Controllable Synthesis And Properties Of Rare Earth Phosphate And Molybdate Luminescent Materials With Diverse Morphologies

In recent years,micro/nano rare earth luminescent materials have been found potential applications in fields of catalysis,biological fluorescent probes and drug delivery.Hollow spherical materials have attracted more and more attentions in the fields of drug delivery system,cosmetics,and photonic crystals due to their unique structural properties?large specific surface area,low density,high surface activity,etc.?and the stable chemical and physical properties.Therefore,the controllable synthesis of micro/nano rare earth luminescent materials with hollow structure has become research focus for researchers.In this dissertation,a series of rare-earth phosphates molybdate luminescent materials have been prepared by hydro/solvothermal route,and the phase,structure,morphology,growth mechanism and luminescent properties were investigated in detail.The well-dispersed and uniform urchin-like hierarchical GdPO₄ hollow spheres have been successfully fabricated via a facile hydrothermal route in the presence of3-aminophenol-formaldehyde?APF?resin microspheres as templates.During the reaction process,CTAB was added to regulate the morphology of the sample,and the time experiment was used to clarify the formation process of the materials.Under UV excitation,the rare earth activator ion doped samples exhibits excellent luminescent properties.Due to the good biocompatibility,high drug loading capacity and good sustained-release properties,the as-synthesized GdPO₄ samples may find potential applications in the biomedical fields of bioimaging,drug delivery,etc.Well-uniform yttrium phosphate?YPO₄?hollow microspheres have been fabricated by a facile solvent thermal process with APF resin microspheres as template without any surfactants.During the reaction process,reaction temperature and component of solvent have great effect on the morphology of the samples.In addition,Tb³⁺and Eu³⁺ions have been doped into the as-synthesized YPO₄ host.The as-obtained phosphors exhibit excellent luminescence properties under ultraviolet,which has potential applications in fluorescence illumination and electronic displays.The YPO₄ hollow microspheres exhibit good biocompatibility by MTT assay.Moreover,ibuprofen?IBU?was used as model drug to investigate the drug loading and sustained-release properties of YPO₄ hollow microspheres.The result indicates that the as-prepared YPO₄ hollow microspheres exhibit excellent drug loading capacity and sustained release behavior,which may be applied as a drug carrier in biomedical field.A facile citrate-assisted hydrothermal route has been developed to synthesize well-defined NaTb?MoO₄?₂ hierarchical nanoflowers with trisodium citrate as surfactant.The pH value of the initial solution,reaction temperature,and component of solvent have a great effect on the morphology and particle size of the products.Photoluminescence spectra show that there is an energy transfer process between MoO₄^2-and Tb³⁺to Eu³⁺in NaTb?MoO₄?₂:Eu³⁺samples.Therefore,the tunable luminescence of the NaTb?MoO₄?₂materials may be realized on the basis of the energy transfer between the host material and the activator ions.