 2 was around 12 nm

SiO 2 paint

( Continued )