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Polymers of chitosan (CS) and polyvinyl alcohol (PVA) were combined effectively to create a synergetic property of both. To this composite, BiOCl:Eu3+ nanoparticles (NPs) were used as an appropriate filler. Vitamin B2 (VB2) was used as a biosafe coupling agent to modify the surface of NPs. Different weight percentage of BCE (50, 100, and 150 wt%) were then created using a casting/solvent evaporation process after being exposed to ultrasonic irradiations. The compatibility of NPs with the blend polymer were enhanced due to the coupling agent. Optical absorbance and thermal stability of compounds were impacted by inserting the modified NPs into the blend polymer. The hydrophilicity reduced for various ratios of the modified NPs loaded in the blend polymer, according to the contact angle measurements. The characteristic emission peaks of Eu3+ ions were observed at 581, 594, 621, 652, and 698 nm after being stimulated by 466 nm. With increased surface modifier concentration, the chromaticity diagram showed that emission colors altered from red to deep red. Reduced space charge polarization of the dipoles was shown to be the cause of the dielectric constant decreasing with frequency. The various resistive and capacitive elements of the produced materials are credited with the non-Debye type relaxation process. The level I-III ridge details are visible in the colorimetric images of fingerprints using the optimized nanofiller in polymer matrix on forensic-related surfaces. The aforementioned results made it abundantly evident that the improved NCs are very beneficial in multidimensional applications. [Display omitted] • Surface modification of CuO nanoparticles by using thiamine as a bio-safe modifier. • PVA-PVP/CuO-VB 1 NCs showed increased antibacterial activity. • Hydrophobicity of PVA-PVP/CuO-VB 1 NC films was also improved. • EDA proved the presence of BSA in the modified NPs as well as in the obtained NCs. [ABSTRACT FROM AUTHOR]

Eu2+ doped Sr 2 MgSi 2 O 7 nanophosphors (SMSO:Eu2+ NPs) have been synthesized by using solid-state reaction method. As Eu2+ concentration increases, energy transfer (ET) between Eu2+ ions dominated attributed to dipole-dipole (d-d) interaction. Besides, temperature-dependent photoluminescence (PL) of optimized SMSO:7Eu2+ NPs is investigated. The emission shifts towards blue with increased temperature. From the temperature-dependent emission, the activation energy, is ∼0.40 eV. CIE coordinate is (0.1476, 0.1141) with CCT value of 3633 K. The optimized phosphor is used to detect LFPs on various surfaces. The level I-III features are clearly identified under UV 365 nm excitation. Several pores properties namely pore size, shape, number, position, type and pore inter-distance are analyzed in detail. The anti-counterfeiting results clearly showed the enhanced intensity owing to its nano-size, reduced light dispersion and increased light absorption. The overall results clearly suggest the optimized SMSO:7Eu2+ NPs are promising luminescent platform for nUV light-emitting diode (LED) and latent fingerprint (LFP) applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Due to the outstanding optical qualities, stimulation-responsive luminous materials have drawn a lot of attention in the anti-counterfeiting application. In this work, the feasibility of applying BaLa 2 ZnO 5 :Bi3+ (BLZO:Bi3+) (0.5–4.0 mol%) phosphor, to multiple stimuli anti-counterfeiting (AC) and latent fingerprint visualization (LFP) is explored and discussed. The prepared luminous security ink from the optimized phosphor is effectively used for the multiple stimuli AC under 325, 355 and 375 nm excitation wavelengths. The results show that the fabricated luminous security ink is highly stable in ultraviolet (UV) light, various chemical environments, and ambient conditions. In addition, powder dusting method is utilized for LFPs detection on porous, non-porous and semi-porous surfaces under different excitation wavelengths. The multilevel features of the phosphor-attached LFP could be identified clearly in all the surfaces. The high-resolution LFPs imaging by scanning electron microscope (SEM) pictures, providing us more precise details on the width, distance, distribution, and forms of fingerprint (FP) pores. All the results reveal that the phosphor is a good potential choice for AC and LFP detection. [Display omitted] • At excitation wavelengths of 325, 355, and 375 nm, the BLZO:Bi3+ phosphor can produce blue, baby blue, and blue-green light. • latent fingerprints clearly captured by using the optimized phosphor in powder dusting method. • The application of the prepared luminous security ink for multiple stimuli anti-counterfeiting has been effectively proven. • Results show that luminous security ink is highly stable in UV light, various chemical environments, and ambient conditions. [ABSTRACT FROM AUTHOR]