A red-emitting composite CMC/Eu(Ⅲ) was synthesized by employing a microwave heating method(70℃, pH7.0,1min) with different ratio of CMC and Eu(Ⅲ), the ratio of CMC:Eu(Ⅲ) was 10:1, 15:1, 19:1 and 28:1, respectively. The structures of the composite were analyzed by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) and SEM. XRD measurement showed that the CMC/Eu composite had lower crystallinity compared with CMC. The FTIR results indicated Eu3+ not only combined with -COO- through the ionic bond but also coordinated with O atom of the –OH and ether bond in CMC. The SEM images showed that CMC/Eu composites had good distribution, and the average particle size was less than 100nm, from which we can say that we had synthesized nano-sized CMC/Eu composite materials. The optical solid state properties were determined using UV-absorption, excitation and emission spectroscopy. The UV-vis spectrum of Eu/CMC solid showed composites' ultraviolet absorption curve and peak position were similar to CMC and their absorption intensities were much stronger than CMC, among them, the 19:1 composite had the highest absorption intensity. The photoluminescence (PL) measurements exhibited a strong red emission band centered at about 616 nm (5D0-7F2) under an excitation wavelength of 395 nm (see Figure). 19:1 simple had strongest fluorescence intensity while 10:1 and 15:1 simple has the minimal fluorescence intensity, which indicated that there was adequate ratio between CMC and Eu3+ which was 19:1and had fluorescence quenching phenomenon when improve the ratio to 28:1 for decreasing fluorescence intensity. Acknowledgement: Supported by the National 973 project under Grant No. 2010CB732201, the National Natural Foundation of China under Grant No. 31270617 .

Effect of different ratio of CMC and Eu(III) on the fluorescence properties and structures of CMC/Eu nanocomposites

249th National Meeting (2015)

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