Search Results (7)

A series of homogeneous hybrid BPA.DA-NVP@Eu₂L₃ materials were obtained through an in situ approach where the luminescent dopant was formed at the molecular level with different contents (0.1; 0.2; 0.5; 1; and 2% by weight). A Europium(III) complex (Eu₂L₃) with quinoline-2,4-dicarboxylic acid was applied as a luminescence additive while a polymer matrix consisted of a combination of bisphenol A diacrylate (BPA.DA) and N-vinylpyrrolidone (NVP) monomers. Synthesis steps and the final materials were monitored by NMR and Fourier transform infrared spectroscopy (FTIR). The emission, excitation spectra, lifetime, and quantum yield measurements were applied for the determination of the photophysical characteristics. The thermal and mechanical properties of the obtained materials were tested via thermal analysis methods (TG/DTG/DSC and TG-FTIR) in air and nitrogen atmospheres, dynamic mechanical analysis (DMA), and hardness and bending measurements. Generally, even a small addition of the metal complex component causes changes in the thermal, mechanical, and luminescent properties. Hybrid materials with a greater europium complex content are characterized by a lower stiffness and hardness while the heterogeneity and the flexibility of the samples increase. A very small amount of an Eu₂L₃ admixture (0.1% wt.) in a hybrid material causes an emission in the red spectral range and the luminescence intensity was reached for the BPA-DA-NVP@1%Eu₂L₃ material. These materials may be potentially used in chemical sensing, security systems, and protective coatings against UV. Full article

Ladder-type polysilsesquioxanes (LPSQs) containing phenyl as a high refractive index unit and cyclic epoxy as a curable unit were found to be excellent candidates for a transparent color conversion layer for displays due to being miscible with organic solvents and amenable to transparent film formation. Therefore, the LPSQs were combined with luminescent lanthanide metals, europium Eu(III), and terbium Tb(III), to fabricate transparent films with various emission colors, including red, orange, yellow, and green. The high luminescence and transmittance properties of the LPSQs–lanthanide composite films after thermal curing were attributed to chelating properties of hydroxyl and polyether side chains of LPSQs to lanthanide ions, as well as a light sensitizing effect of phenyl side chains of the LPSQs. Furthermore, Fourier-transform infrared (FT-IR) and X-ray photoelectron spectroscopy and nanoindentation tests indicated that the addition of the nanoparticles to the LPSQs moderately enhanced the epoxy conversion rate and substantially improved the wear resistance, including hardness, adhesion, and insusceptibility to atmospheric corrosion in a saline environment. Thus, the achieved LPGSG–lanthanide hybrid organic–inorganic material could effectively serve as a color conversion layer for displays. Full article

In this study, novel hybrid materials exhibiting luminescent properties were prepared and characterized. A top-down approach obtained a series of polymeric materials with incorporated different amounts (0.1; 0.2; 0.5; 1, and 2 wt.%) of dopants, i.e., europium(III) and terbium(III) 1H-pyrazole-3,5-dicarboxylates, as luminescent sources. Methyl methacrylate and bisphenol A diacrylate monomers were applied for matrix formation. The resulting materials were characterized using Fourier transform infrared spectroscopy (FTIR) and thermal analysis methods (TG-DTG-DSC, TG-FTIR) in air and nitrogen atmosphere, as well as by luminescence spectroscopy. The homogeneity of the resulting materials was investigated by means of optical microscopy. All obtained materials exhibited good thermal stability in both oxidizing and inert atmospheres. The addition of lanthanide(III) complexes slightly changed the thermal decomposition pathways. The main volatile products of materials pyrolysis are carbon oxides, water, methyl methacrylic acid and its derivatives, bisphenol A, 4-propylphenol, and methane. The luminescence properties of the lanthanide complexes and the prepared hybrid materials were investigated in detail. Full article

Theranostics (bifunction of therapeutics and diagnostics) has attracted increasing attention due to its efficiency that can reduce the physical and financial burden on patients. One of the promising materials for theranostics is calcium phosphate (CP) and it is biocompatible and can be functionalized not only with drug molecules but also with rare earth ions to show photoluminescence that is necessary for the diagnostic purpose. Such the CP-based hybrids are formed in vivo by interacting between functional groups of organic molecules and inorganic ions. It is of great importance to elucidate the interaction of CP with the photofunctional species and the drug molecules to clarify the relationship between the existing state and function. Well-designed photofunctional CPs will contribute to biomedical fields as highly-functional ormultifunctional theranostic materials at the nanoscales. In this review, we describe the hybridization between CPs and heterogeneous species, mainly focusing on europium(III) ion and methylene blue molecule as the representative photofunctional species for theranostics applications. Full article

A europium(III) hybrid material Eu(tta)₃bpdc-SiO₂@mTiO₂ (Htta = 2-thenoyltrifluoroacetone, H₂bpdc = 2,2′-bipyridine-3,3′-dicarboxylic acid) was successfully designed and synthesized by the covalent grafting complex Eu(tta)₃bpdc to SiO₂@mTiO₂ core–shell nanosphere. The FT-IR, PXRD, XPS, TEM, HRTEM, SAED, TGA and PL were performed to characterize these materials. The results indicate that core–shell nanosphere structure and anatase crystallites of SiO₂@mTiO₂ are retained well after grafting the europium complex. Hybrid material Eu(tta)₃bpdc-SiO₂@mTiO₂ displays uniform nanosphere structure, bright red color and long lifetime, which can serve as a multicolor emission material modulated by using Al³⁺ ions via the cation exchange approach under a single-wavelength excitation. To the best of our knowledge, this work is the first multicolor emissive sensor for Al³⁺ ions based on the lanthanide hybrid material. Full article

Novel hybrid materials based on the poly(methyl methacrylate) (PMMA) matrix and lanthanide(III) carboxylates Eu:2,6-DClB and Tb:2,6-DClB were synthesized and carefully analyzed in the context of their potential application in optically active polymer-based optical fibers. To determine the usefulness of the obtained materials, a careful thermal, mass spectroscopy, and optical characterization was performed, focusing on the features critical for the technology of optical fiber processing. In addition, the luminescent features of both lanthanide complexes and the resulting hybrid composites were carefully investigated to identify the processes responsible for light emission and to analyze the influence of the PMMA host on light emission intensity and spectral characteristics. The obtained results showed that both lanthanide carboxylate complexes exhibited intense luminescence in the red and green spectral range, typical of europium and terbium dopants, and that those features were well preserved after introducing them into the PMMA polymer. Thermal analysis also proved that introducing the luminescent additives did not significantly affect the thermal properties of both hybrid materials, thus enabling further processing into the form of optical fibers. Full article

Here we discuss the influence of two different cations on the emissive properties of the highly emissive [Eu(fod)₄]⁻ anion. The studied Eu(III) salts were [C₁₆Pyr][Eu(fod)₄] (1), and the previously reported [Chol][Eu(fod)₄]. C₁₆Pyr stands for N-cetylpyridinium, Chol for cholinium and fod for 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate. 1 is classified as ionic liquid, with melting point close to 60 °C, and presented a luminescence quantum yield of (ϕ) 100%. Ultrabright emissive photopolymers were obtained for the first time using polysulfone as the host matrix. The films were prepared with incorporation of 10% (w/w) of 1 and [Chol][Eu(fod)₄] in the polymeric matrix, which improved its thermal stability. Additionally, the luminescence of CholEu(fod)₄/PSU presented a strong temperature dependence with a ratiometric thermal behavior. Full article