GB/T 24491-2009Multi-walled carbon nanotubes (English PDF)

3.1 Multi-walled carbon nanotubes; MWCNTs

A hollow quasi-one-dimensional tubular nanocarbon material that is coaxially nested by curling three or more layers of graphite sheets.

5.1 Basic features

a) Appearance: Black powder or granule, without obvious agglomeration.

b) Morphology: Observed with transmission electron microscope magnification over 100,000 times, multi-walled carbon nanotubes are fibrous. The ratio of length to diameter is greater than 20. Along the axis of the fiber, it is a hollow tube. There can be a bamboo-like partition inside the hollow tube. The graphite sheets on the tube wall can have a certain inclination relative to the central axis of the tube.

5.2 Requirements

The technical requirements of multi-walled carbon nanotubes shall meet the requirements in Table 1.

7.1 Inspection classification

The inspection specified in this Standard is divided into exit-factory inspection and type inspection.

7.1.1 Exit-factory inspection

Each batch of products shall be inspected for appearance and morphology, average outer diameter, multi-walled carbon nanotube content, and ash content.

7.1.2 Type inspection

Type inspection shall be carried out randomly when one of the following situations occurs:

a) When there is a change in the batch number, model, supplier, etc. of raw materials;

b) When there is a change in the production process;

c) When the normal production lasts for 3 months;

d) When the production equipment stops production for more than 3 months and starts production for the first time;

e) When customers make special requirements. All technical requirements specified in this Standard shall be inspected.

7.2 Inspection and acceptance rules

7.2.1 Inspection and acceptance

7.2.1.1 The exit-factory inspection and acceptance of multi-walled carbon nanotubes shall be carried out by the quality and technical supervision department of the supplier.

The supplier shall ensure that the delivered multi-walled carbon nanotubes comply with the provisions of this Standard or the contract.

7.2.1.2 The buyer has the right to inspect and accept any inspection item specified in this Standard or the contract. The acceptance inspection shall be carried out within 15 days from the date of delivery of the goods.

7.2.2 Batching rules

Multi-walled carbon nanotubes shall be submitted in batches for acceptance. Each batch consists of multi-walled carbon nanotubes with the same production process, the same outer diameter, and the same quality grade. The net weight of each batch of products bag and seal it. Then put a layer of polyethylene sealing bag outside the sealing bag.

Seal it. The net weight of each package is 1.0 kg or 5.0 kg. If there is any special packaging requirement, it can be negotiated by both parties.

a) Product name;

b) Trademark;

A.1 Principle

Transmission electron microscopy can magnify the sample image hundreds of thousands or even millions of times. Point resolution can reach 0.1 nm. During the test, the electron beam passes through the sample through the lens system, which can reflect the shape, microstructure and impurity content of the sample. This method can qualitatively analyze the samples as multi-walled carbon nanotubes. It can quantitatively determine the inner and outer diameters and lengths of multi-walled carbon nanotubes. At the same time, it can quantitatively test the number of particulate matter in the multi-walled carbon nanotube sample.

A.2 Reagents

Ethanol: analytically pure.

A.3 Devices

a) Transmission electron microscope: the point resolution is less than 0.3 nm.

b) Ultrasonic cleaner: 100 W.

c) Desiccator: Phi 300 glass desiccator.

A.4 Specimen preparation and storage

a) Put about 0.1 mg of multi-walled carbon nanotubes into an agate mortar. After grinding it, put it in a specimen bottle.

b) Add 10 mL of ethanol to the specimen bottle. After capping the sample bottle, put the sample bottle into the ultrasonic cleaner and sonicate for 20 min.

c) Use a pipette with a diameter of less than 3 mm to pipette a little suspension. Drop it on the surface of the previously prepared microgrid for transmission electron microscopy. Dry in air.

d) Put the microgrid that carries the sample into a sample box. Then transfer the sample box to a desiccator for storage. […]

A.5 Test procedures