1993/01/01 by María Ángeles Villegas Broncano, Villegas, Maria Angeles, Pascual, Luis +2
Engineering · Materials Science · #660 #Advanced ceramic materials synthesis #Glass properties and applications #Recycling and utilization of industrial and municipal waste in materials production
paper · doi:10.34657/14022
openalex publication_date 1993/01/01 · openalex created_date 2016/08/23 · openalex updated_date 2026/07/01
Samples of the systems R<sub>2</sub>O-SiO<sub>2</sub> (R = lithium, sodium, potassium), B<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub> and Na<sub>2</sub>O-B<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub> were prepared by the sol-gel route. After gelation and drying, heat treatments under ammonia atmosphere were carried out up to 1100 °C. The whole nitrogen content (in wt%) of nitrided gels was determined with a Leco equipment. The maximum nitrogen content (in wt%) in lithium silicate gels was 12.6; in binary borosilicate gels 5.0 and in sodium borosilicate gels 7.6. The existence of silicon oxynitride (Si<sub>2</sub>ON) in some samples treated under ammonia has been demonstrated by X-ray diffraction. The nature and amount of the alkaline oxides play an important role in nitridation. The nitrogen percentage content incorporated seems to depend on the whole content of crystalline phases formed during thermal treatment, on the devitrification and on the phase separation of the samples. In borosilicate glasses a higher nitrogen incorporation with increasing B<sub>2</sub>O<sub>3</sub> content was observed. In these samples, devitrification and phase separation, respectively, also affected nitridation.