Physical and chemical properties of hydroxyapatite-based materials synthesized from food industry residues by means of an improved sol-gel method

Abstract

The utilization of industrial wastes is a fundamental part of the circular economy paradigm. The present work shows that solid hydroxyapatite-type materials can be synthesized from food industry residues (i.e. eggshells and mollusk shells) utilizing an experimental methodology based on the modified sol-gel method. For this work, less toxic and less expensive raw materials than those used in classical syntheses have been used. It has also been proposed the use of a natural substance as a porosity generating agent to prepare materials with different physical and chemical properties. Through the use of different analytical techniques, the synthesized materials were characterized. It was confirmed the main phase as hydroxyapatite, in addition to a secondary phase of tricalcium phosphate, calcium carbonate residues of calcium oxide were also identified as residues. Aging temperature and calcination temperature are parameters that other authors have reported influencing the physical and chemical properties of the synthesized materials, in this work it has been confirmed the relationship between the amount of porosity generating agent and the amount of Sol. C also influences the properties of hydroxyapatite-type materials, as an example was determined how is modified the percentage of hydroxyapatite phase.