Water dispersible ligand-free rare earth fluoride nanoparticles: water transfer versus NaREF₄-to-REF₃ phase transformation

Abstract

Crystalline phase and rare-earth (RE) ion choice were identified as key parameters for NaREF4-to-REF3 phase transformation versus water transfer during ligand removal from small NaREF4 nanoparticles at low pH.

Phytoglycogen Encapsulation of Lanthanide‐Based Nanoparticles as an Optical Imaging Platform with Therapeutic Potential

“…[25][26][27] In spite of the broad range of surface modification protocols available to render these UCNPs water-dispersible, care must be taken to evaluate their luminescent, colloidal, and chemical stability following surface modification. [28][29][30] In this context, the encapsulation of UCNPs by lipid layers or amphiphilic polymers provides an additional hydrophilic ligand layer on top of the original hydrophobic oleate (OA) ligands at the UCNP surface. This approach has been shown to be an efficient and noncytotoxic strategy toward colloidal stability in aqueous media, with the benefit of preserving the integrity of the UCNP surface to maintain bright luminescence.…”

Single Er3+, Yb3+: KGd3F10 Nanoparticles for Nanothermometry

“…UC processes are particularly efficient on fluoride host materials in comparison with other UC matrices, presenting good thermal and chemical stabilities ( Haase and Schäfer, 2011 ). Nevertheless, in more recent studies, some authors have pointed out the importance of evaluating the risk to phase transformation or the effect of ion dissolution on the nanoparticle luminescence and their integrity, indicating possibility to be dependent on time, particles concentration in aqueous medium and an effective prevention using different strategies as e.g., surface functionalization ( Lahtinen et al, 2017 ; Liu et al, 2020 ).…”

NaY(MoO4)2-based nanoparticles: synthesis, luminescence and photocatalytic properties

“…1,14,15,16,17 Only Ding et al have obtained uniform nanoparticles by a solvothermal procedure in the presence of oleic acid and oleylamine as capping agents. 22 However, such nanoparticles were hydrophobic as a consequence of the adsorption of such organic molecules on their surface, which precludes their use in some applications, unless they are rendered hydrophilic through post-synthesis ligand exchange strategies, 23,24 which in some cases affect the size, shape and composition of the particles. 24 Therefore, it remains as challenge to develop novel procedures for the synthesis of uniform Ln-doped NaY(MoO 4 ) 2 nanoparticles.…”

“…22 However, such nanoparticles were hydrophobic as a consequence of the adsorption of such organic molecules on their surface, which precludes their use in some applications, unless they are rendered hydrophilic through post-synthesis ligand exchange strategies, 23,24 which in some cases affect the size, shape and composition of the particles. 24 Therefore, it remains as challenge to develop novel procedures for the synthesis of uniform Ln-doped NaY(MoO 4 ) 2 nanoparticles. Among different alternatives, the use of polyols as solvents in wet-chemical precipitation methods seems to be attractive, as polyols are known both to limit particle growth and to confer hydrophilic character to the precipitated particles.…”