Silicic acid, aluminum magnesium sodium salt

Nanomaterial Zeta potential

Administrative data

Endpoint:

nanomaterial Zeta potential

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

no guideline available

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht Rheinland-Pfalz

Type of method:

other: electroacoustic method

Details on methods and data evaluation:

The electroacoustic method is used for the determination of zeta potential respectively related properties like the iso-electric point of concentrated dispersions. A pulse technique device measures the electroacousitc signal at frequencies from 1 to 10 MHz for either pure liquids or colloids. Ultrasound induces a motion of particles relative to the liquid. This motion disturbs the double layer shifting a screening cloud of counter-ions. This displacement of the ionic cloud with respect t the particle surface creates a dipole moment. The sum of these dipole moments over many particles creates an electric field, which is measured as the electroacoustic vibration current (CVI). This filed depends on the value of zeta potential, which is calculated applying an appropriate theory. Furthermore, other colloidal parameter like dynamic mobility, Debye length and surface charge can be determined.

Sampling:

10 g of the test item (powder) was added to 90 g deionized water (10.0 wt.%). This suspension was stirred for 5 minutes using a standard lab dissolver. The zeta potential was measured using the DT-300. All measurements were carried out three times.
The particle size of the test item for calculation (particle size) was measured with laser diffraction method.

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, aluminum magnesium sodium salt

EC Number:

234-919-5

EC Name:

Silicic acid, aluminum magnesium sodium salt

Cas Number:

12040-43-6

Molecular formula:

Na(0.017-1.739)Mg(0.008-0.823)Al(0.002-0.2473)SiO(2.018-3.837)

IUPAC Name:

aluminium(3+) magnesium(2+) sodium tris(oxosilanebis(olate))

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Results and discussion

Zeta potential

Key result

Zeta potential:

93.8 mV

St. dev.:

0.45

pH:

7

Medium:

water

Any other information on results incl. tables

Sample	Zeta potential [mV]	Conductivity [S/m]	Resistance [Qm]	D50 [pm]	St.dev
test item	-93.8	0.131	7.63	4.82	0.45

Applicant's summary and conclusion

Conclusions:

Test item shows a Zeta potential of -93.8 mV.