title: Novel multifunctional nanocomposites: magnetic mesoporous silica nanospheres covalently bonded with near-infrared luminescent lanthanide complexes.
abstract: In this paper, we report the fabrication and characterization of magnetic mesoporous silica nanospheres covalently bonded with near-infrared (NIR) luminescent lanthanide complexes [denoted as Ln(DBM)(3)phen-MMS (Ln = Nd, Yb)]. Ln(DBM)(3)phen-MMS (Ln = Nd, Yb) nanospheres with an average size of 80-130 nm were synthesized via incorporation of the chelate ligand 5-[N,N-bis-3-(triethoxysilyl)propyl]ureyl-1,10-phenanthroline (phen-Si) into the framework of magnetic mesoporous silica (denoted as phen-MMS), followed by introduction of the Ln(DBM)(3)(H(2)O)(2) (Ln = Nd, Yb) complexes into the nanocomposites via a ligand exchange reaction. The morphological, structural, textural, magnetic, and NIR luminescent properties were well-characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), N(2) adsorption-desorption, a superconducting quantum interference device (SQUID), and photoluminescence spectra. These nanocomposites, which possess high surface area, high pore volume, and well-defined pore size, exhibit two-dimensional hexagonal (P6mm) mesostructures. After ligand-mediated excitation, Ln(DBM)(3)phen-MMS (Ln = Nd, Yb) nanocomposites exhibit the characteristic NIR emission of Nd(3+) and Yb(3+), respectively. Magnetic measurements reveal that these mulfunctional nanocomposites possess superparamagnetic properties at 300 K. The high magnetization values make the nanocomposites respond to the external magnetic field quickly. Additionally, the results indicate that Nd(DBM)(3)phen-MMS nanocomposites may have potential applications for laser systems or the optical amplifiers operating at 1.3 microm and Yb(DBM)(3)phen-MMS nanocomposites have several advantages for potential applications in drug delivery or optical imaging.
authors.affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Feng
authors.forename: Shu-Yan
authors.initials: SY
authors.lastname: Song
authors.forename: Rui-Ping
authors.initials: RP
authors.lastname: Deng
authors.forename: Wei-Qiang
authors.initials: WQ
authors.lastname: Fan
authors.forename: Hong-Jie
authors.initials: HJ
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D007259:Infrared Rays; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D049408:Luminescent Agents / Q000138:chemical synthesis / Q000737:chemistry; D008280:Magnetics; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry*; D054118:Nanospheres / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D016062:Porosity; D053838:Scattering, Small Angle; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D028581:Lanthanoid Series Elements; D049408:Luminescent Agents; D009942:Organometallic Compounds; D012822:Silicon Dioxide