Silicic acid, aluminum magnesium sodium salt

Nanomaterial porosity

Administrative data

Endpoint:

nanomaterial porosity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: Mercury Porosimetry (DIN 66133)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: True Density by He-Pycnometrie (DIN 66137-2)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: BET surface area (DIN ISO 9277)

Deviations:

no

GLP compliance:

yes

Type of method:

BET

Remarks:

DIN ISO 9277

Details on methods and data evaluation:

Pore analysis by mercury porosimetry is performed with a PORENIASTER GOGT. The method is based on the Washburn-Equation, which describes the relationship between pore diameter and applied pressure for a non-wetting liquid like mercury.
Using the POREIVIASTER 60 GT, filling of the penetrometers before analysis is performed in horizontal position: due to this fact a hydrostatic mercury pressure on the sample is also avoided as a non—detected pore filling. The resulting intrusion curves will be plotted over pressure, resp. pore diameter. Because the measurement starts at low pressures, large pores will be filled first and therefore - in standard cases — pore size decreases from left to right side of the chart.

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

Data gathering

Instruments:

Pore analysis by mercury porosimetry is performed with a Quantachrome POREMASTER 60GT.
True Density: ULTRAPYC 1200eT was used for gas pycnometry.
BET surface area: QUANTACHROME AUTOSORB-3, with nitrogen, at 77 K

Results and discussion

Porosity (fraction of void space in the material)

Key result

Mean:

73.2 %

Specific pore volume

Key result

Mean:

1.267 cm³/g

Modal pore diameter

Key result

Mean:

0.3 other: µm

Any other information on results incl. tables

From the Normalized Volume curve one could see, that there is a more or less continuous intrusion from approx. 200 µm down to approx. 0,01 µm.The first part in the range between 200 µm and 0,4 µm we would interpret as filling of inter-particle-void. Below 0,4 µm the intrusion curves becomes much more steep. This range we would see as pore filling.

He-Density	Total- Intrusion- Volume	Inter-Particle- Void	Pore-Volume	Most frequent pore diamter (Mode)	Porosity	Particle Density
[g/cm^3]	[ cnfYg]	[ cnfYg]	[ cm^3/g]	[\im]	[%]	[g/cm^3]
2.151	2.945	1.673	1.267	0.30	73.2	0.577

Remarks to the table:

•     The most frequent pore diameter represents the peak maximum of the poresize distribution curve

•      Porosity = PoreVolume / (PoreVolume + 1/He-Density) x 100%

•      Particle-Density = 1 / (PoreVolume + 1 /He-Density)

Result for BET surface area: multipoint-BET: 57,9 m²/g

Applicant's summary and conclusion

Conclusions:

Test item shows a porosity of 73.2% with 0.3 µm as most frequent pore diameter and a specific pore volume of 1.267 cm³/g.