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;; 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, Magnetic lifter 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 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 http://www.999magnet.com/products/131-magnetic-lifter 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