Production technology of aerogel thermal insulation fiber felt
1. Dissolve A certain amount of A Babor sol in 800 mL water, and add concentrated sulfuric acid to control the pH value of A solution at 3~3.5. Put the glass fiber into the Muffle furnace at 450 ℃ for 1 h, after cooling, cut the short fiber with A growth rate of about 5 mm, take 3 g into the above solution A, and stir fully to make a uniform dispersion. Pour the fiber dispersing liquid into the self-made filter device, open the valve to discharge the dispersing liquid, and make the fiber deposited on the 60-mesh copper net to obtain the formed fiber filter felt; The fiber filter felt was gripped on both sides with copper mesh, and soaked in NaOH solution with pH=12 at room temperature (25 ℃) for 30 min. After removal, the fiber filter felt was cleaned with deionized water for 3 to 4 times and dried at room temperature, so that the surface was exposed to a large number of SI-OH bonds.
2, surface roughening treatment
Nano-silica with mass fraction w=0~4% was added to 60 mL anhydrous ethanol for ultrasonic dispersion. The dried fiber filter felt was soaked in silica dispersion for 20 min at room temperature and then taken out and dried in a drying box at 40 ℃ to obtain the coarse-treated fiber filter felt.
3, fiber felt hydrophobic modification
(1) Preparation of epoxy resin solution
Take the mass fraction w(KH550)= 0.01%-0.5%, add it to 120 mL of ethanol aqueous solution (anhydrous ethanol: deionized water =3:1(volume ratio)), electromagnetic stirring for 1 h, and then add the diluted epoxy resin with mass fraction of 1%-2%, electromagnetic stirring for 30 min. At last, the phenolic resin with mass fraction of 0.2%~0.8% was added, and the epoxy resin solution was obtained by electromagnetic stirring for 10 min. The epoxy resin was dissolved and diluted by ethyl acetate.
(2) hydrophobic modification of fiber filter felt
The coarsed-fiber filter felt was slowly immersed in the epoxy resin solution prepared above, taken out after 2 min, heated in a drying box at 40 ℃ for 1.5 h, the ethyl acetate was removed, and then transferred to the Muffle furnace, and cured at 150 ℃ for 4 h to obtain the hydrophobic fiber filter felt.
