mercaptoacetic acid modification of the hexagonal phase NaYF_4: Yb, Er upconversion effects of nanomaterials

Title: mercaptoacetic acid modification of the hexagonal phase NaYF_4: Yb, Er upconversion effects of nanomaterials

Author: Dan

Degree-granting units: Jilin University

Keywords: NaYF_4;; nano-materials;; Magnetic lifter conversion;; surface modification

Summary:

This paper first phase reaction at high temperature oil in the oil-amine prepared hexagonal phase NaYF_4: Yb, Er nanocrystals, in the 980-nm infrared excitation of the sample can emit bright visible light. Experiment, the concentration of rare earth ions and fluoride source proportional to 1 / 4. Can be controlled by regulating the temperature of its crystalline structure, when the temperature at 320 ℃, it can generate a pure hexagonal phase NaYF_4: Yb, Er nanocrystals.

To make synthetic upconversion nanocrystals can be applied in biomedicine, it must first be changed by the hydrophobic water-soluble. We selected mercaptoacetic acid as a surfactant, and in the oil-amine synthesized NaYF_4 nanocrystals to ligand exchange, with its one end of the thiol with the rare-earth ions Y ~ (3) coordination, the other end of the carboxyl extend and enhance its water-soluble at the same time, also makes the surface of upconversion nanocrystals with biologically active carboxyl functional groups. By scanning electron microscopy (SEM) and X-ray diffraction (XRD) characterization of surface modification was observed after the sample morphology and crystal structure in almost no change. Description of mercaptoacetic acid-modified samples without any side effects.

Then the paper went on to study http://www.999magnet.com/products/131-magnetic-lifter mercaptoacetic acid modification of the light-emitting surface of the sample after the changes in optical properties, through the emission spectra and fluorescence dynamics of the two samples obtained before and after modification of the life of light level, rising edge, the fluorescence branching ratio, luminous intensity the relationship between power and stimulate research on the local environment of rare-earth doped materials, upconversion effects.

Finally, the synthesis of water-soluble hexagonal NaYF_4: Yb, Er luminescence in biological samples in a preliminary application to explore, using MTT assay on hepatoma cells for toxicity analysis, the follow-up for the best when the concentration of biological probes.

Degree Year: 2010