Back
 WJNSE  Vol.2 No.2 , June 2012
A Method to Improve the Up-Conversion Fluorescence of Polymer Modified NaYF4:Yb,Er(Tm) Nanocomposites
Abstract: The modification of NaYF4:Yb,Er(Tm) nanoparticles synthesized in the presence of an ionic surfactant is critical to their application in biological fields for better solubility and biocompatibility. In this work, NaYF4:Yb,Er(Tm) was transformed from insoluble, inactive to hydrophilic, biocompatible via ligand exchange modification with polyacrylic acid (PAA). Ligand exchange was carried out at room temperature when a colloidal solution of NaYF4:Yb,Er(Tm) in tetrahydrofuran (THF) was treated with excess PAA. The PAA modified NaYF4:Yb,Er(Tm) nanoparticles got better surface properties but with declined inner up-conversion fluorescence. Generally, coating an analogous layer of material outside the core nanoparticles can improve the optical properties of the core. Accordingly, NaYF4:Yb,Er(Tm)/NaYF4 nanoparticles were synthesized before PAA modification to avoid the optical intensity decaying. The result of fluorescence test proved that the water soluble NaYF4:Yb,Er(Tm)/NaYF4/PAA nanocomposites had a sound up-conversion property compared with that of NaYF4:Yb,Er(Tm)/PAA. Furthermore, the up-conversion fluorescence property of the nanocomposite varied with the doping ratio of Er(Tm) to Yb and the possible mechanism for this change was also discussed.
Cite this paper: W. Cui, S. Ni, S. Shan and X. Zhou, "A Method to Improve the Up-Conversion Fluorescence of Polymer Modified NaYF4:Yb,Er(Tm) Nanocomposites," World Journal of Nano Science and Engineering, Vol. 2 No. 2, 2012, pp. 41-46. doi: 10.4236/wjnse.2012.22007.
References

[1]   N. Menyuk, K. Dwight and J. W. Pierce, “NaYF4:Yb, Er—An Efficient Upconversion Phosphor,” Applied Physics Letters, Vol. 21, No. 4, 1972, pp. 159-163. doi:10.1063/1.1654325

[2]   G. S. Yi and G. M. Chow, “Synthesis of Hexagonal-Phase NaYF4:Yb,Er and NaYF4:Yb,Tm Nanocrystals with Efficient Up-Conversion Fluorescence,” Advanced Functional Materials, Vol. 16, No. 18, 2006, pp. 2324-2329. doi:10.1002/adfm.200600053

[3]   F. van de Rijke, H. Zijlmans, S. Li, T. Vail, A. K. Raap, R. S. Niedbala and H. J. Tanke, “Up-Converting Phosphor Reporters for Nucleic Acid Microarrays,” Nature Biotechnology, Vol. 19, 2001, pp. 273-276. doi:10.1038/85734

[4]   G. S. Yi, H. C. Lu, S. Y. Zhao, G. Yue, W. J. Yang, D. P. Chen and L. H. Guo, “Synthesis, Characterization and Biological Application of Size-Controlled Nanocrystalline NaYF4:Yb,Er Infrared-to-Visible Up-Conversion Phosphors,” Nano Letters, Vol. 4, No. 11, 2004, pp. 2191-2196. doi:10.1021/nl048680h

[5]   S. W. Kim, S. Kim, J. B. Tracy, A. Jasanoff and M. G. Bawendi, “Phosphine Oxide Polymer for Water-Soluble Nanoparticles,” Journal of the American Chemical Society, Vol. 127, No. 13, 2005, pp. 4556-4557. doi:10.1021/ja043577f

[6]   T. R. Zhang, J. P. Ge, Y. X. Hu and Y. D. Yin, “A General Approach for Transferring Hydrophobic Nanocrystals into Water,” Nano Letters, Vol. 7, No. 10, 2007, pp. 3203-3207. doi:10.1021/nl071928t

[7]   W. J. Lin, F. Karolina, G. Gerald, R. B. Ghasem, H. Sean, S. Vlad, H. S. Edward, D. S. Gregory and A. W. Mitchell, “Highly Luminescent Lead Sulfide Nanocrystals in Organic Solvents and Water through Ligand Exchange with Poly (Acrylic Acid),” Langmuir, Vol. 24, No. 15, 2008, pp. 8215-8219. doi:10.1021/la800568k

[8]   X. P. Zhou, S. S. Li, X. L. Chen, Q. Zhu, Z. Q. Wang and J. Zhang, “Formation of Nanocrystalline Matrix of Sodium Rare Earth Fluoride Up-Conversion Phosphors,” Journal of Nanoscience and Nanotechnology, Vol. 8, No. 10, 2008, pp. 1392-1397.

[9]   G. S. Yi and G. M. Chow, “Water-Soluble NaYF4:Yb, Er(Tm)/NaYF4/Polymer Core/Shell/Shell Nanoparticles with Significant Enhancement of Upconversion Fluorescence,” Chemistry of Materials, Vol. 19, No. 3, 2007, pp. 341-343. doi:10.1021/cm062447y

[10]   H. S. Qian and Y. Zhang, “Synthesis of Hexagonal-Phase Core-Shell NaYF4 Nanocrystals with Tunable Upconversion Fluorescence,” Langmuir, Vol. 24, No. 21, 2008, pp. 12123-12125. doi:10.1021/la802343f

[11]   H. X. Hai, Y. W. Zhang, L. D. Sun and C. H. Yan, “Highly Efficient Multicolor Up-Conversion Emissions and Their Mechanisms of Monodisperse NaYF4:Yb,Er Core and Core/Shell-Structured Nanocrystals,” The Journal of Physical Chemistry C, Vol. 111, No. 37, 2007, pp. 13721-13729. doi:10.1021/jp073920d

[12]   S. Perviz, “Effect of Sodium Oleate on the Agglomeration of Calcium Carbonate,” Crystal Research and Technology, Vol. 40, No. 3, 2005, pp. 226-232. doi:10.1002/crat.200410330

[13]   K. Verm?hlen, H. Lewandowski, H. D. Narres and E. Koglin, “Adsorption of Polyacrylic Acid on Aluminium Oxide: DRIFT Spectroscopy and Ab Initio Calculations,” Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 170, No. 2-3, 2000, pp. 181-189. doi:10.1016/S0927-7757(00)00408-8

[14]   S. S. Wei, Y. Zhang and J. R. Xu, “The Dynamic Rheology Behaviors of Reactive Polyacrylic Acid/Nano-Fe3O4 Ethanol Suspension,” Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 296, No. 1-3, 2007, pp. 51-56. doi:10.1016/j.colsurfa.2006.09.021

[15]   L. Y. Wang and Y. D. Li, “Controlled Synthesis and Luminescence of Lanthanide Doped NaYF4 Nanocrystals,” Chemistry of Materials, Vol. 19, No. 4, 2007, pp. 727-734. doi:10.1021/cm061887m

[16]   G. F. Wang, W. P. Qin, J. S. Zhang, L. L. Wang, G. D. Wei, P. F. Zhu and K. Ryongjin, “Controlled Synthesis and Luminescence Properties from Cubic to Hexagonal NaYF4:Ln3+ (Ln = Eu and Yb/Tm) Microcrystals,” Journal of Alloys and Compounds, Vol. 475, No. 1-2, 2009, pp. 452-455. doi:10.1016/j.jallcom.2008.07.050

[17]   X. Chen, W. J. Wang, X. Y. Chen, J. H. Bi, L. Wu, Z. H. Li and X. Z. Fu. “Microwave Hydrothermal Synthesis and Upconversion Properties of NaYF4:Yb3+, Tm3+ with Microtube Morphology,” Materials Letters, Vol. 63, No. 12, 2009, pp. 1023-1026. doi:10.1016/j.matlet.2009.01.075

[18]   C. H. Liu, H. Wang, X. Li and D. P. Chen, “Monodisperse, Size-Tunable and Highly Efficient β-NaYF4:Yb,Er(Tm) Up-Conversion Luminescent Nanospheres: Controllable Synthesis and Their Surface Modifications,” Journal of Materials Chemistry, Vol. 19, No. 21, 2009, pp. 3546-3553. doi:10.1039/b820254k

[19]   J. F. Suyver, J. Grimm, M. K. van Veen, D. Biner, K. W. Kramer and H. U. Güdel, “Upconversion Spectroscopy and Properties of NaYF4 Doped with Er3+, Tm3+ and/or Yb3+,” Journal of Luminescence, Vol. 117, No. 1, 2006, pp. 1-12. doi:10.1016/j.jlumin.2005.03.011

 
 
Top