Sonochemical effect on size reduction of CaCO3 nanoparticles derived from waste eggshells

Area of Science:

• Materials Science
• Nanotechnology
• Green Chemistry

Background:

• Eggshells are a rich source of calcium carbonate (CaCO3).
• Traditional methods for nanoparticle synthesis can be energy-intensive and environmentally unfriendly.
• Developing sustainable methods for producing high-value nanomaterials from waste products is crucial.

Purpose of the Study:

• To develop a novel, eco-friendly approach for synthesizing high-surface-area calcium carbonate (CaCO3) nanoparticles.
• To utilize waste eggshells as a sustainable precursor for nanoparticle production.
• To investigate the influence of different solvents on the characteristics of the produced CaCO3 nanoparticles.

Main Methods:

• A hybrid mechanochemical and sonochemical approach was employed.
• Eggshells were mechanically milled (ball milling) in a wet condition.
• Milled particles were subjected to sonochemical treatment using N,N-dimethylformamide (DMF), decahydronaphthalene (Decalin), or tetrahydrofuran (THF).

Main Results:

• The combined mechanochemical and sonochemical method successfully produced calcium carbonate (CaCO3) nanoparticles from eggshells.
• Transmission electron microscopy (TEM) revealed distinct particle shapes and sizes depending on the solvent used.
• N,N-dimethylformamide (DMF) resulted in the most pronounced sonochemical effect, yielding irregular platelet-shaped nanoparticles of approximately 10 nm.
• The synthesized nanoparticles exhibited a high BET surface area of 43.687 m²/g.

Conclusions:

• The developed mechanochemical-sonochemical technique offers an efficient and sustainable route for producing high-surface-area calcium carbonate (CaCO3) nanoparticles from eggshells.
• The choice of solvent significantly impacts the morphology and size of the nanoparticles.
• This method presents a promising alternative for valorizing eggshell waste into advanced nanomaterials.