Author(s)

Brahim Bachachir¹, Yassine Er-Rouissi¹, Radouane Makhlouk¹, Achraf Harrati², Abdeslam El Bouari², Said Aqdim^1,3*

¹Faculty of Sciences Ain Chock, Laboratory of Materials Engineering for Environment and Valorization, Hassan II University, Casa-blanca, Morocco.
²Faculty of Sciences Ben-M’sik, Laboratory Physical-Chemistry of Applied Materials, Hassan II University, Casablanca, Morocco.
³Department of Chemistry, Faculty of Science, Mineral Chemistry Laboratory, Hassan II University Ain Chock, Casablanca, Morocco.

The glass series 50P₂O₅-25CaO-(25-x)Na₂O-xCoO (with (0 ≤ x ≤ 25; mol%), has been prepared by direct melting at 1080°C ± 20°C. The introduction of cobalt in calcium phosphate glasses is used to compare its effect with calcium in inhibition corrosion. The dissolution rate has been investigated. It indicated an improvement of chemical durability when the cobalt oxide increases in the network glass at the expense of Na₂O content. Both, IR spectroscopy and X-ray diffraction have confirmed the structure changes when the CoO content increases in the glass. This change results in the disappearance of isolated orthophosphate groups followed of a polymerizing of the structure from isolated orthophosphate towards pyrophosphate chains (Q¹) by promoting the formation of olygophosphates (mixed Q¹-Q²) rich in pyrophosphates. Analysis of the density values, showed an increase of density with the increase CoO content. The covalent radius values of oxygen r_cal (O^2-) indicate a significant decrease and therefore a relatively high reinforcement of the metal-oxygen-phosphorus (Co-O-P) bonds. SEM micrograph confirms the evolution of the glass structural morphology. The sample having a maximum CoO content confirms a homogeneous glass phase with quite crystalline particles. This property is prerequisite for many interesting industrial applications.

Chemical Durability Phosphate Glasses, Cobalt Oxide, Density, DTA, DRX, IR, SEM Micrograph

Bachachir, B. , Er-Rouissi, Y. , Makhlouk, R. , Harrati, A. , El Bouari, A. and Aqdim, S. (2021) Structural Features and Properties of the Vitreous Part of the System 50P₂O₅-25CaO-(25-x)Na₂O-xCoO (with 0 ≤ x ≤ 25; mol%). Advances in Materials Physics and Chemistry, 11, 254-266. doi: 10.4236/ampc.2021.1112021.