化学学报 ›› 2014, Vol. 72 ›› Issue (1): 89-94.DOI: 10.6023/A13101064 上一篇    下一篇

研究论文

一锅法制备YF3:Yb3+-Er3+纳米晶复合PNIPAm-co-PAA纳凝胶及其荧光温敏行为

宋秋生, 杨森森, 盛锐, 李谭   

  1. 合肥工业大学化工学院 合肥 230009
  • 收稿日期:2013-10-16 出版日期:2014-01-14 发布日期:2013-12-17
  • 通讯作者: 宋秋生,E-mail:sqshfut@126.com E-mail:sqshfut@126.com
  • 基金资助:

    项目受安徽省教育厅自然科学研究项目(No. 2009AJZR0137)和合肥工业大学创新基金(No. 2013CXSY340)资助.

One-pot Preparation of YF3:Yb3+-Er3+/PNIPAm-co-PAA Thermosensitive Fluorescent Nanogels

Song Qiusheng, Yang Sensen, Sheng Rui, Li Tan   

  1. School of Chemical Engineering, Hefei University of Technology, Hefei 230009, China
  • Received:2013-10-16 Online:2014-01-14 Published:2013-12-17
  • Supported by:

    Project supported by the Science Foundation of Educational Department of Anhui Province of China (grant No. 2009AJZR0137) and Innovational Foundation of Hefei University of Technology (grant No. 2013CXSY340).

采用巯基乙胺为配体,以硝酸铒(Er(NO3)3),硝酸镱(Yb(NO3)3),硝酸钇(Y(NO3)3)和氟化铵(NH4F)为原料,水热法制备表面含NH2基团的活性YF3:Yb3+-Er3+纳米晶;以过硫酸钾(K2S2O8)为引发剂,借助1-乙基-(3-二甲基氨基丙基)碳酰二亚胺(EDC)与N-羟基丁二酰亚胺(NHS)的偶联反应,在活性纳米晶存在下,进行N-异丙基丙烯酰胺(NIPAm),NN'-亚甲基双丙烯酰胺(BIS)与丙烯酸的自由基共聚合,一锅法制备了YF3:Yb3+-Er3+/PNIPAm-co-PAA荧光温敏纳凝胶. 对制备的纳米晶及纳凝胶的结构与荧光性能进行了表征. 结果表明,纳米晶的粒径为6~10 nm,呈单分散分布;纳凝胶的粒径呈多分散分布,粒径主要分布在100~300 nm. PL光谱分析表明,活性YF3:Yb3+-Er3+纳米晶的4F7/24I15/2跃迁,在483和496 nm处产生明显的能级劈裂;纳凝胶中,该能级劈裂依然存在,但随温度升高发生耦合;环境温度对纳凝胶的上转换发光强度产生明显影响.

关键词: YF3:Yb3+-Er3+, 纳米晶, PNIPAm-co-PAA, 温敏性, 纳凝胶, 荧光强度

Rare-earth nanocrystals are a family of important nanomaterials due to their unique optical and electronic properties, and they are paid more attention for their applications in the areas of solar energy system, molecular imaging, optoelectronics and catalysis fields. The incorporation of rare-earth nanocrystals into smart gels, which combines the PL features of rare-earth nanocrystals with the reversible and stimuli-responsive properties of smart gels, will provide a new generation of fluorescence markers for practical application. In this paper, we report a one-pot method to prepare thermosensitive fluorescent nanogels from rare earth nanocrystals and PNIPAm-co-PAA nanogels. Firstly, using cysteamine, Er(NO3)3, Yb(NO3)3, Y(NO3)3 and NH4F as raw materials, active YF3:Yb3+-Er3+ nanocrystals with-NH2 groups were synthesized by hydrothermal method. After that, in the present of the as-prepared active YF3:Yb3+-Er3+ nanocrystals, N-isopropyl acrylamide (NIPAm) and N,N'-methylene bisacrylamide (BIS) were initiated by K2S2O8. Finally, thermosensitive fluorescent nanogels of YF3:Yb3+-Er3+/PNIPAm-co-PAA were fabricated by free radical polymerization and in-situ coupling reactions of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The microstructure and performance of the as-prepared YF3:Yb3+-Er3+ nanocrystals and the complex nanogels were investigated by differential scanning calorimeter (DSC), photoluminescence (PL), Fourier transform infrared (FTIR), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). As the evidence from the HRTEM images, active YF3:Yb3+-Er3+ nanocrystals show well monodispersity with their size of about 6~10 nm, and the complex nanogels are polydisperse ones with their size of about 100~300 nm. The results of PL spectra at various temperatures suggest that, the active YF3: Yb3+-Er3+ nanocrystal present weak double emitting peaks around 483 and 496 nm, which are resulted from the energy level splitting of 4F7/24I15/2 transition of Er3+. As for the complex nanogels, the phenomenon of energy level splitting of Er3+ is different from that of the nanocrystals, with increasing ambient temperatures, double emitting peaks around 483 and 496 nm couple into an emitting peak around 489 nm gradually, and their intensity decreases correspondingly.

Key words: YF3:Yb3+-Er3+nanocrystals, PNIPAm-co-PAA, thermosensitive, nanogel, PL intensity