Pyrrolo[3,4-c]pyrrole-1,4-dione, 3,6-bis([1,1'-biphenyl]-4-yl)-2,5-dihydro-

Particle size distribution (Granulometry)

Link to relevant study record(s)

Reference

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions)

Deviations:

no

GLP compliance:

yes

Type of method:

Laser scattering/diffraction

Type of distribution:

volumetric distribution

Key result

Percentile:

other: 100%

Mean:

< 2 µm

Remarks on result:

other: wet dispersion by sonication

The determination of the particle size distribution was performed using a Malvern 2600 Laser Diffraction Apparatus.

Visual investigation:

The test substance consisted of smaller and larger red coloured agglomerates. These agglomerates consisted of very large numbers of small amorphous, irregular shaped particles. The diameter of the largest particles was < 2 μm. In both the dry sample and in the suspensions (without sonication) the particles were agglomerated. After sonication for 20 seconds of the samples, an increase in small particles together with a break-down of the agglomerates was observed. After a sonication period of 280 seconds, there were almost no agglomerates left.

Determination of the dispersibility of the test substance:

In water the test substance was floating on the surface, no dispersion was formed. Mixing the test substance with ethanol or cyclohexane gave a good dispersion. The dispersion with cyclohexane did contain more agglomerates on the bottom. In neither liquid there was any visible dissolving (no colouration of the liquid was observed). As a result of the tests, ethanol was chosen as test medium.

Laser Diffraction Analysis:

The results of the Malvern analysis show that after 20 seconds of sonication a fairly stable dispersion of particles in ethanol is reached. It should be remarked that the results for these very small particles with this instrument have a low accuracy, since only reliable results are obtained for samples containing less than about 15% (v/v) particles with diameters smaller than 1.2 μm (for the 63 mm lens). Still the conclusion can be made that a vast majority of the particles is smaller than 2 μm. In conclusion, the particle size distribution is: 100% (v/v) < 2 μm.

Conclusions:

The particle size distribution of the test substance was determined to be 100% (v/v) < 2 μm

Description of key information

Wet dispersion:

100% (v/v)= <2 μm

Additional information

Bulk form:

The determination was conducted by laser diffraction method according to OECD Guideline 110.

The results of the Malvern analysis show that after 20 seconds of sonication a fairly stable dispersion of particles in ethanol is reached.

It should be remarked that the results for these very small particles with this instrument have a low accuracy, since only reliable results are obtained for samples containing less than about 15% (v/v) particles with diameters smaller than 1.2 ym (for the 63 mm lens).

Still the conclusion can be made that a vast majority of the particles is smaller than 2 µm