Synthesis and characterization of β-spodumene by a new sol–gel route assisted by whey protein

Abstract

Spodumene (LiAlSi₂O₆) has gained attention due to its versatile applications, which include ionizing radiation dosimetry, observed in either monoclinic (α-spodumene) or tetragonal (β-spodumene) symmetries. β-spodumene has been produced by solid-state reactions and conventional sol–gel methods, which are challenging due to the need for high temperatures and costly reagents, respectively. Alternative routes like the Pechini method and proteic sol–gel methods are promising because they can reduce production costs and environmental pollution. This paper aims to synthesize and characterize β-spodumene using a new sol–gel route assisted by whey protein. In this method, proteins act as chelating agents, aiding in the formation of stable colloidal solutions (sol) containing inorganic precursors. These solutions undergo gelation processes to form a solid connected porous structure (gel), which can then be thermally treated to promote crystallization and obtain the desired material. The process involved subjecting the material to thermal treatments exceeding 800 °C, leading to the crystallization of β-spodumene structure at 1000 °C. Additionally, a thermal treatment at 1100 °C facilitated the elimination of residual sulfur (S) resulting from protein combustion. For sample characterizations, thermogravimetric analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray fluorescence (XRF) measurements were performed. Preliminary results indicate that β-spodumene was successfully synthesized using the new sol–gel route assisted by whey protein. The potential of whey protein as an eco-friendly chelating agent is highlighted, suggesting possible environmental benefits and paving the way for future advancements in this research area.

Graphical Abstract