Structure and Dissolution Properties of Phosphate Glasses for Glass Fertilizer

Abstract

For usage of glass fertilizer, physical and dissolution properties were investigated according to variation of the SiO2 and K2O contents in silicate glasses. In glass forming region, K2O/P2O5 0-0.24, SiO2/(SiO2+P2O5) 0-0.29 and CaO/P2O5 0-1.00 were fabricated as clear glass in K2O-CaO-SiO2-P2O5 glass system. The glass transition temperature (Tg) and softening temperature (Ts) were gradually shifted to the higher temperature range according to increase of SiO2 contents. The K2O contents, which could cause the structure change from network structure to polymeric chain structure, have direct proportion with the thermal expansion coefficient and inverse proportion with Tg and Ts. The change of the K2O/P2O5 ratio was a main factor to control chemical durability and physical properties such as density and hardness. In the abnormal glass properties such as fast dissolution in aqueous solution, it was presented that the glass can be a good candidate for agriculture fertilizer.

Innovative Formulations of Phosphate Glasses as Controlled-Release Fertilizers to Improve Tomato Crop Growth, Yield and Fruit Quality

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Enhancement of structural and optical properties of transparent sodium zinc phosphate glass–ceramics nano composite

“…In recent years, scientists had investigated phosphatebased glasses for various technological applications including sealing materials, solid-state electrolytes [2,3], radioactive waste containment [4], laser technologies, medical applications such as degradable tissue and bone scaffolds [5], and agro-fertilizers with controlled solubility [6,7].…”

Effect of K₂O Contents on the Releasing of Nutrient Ions from Phosphate Glass System

“…Recently, the potential of phosphate glass to be glass fertilizer has been extensively studied [1]. Glass fertilizer is a type of glass matrix embedded with several macro and micro elements such as phosphorus, potassium, calcium and magnesium which is important for plant developments [2].…”