Pore development in alumino-silicate fiber treated in hydrofluoric acid solutions

Melt-blown alumino-silicate ceramic fibers were treated in hydrofluoric acid solutions at room temperature to produce microporous refractory fibers. The pore development of the fibers was studied as a function of HF concentration and treatment time. Surface area and weight loss of fibers was measured simultaneously after exposure to the HF solutions. Changing the HF concentration of the solution from 0.25 to 1.5 mol dm−3 linearly increased the weight loss from 8 to 46%. At HF concentration ranged from 0.5 to 1.5 mol dm−3, BET area also linearly increased from 8 to 40 m2 g−1 with increasing treatment time from 6 to 48 h. The dominant pore size of the HF treated fibers had a radius range of 1.7–1.9 nm. Fourier Transform infrared (FTIR) spectra of the obtained microporous fibers showed that absorption bands in the range of 2700–3100 cm−1 and 3200–3700 cm−1 increased with increasing BET area of fiber.