Hydrofluoric acid corrosion kinetics of silicate glass used to prepare glass hollow fibre membranes

One important process during the preparation of glass hollow fibre membranes is the acid-leaching procedure of the phase separated glass. Herein, the hydrofluoric acid corrosion behaviour of silicate glass was studied. The weight change W-1 increased in direct proportion to the HF content c, and the slope W-1/c increased in direct ratio to the corrosion time t. The activation energy Ea, enthalpy Delta H and entropy Delta S between silicate glass and HF solution at different content c, were also calculated. The positive sign of Delta H reflected that an endothermic reaction between silicate glass and HF solution took place. The activation energy Ea and entropy AS decreased with increasing HF content. The results suggests that the energy barrier of corrosion reaction and the disordered level in the system decreased with the increasing HF content. In other words, the stable phases SiF4 and Na2SiF6 were produced more easily when high HF contents were used.