RT Generic
T1 A versatile and scalable route for tailoring silica shells on hydrophobic nanoparticles
A1 Carlos Alarcón-Fernández, 
A1 Zabala Gutiérrez, Irene
A1 Méndez González, Diego
A1 Khouloud Hamroui, 
A1 Concepción Cascales, 
A1 Melle Hernández, Sonia
A1 Gómez Calderón, Óscar
A1 Laurenti, Marco
AB Encapsulating hydrophobic nanoparticles (NPs) with a hydrophilic silica shell has proven critical for expanding their applicability to aqueous media, favoring their incorporation into composite materials, and tunning their surface properties  (specific surface, thickness and spacing) during the design of nano/micro systems. However, a generalized, scalable method that achieves simultaneous control over both shell thickness and applicability across chemically diverse core materials remains a significant synthetic challenge. Here, we present a versatile and scalable methodology for robustly coating various hydrophobic core materials with a silica shell of precisely tunable thickness. Our approach integrates an efficient ligand-exchange procedure, utilizing nitrosonium tetrafluoroborate (NOBF4) to substitute surface oleate ligands with weakly coordinating  anions, thereby enabling phase transfer to N,N-Dimethylformamide (DMF). This hydrophilic intermediate is then directly coated using a modified Stöber process. By systematically tuning the  NH3/TEOS ratio and the total precursor concentration, we demonstrate precise control over the shell thickness, successfully synthesizing uniform silica coatings ranging from thin (~6 nm) to ultra-thick shells (over 500 nm, yielding total diameters >1 µm) on individual nanoparticles. We validate the versatility of this integrated protocol by applying it to both rare-earth Upconversion Nanoparticles (UCNPs) of varying shapes, crystal phases and sizes, and magnetic Fe3O4 nanoparticles. This robust and reproducible method offers a generalized platform for the high-throughput production of core-shell NP@SiO2 structures with tailored dimensions, which is essential for engineering advanced materials for diverse applications in sensing, catalysis, and composite systems.
PB Royal Society of Chemistry
YR 2026
FD 2026
LK https://hdl.handle.net/20.500.14352/133871
UL https://hdl.handle.net/20.500.14352/133871
LA eng
NO UCNPs emissions datasets used for the stability assay.
NO MICIU
DS Docta Complutense
RD 6 abr 2026