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Remarkable laser-driven upconverting photothermal effect of Cs3LnF6@glass nanocomposites for anti-counterfeiting
摘要： Currently, advanced security strategies have aroused widely interest in anti-counterfeiting field to ensure the authentic items difficult to be replicated. Herein, cubic Cs3LnF6 (Ln = Y, Yb, Lu, Sc) nanocrystals embedded glasses are successfully prepared via an in-situ glass crystallization strategy. Emitting centers, such as Eu3+, Er3+, Ho3+ and Tm3+, can be incorporated into the precipitated Cs3YF6, Cs3YbF6 and Cs3LuF6 crystal lattices but remain in glass matrix rather than in Cs3ScF6 crystals for large ionic radius mismatch between lanthanide activators and Sc3+ host ions. It is demonstrated that upconverting quantum yields of all the Yb/Er: Cs3LnF6@glass samples are higher than those of well-known cubic/hexagonal Yb/Er: α/β-NaYF4@glass samples. Specifically, Yb/Er: Cs3LuF6@glass exhibits a maximal quantum yield of ~0.30%, which is superior to Yb/Er: β-NaYF4 @glass (~0.19%). Impressively, Er: Cs3YbF6@glass shows a remarkable 980 nm laser-induced photothermal effect, leading to significant alteration of upconversion emissive color from red to green with increase of incident laser power. As a prototype of the concept for practical application, a series of luminescent patterns using Er: Cs3YbF6@glass upconverting inks are constructed by a screen-printing technique and show distinct laser-power-sensitive emissive colors, being feasible for high-level anti-counterfeiting. The present work exploits a new anti-counterfeiting strategy by developing highly efficient laser-induced upconverting photothermal materials.
关键词： Anticounterfeit,Nanocomposites,Upconversion,Lanthanide ions,Photothermal effect,Luminescent glasses
更新于2025-10-22 19:38:57
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Lanthanide complexes with 2-(tosylamino)-benzylidene-N-(aryloyl)hydrazones - universal luminescent materials
摘要： Lanthanide complexes Ln(L1)(HL1) (Ln = Lu, Yb, Er, Gd, Eu, Sm) and Ln(L2)(HL2) (Ln = Lu, Yb, Gd, Eu) with 2-(tosylamino)-benzylidene-N-(aryloyl)hydrazones (H2L1, aryloyl = 2-hydroxybenzoyl; H2L2, aryloyl = Isonicotinoyl) were obtained with the aim to explore them as new luminescent materials. They were found to form monomeric species independently on the aryloyl nature, their crystal structures were determined from single crystal X-ray data (Yb(L2)(HL2)·0.5(C2H5OH)), as well as from powder X-ray data by Rietveld refinement (Eu(L1)(HL1)). Ytterbium complexes exhibited intense luminescence, which allowed using them in host-free OLEDs, which demonstrated remarkable efficiency of NIR electroluminescence (50 μW/W) at low voltage (5V). Special mechanism of europium luminescence quenching allowed using europium complexes as luminescent thermometers, which demonstrated very high sensitivity up to 12%/K. The theory of luminescence thermometry based on three-level system was proposed which allowed predicting sensitivity with high accuracy (error within 20%).
关键词： lanthanide complexes,OLEDs,luminescent thermometry,NIR emission,luminescent materials
更新于2025-09-23 15:23:52
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Paintable Room Temperature Phosphorescent Liquid Formulations of Alkylated Bromonaphthalimide
摘要： Organic phosphors have been widely explored with an understanding that crystalline molecular ordering is a requisite for enhanced intersystem crossing. In this context, we explore the room temperature phosphorescence features of a solvent-free organic liquid phosphor in air. Given alkyl chain substitution varied the physical states of bromonaphthalimides, phosphorescence remained unaltered for the solvent-free liquid in air. As the first report, a solvent-free liquid of a long swallow tailed bromonaphthalimide exhibits room temperature phosphorescence in air. Doping of the phosphor with carbonyl guests resulted in enhanced phosphorescence and hence a large area paintable phosphorescent liquid composite with improved lifetime and quantum yield is developed.
关键词： phosphorescence,organic liquids,excimer,luminescent thermometer,liquid phosphor
更新于2025-09-23 15:23:52
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Sustainable Liquid Luminescent Solar Concentrators
摘要： Luminescent solar concentrators (LSCs) are photovoltaic (PV) complementary devices to overcome the mismatch between the Si-based PV cells, response and the solar spectrum, allowing PV urban integration. Challenges for the luminescent layer include the use of abundant and sustainable natural organic molecules. Here, LSCs composed of a glass container and based on bundles of cylindrical hollow-core plastic optical fibers filled with aqueous solutions of R-phycoerythrin (R-PE), extracted from Gracilaria sp. algae are presented. The R-PE solutions absorb in the UV/visible spectral range (300–550 nm) and convert this radiation into red-emission (550–700 nm) with a maximum absolute quantum yield of ≈0.39. In this work, LSCs with distinct geometries are reported, in which the R-PE emission yields optical conversion efficiency values up to ≈6.88% and ≈4.74% for a planar device and for a bundle of cylindrical LSCs, respectively, which are the largest values known for liquid-based LCSs using sustainable emitting centres. Moreover, the coupling of the LSCs to commercial Si-based PV devices yields power conversion efficiency values of ≈0.27% (planar) and ≈23.03 × 10?3%, (bundle). These values illustrate the potential of this approach for the development of natural-based LSCs meeting the requirements of reliable, sustainable, and competitive energy systems.
关键词： sustainability,organic–inorganic hybrids,luminescent solar concentrators,R-phycoerythrin,natural optically active center,bundles
更新于2025-09-23 15:23:52
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Structural diversity, magnetic properties, and luminescent sensing of four coordination polymers based on 6-(3,5-dicarboxylphenyl)nicotinic acid
摘要： Four coordination polymers (CPs), namely, [Ni(HDNA)(bibp)(H2O)]n (1), [Co(HDNA)(bibp)]n (2), {[Co(HDNA)(bibp)]·H2O}n (3) and {[Zn(HDNA)(bibp)]·H2O}n (4), have been synthesized from the mixed-ligand strategy of 6-(3,5-dicarboxylphenyl)nicotinic acid (H3DNA) and 4,4′-bis(benzimidazo-1-ly)benzene (bibp). Structural analyses revealed that four CPs all feature 2D sheets with diverse nets from {44.62}-sql net (1), {Co2(COO)2} SBUs based {44.62}-sql net (2), to 4-connected {65.8} sheet (3 & 4). Besides, the temperature-dependent magnetic susceptibilities of CPs 1-3 were investigated. And the luminescent sensing indicated CP 4 is a good bifunctional sensor for Fe3+ and Cr2O7 2- ions.
关键词： Structural diversity,Coordination polymers,Luminescent sensing,Magnetic property,Polycarboxylic acid ligand
更新于2025-09-23 15:23:52
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Identification performance of two luminescent lanthanide–organic frameworks
摘要： By the reaction of organic ligands, 2-(3,4-dimethylphenyl)-1H-imidazole-4,5-dicarboxylic acid (H3DMPhIDC) and terephthalic acid (H2DCB) with Eu3+ or Tb3+ ions, respectively, two luminescent metal-organic frameworks (MOFs) [Ln(H2DMPhIDC)(DCB)]n [Ln = Eu (1); Tb (2)] have been constructed. Both MOFs 1 and 2 are isostructural and show two-dimensional structures, which were fully characterized by single crystal X-ray diffraction, elemental analysis, and infrared spectroscopy. Both MOFs have excellent thermal and water stability, and indicate characteristic lanthanide metallic luminescence. Importantly, they can significantly recognize Fe3+ cation in aqoues solutions. Their sensing mechanisms have been suggested according to structural analyses, PXRD data and UV-Vis determinations.
关键词： recognition,crystal structure,luminescent MOFs,fluorescence quenching
更新于2025-09-23 15:23:52
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Composite up-conversion luminescent films containing a nanocellulose and SrF2:Ho particles
摘要： The synthesis of up-conversion luminescent composite films based on a nanocellulose matrix containing Sr1-xHoxF2+x particles was proposed. The combination of sulfuric acid hydrolysis and ultrasonication allowed us to synthesize a series of stable nanocellulose dispersions from various raw materials (powdered sulphate bleached wood pulp, Blue Ribbon filter paper, and microcrystalline cellulose Avicel). The size distribution of cellulose nanoparticles in the aqueous dispersions was determined. Cellulose nanocrystals (CNC) and/or cellulose nanofibrils (CNF) dispersions were used to fabricate thin films by solution casting followed by solvent evaporation under ambient conditions. The size and shape of cellulose nanoparticles, surface morphology, crystallinity index of nanocellulose, polymerization degree, and optical properties were studied. By mixing aqueous dispersions of CNC with up-conversion Sr1-xHoxF2+x particles, homogeneous suspensions were obtained. Finally, a solution casting technique was used to prepare CNC/Sr1-xHoxF2+x and CNC/CNF/Sr1-xHoxF2+x nanocomposite films. CNC/CNF dispersions were utilized for the production of flexible, durable, transparent composite films. The synthesized nanocomposites demonstrated intense red luminescence upon Ho3+ excitation by 1912 nm laser radiation. The obtained up-conversion luminescent composite films can be considered as a promising material for photonics, in particular for near-IR laser labeling and radiation visualization, luminescent sensorics.
关键词： Nanocomposites,Up-conversion luminescent films,Cellulose nanofibrils,Cellulose nanocrystals,SrF2:Ho3+
更新于2025-09-23 15:23:52
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Water-Stable Metal–Organic Frameworks with Selective Sensing on Fe <sup>3+</sup> and Nitroaromatic Explosives, and Stimuli-Responsive Luminescence on Lanthanide Encapsulation
摘要： Three water-stable luminescent MOFs [Zn4(bptc)2(NMP)3(DMF)(H2O)2]n (1-a), [Cd4(bptc)2(NMP)3(DMF)2(H2O)1]n (1-b), and {[Zn2(bptc)(DMA)(H2O)2]·(DMA)2·H2O}n (2), possessing similar chemical components (M2:L1:Sol3) and topology structures, were synthesized by solvents control. Their excellent sensing on iron(III) cation and nitroaromatic explosives (NACs) with great selectivity, sensitivity and a high Ksv (4.54 × 10^4 for 1-b on PNP) were observed by quenching effects. Furthermore, Zn-MOFs exhibit interesting stimuli-responsive luminescence enhancement after the encapsulation of a series of IIIB cations stimulated different luminescent emitting and intensity enhancement through host–guest processes of the pores in MOFs, especially for two distinct responses of Zn-MOF on a Tb3+ cation.
关键词： stimuli-responsive,nitroaromatic explosives,luminescent,water-stable,lanthanide encapsulation,iron(III),metal-organic frameworks,sensing
更新于2025-09-23 15:23:52
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Highly Efficient Luminescent Liquid Crystal with Aggregation-Induced Energy Transfer
摘要： A luminescent liquid crystal molecule (TPEMes) with efficient solid-state emission is rationally constructed via the chemically conjugation of blue-emitting tetraphenylethene cores and luminescent mesogenic tolane moieties, which are both featured with aggregation-induced emission properties. As for this fluorophore, aggregation induced energy transfer from the emissive tolane mesogens to the lighting-up tetraphenylethene units endows the molecule pure blue emission in the suspension and bulk state. Combining DSC, POM and 1D XRD experiments, TPEMes is deduced to adapt thermodynamically more stable layered crystalline phase, and can be 'frozen' into a monotropic smectic mesophase due to kinetic reasons. As a result of more densely packing of TPEMes in the crystalline phase indicated by 1D XRD, the luminescence of TPEMes in crystalline phase has blue-shifted with 17 nm relative to the metastable mesophase.
关键词： tolane,tetraphenylethene,aggregation induced emission,aggregation induced energy transfer,hexagonal columnar phase,luminescent liquid crystals
更新于2025-09-23 15:23:52
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A method for particulate matter 2.5 (PM2.5) biotoxicity assay using luminescent bacterium
摘要： The ability to analyze biotoxicity of atmospheric pollution plays an important role in public health. It provides the potential to directly analyze the health information of at-risk individuals. Although air quality standards have received significant attention in many countries, the potential for better biotoxicity assessment has remained largely unexplored. Here we propose a method using one kind of luminescent bacterium Photobacterium phosphoreum to detect the biotoxicity of atmospheric particulate matter ≤ 2.5 μm (PM2.5). Combined with the results of air pollution data of the year 2013–2014, this method has been proven to have good biotoxicity detection performance, and can evaluate the severity of at least 85% of PM2.5 related biotoxicity in Shanghai during this time period. Based on an established algorithm of this detection system, the biotoxicity of twelve PM2.5 real samples (collected over a month) were tested and divided into different biotoxicity levels. It allows an effective evaluation of biotoxicity of PM2.5 due to the quick and sensitive response of bioluminescence to the concentration of toxic components, which provides a valuable reference to evaluate the biotoxicity of PM2.5. This established method can be easily applied to the analysis and evaluation of any other PM2.5 samples assay by following the steps.
关键词： Atmospheric PM2.5,Public health,Photobacterium phosphoreum,Air pollution,Luminescent bacterium,Biotoxicity detection
更新于2025-09-23 15:23:52