Registration Dossier

Physical & Chemical properties

Nanomaterial agglomeration / aggregation

Currently viewing:

Administrative data

Endpoint:
nanomaterial agglomeration/aggregation
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The documentation provided in the full study report was sufficient for the data evaluation. Subjective assessment of sample agglomeration/aggregation based on viewing SEM images. Thus, the study was regarded as reliable with restrictions.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report date:
2012

Materials and methods

Test guideline
Qualifier:
no guideline followed
GLP compliance:
no
Type of method:
scanning electron microscopy
Details on methods and data evaluation:
A Philips XL30 field emission Scanning Electron Microscope (SEM) was used for this study. The optimal spatial resolution of the microscope was from 2-5 nm with varying accelerating voltage from 30 KV to 1 kV. Images of ZnO particles were acquired at an accelerating voltage of 5 kV, a working distance of ≈ 10 mm, and a tilt angle 0°. An SEM metal stub was covered with adhesive conducting tape and a small amount of “as received” ZnO powder
(around 5 mg) was sprinkled over the tape. The surface of the powder sample was flattened with a spatula. Excess powder was removed by gently tapping the stub on its side until a light coating of powder on the surface became apparent. The nanoparticles were thinly sputtered with iridium using a Polaron SC570 sputter coater. Sputtering was conducted under vacuum while passing gas was argon. The coating deposition time was 20 seconds at a plate current of 50mA, giving a coating thickness of approximately 1 nm.

Test material

Constituent 1
Test material form:
solid: nanoform

Data gathering

Instruments:
Philips XL30 field emission Scanning Electron Microscope (SEM)

Results and discussion

Applicant's summary and conclusion

Conclusions:
SEM images reveal that ZnO particles as powder without media were agglomerated. The particle size was smallest for sample NM 112 and largest for NM 113, consistent with analyses of TEM images (please refer to IUCLID section 4.1).
Executive summary:

CSIRO, 2012 investigated the agglomeration/aggregation of the nanomaterials. Therefore a Philips XL30 field emission SEM was used for this study. The optimal spatial resolution of the microscope was from 2-5 nm with varying accelerating voltage from 30 kV to 1 kV. Images of ZnO particles were acquired at an accelerating voltage of 5 kV, a working distance of ≈ 10 mm, and a tilt angle 0°. An SEM metal stub was covered with adhesive conducting tape and a small amount of “as received” ZnO powder (around 5 mg) was sprinkled over the tape. The surface of the powder sample was flattened with spatula. Excess powder was removed by gently tapping the stub on its side until a light coating of powder on the surface became apparent. The nanoparticles were thinly sputtered with iridium using a Polaron SC570 sputter coater. Sputtering was conducted under vacuum while passing gas was argon. The coating deposition time was 20 seconds at a plate current of 50 mA, giving a coating thickness of approximately 1 nm. SEM images reveal that ZnO particles as powder without media were agglomerated. The particle size was smallest for sample NM112 and largest for NM113, consistent with analyses of TEM images (please refer to IUCLID section 4.1).