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Synthesis and investigation of charge transport properties in adducts of hole transporting carbazole derivatives and push-pull azobenzenes
摘要： In order to investigate the viability of a material design for bulk heterojunction (BHJ) organic solar cells, where hole transporting group is bound to the donor moiety, we report the synthesis and charge transport characteristics of 3-(diphenylamino)carbazolyl- functionalized derivatives of 2-(4-((4-(dimethylamino)phenyl)diazenyl)benzylidene)-1H-indene-1,3-dione (DMAAzi) chromophore. Three different bounding configurations were examined in these adducts. Additionally, a trityl- functionalized derivative of DMAAzi was prepared and used for comparison purposes. All of the synthesized materials form thin amorphous films from volatile organic solvents and exhibit glass transition temperatures in the range from 89 °C to 124 °C. The molecular ionization energy and electron affinity energy levels in thin films were measured. Photo-induced time of flight (ToF) method was used in to determine charge carrier drift mobilities. It was found out that the formation of deep charge trap states with local energies at approximately 0.60 - 0.78 eV takes place and has a considerable negative effect on the hole drift mobility of the investigated compounds.
关键词： charge transport,molecular glasses,carbazole,organic photovoltaics,azobenzene dyes
更新于2025-09-04 15:30:14
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Color Build-Up and UV-protection Performance of Encapsulated Photochromic Dye-Treated Cotton Fabrics
摘要： A spirooxazine-based photochromic dye was encapsulated by an oil-in-water emulsion, solvent evaporation method. The encapsulated dye was applied to cotton fabric by a pad-cure process with different binder types. Ultraviolet (UV) protection was increased with application of the encapsulated photochromic dye. The type of binder used affected the photochromic color build-up during UV irradiation and could modify the UV protection imparted by the encapsulated photochromic dyes on textiles.
关键词： UV Protection,Binders,Photochromic Dyes,Encapsulation,Color
更新于2025-09-04 15:30:14
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Performance of Fluorescent Cell-Labeling Dyes under Simulated Europa Mission Radiation Doses
摘要： We investigated the performance of several commonly used fluorescent dyes after exposure to a simulated Europa mission total ionizing radiation dose of 300 krad (3 kGy) applied using a 60Co source. Dyes irradiated in aqueous solution or as lyophilized powders were evaluated for absorbance and emission spectra, quantum yield, and where appropriate, ability to label cells or nucleic acids. Although some dyes showed significant increase or decrease in quantum yield with the dose, their spectra and cell-labeling properties remained essentially unchanged after irradiation in powder form. Irradiation in aqueous solution led to significantly greater changes, including a large blue shift in the DNA intercalator propidium iodide. These results suggest that many fluorescent probes are appropriate for use in astrobiological missions to Europa, but that SYTO9 and propidium iodide should be used with caution or not mixed with each other, as is commonly done in "Live/Dead" labeling applications.
关键词： Europa mission,fluorescent dyes,ionizing radiation,cell-labeling,astrobiology
更新于2025-09-04 15:30:14
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Indolizine-Cyanine Dyes: Near Infrared Emissive Cyanine Dyes with Increased Stokes Shifts
摘要： Molecular engineering strategies designed to red-shift cyanine dye absorptions and emissions further into the near infrared (NIR) spectral region are explored. Through the use of a novel donor group, indolizine, with varying cyanine bridge lengths, dye absorptions and emissions were shifted deeper into the NIR region than common indoline-cyanines. Stokes shifts resulting from intramolecular steric interactions of up to ~60 nm in many cases were observed and explained computationally. Molecular brightnesses of up to 5,800 deep into the NIR region were observed. Structure-property relationships are explored for the 6 indolizine-cyanine dyes with varying cyanine bridge length and indolizine substituents showing broad absorption and emission tunability. The dyes are characterized by crystallography, and the photophysical properties are probed by varying solvent for absorption and emission studies. Computational data show involvement of the entire indolizine π-system during light absorption, which suggests these systems can be tunable even further into the NIR region through select derivatizations.
关键词： Photophysical Properties,Stokes Shifts,Near Infrared Emissive,Molecular Brightness,Indolizine-Cyanine Dyes
更新于2025-09-04 15:30:14
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Preparation of ZnO Nanoparticles Under Ultrasonic Irradiation and Photocatalytic Performance of ZnO Nanoparticles Multilayer Films
摘要： Zinc oxide nanoparticles were synthesized by the reaction of an aqueous-alcoholic solution containing zinc nitrate hexahydrate and sodium hydroxide under ultrasonic irradiation at room temperature. The crystallinity, morphology and optical property of ZnO nanoparticles were examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and UV-visible spectrophotometer. Zinc oxide nanoparticles multilayer films were prepared dipping glass slide, which had been cleaned with a piranha solution, into a ZnO solution by ultrasonic irradiation. The ZnO nanoparticles multilayer films were evaluated as a photocatalyst in the photocatalytic degradation of organic dyes, such as methylene blue, methyl orange and rhodamine B, under ultraviolet light at 254 nm.
关键词： Multilayer films,Photocatalytic activity,Zinc oxide nanoparticles,Organic dyes,UV-visible spectrophotometer
更新于2025-09-04 15:30:14
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Enhanced Photocatalytic degradation of methylene blue dye using CuS-CdS nanocomposite under visible light irradiation
摘要： The inorganic nanoparticles based semiconductor photocatalyst has attracted widespread attention for the practical applications in sustainable energy and environmental remediation due to its low cost, eco-friendly, high efficiency and ease of process. CuS, CdS and CuS-CdS nanocomposite photocatalysts have been successfully synthesized by a simple hydrothermal approach. The phase purity, composition and surface morphology of as synthesized nanomaterials were characterized using various analytical techniques. The photocatalytic activities of the as-prepared materials have been evaluated by the degradation of methylene blue (MB) dye in the presence of hydrogen peroxide (H2O2) which served as an oxidant under visible light irradiation. MB dye (10 ppm) was degraded by about 80%, 59% and 99.97% for CuS, CdS and CuS-CdS nanocomposite respectively at 10 min. The results demonstrate that CuS-CdS nanocomposite exhibited excellent photocatalytic activity as compared to the CuS and CdS is which mainly attributed to large surface area, narrow band gap, high adsorbing capacity of the dye and also low recombination of the photo-generated electrons and holes. Further, electrochemical impedance (EI) measurement revealed that as prepared CuS-CdS nanocomposite suggested that as compared to CuS and CdS, the CuS-CdS nanocomposite exhibits rapid migration of photo-induced charge carriers. In addition, the CuS-CdS nanocomposite demonstrated that good stability towards photocatalytic degradation even after repeated usage. Finally, a suitable photocatalytic reaction mechanism has been proposed to indicate the photocatalytic performance of the nanocomposite.
关键词： Methylene blue dyes,hydrogen peroxide,CuS-CdS,photocatalytic activity.,charge carrier
更新于2025-09-04 15:30:14
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Donor-π-acceptor dye-sensitized photoelectrochemical and photocatalytic hydrogen evolution by using Cu2WS4 co-catalyst
摘要： Photoelectrochemical and photocatalytic hydrogen evolution reaction (HER) have been investigated by using metal free donor-acceptor (D-A) and donor-p-acceptor (D-p-A) dyes, which are abbreviated as MC-32 and MC-048, respectively, sensitized TiO2 as a photocatalyst with or without Cu2WS4 co-catalyst. This co-catalyst is synthesized by a low-cost and simple hot injection method, under visible light illumination. The photoactivities of these dyes have been clarified according to their structural, optical and electrochemical properties. Photocatalytic activities have been slightly increased when added the Cu2WS4 co-catalyst (dye/TiO2/Cu2WS4). This catalytic activity is also compared to that of noble metal Pt (dye/TiO2/Pt). It has been found that 121 mmolg-1h-1, 179 mmolg-1h-1, 348 mmolg-1h-1, 212 mmolg-1h-1, 422 mmolg-1h-1 and 1139 mmolg-1h-1 hydrogen have been evolved by using MC-32/TiO2, MC-32/TiO2/Cu2WS4, MC-32/TiO2/Pt, MC-048/TiO2, MC-048/TiO2/Cu2WS4 and MC-048/TiO2/Pt, respectively.
关键词： Dye sensitization,Donor-p-acceptor dyes,Hydrogen evolution
更新于2025-09-04 15:30:14
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Insight into the Dynamics of Different Fluorophores in the Interior of Aerosol OT Lamellar Structures in Presence of Sugars: From Picosecond-to-Femtosecond Study
摘要： It is well reported that sugar molecules provide different types of stabilization to the biomembranes both in vitro as well as in vivo. In the present article, our focus is to investigate the interactions of two sugar molecules (sucrose and sucralose) with the lamellar structures of aerosol OT (AOT). We have attempted the structural characterization of the lamellae in presence and absence of the sugars with the aid of dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), Fourier transformed infrared spectroscopy (FTIR), polarized optical microscopy (POM) and cryogenic-transmission electron microscopic (Cryo-TEM) techniques. In this study, we have chosen three Coumarin dyes, which show a wide variation of hydrophobicity and performed a combination of steady-state and time-resolved fluorescence measurements to unveil the inner detail of the location of the sugars and their specific interactions with the lamellar structures. Our study reveals that sucrose molecules are present in the interfacial region with a major population whereas the most probable location of sucralose is the interior of the AOT bilayer. Therefore, sucralose molecules probably penetrate the bilayer by decreasing the efficient packing of AOT. The important essence of this study is the location and the interactions of sucralose with the lamellae which may provide a future direction to the transportation of the drug molecules in the biomembrane.
关键词： sugar molecules,fluorescence measurements,lamellar structures,AOT,Coumarin dyes
更新于2025-09-04 15:30:14
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All-Optical Poling and Two-Photon Absorption in Heterocyclic Azo Dyes with Different Side Groups
摘要： We investigated the optical properties of heterocyclic azo dyes with different side groups prepared: as powders, in PMMA matrix and side-chain polymers. We characterized the nonlinear optical effects of these compounds by Z-scan and all-optical poling techniques and supported these experiments with theoretical modeling. It was also found that these materials show strong two-photon absorption cross-sections exceeding 20 GM, which is one order of magnitude stronger than that of similar materials (azobenzene and p-aminoazobenzene). Our study reveals the dominant role of the side-chain system over the guest-host one and stress out the importance of the substituent in the efficiency of the poling process.
关键词： All-Optical Poling,Hybrid Materials,Heterocyclic Azo Dyes,Two-Photon Absorption,Plasmonics,Optical,Magnetic
更新于2025-09-04 15:30:14
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Guiding the Design of Organic Photocatalyst for PET-RAFT Polymerization: Halogenated Xanthene Dyes
摘要： By examining structurally similar halogenated xanthene dyes, this study establishes a guiding principle for resolving structure?property?performance relationships in the photocontrolled PET-RAFT polymerization system (PET-RAFT: photoinduced electron/energy transfer?reversible addition?fragmentation chain transfer). We investigated the effect of the halogen substituents on the photophysical and electrochemical properties of the xanthene dyes acting as photocatalysts and their resultant effect on the performance of PET-RAFT polymerization. Consideration of the structure?property?performance relationships allowed design of a new xanthene photocatalyst, where its photocatalytic activity (oxygen tolerance and polymerization rate) was successfully optimized for PET-RAFT polymerization. We expect that this study will serve as a theoretical framework in broadly guiding the design of high performance photocatalysts for organic photocatalysis.
关键词： PET-RAFT polymerization,structure?property?performance relationships,oxygen tolerance,photocatalysts,halogenated xanthene dyes
更新于2025-09-04 15:30:14