Dyes and Pigments最新文献

Phosphorescent metal complexes find widespread application in organic light-emitting diodes (OLEDs), with iridium(III) complexes being particularly favored for their superior performance. Owing to the flexible modifications of both main and auxiliary ligands, the photophysical properties of iridium(III) complexes can be finely tuned. In this study, two red neutral iridium(III) complexes, designated as Ir1 and Ir2, are successfully synthesized and characterized. Various auxiliary ligands including acetylacetone and 2-picolinic acid are employed in combination with 1-(6-methoxynaphthalene-2-yl)isoquinoline as the cyclometalating ligand. Both complexes exhibit red emission, with Ir1 emitting at 631 nm and Ir2 at 615 nm. Furthermore, they demonstrated good solubility in common organic solvents, facilitating device fabrication via solution methods. Electroluminescent (EL) devices based on complexes Ir1 and Ir2 are further prepared using spin-coating method, achieving maximum external quantum efficiencies (EQEs) of 3.30 % and 4.52 %, respectively, and both devices exhibited bright red EL with CIE coordinates of (0.68, 0.32) and (0.66, 0.34), which were very close to the standard red coordinates of (0.67, 0.33).

In the last years, the growing attention towards environmental sustainability and circular economy has led to a renewed interest in the use of eco-friendly and recyclable materials in various sectors.

Developing innovative dye sensitized solar cells (DSSCs) based on microbial pigments, is very important to meet the demands of sustainable devices. Microbial extracts obtained from Talaromyces atroroseus GH2, Arthrobacter bussei CP30 and Paracoccus bogoriensis BOG6 cultivations, and characterized by HPLC-DAD-ESI-MS analyses, have been used in this work for this purpose. The extracted pigments were tested to evaluate their suitability as photosensitizers through co-sensitization method. UV–vis measurements were carried out to determine the absorbance intensity, while Photoelectrochemical and Electrochemical Impedance Spectroscopy (EIS) analyses were applied to evaluate the devices' photovoltaic parameters and impedance characteristics. The best device, obtained by the co-sensitization of the dyes produced by Talaromyces atroroseus GH2/Paracoccus bogoriensis BOG6, exhibited a Jsc of 1.59 mA/cm², Voc of 0.35 V, FF of 0.62, and a PCE of 0.34 %. This study highlights the potential of microbial-derived pigments in the development of DSSCs.

Indigo (IND) and its natural derivatives, including Tyrian purple and indirubin (INR), are examples of molecules with a history of millions of years. They also illustrate molecular evolution and longevity, linked to their extraordinary molecular stability associated with excited state decay mechanisms. In the excited state, these molecules efficiently undergo a radiationless deactivation process resulting in negligible fluorescence and triplet state formation (less than 0.1 % of the quantum loss in indigo for both processes). Here, we demonstrate that in isoindigo (ISO) this process is even more efficient than in IND, resulting in nearly 100 % of the excited state deactivation. In IND, the molecular mechanism behind this decay process involves intramolecular proton transfer (ESPT). In the case of INR, ESPT efficiently competes with the formation of a conformational species –the syn-rotamer– for deactivation to the ground state. With ISO, the ESPT process is absent. Instead, the deactivation mechanism involves a rotation of a few degrees around the central C–C bond, aRotational Isomerization (RI). This rotation leads to a sloped conical intersection (CI), making the radiationless deactivation process more efficient than the ESPT found with IND.

Dyes in industrial wastewater are often toxic, polluting the environment, and harmful to animals and humans. The conventional methods of removing the dyes from wastewater are physical adsorption, precipitation, biodegradation, and photodegradation. Here we report the use of ionic liquids (ILs) to extract dyes from wastewater for the fabrication of fluorescence/afterglow materials. This method not only reduces the dye concentration by two to three orders of magnitude, but also obtains luminescent materials for anti-counterfeiting application. Diverse dyes such as rhodamine, acridones, difluoroboron compounds, and polycyclic aromatic hydrocarbons (PAHs) have been tested as model dyes in wastewater. In the case of rhodamine and some PAHs, fluorescence materials that exhibit diverse colors can be obtained after extraction by ILs. For difluoroboron compounds, room-temperature phosphorescence (RTP) materials have been achieved after extraction. Interestingly, in the case of acridones, the emergence of RTP/TADF dual afterglow emission has been evidenced in ILs, where TADF represents thermally activated delayed fluorescence. By the combination of these luminescent materials, lifetime-coded and multicolor-coded anti-counterfeiting functions have been demonstrated.

The search for multifunctional derivatives is of paramount importance in material science considering sustainability, practicality, and applicability. For this reason, this article presents a multifunctional benzotriazole derivative synthesized through rational design, showcasing its versatility across diverse applications. The tailored functionality of the compound enables it to serve in photonics as an optical waveguide, as smart material as stimuli responsiveness material, and as a gelator for drug crystallization in pharmaceuticals. This work underscores the power of rational design for organic synthesis in creating versatile materials with broad applicability.

The synthesis of luminescent self-healing materials together with outstanding comprehensive mechanical features is yet a significant challenge due to the contradictory relationship between the self-healing features and mechanical characteristics. In this work, a lanthanide-based photoluminescent elastomer exhibiting super toughness and fast self-healing behavior was prepared via first synthesizing a photoluminescent complex and then utilizing which as the effective functional cross-linkers. The complexes were synthesized with p-aminobenzoic acid and 1,10-Phenanthroline as ligands, Ln³⁺ as the central luminescent ions. The backbone of the polymers was obtained by the polymerization of tolylene-2,4-diisocyanate-terminated polypropylene glycol (PPG-NCO) and isophorone diamine (IPDA). The addition of the complex as a cross-linking agent increases the degree of cross-linking of the polymer chains, and endows the material with good mechanical properties. In addition, self-healing properties was achieved thanks to the dynamic synergistic effect of Ln³⁺-ligand bonding and inter-amide hydrogen bonding. Furthermore, by varying the molar ratio of Eu³⁺/Tb³⁺, multi-color emission which ranging from red to green, has been accomplished. We are confident that the method employed in this study offers a little inspiration on the preparation of toughened luminescent products with self-healing features, which have wide ranging of applications in flexible optical devices, advanced information encryption, and other fields.

Lipid droplets (LDs), as intracellular lipid storage organelles, play an important role in maintaining lipid balance. The imbalance of lipid may lead to diseases, therefore, it is of great significance to monitor and evaluate the characteristics of LDs. Herein, we report the design and synthesis of a small molecular fluorescent probe MDXB (2-(2-(6-methoxy-2,3-dihydro-1H-xanthen-4-yl) vinyl) benzothiazole), which facilitates the detection of the viscosity change of intracellular LDs. MDXB follows the motion-induced change in emission (MICE) effect, wherein the –CC- bond is used as a rotation axis, and the fluorescence maybe enhanced with the increase of viscosity. MDXB exhibits a red emission at 640 nm with a large Stokes shift of ca. 180 nm, in addition to excellent photostability, which endow it with the capability of long-term imaging. The cellular imaging investigations illustrated the enhancement on the reactive oxygen species (ROS) content and the increment on LDs viscosity in the constructed cell models, e.g., cell inflammation and heavy metal ion stimulation. We thus expect MDXB to be a potential tool for the monitoring the viscosity changes of LDs and the evaluation of concurrent intracellular biological processes.

All-small-molecule organic solar cells exhibit high reproducibility than polymer-based cells. Benzodithiophene and oligothiophene based derivatives are the most widely studied small molecule donors. The lower synthetic complexity and superior stability make oligothiophene based derivatives more promising for large scale production. Recently, a thiazole-centered oligothiophene donor Tz6T yields a high efficiency but deserves further improving. Substitution of halogen atoms on the end groups is proven to affect molecular packing through various non-covalent intermolecular interactions. Here we adopt terminal group engineering to regulate the optoelectronic properties of Tz6T. Through chlorine substitution, highest efficiency (9.60 %) is achieved in Tz6T-PH-Cl-4: eC9-4F binary device. Our results shed light on the structure-function relationship, and provide valuable insights into the regulation of phase separation.

Due to the molecular wire effect, the fluorescent conjugated polymer (FCP) is always one of the focus of the sensor field. However, the complicated synthesis of FCP usually hinders their further practical application. Meanwhile, the multifunctional fluorescence sensor, which can distinguish multi-analyte only by one sensing material, presents high potential prospect in the real application. Here, a relatively simple benzimidazole-based FCP P1 via Suzuki polymerization was synthesized and further used as a multifunctional fluorescence sensor: P1 can not only efficiently detect Fe³⁺ in solution with a limit of detection (LOD) of 60 nM, but also monitor 2, 4-dinitrotoluene (DNT) vapor with a low LOD of 3.3 ppb. Furthermore, the simple P1 filter paper sensor was prepared and enable visual detection of Fe³⁺ and DNT with high performances of portability, flexibility and practicability.

Before gluing, bonding, and painting, a variety of materials' surfaces can be modified using the widely used plasma treatment technique. These materials include plastics, glass, metals, and wood. Materials' physical and chemical properties are changed in an environmentally responsible way to enhance or confer particular qualities. The recently used technology known as low-temperature atmospheric pressure plasma (LTAPP) allows heat-sensitive materials to be surface modified in a simple, one-step process. Polymer-based materials are frequently surface modified using LTAPP treatment to improve adhesion, printability, and surface sterility. Polyester's superior mechanical and physical qualities have led to its widespread use as a technical textile and garment material in the form of fibers, films, and plastics. Its limited versatility in terms of end use has been caused by its poor surface properties as the hydrophobic nature of polyester surface, roughness, the crystallinity, and lack of dyeability which are the main drawback restricting its use in different textile applications especially during wet treatments unlike natural fibers. In order to increase the fabric's hydrophilicity and dyeability, the surface of a polyester fabric was altered in this study using atmospheric pressure plasma treatment with atmospheric plasma jet and dielectric barrier discharge (APJ-DBD) technology in air. The primary obstacles in making dielectric barrier discharge (DBD) plasma treatment suitable for industrial purposes are the extended duration of treatment and the utilization of elevated voltage levels. The combination between the atmospheric plasma jet and the dielectric barrier discharge reduces the optimal treatment time to 1 min and the applied voltage to 3.3 kV. After being exposed to oxygen plasma species for a brief period of time (between 30 and 300 s), and were analyzed using an X-ray diffraction machine, an X-ray photoelectron spectroscopy (XPS), static contact angle, and a scanning electron microscope (SEM) to investigate changes in the morphology and chemical nature of the surface, respectively. Fabric wettability increased as a result of plasma treatment, which also increased the fabric's surface roughness, as demonstrated by SEM and X-ray diffraction. The contact angle decreases by increasing the treatment time. The dyeability of untreated and plasma-treated samples was examined with respect to washing, rubbing, perspiration, sublimation, and light fastness. Additionally, color strength was examined. Adequately, compared to the untreated fabric, polyester treated with plasma showed improved dyeing performances. The technical reactivity of poly (ethylene-terephthalate) (PET) fabrics was found to be effectively increased by atmospheric air plasma treatment, creating new avenues for surface modification in light of the expanding environmental and energy-saving concerns.