Nanocrystalline and Amorphous Calcium Carbonate from Waste Seashells by Ball Milling Mechanochemistry Processes
Nanocrystalline calcium carbonate (CaCO) and amorphous CaCO (ACC) are materials of increasing technological interest. Nowadays, they are mainly synthetically produced by wet reactions using CaCO reagents in the presence of stabilizers. However, it has recently been discovered that ACC can be produce...
| Autores: | , , , , , , , , , , , |
|---|---|
| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/355292 |
| Acesso em linha: | http://hdl.handle.net/10261/355292 |
| Access Level: | acceso abierto |
| Palavra-chave: | Ball milling Calcite Carbonate minerals Milling (machining) Molluscs Nanocrystalline materials Nanocrystals Amorphous calcium carbonate Biogenics Geogenic Mechano-chemistry Mg calcites Mineral phasis Nanocrystalline and amorphous Nanocrystallines Species specifics Stabiliser Calcium carbonate |
| Resumo: | Nanocrystalline calcium carbonate (CaCO) and amorphous CaCO (ACC) are materials of increasing technological interest. Nowadays, they are mainly synthetically produced by wet reactions using CaCO reagents in the presence of stabilizers. However, it has recently been discovered that ACC can be produced by ball milling calcite. Calcite and/or aragonite are the mineral phases of mollusk shells, which are formed from ACC precursors. Here, we investigated the possibility to convert, on a potentially industrial scale, the biogenic CaCO (bCC) from waste mollusk seashells into nanocrystalline CaCO and ACC. Waste seashells from the aquaculture species, namely oysters (Crassostrea gigas, low-Mg calcite), scallops (Pecten jacobaeus, medium-Mg calcite), and clams (Chamelea gallina, aragonite) were used. The ball milling process was carried out by using different dispersing solvents and potential ACC stabilizers. Structural, morphological, and spectroscopic characterization techniques were used. The results showed that the mechanochemical process produced a reduction of the crystalline domain sizes and formation of ACC domains, which coexisted in microsized aggregates. Interestingly, bCC behaved differently from the geogenic CaCO (gCC), and upon long milling times (24 h), the ACC reconverted into crystalline phases. The aging in diverse environments of mechanochemically treated bCC produced a mixture of calcite and aragonite in a species-specific mass ratio, while the ACC from gCC converted only into calcite. In conclusion, this research showed that bCC can produce nanocrystalline CaCO and ACC composites or mixtures having species-specific features. These materials can enlarge the already wide fields of applications of CaCO, which span from medical to material science. |
|---|