RT Journal Article T1 Crystallization of calcium carbonate and calcium phosphate phases in silica hydrogel: morphological and compositional characterization A1 Sánchez Pastor, Nuria A1 Jorge Pinto, Andre Filipe A1 Del Buey Fernández, Pablo A1 Astilleros García-Monge, José Manuel AB The present study showcases a series of crystallization experiments using a specially designed double diffusion system to grow crystals belonging to the calcium carbonate–phosphate system. The experimental U-shaped device comprised two vertical solution containers, separated by a horizontal column of silica hydrogel. Each container was filled with 0.5 M CaCl2 and 0.5 M Na2CO3 solutions, which diffused through the gel column over time. Na3PO4 solutions, with 50 and 500 ppm concentrations, were incorporated into the gel in different experiments, resulting in a homogeneous distribution of phosphate concentrations within the diffusion column. After 15- and 30-day incubation periods post-nucleation, the crystals formed in different sections of the gel were carefully extracted and studied with scanning electron microscopy and electron microprobe. Additionally, Raman spectra were collected from the samples using a confocal Raman microscope, providing further insights into their molecular composition and structural properties. The obtained results show that under the induced experimental conditions (i) phosphate incorporates into calcite’s structure, and (ii) the growth of calcium phosphates in the presence of carbonate ions involves the sequential, heterogeneous nucleation of CO3-bearing OCP/HAP-like phases, with Raman spectral characteristics very similar to those of bioapatites. PB MDPI YR 2024 FD 2024-07-10 LK https://hdl.handle.net/20.500.14352/107738 UL https://hdl.handle.net/20.500.14352/107738 LA eng NO Sánchez-Pastor, Nuria, et al. «Crystallization of Calcium Carbonate and Calcium Phosphate Phases in Silica Hydrogel: Morphological and Compositional Characterization». Crystals, vol. 14, n.o 7, julio de 2024, p. 635, https://doi.org/10.3390/cryst14070635 NO Ministerio de Ciencia e Innovación DS Docta Complutense RD 12 abr 2025