Color-Tunable Eu(3+) and Tb(3+) co-doped nanophosphors synthesis by plasma-assisted method

With increasing health consciousness, Y₂O₃‐based rare earth nanophosphors are considered as promising luminescent complexes for bio‐applications. In the present study, an atmospheric pressure plasma‐electrochemical technique is demonstrated for the synthesis of Eu³⁺/Tb³⁺ single‐doped or co‐doped Y₂O₃ nanophosphors from merely an aqueous solution of the corresponding rare earth nitrite salts. Systematic experiments were performed to prepare (Y₁‐x‐yEuxTby)₂O₃ nanophosphors of various Tb³⁺ and Eu³⁺ ratios (x:y = 1:0, 2:1, 1:1, 1:2, and 0:1), with the ultimate goal to achieve the colour tunability by simply adjusting the dopant compositions. Results indicated successfulness synthesis of crystalline Eu/Tb single‐doped and co‐doped Y₂O₃ nanophosphors with Tb³⁺ and Eu³⁺ ions being uniformly incorporated into the Y₂O₃ host matrix. The generated products showed apparent downshift behaviour under ultraviolet irradiation, and characteristic spectral excitation and emission bands were detected by the photoluminescence measurement. Furthermore, by adjusting the relative composition ratios of the terbium and europium ions, the emission colours were shown to be regulated to a large extent. The demonstrated process can be characterized as simple, versatile and environmentally‐friendly, featuring great flexibility in colour tunability, and therefore can present a considerable interest for emerging nanofabrication applications.LiangLiang Lin, XinTong Ma, Sergey A. Starostin, SiRui Li, Volker Hessel, Jie Shen, ShaoMing Shang, and HuJun X

A multi-controlled drug delivery system based on magnetic mesoporous Fe<inf>3</inf>O<inf>4</inf>nanopaticles and a phase change material for cancer thermo-chemotherapy

© 2017 IOP Publishing Ltd. Herein a novel multi-controlled drug release system for doxorubicin (DOX) was developed, in which monodisperse mesoporous Fe 3 O 4 nanoparticles were combined with a phase change material (PCM) and polyethylene glycol 2000 (PEG2000). It is found that the PCM/PEG/DOX mixture containing 20% PEG could be dissolved into water at 42 °C. The mesoporous Fe 3 O 4 nanoparticles prepared by the solvothermal method had sizes of around 25 nm and exhibited a mesoporous microstructure. A simple solvent evaporation process was employed to load the PCM/PEG/DOX mixture on the mesoporous Fe 3 O 4 nanoparticles completely. In the Fe 3 O 4 @PCM/PEG/DOX system, the pores of the Fe 3 O 4 nanoparticles were observed to be filled with the mixture of PCM/PEG/DOX. The Fe 3 O 4 @PCM/PEG/DOX system showed a saturation magnetization value of 50.0 emu g -1 , lower than 71.1 emu g -1 of the mesoporous Fe 3 O 4 nanoparticles, but it was still high enough for magnetic targeting and hyperthermia application. The evaluation on drug release performance indicated that the Fe 3 O 4 @PCM/PEG/DOX system achieved nearly zero release of DOX in vitro in body temperature, while around 80% of DOX could be released within 1.5 h at the therapeutic threshold of 42 °C or under the NIR laser irradiation for about 4 h. And a very rapid release of DOX was achieved by this system when applying an alternating magnetic field. By comparing the systems with and without PEG2000, it is revealed that the presence of PEG2000 makes DOX easy to be released from 1-tetradecanol to water, owing to its functions of increasing the solubility of DOX in 1-tetradecanol as well as decreasing the surface tension between water and 1-tetradecanol. The novel drug release system shows great potential for the development of thermo-chemotherapy of cancer treatment

Incandescent Lamp-Like White-Light Emission from Doped and Undoped Oxide Nanopowders

We report the production of a broad band emission (ranging from 400 to 900 nm) following the monochromatic infrared light (803.5 nm) continuous wave excitation of either nominally un-doped or Nd-doped up to 20% yttrium oxide (Y2O3) nanopowders, Y3Al5O12(YAG) and Cr3+doped Gd3Ga5O12(GGG) nanocrystallites. Our experimental results indicate that such emission feature is (i) a nano-scale phenomenon, (ii) demands a threshold pumping power, (iii) cannot be ascribed to an overlap of sharp emission bands in the un-doped case and, (iv) even if assisted by the dopant presence, is a host matrix-related process. In the case of the Y2O3-based samples, we demonstrate the possibility to obtain \u201cwarm\u201d white light with high efficiency and color rendering index approaching the theoretical limit with an alternative approach. Our experimental results make our white light emission very interesting at both fundamental and applicative levels and may open the way to an alternative route with respect to incandescent lamp