10.1021/acs.chemmater.9b01155.s002
Miao Wang
Miao
Wang
Yu Zhang
Yu
Zhang
Qiaofeng Yao
Qiaofeng
Yao
Michael Ng
Michael
Ng
Ming Lin
Ming
Lin
Xu Li
Xu
Li
Kishore Kumar Bhakoo
Kishore Kumar
Bhakoo
Alex Y. Chang
Alex Y.
Chang
Federico Rosei
Federico
Rosei
Fiorenzo Vetrone
Fiorenzo
Vetrone
Morphology Control of Lanthanide Doped NaGdF<sub>4</sub> Nanocrystals via One-Step Thermolysis
American Chemical Society
2019
morphology
ratio
One-Step Thermolysis β- phase NaGdF 4 nanocrystals
upconverting nanocrystals
hot-injection
approach
T 2 contrast agents
transition
Lanthanide Doped NaGdF 4 Nanocrystals
α- phase nanoparticles
synthesis
nanoplate
thermolysi
monodispersed uniform nanorods
upconversion luminescence intensity
2019-06-03 00:00:00
Media
https://acs.figshare.com/articles/media/Morphology_Control_of_Lanthanide_Doped_NaGdF_sub_4_sub_Nanocrystals_via_One-Step_Thermolysis/8300621
β-phase
NaGdF<sub>4</sub> nanocrystals doped with Er<sup>3+</sup> and Yb<sup>3+</sup> possessing diverse morphologies were
synthesized from the thermolysis of trifluoroacetate precursors in
1-octadecene and oleic acid by modifying the hot-injection strategy.
Modulation of the injection temperature during the hot-injection step
was an effective approach to control the size and shape of the prepared
nanocrystals and allowed for the direct synthesis of nanorods. Here,
we report for the first time the fabrication of monodispersed uniform
nanorods through a one-step thermolysis approach. The different supersaturation
caused by the different temperatures could directly manipulate the
nucleation and growth of α-phase nanoparticles before the α
→ β phase transition, subsequently influences the Ostwald
ripening mode during the α → β phase transition,
and consequently affects their morphology (i.e., nanorods, nanospheres,
nanoprisms, nanoplates, and nanodisks), uniformity, and monodispersity.
The upconversion luminescence intensity decreased with increase of
the surface to volume ratio of the upconverting nanocrystals, and
a higher ratio of green to red emission was observed when the aspect
ratio was close to 1. The negative contrast enhancement on <i>T</i><sub>2</sub>-weighted magnetic resonance images caused
by the upconverting nanocrystals was increased with increasing size
with the exception of the nanorods, which performed the best as <i>T</i><sub>2</sub> contrast agents despite being smaller compared
to the nanoplates. Our work provided strong evidence for the use of
morphology controlled synthesis in NaGdF<sub>4</sub> based upconverting
nanocrystals and their implementation in multifunctional nanoplatforms
for future biomedical applications.