Multi-Walled Carbon Nanotubes (MWCNT), synthetic graphite in tubular shape

Nanomaterial porosity

Administrative data

Endpoint:

nanomaterial porosity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019 / 2021

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Reference 3

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

GLP compliance:

no

Type of method:

weighing

Details on methods and data evaluation:

Ray-ran bulk density apparatus and Mettler Toledo ME204 analytical balance

Sampling:

The sample powder was positioned at the cylindrical cup of Ray-ran bulk density apparatus fabricated for ASTM D1895 Method A. The weight of the sample was measured three times using Mettler Toledo ME204 analytical balance.

Test material

Test material information

Constituent 1

Reference substance name:

carbon

EC Number:

936-414-1

Molecular formula:

C

IUPAC Name:

carbon

Test material form:

solid: nanoform, no surface treatment

Details on test material:

-- Jenotube 6A - SIP
Purity (wt%) : 98 – 99.2
Bundle length : 10.6 μm – 211.1 μm
Bundle diameter : 0.6 μm – 8.8 μm
Tube diameter : 4.4 nm – 12.8 nm
BET surface area (m²/g) : 576 – 742
Number of walls : 3 – 9

-- Jenotube 8A – SIP
Purity (wt%) : 98.5 – 99.7
Bundle length : 1.9 μm – 552.0 μm
Bundle diameter : 0.33 μm – 7.93 μm
Tube diameter : 5.1 nm – 11.6 nm
BET surface area (m²/g) : 541 – 618
Number of walls : 5 – 8

-- Jenotube 10A – SIP
Purity (wt%) : 97.8 – 99.2
Bundle length : 9.4 μm – max. 106.4 μm
Bundle diameter : 1.1 μm – 15.24 μm
Tube diameter : 7.9 nm – max. 14.2 nm
BET surface area (m²/g) : 223 – 278
Number of walls : 5 – 12

-- Jenotube 10B – SIP
Purity (wt%) : 97.3 – 98.9
Bundle length : 10.5 μm – 117.7 μm
Bundle diameter : 1.1 μm – 15.4 μm
Tube diameter : 8.3 nm – 17.9 nm
BET surface area (m²/g) : 181 – 249
Number of walls : 7 – 18

-- Jenotubes 6A, 8A, 10A and 10B
Shape category : elongated
Shape of particles : tube
Pure shape : yes
Crystal structure : crystalline
Pure structure : yes
Crystal system : armchair, zig-zag and chiral
Surface treatment/functionalisation : no
State of aggregation : agglomerated

Results and discussion

Porosity (fraction of void space in the material)

Porosity (fraction of void space in the material) 1

Key result

Mean:

96.9 %

Remarks on result:

other: Jenotube 10B

Porosity (fraction of void space in the material) 2

Key result

Mean:

98.8 %

Remarks on result:

other:

Remarks:

Jenotube 6

Porosity (fraction of void space in the material) 3

Key result

Mean:

99.6 %

Remarks on result:

other:

Remarks:

Jenotube 8

Porosity (fraction of void space in the material) 4

Key result

Mean:

99.4 %

Remarks on result:

other: Jenotube 10A

Modal pore diameter

Key result

Mean:

>= 37.85 - <= 38.1 nm

Any other information on results incl. tables

See details in study reports. Full study reports are attached to the references given under section "Data source".

Applicant's summary and conclusion

Conclusions:

The true density of all the members of the set of MWCNT is 2.1 g/cm³, whereas the bulk density (determined by the weighing method) ranges between 8.1 mg/cm³ and 65 mg/cm³.
From bulk density and true density, a porosity between 96.9% and 99.6% was determined for the four members of the set of MWCNT.

Executive summary:

The true density of all the members of the set of MWCNT is 2.1 g/cm³, whereas the bulk density (determined by the weighing method) ranges between 8.1 mg/cm³ and 65 mg/cm³.
From bulk density and true density, a porosity between 96.9% and 99.6% was determined for the four members of the set of MWCNT.