title: Elucidation of the structural role of fluorine in potentially bioactive glasses by experimental and computational investigation.
abstract: Glasses belonging to the Na(2)O-CaO-P(2)O(5)-SiO(2) system and modified by CaF(2) substitution for CaO and Na(2)O alternatively, were synthesized and characterized experimentally and computationally. The results of molecular dynamics simulations show that fluorine is almost exclusively bonded to modifier cations (Ca and Na) with coordination number close to 4. A similar mean coordination number value is found in the crystal phases obtained by means of thermal treatment at fixed temperature. Addition of fluorine increases the polymerization of silicate tetrahedra by removing modifiers from the siliceous matrix. No appreciable amount of Si-F bonds are detected.
authors.affiliation: Department of Chemistry and SCS Center, University of Modena and Reggio Emilia, Via G. Campi 183, Modena, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Lusvardi
authors.forename: G
authors.initials: G
authors.lastname: Malavasi
authors.forename: M
authors.initials: M
authors.lastname: Cortada
authors.forename: L
authors.initials: L
authors.lastname: Menabue
authors.forename: M C
authors.initials: MC
authors.lastname: Menziani
authors.forename: A
authors.initials: A
authors.lastname: Pedone
authors.forename: U
authors.initials: U
authors.lastname: Segre
mesh_terms: D003198:Computer Simulation; D005461:Fluorine / Q000737:chemistry*; D017611:Fluorine Compounds / Q000737:chemistry; D005898:Glass; D007477:Ions / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D017611:Fluorine Compounds; D007477:Ions; D005461:Fluorine