Thermal properties of nanofluids using hydrophilic and hydrophobic LiYF₄:Yb/Er upconverting nanoparticles.

ABSTRACT: Luminescent nanoparticles have shown great potential for thermal sensing in bio-applications. Nonetheless, these materials lack water dispersibility that can be overcome by modifying their surface properties with water dispersible molecules such as cysteine. Herein, we employ LiYF₄:Er³⁺/Yb³⁺ upconverting nanoparticles (UCNPs) capped with oleate or modified with cysteine dispersed in cyclohexane or in water, respectively, as thermal probes. Upconversion emission was used to sense temperature with a relative thermal sensitivity of ∼1.24% K^-1 (at 300 K) and a temperature uncertainty of 0.8 K for the oleate capped and of 0.5 K for cysteine modified NPs. To study the effect of the cysteine modification in the heat transfer processes, the thermal condu

SUBMITTER: Goncalves JM 

PROVIDER: S-EPMC10898443 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature