Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin, China.
Dalton Trans. 2012 Oct 14;41(38):11716-24. doi: 10.1039/c2dt30954h. Epub 2012 Aug 28.
Monodisperse rare earth (RE) fluoride colloidal nanocrystals (NCs) including REF(3) (RE = La, Pr, Nd), NaREF(4) (RE = Sm-Ho, Y) and Na(5)RE(9)F(32) (RE = Er, Yb, Lu) have been successfully synthesized by a facile one-step method using oleic acid as surfactant and 1-octadecene as solvent. The phase, morphology, size, and photoluminescence properties of as-synthesized NCs were well investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FT-IR), and photoluminescence (PL) spectra. The results reveal that the as-synthesized NCs consist of monodisperse colloidal NCs with narrow size distribution, which can easily disperse in non-polar cyclohexane solvent. The as-prepared NCs exhibit a rich variety of morphologies and different crystal phases (hexagonal or cubic), which may be related to the inherent natures of different rare earth ions. The possible formation mechanism of NCs with diverse architectures has been presented. In addition, representative Yb/Er, Yb/Tm, or Yb/Ho co-doped NaGdF(4) and Na(5)Lu(9)F(32) NCs exhibit intensive multicolor up-conversion (UC) luminescence under a single 980 nm NIR excitation, displaying potential applications in bioimaging and therapy. Moreover, transparent and UC fluorescent NCs-polydimethylsiloxane (PDMS) composites with regular dimensions were also prepared by an in situ polymerization route.
单分散稀土氟化物胶体纳米晶体（NCs），包括 REF(3)（RE = La、Pr、Nd）、NaREF(4)（RE = Sm-Ho、Y）和 Na(5)RE(9)F(32)（RE = Er、Yb、Lu），已通过简便的一步法成功合成，该方法使用油酸作为表面活性剂，十八烯作为溶剂。通过 X 射线衍射（XRD）、透射电子显微镜（TEM）和高分辨率透射电子显微镜（HRTEM）、傅里叶变换红外光谱（FT-IR）和光致发光（PL）光谱对合成的 NCs 的物相、形貌、尺寸和荧光性质进行了研究。结果表明，所合成的 NCs 由单分散胶体 NCs 组成，具有窄的尺寸分布，很容易在非极性环己烷溶剂中分散。所制备的 NCs 表现出丰富的形貌和不同的晶体相（六方或立方），这可能与不同稀土离子的固有性质有关。提出了具有不同结构的 NCs 的可能形成机制。此外，代表性的 Yb/Er、Yb/Tm 或 Yb/Ho 共掺杂的 NaGdF(4)和 Na(5)Lu(9)F(32) NCs 在单一 980nm 近红外激发下表现出强烈的多色上转换（UC）发光，在生物成像和治疗方面具有潜在的应用。此外，还通过原位聚合途径制备了具有规则尺寸的透明 UC 荧光 NCs-聚二甲基硅氧烷（PDMS）复合材料。
