What happens to glass fiber under extreme chemical conditions?

In this study, the properties of E-glass fiber (GF) (0.5 g) exposed to sulfuric acid (100 mL, c(H)+ = 0.1 mol/L) and potassium hydroxide (100 mL, c(OH)- = 0.1 mol/L) solutions were studied. The results showed that after acid treatment, the GF was damaged with decreased tensile strength, and spiral cracks developed on the fiber surface. Acid corrosion of the GF was mainly attributed to the depletion of metal ions in the GF, and the ion-depletiondepth model was proposed to explain the mechanism. In the alkali solution, the -Si-O-Si- bonds in the network structure of the GF were degraded by the OH- ions, resulting in the destruction of the glass network. It formed a corrosion layer with sheet-like nanostructures on the fiber surface, which prevented further attack of alkali ions on the fiber. Comparative results of the tensile strength of the treated GF confirmed that the filament was more susceptible to acid attack than alkali attack.