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

Nanomaterial Zeta potential

Administrative data

Endpoint:

nanomaterial Zeta potential

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Principle of test: (electrophoretic) light scattering with Malvern Zetasizer Nano ZS (Malvern Instruments GmbH, Herrenberg, Germany)

GLP compliance:

no

Type of method:

electrophoresis

Details on methods and data evaluation:

The zeta potential of the test item at the pH-values relevant for the test (4, 7, 9) was determined using a Malvern Zetasizer Nano ZS (Malvern Instruments GmbH, Herrenberg, Germany). The reference material Zeta Potential Transfer Standard (- 42 mV ± 4.2 mV, DTS1235, Malvern Instruments, Germany) was analyzed as quality assurance sample before and after the test item sample measurements (tolerance with 10 % instrument uncertainty: -47.12 - -37.04 mV).
An amount of 10.51 mg of PR 254 (nanoform) was weighed into a 250 mL glass beaker and mixed with 1 mL of UHQ for pre-wetting (overnight). After 24 h, to the pre-wetted paste 149 mL of UHQ were added achieving a nominal concentration of 70.07 mg/L. This mixture was then sonicated at 38 % amplitude for 10 min using an ultrasonic probe (HD4200, Bandelin).
For analysis the test item dispersion was diluted to the extent that it still shows a coloration. For zeta potential analysis the test item dispersion was diluted 2.6-fold in UHQ-water + 5 mM NaHCO3, adjusted to pH 4, 7 and 9 and analyzed with a nominal concentration of 26.3 mg/L and a particle number concentration of 3.2 x 1014 particles/L. Table 1 shows the measured zeta potentials of the test item at the different pH values

Sampling:

- Short description of the method and its scientific and technical basis.
- Description of reference measurements and samples: The reference material Zeta Potential Transfer Standard (- 42 mV ± 4.2 mV, DTS1235, Malvern Instruments, Germany) was analyzed as quality assurance sample before and after the test item sample measurements (tolerance with 10 % instrument uncertainty: -47.12 - -37.04 mV).
- Technical equipment: Malvern Zetasizer Nano ZS (Malvern Instruments GmbH, Herrenberg, Germany)
- Reagents (if applicable): -
- Preparation of test samples and references (including the use of energy and dispersants): An amount of 10.51 mg of PR 254 (nanoform) was weighed into a 250 mL glass beaker and mixed with 1 mL of UHQ for pre-wetting (overnight). After 24 h, to the pre-wetted paste 149 mL of UHQ were added achieving a nominal concentration of 70.07 mg/L. This mixture was then sonicated at 38 % amplitude for 10 min using an ultrasonic probe (HD4200, Bandelin).

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

401-540-3

EC Name:

-

Cas Number:

84632-65-5

Molecular formula:

C18H10Cl2N2O2

IUPAC Name:

3,6-bis(4-chlorophenyl)-1H,2H,4H,5H-pyrrolo[3,4-c]pyrrole-1,4-dione

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: D23508919P1 (red powder)
- Expiration date of the lot/batch: not available
- Purity test date: not available

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature, keep in original container; store container tightly closed in well-ventilated place
- Stability under storage conditions: stable
- Stability under test conditions: stable
- Solubility and stability of the test substance in the solvent/dispersant/vehicle/test medium: Only a small amount of the test substance entered the solution within the ultrasonic treatment.
- Reactivity of the test substance with the solvent/vehicle /test medium (if applicable): not applicable

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: pre-wetting overnightand sonification at 38 % amplitude for 10 min
- Preliminary purification step (if any): none

INFORMATION ON NANOMATERIALS
- see LE composition

Results and discussion

Zeta potential

Zeta potential 1

Key result

Zeta potential:

-10.93 mV

St. dev.:

0.29 mV

pH:

4

Zeta potential 2

Key result

Zeta potential:

-26.6 mV

St. dev.:

1.06 mV

pH:

7

Zeta potential 3

Key result

Zeta potential:

-35.13 mV

St. dev.:

0.45 mV

pH:

9

Any other information on results incl. tables

Zeta Potential Transfer Standard (tolerance  - 47.12 – - 37.04 mV):

- mean (n=3): -41.97

- SD (n=3): 1.36

Applicant's summary and conclusion

Conclusions:

The determined values for the zeta potential of PR 254 are negative in the investigated pH-range (pH 4 – 9). Furthermore, the data reveal that the zeta potential is lower at pH 4 than at pH 7 and 9. The data indicate that the zeta potential seems to decrease to a point of zero charge with possible charge reversal at lower pH-values. Thus, the dispersion of the nanoform seems to be stabilized to a certain extend towards agglomeration interactions at higher pH values, whereas at lower pH-values increased agglomeration can be expected.