Barium carbonate

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:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2022

Report date:

2022

Materials and methods

Details on methods and data evaluation:

The zeta potential is a key indicator of the stability of colloidal dispersions. The magnitude of the
zeta potential indicates the degree of electrostatic repulsion between adjacent, similarly charged
particles in a dispersion. For molecules and particles that are small enough, a high zeta potential
will confer stability, i.e., the solution or dispersion will resist agglomeration and thus precipitation.
When the potential is small, attractive forces may exceed this repulsion and the dispersion may
break and precipitate. Colloids with high zeta potential (negative or positive) are electrically
stabilized while colloids with low zeta potentials tend to coagulate or flocculate

Test material

Test material information

Constituent 1

Reference substance name:

Barium carbonate

EC Number:

208-167-3

EC Name:

Barium carbonate

Cas Number:

513-77-9

Molecular formula:

BaCO3

IUPAC Name:

barium carbonate

Test material form:

solid: nanoform

Data gathering

Instruments:

ZetaSizer Nano ZS (Malvern, UK)

Results and discussion

Zeta potential

Zeta potential 1

Zeta potential:

-1.45 mV

pH:

2

Zeta potential 2

Zeta potential:

-3.48 mV

pH:

3

Zeta potential 3

Zeta potential:

-8.09 mV

pH:

4

Zeta potential 4

Zeta potential:

-9.1 mV

pH:

5

Zeta potential 5

Zeta potential:

-12.6 mV

pH:

6

Zeta potential 6

Zeta potential:

-14.53 mV

pH:

7

Zeta potential 7

Zeta potential:

-16.73 mV

pH:

8

Zeta potential 8

Zeta potential:

-20.2 mV

pH:

9

Zeta potential 9

Zeta potential:

-22.23 mV

pH:

10

Zeta potential 10

Zeta potential:

-25.27 mV

pH:

11

Zeta potential 11

Zeta potential:

-38.27 mV

pH:

12.2

Any other information on results incl. tables

The dispersion that visually appeared slighty white in alkaline conditions turned to completely clear while decreasing the pH from pH 7 to pH6, suggesting a dissolution of the material at acidic pH. Based on these results, pH10, pH11 and pH12 were selected to test the stability of the dispersion.

Applicant's summary and conclusion

Conclusions:

The Zeta potential ranged from -1.45 to -38.3 mV in a NaOH solution at pH = 2.0 to 12.2.

Executive summary:

The zeta potential was determined in a non-GLP compliant study using a Malvern ZetaSizer Nano. For this measurement, the powdered sample was dissolved in a 10E-2 M NOH solution (pH 12.2) which was brought step by step from pH 11 to 2. At each step the zeta-potential of the dispersion was measured.