SN/T 1690.3-2019New textile fiber composition analysis method. Part 3: Qualitative identification of graphene modified fiber (English PDF)

3.1 Graphene

Each carbon atom is SP2 hybridized with three adjacent carbon atoms to form a honeycomb structure of carbon atom layer.

[T/CGIA 001-2018, definition 2.1]

3.2 Graphene modified fiber

Take other materials as basic raw materials, add graphene, and prepare fiber structure features and graphene functions through different spinning processes Sex as one fiber.

[T/CGIA 002-2018, definition 3.3]

3.3 Graphene nylon fiber

Using polyamide as the basic raw material, through the graphene blending melt spinning process, the nylon fiber structure characteristics and graphene function are prepared.

A fiber that integrates performance.

[T/CCFA 01034-2017, definition 3.1]

3.4 Graphene viscose fiber

Graphene is blended with cellulose fiber pulp as the basic raw material, and the wet spinning process is used to prepare viscose staple fiber structure.

It is a fiber that combines the functional properties of graphene.

[T/CCFA 01032-2017, definition 3.1]

3.5 Graphene polyester fiber

Using polyester (PET) as the basic raw material, through the graphene blending melt spinning process, the preparation has the structural characteristics of polyester fiber and graphite A fiber with ene functionality as a whole.

[T/CCFA 01031-2017, definition 3.1].

6.1 Microscopy

6.1.1 Test instruments and tools

Hastelloy slicers, slides, coverslips, biological microscopes.

6.1.2 Reagents

Liquid paraffin.

6.1.3 Test method

6.1.3.1 Longitudinal observation

Tear the sample into thin bundles and arrange them in order, take a sample of appropriate length, place it on a glass slide, add a small amount of liquid paraffin, and cover with a cover glass Place it on the stage of a biological microscope of 100 times to 500 times to observe its shape, and record the longitudinal characteristics of the sample.

6.1.3.2 Cross-sectional observation

Place the cross-section of the sample prepared with the Hastelloy microtome on a glass slide, add a small amount of liquid paraffin, and cover with a cover glass (be careful not to to bring in air bubbles), place it on the stage of a biological microscope at 100 to 500 times to observe its shape, and record the cross-sectional characteristics of the sample.

6.1.4 Identification

Refer to Appendix A, and refer to Appendix C and Appendix D for identification.

6.2 Dissolution method

6.2.1 Test instruments and tools

6.2.1.1 Thermometer (0°C~100°C).

6.2.1.2 Analytical balance (sensitivity 1 mg).

6.2.1.3 Electric heating constant temperature water bath (30°C~100°C).

6.2.1.4 Electric furnace, glass suction filter bottle, beaker, test tube, tweezers, glass rod, crucible tongs.

6.2.2 Reagents

Unless otherwise specified, all reagents used are of analytical grade. The water is Grade 3 water specified in GB/T 6682.

Concentrated sulfuric acid (with a density of 1.83 g/L at 20 °C), concentrated hydrochloric acid (with a density of 1.18 g/L at 20 °C), concentrated nitric acid (with a density of 1.40 g/L at 20 °C), Formic acid (density 1.12 g/L at 20 °C), hydrofluoric acid (density 1.15 g/L at 20 °C), sodium hydroxide, N-dimethylformamide, dimethyl formamide Sulfoxide, sodium hypochlorite, cyclohexanone, cuproamine, glacial acetic acid, acetone, tetrahydrofuran, potassium thiocyanate, phenol, copper cyclohexanone, acetonitrile, pyridine Pyridine, carbon tetrachloride, dichloromethane, dioxane, ethyl acetate.

6.2.3 Test method

Put about 100 mg of sample in a test tube, and inject 10 mL of reagent (the bath ratio of sample to reagent is 1.100). At room temperature, use glass Stir the rod for 5 minutes and observe the dissolution of the reagent on the sample. Samples that are difficult to dissolve at room temperature need to be boiled and stirred with a glass rod Move for 3 min, depending on the degree of dissolution. Record the dissolution of the sample in various solvents and conditions.

Note 1.The test should be carried out in a fume hood, because many solvents are highly volatile and toxic; do not use open flames when heating, pay attention to fire prevention Safe because many reagents are flammable.

Note 2.Normal temperature refers to (25-30)°C, and boiling refers to the boiling of the solvent.

6.2.4 Identification

Compare with Appendix B, and refer to Appendix C and Appendix D for identification.

6.3 Raman spectroscopy

6.3.1 Principle

When a laser beam irradiates the sample, an inelastic collision occurs between the sample molecule and the photon, that is, Raman scattering occurs. With the aid of the instrument by plotting the intensity value of Raman scattering with the corresponding Raman shift value, the Raman spectrum of the sample can be obtained, and each characteristic peak of Raman shift in the spectrum both contain information about the molecular structure of the sample. Different substances have different Raman spectra. Using this principle, the unknown fiber and the known fiber Vi's Raman spectra are compared to distinguish fiber types.

6.3.2 Instruments and tools

Raman spectrometer. with a laser light source, the wavelength of the light source is 532 nm or 785 nm, and the spectral range is not less than 300 cm-1~3500 cm-1, the spectral resolution is better than 5 cm-1.

6.3.3 Test method

6.3.3.1 Turn on the instrument

According to the operating procedure of the instrument, turn on the Raman spectrometer, warm up for half an hour until the instrument is stable, and select 0.4 MW of power.

6.3.3.2 Choose appropriate scanning conditions

Choose the appropriate light source wavelength and scan times.

6.3.3.3 Test sample

Clamp the sample into the focus bracket of the Raman spectrometer laser, and then measure, record the Raman dispersion of 300 cm-1~3500 cm-1 Radio spectrum. The test site of the sample should cover all the fibers in the sample.

6.3.4 Identification

Refer to Appendix C and Appendix D for identification. Clarify the selected area and position of the selected area scan and the selected point scan, the peak of the graphene G peak the peak position is near 1580 cm-1; the peak position of D peak is near 1270 cm-1~1450 cm-1; the 2D peak is near 2700 cm-1.Compare graphene in the measurement results of the modified fiber, if the peak positions are consistent and I2D/IG >= 0.35, it means that the fiber contains graphene.