Enthalpy of mixing in 0.8[xB2O3–(1−x)P2O5]–0.2Na2O glasses at 298K

Thermodynamical miscibility in 0.8[xB2O3–(1−x)P2O5]–0.2K2O glasses

“…These data are qualitatively consistent with previous HF solution calorimetry on the 0.8[xB 2 O 3 -(1 À x)P 2 O 5 ]-0.2Na 2 O glass system [16]. 6)) which is fitted to the data by square root method.…”

“…Systematic studies on glass transition temperature in mixed former glasses have been reported in the literature. Most of the investigated systems contain B 2 O 3 and P 2 O 5 as network formers [16,22,23]. P 2 O 5 has also been associated with TeO 2 [24,25].…”

“…This calorimeter was built several years ago in the 'Centre de Thermodynamique et Microcalorimetrie du CNRS -Marseille'. Both the apparatus and the operating method have been described elsewhere [16][17][18][19]. Only a brief description will be given below.…”

“…For example, Julsrud and Kleppa have investigated some borophosphate glassy systems such as (NaPO 3 ) 2 -B 2 O 3 and Na 4 P 2 O 7 -(NaBO 2 ) 2 by high-temperature direct reaction calorimetric measurements [15]. More recently, hydrofluoric acid (HF) solution calorimetry measurements were performed on the 0.8[xB 2 O 3 -(1 À x)P 2 O 5 ]-0.2Na 2 O glassy system [16]. According to these analysis, the borophosphate glasses show significant exothermic mixing enthalpies reflecting strong chemical interactions in the solutions.…”

Application of Solution Calorimetry to the Prediction of 20.15[(2.038 + x)SiO<sub>2</sub>-(1.457 － x)Na<sub>2</sub>O]-2.6-P<sub>2</sub>O<sub>5</sub>-26.95CaO Glass Bioactivity

“…As the reaction between the glassy oxides cannot be carried out directly into the calorimeter at ambient temperature due to kinetic limitations, the well-known dissolution method is applied. This indirect method based on a Hess thermodynamic cycle consists in the successive dissolutions in the same solvent and at the same temperature of all the compounds involved in the reaction of formation [12][13][14]. HF calorimetric experiments were performed with a swinging calorimeter.…”