1. X-ray diffraction (XRD)
The instrument used in this paper is an X-ray diffractometer. The test process is as follows: the prepared sample film is flattened into the sample cell and flattened gently, using a copper target CuKα (λ=0.15406 nm) with a copper anode and a graphite monochromator . The scanning speed is 4°.min', and the scanning range is 5~65°.
2. Infrared spectrometer (FTIR)
The material was characterized by Fourier transform infrared spectroscopy (FTIR, NICOLET 6700). The test process is as follows: fully dry the modified material and potassium bromide in a vacuum oven (60℃.), then uniformly compress the tablet with a tablet press, and characterize it with Fourier transform infrared spectroscopy. The wavelength range is 600~ 4000 cmi'.
3. Mechanical performance test
The mechanical performance test adopts an electronic multifunctional testing machine. Firstly, various film samples with a length of 60 mm and a width of 20 mm were cut out from the film for experiments, and the stretching rate was 10 mm-min; and the thickness average value of the three film thicknesses was taken. Finally, the elongation at break and the tensile strength were tested 5 times to get the average value respectively.
4. Determination method of amine value content
The total amine value indicates that the hydrochloric acid consumed for titrating amines in 1 g of the sample under specified conditions is equivalent to potassium hydroxide (mgKOH.g^-1).
Reagents: hydrochloric acid, 0.1 mol/L standard solution; deionized water; methyl orange
Operation steps: Accurately weigh 0.01 g of NaLs and amine-NaLs samples (accurate to 0.0001 g), place them in a 100 mL Erlenmeyer flask, add 50 mL of deionized water, and after the samples are completely dissolved, add five drops of methyl orange to indicate After shaking well, titrate with hydrochloric acid standard solution to red, and keep it for 30s without fading, which is the end point.
Titrated amine-NaLs hydrochloric acid volume (after correction) = titrated amine-NaLs hydrochloric acid volume - titrated NaLs hydrochloric acid volume. Calculation of amine value results, such as formula (2-1):
Among them, Y: amine value, mgKOH/g; C: concentration of hydrochloric acid, mol/L; V: volume of hydrochloric acid consumed for titration, mL; mo: sample mass, g.
5. Free water and bound water content test of the membrane
The free water content and bound water content in the membrane have a great influence on the separation performance of the membrane. The steps of testing the bound water and free water content in the film in this thesis : (1) Spray water in the form of water mist, put the film under the water mist, and test the weight of the film (m1, mg) after spraying a certain amount of water. (2) Remove free water. The film was dried in a blast oven at 100°C for 6 hours, and the test weight (m2, mg) was quickly taken out. (3) Remove bound water. The film was dried in a blast oven at 150 °C for 6 hours, and the test weight (mo, mg) was taken out quickly. The free water content (Wf, %) and the bound water content (W%, %) can be calculated using the formula (2-2, 2-3), and each film is tested 5 times, and the average value is taken.
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