Borate, lithium borate, and borophosphate powders by sol–gel precipitation

• Published in: Journal of sol-gel science and technology Vol. 45; no. 3; pp. 237 - 243
• Main Authors: Bengisu, M., Yilmaz, E., Farzad, H., Reis, S. T.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.03.2008; Springer; Springer Nature B.V
• Subjects: Boron oxides; Ceramics; Chemistry; Chemistry and Materials Science; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Composites; Crystal structure; Crystallinity; Durability; Exact sciences and technology; General and physical chemistry; Glass; Heat treatment; Inorganic Chemistry; Lithium; Lithium borates; Lithium oxides; Materials Science; Nanotechnology; Natural Materials; Optical and Electronic Materials; Organic chemistry; Original Paper; Phosphorus pentoxide; Sol-gel processes; P; Sol–gel; Borate; Chemical durability; Glass; O; Precipitation; Sol gel process; Durability; Lithium; Sol-gel; Borate; P2O5; Powder
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-008-1681-8

Borate, lithium borate and borophosphate powders were synthesized by the sol–gel method. Triethyl borate, lithium methoxide, and orthophosphoric acid were used as precursors for B 2 O 3, Li 2 O, and P 2 O 5 , respectively. Powders were characterized by FTIR, DTA, XRD and SEM techniques. Powders from the Li 2 O–B 2 O 3 system exhibited glassy features while borate and borophosphate powders contained mainly crystalline B 2 O 3 according to XRD analysis. However, a 500 °C heat treatment transformed these crystalline powders into glass powders. Conversely, heat treatment of Li 2 O–B 2 O 3 powders transformed their structure from glassy to crystalline (Li 2 B 4 O 7 ). Chemical durability studies conducted in water at 60 °C showed that minor additions of P 2 O 5 into borate and lithium borate powders improved their chemical durability significantly. Furthermore, Li 2 O and P 2 O 5 acted synergistically on the chemical durability when added simultaneously to borate compositions.