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Phosphate-Doped Borosilicate Enamel Coating Used To Protect Reinforcing Steel From Corrosion, Xiaoming Cheng

Doctoral Dissertations

"Phosphate-doped sodium borosilicate glasses were developed for enamel coatings to provide corrosion protection for reinforcing steel in concrete. Phosphates have low solubilities in borosilicate glasses, generally less than about 4 mol%, and are incorporated mainly as isolated PO₄^3- and P₂O₇^4- anions, along with some borophosphate bonds. With the addition of P₂O₅, the silicate network is repolymerized and tetrahedral borates are converted to trigonal borates, because the phosphate anions scavenge sodium ions from the borosilicate network. The addition of Al₂O₃ significantly increases the solubility of P₂O …