Alkali metal tetrakis (perfluoro-alcoholato)metallate

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:

May - September 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

ISO 13320 (Particle size analysis - Laser diffraction methods)

Version / remarks:

1.12.2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

Laser scattering/diffraction

Specific details on test material used for the study:

Appearance: white powder

Mass median aerodynamic diameter:

526.69 µm

Geometric standard deviation:

19.26

Percentile:

D10

Mean:

107.09 µm

St. dev.:

3.48

Remarks on result:

other: GRADIS method

Remarks:

Agglomerates

Percentile:

D50

Mean:

526.69 µm

St. dev.:

19.26

Remarks on result:

other: GRADIS method

Remarks:

Agglomerates

Percentile:

D90

Mean:

1 072.87 µm

St. dev.:

33.7

Remarks on result:

other: GRADIS method

Remarks:

Agglomerates

Percentile:

D10

Mean:

>= 3.93 - <= 4.28 µm

Remarks on result:

other: RODOS/L 4 bar

Remarks:

primary particles

Percentile:

D50

Mean:

>= 68.08 - <= 84.39

Remarks on result:

other: RODOS/L - 4 bar

Remarks:

primary particles

Percentile:

D90

Mean:

>= 269.71 - <= 370.04

Remarks on result:

other: RODOS/L 4 bar

Remarks:

primary particles

Verification and calibration: Every measuring cell was checked with the corresponding reference substance. As different ranges (Range 1, Range 3 and Range 5) could be used, the different ranges were also checked with the corresponding reference substance. The following ranges were used for following test methods: GRADIS/L weak dry dispersion with range 7 and RODOS/L intense dry dispersion with range 5. For both methods and range a reference sample (SiC) was measured as reference substance.

 

Pre-Tests: The test item was visually inspected prior to the measurement (visual, by microscope). No particles were larger than 2800 µm.

 

Particle Size Distribution

Dry dispersion method GRADIS/L: For each dispersion method 4 measurements were performed with the test substance. The sample flow of the singular measurement 1 was too high. Therefore, the measurement 1 was only used to adjust the parameter for an optimal obscuration and measurement. This measurement was not used for evaluation and not reported in the final report. The results of measurements 2 - 4 were given in the following table.

Table 1a: Particle size distribution of test method GRADIS/L

GRADIS/L	Measurement	D10 (µm)	D50 (µm)	D90 (µm)
	No. 2	107.79	515.41	1044.51
	No. 3	110.17	548.92	1110.13
	No. 4	103.31	515.72	1063.97

 

The Averaged Particle Size was calculated by the instrument as follows:

Table 1b Average particle size distribution of test method GRADIS/L

Particle size	D10 (µm)	D50 (µm)	D90 (µm)
Value	107.09	526.69	1072.87
Standard deviation	3.48	19.26	33.70

 

The width of distribution for the test substance with the test method GRADIS/L is for D10 103.31 – 110.17 µm, for D50 515.41 – 548.92 µm and for D90 1044.51 – 1110.13 µm.

 

Dry dispersion method RODOS/L:

First measurement series – 1 bar: For the dispersion method 4 measurements were performed with the test substance. The sample flow of the singular measurement 1 was too low. Therefore, the measurement 1 was only used to adjust the parameter for an optimal obscuration and measurement. This measurement was not used for evaluation and not reported in the final report. The results of measurements 2 - 4 are given in the following table:

Table 2a Particle size distribution of test method RODOS/L 1 bar

RODOS/L 1 bar	Measurement	D10 (µm)	D50 (µm)	D90 (µm)
	No. 2	11.78	114.64	370.19
	No. 3	11.53	120.71	382.02
	No. 4	11.58	118.23	377.94

 

The Averaged Particle Size was calculated by the instrument as follows:

Table 2-b Average particle size distribution of test method RODOS/L 1 bar

Particle size	D10 (µm)	D50 (µm)	D90 (µm)
Value	11.63	117.86	376.72
Standard deviation	0.13	3.05	6.01

The width of distribution for the test item with the test method RODOS/L - 1 bar is for D10 11.53 – 11.78 µm, for D50 114.64 – 120.71 µm and for D90 370.19 – 382.02 µm.

 

Second measurement series – 2 bar: For the dispersion method 7 measurements were performed with the test substance. At the fifth and sixth measurement the sample flow was blocked. Therefore, these measurements were not used for evaluation and the data is not provided in the final report, but archived with the raw data of the study in the GLP-archive of the test facility. The results of measurements 1 – 4 and 7 are are given in the following table:

Table 3-a Particle size distribution of test method RODOS/L 2 bar

RODOS/L 2 bar	Measurement	D10 (µm)	D50 (µm)	D90 (µm)
	No. 1	6.75	75.97	276.56
	No. 2	8.54	109.60	373.93
	No. 3	7.61	89.80	290.43
	No. 4	8.92	116.94	381.77
	No. 7	8.23	103.89	359.69

 

5 individual measurements were performed. As the distribution of the values is too high due to the behaviour of the particles (e.g. in-homogeneous particle distribution, agglutination etc.) and therefore no mean value with a deviation below 5 % can be calculated, the collected valid measured values are given as a range. The width of distribution for the test item with the test method RODOS/L- 2 bar is for D10 6.75 – 8.92 µm, for D50 75.97 – 116.94 µm and for D90 276.56 – 381.77 µm.

 

Third measurement series – 4 bar: For the dispersion method 6 measurements were performed with the test substance. At the fifth measurement the sample flow was blocked. Therefore, this measurement was not used for evaluation and the data is not provided in the final report, but archived with the raw data of the study in the GLP-archive of the test facility.

The results of measurements 1 – 4 and 6 are given in the following table:

Table 8.4-a Particle size distribution of test method RODOS/L 4 bar

RODOS/L 4 bar	Measurement	D10 (µm)	D50 (µm)	D90 (µm)
	No. 1	4.28	68.08	270.46
	No. 2	4.28	69.04	269.71
	No. 3	4.25	75.11	287.62
	No. 4	4.09	75.75	289.37
	No. 6	3.93	84.39	370.04

 

5 individual measurements were performed. As the distribution of the values is too high due to the behaviour of the particles (e.g. in-homogeneous particle distribution, agglutination etc.) and therefore no mean value with a deviation below 5 % can be calculated, the collected valid measured values are given as a range. The width of distribution for the test item with the test method RODOS/L- 4 bar is for D10 3.93 – 4.28 µm, for D50 68.08 – 84.39 µm and for D90 269.71 – 370.04 µm.

 

Validity

The deviation between the singular measurements for the measurement of RODOS -1 bar did not exceed 5 % and for the measurement of GRADIS did not exceed 10 %. As the deviation of the measurements of RODOS -2 bar and RODOS- 4 bar did exceed 5 %, the values were given in a range. No observations were made which might cause doubts on the validity of the study out-come. Therefore, the result of the study is considered valid.

Conclusions:

The test item AM(pfa)4 has a median particle size D50 = 526.69 ± 19.26 µm at the dispersion method GRADIS/L.
Due to particle size decrease with increasing pressure (1, 2 and 4 bar) in RODOS/L measurements, the GRADIS/L results are considered to reflect agglomerate size values. For primary particle size, the lowest determined values at 4 bar using the RODOS/L method (D50 = 68.08 – 84.39 µm) are considered representative.

Executive summary:

The test item AM(pfa)4 has a median particle size D50 = 526.69 ± 19.26 µm at the dispersion method GRADIS/L, a median particle size D50 = 117.86 ± 3.05 µm at the dispersion method RODOS/L with a dispersion pressure 1 bar, a median particle size D50 = 75.97 – 116.94 µm at the dispersion method RODOS/L with a dispersion pressure 2 bar and a median particle size D50 = 68.08 – 84.39 µm at the dispersion method RODOS/L with a dispersion pressure 4 bar.

The average particle size distribution of the test methods GRADIS/L and RODOS/L are also provided in the following table:

Table Particle size distribution Overview

GRADIS	Particle size	D10 (µm)	D50 (µm)	D90 (µm)
	Value	107.09	526.69	1072.87
	Standard deviation	3.48	19.26	33.70
RODOS/L- 1 bar	Particle size	D10 (µm)	D50 (µm)	D90 (µm)
	Value	11.63	117.86	376.72
	Standard deviation	0.13	3.05	6.01
RODOS/L- 2 bar	Particle size	D10 (µm)	D50 (µm)	D90 (µm)
	Value	6.75 – 8.92	75.97 – 116.94	276.56 – 381.77
RODOS/L- 4 bar	Particle size	D10 (µm)	D50 (µm)	D90 (µm)
	Value	3.93 – 4.28	68.08 – 84.39	269.71 – 370.04

 

The particle size distribution of the dry weak dispersion test method GRADIS/L showed that the particles, as they exist, were agglomerated. The particle size distribution of the dry intense dispersion test method RODOS/L showed that the particles could be dispersed by the dispersion pressure to smaller particles.

The particle size became slightly smaller particles with increasing dispersion pressure. The measurements of RODOS – 2 bar and RODOS- 4 bar showed wide ranges of the particle distribution for D10, D50 and D90 with smaller particle size but also higher particle sizes. This could be due to the behaviour of the particles (e.g. inhomogeneous particle distribution and strongly agglomerated particles). Also, the results could be explained by some agglomerates being quite robust whereas others are not that can be already strongly dispersed with weak dispersion pressure. However, the change in particle size with increasing dispersion pressure could have also been caused by particle destruction.

No observations were made which might cause doubts on the validity of the study outcome. Therefore, the result of the study is considered valid.

Description of key information

The test item AM(pfa)4 has a median particle size D50 = 526.69 ± 19.26 µm at the dispersion method GRADIS/L. Due to particle size decrease with increasing pressure (1, 2 and 4 bar) in RODOS/L measurements, the GRADIS/L results are considered to reflect agglomerate size values. For primary particle size, the lowest determined values at 4 bar using the RODOS/L method (D50 = 68.08 – 84.39 µm) are considered representative.