A novel scheme to obtain tunable fluorescent colors based on electrospun composite nanofibers

Abstract

Europium complexes Eu(BA) 3 phen (BA = benzoic acid, phen = 1,10-phenanthroline) and Terbium complexes Tb(BA) 3 phen are incorporated into polyvinyl pyrrolidone (PVP) and electrospun into [Eu(BA) 3 phen + Tb (BA) 3 phen]/PVP composite nanofibers. The morphologies and properties of the final products are investigated via scanning electron microscopy, energy dispersive spectrometry,X-ray powder diffractometry, fluorescence spectroscopy, Fourier-transform infrared spectroscopy and thermogravimetry. The diameter of the composite nanofibers is 431.55 ± 3.14 nm. The obtained composite nanofibers are amorphous in structure and stable below 220°C. By adjusting the ratio of Eu(BA) 3 phen to Tb (BA) 3 phen complexes, the fluorescence color of composite nanofibers can be tuned from red to yellow, yellow green, and green under the excitation of 276-nm single-wavelength ultraviolet light. Besides, the fluorescence lifetime of Eu 3+ ions in composite nanofibers is extended gradually, while that of Tb 3+ ions is decreased slowly with increase of Tb (BA) 3 phen content. The novel color-tunable composite nanofibers have potential applications in the fields of optical devices, color displays and sensor systems.

Highly Efficient Fluorescent Material Based on Rare-Earth-Modified Polyhydroxyalkanoates

“…Quantum dots (QDs) are inorganic semiconductor nanoparticles that offer several advantages as a new fluorescent material over conventional fluorescent dyes, including greater photo yield, greater resistance to photobleaching and a wider range of excitation/emission wavelengths. ,, In spite of such strengths, the potential toxicity of QDs due to the liberation of free ions and their poor solubility depending on the process of particle synthesis and surface modification, are big concerns that restrict their wider applications in biological fields. ,, The choice of the rare earth fluorescent materials has been driven by their fascinating light emission properties, such as their sharp and intense excited-state luminescence, narrow-width and visible emission bands, long decay time and high quantum yields. ,− Apart from scandium and yttrium, rare earth metal ions comprise 15 lanthanide (Ln) elements with typical electron configurations of [Xe]­4f n ( n = 0–14), which can generate different electronic levels, bringing about the unique photoluminescent property for almost all Ln 3+ . Nevertheless, the “buried” nature of the f orbitals and the forbidden transitions of electrons between 4f orbitals require an “antenna” for improving the absorption of energy to activate the f-f transitions of rare earth metal ions. , Because of this reason, various organic ligands have been chosen as “antenna” to prepare rare earth organic complexes such as rare earth carboxylate complexes, rare earth β-diketone complexes and rare earth macrocyclic complexes . However, these molecules likewise show several shortcomings such as the biotoxicity, poor mechanical flexibility, easy photodegradation and instability under thermal stress, which inevitably undermine their value.…”

“…28 Nevertheless, the "buried" nature of the f orbitals and the forbidden transitions of electrons between 4f orbitals require an "antenna" for improving the absorption of energy to activate the f-f transitions of rare earth metal ions. 28,29 Because of this reason, various organic ligands have been chosen as "antenna" to prepare rare earth organic complexes such as rare earth carboxylate complexes, 30 rare earth β-diketone complexes 31 and rare earth macrocyclic complexes. 32 However, these molecules likewise show several shortcomings such as the biotoxicity, poor mechanical flexibility, easy photodegradation and instability under thermal stress, which inevitably undermine their value.…”

A new route to fabricate PbS nanofibers and PbSe nanofibers via electrospinning combined with double-crucible technique

“…Double-crucible technique has been proved to be an efficient, convenient and simple way to fabricate nanofibers, nanobelts and hollow nanofibers [24]. Meanwhile, electrospinning is a promising, straightforward and convenient way to prepare one-dimensional (1D) nanomaterials [25,26] with diameters ranging from tens of nanometers up to micrometers owing to its easy control and low cost, including nanofibers [27,28], core-shell structured nanofibers [29,30], core-shell structured nanotubes [31,32], nanowires [33], nanosheets [34,35] and nanobelts [36][37][38], etc. Nevertheless, the fabrication of PbS or PbSe nanofibers via electrospinning combined with a doublecrucible technique is not reported.…”

Flexible composite nanobelts: facile electrospinning construction, structure and color-tunable photoluminescence

“…However, pure rare earth complexes have serious limitations in practical applications as a reason of their poor mechanical properties and physicochemical stabilities. Rare earth complexes were usually added into a polymer matrix to form polymer-based composites in order to overcome the defects, and the composites can present excellent fluorescent properties and the enhanced mechanical performance [27].…”