查看更多>>摘要：Materials capable of circularly polarized luminescence (CPL) have generated intensive interest for their potential applications. However, constructing chiral molecules with tunable CPL signals remains a challenge. In this paper, two pairs of binaphthylamine based chiral donors R/S-2 and R/S-3 were synthesized by Pd-catalyzed C-N coupling and intramolecular oxidative coupling with good yields. Then three pairs of chiral D-A type molecules R/S-4~6 can be synthesized by introducing two kinds of achiral acceptors. The extention of the chiral binaphthy skeleton endows these chiral compounds with CPL signals ranged from 417 nm to 544 nm in solutions and film states. The gium can be up to-2.9 x 10~3 for R-2 in solution. The introduction of terephthalonitrile as acceptor endow R/S-4 thermally activated delayed fluorescence (TADF). Furthermore, when benzophenone is chosen as achiral acceptor, the obtained chiral D-A molecules R/S-5 and R/S-6 can exhibit reversed CPL signals compared with their corresponding chiral donors. This work demonstrates the introduction of chiral D-A structure not only alters the wavelength of the CPL signals but also can reverse the CPL sign.
查看更多>>摘要：In this work, two novel compounds, namely TCzlDF and TCz4DF, were reported as the host materials for green organic light emitting devices. These two bipolar materials are constructed from hole transport group carbazole and electron transport group triazine, which have high thermal stability, suitable energy levels and good charge transfer abilities. The green phosphorescent OLEDs based on these two materials exhibit quite good performance. The maximum external quantum efficiency (EQE) of device Gl based on TCzlDF can be achieved 16.5%, and the EQE of device based on TCz4DF can also reach 15.4%. At die same time, the efficiency roll-off of these devices is very insignificant. Under 1000 cd m"2 brightness, the EQEs of devices Gl and G2 can reach 16.4% and 15.2%, which are almost equal to their maximum values.
查看更多>>摘要：Phenothiazine based dyes are widely explored dyes for their antibacterial and photosensitising applications. Despite their amazing optical and photosensitising (theranostic) properties, their usage in nanomedicine is very low compared to other organic dyes. This is due to the lack of reactive functional groups for encapsulating them into metal oxide nanoparticles. This work describes the synthesis of three different phenothiazinium alkoxysilane derivatives by oxidative amination of lOH-phenothiazine using amino alkoxysilanes. The new derivatives were characterized using NMR, FT-IR, DSC/TGA, and mass spectral studies. Optical and photosensitising properties (absorption spectrum, photostability, and singlet oxygen quantum yield) of the silane derivatives were investigated using UV-Visible spectroscopy. These compounds are suitable for conjugation with silica in the sol-gel synthesis of silica nanoparticles and silica surface coaters, which will reduce dye leakage and improve the dye efficacy in the treatment of cancer and light activated antimicrobial surfaces.
查看更多>>摘要：A dual-layer structure combining the properties of two polymers is demonstrated to be efficient in strengthening the mid-to-far infrared modulation. Prior to the assembly of bilayer devices, the infrared adjustment capability of single-layer devices poly(3,4-ethylenedioxythiophene) (PEDOT) poly(pyrrole) (PPY) and poly(aniline) {PANI) with different polymerization charges is scrutinized. The results exhibit that the optimal polymerization charge affording the highest reflectance variation is inconsistent between the mid-wavelength and long-wavelength bands in PEDOT and PPY devices. However, through the arrangement of deposition sequence and relative thickness of PEDOT and PPY coatings, a device with the reflectance contrast of 0.662 in the mid-wavelength and 0.281 in the long-wavelength bands was obtained utilizing a bilayer film PEDOT-0.2C/PPY-0.3C. Further FTIR and UV-Vis spectra show that the bilayer films are successfully formed and both polymers play a role in the electrochemical process. Different morphologies of bilayer films with reverse positions observed by SEM images account for the correlation between the infrared regulation performance and deposition sequence.
查看更多>>摘要：Traditional photonic crystal microspheres have internal pores and can only be fabricated by self-assembly of colloidal nanoparticles. Therefore, their internal vulnerability to contamination and poor structural stability limit their further application. Therefore, we proposed a new method of photonic crystal composite microsphere fabrication by combining polymerisation with the self-assembly process. The droplets composed of colloidal nanoparticles, monomer, and initiator in continuous phase are obtained by a Shirasu porous glass (SPG) membrane emulsification undergo polymerised and self-assembled to obtain organic-inorganic photonic crystal composite microspheres. Since the self-assembled colloidal nanoparticles are immobilized in the polymer cross-linked network, the composite microspheres exhibit high structural stability. Based on this, we fabricated SiCV PHEMA photonic crystal composite microspheres by polymerisation and self-assembly process. Compared with the pure SiO2 photonic crystal microspheres fabricated by the same method, the composite microspheres exhibit high structural stability, color saturation, and good hydrophobicity due to the self-curling of the material driven by hydrogen bonding during polymerisation. In addition to the potential applications as dyes, biosensors, and in light, these composite microspheres overcome the difficulty of bulk generation of traditional photonic crystal microspheres and have the potential for industrialized mass production.
查看更多>>摘要：Colorful aluminum pigments are commercial demand for the pursuit of a range of aesthetic over the last few years. In this study, a general approach for preparation of colored aluminum pigments is reported by two-step process of poly(dopamine) (PDA) encapsulation and dye conjugation. Firstly, the surface of the aluminum pigment was encapsulated by a PDA layer in an alkaline/ethanol environment (PDA@A1), and orthogonal experiments were investigated to explore the optimal reaction conditions. Secondly, using Disperse orange 11 as typical dye, the PDA@A1 were colored by the Michael addition reaction between the functional dyes and quinone structures in the PDA layer. The morphology, component and structure of the colored aluminum pigments was characterized by FTIR, SEM, XPS and TG. The results showed that the corrosion resistance and wettability of colored aluminum pigments were significantly improved. This wok provides a new general strategy for the preparation of colorful aluminum pigments with PDA as the protected and functional layer.
查看更多>>摘要：Three types of 4'-methoxychalcone derivatives Cha-1 ~ Cha-9 with different electron-withdrawing or electron-donating substituents at different positions were synthesized and studied. When the A ring has a hydroxyl group at the 2-position, the strong electron-donating groups at the 4-position of the B ring was more conducive to the near-infrared and aggregation-enhanced emission (AEE) features of the compound than the electron withdrawing groups. The single-crystal analysis confirmed that the good planarity of the 4'-methoxychalcone derivatives favors their fluorescence quantum yields. Moreover, chalcone fluorophores with different fluorescence properties could be obtained by modulating substituent at the 2-position of A ring. In addition, Cha-9 was selected as the AEE luminogen to locate the lysosomes in HeLa cells. These results provided fundamental knowledge for the design and application of 4'-methoxychalcone derivatives of aggregation-induced emission (AIE) compounds.
查看更多>>摘要：Using l-(4-(dimethylamino)phenyl)ethanone, a series of asymmetric aza-BODIPYs carrying the dimethylamino (-NMe2) group were successfully prepared (Scheme 1). The solid-state structure of trifluoromethyl substituted aza-BODIPY (CF3-BDP) was confirmed by X-ray crystallographic analysis, and the boron atom in the center showed a slightly distorted sp3 hybridization. The maxima absorption of aza-BODIPYs with the-NMe2 group were found to locate in the range of 740-780 nm. Their molar extinction coefficients are high, but the fluorescence quantum yields are very low, mainly due to the intramolecular charge transfer (ICT) effect from the-NMe2 group to aza-BODIPY scaffold. The singlet oxygen yields of CF3-BDP was calculated to be 0.053 and slightiy higher than that (Φ_A = 0.02) of tetraphenyl aza-BODIPY. In order to improve water-solubility and biocompatibility, we prepared dye nanoparticles by self-assembly. Based on the photothermal properties of CF3-BDP nanoparticles (NPs), methoxy substituted aza-BODIPY (OMe-BDP) NPs and ring-fused substituted aza-BODIPY (OMeR-BDP) NPs, the photothermal conversion efficiencies of CF3-BDP NPs, OMe-BDP NPs and OMeR-BDP NPs were calculated to be 49%, 49% and 50%, which are comparable to those (35-50.5%) of the reported aza-BODIPY-based photothermal agents (PTAs). CF3-BDP NPs could efficiently kill cancer cells through the photothermal effect by near-infrared laser irradiation, and CF3-BDP NPs are highly desirable for the photothermal therapy.
查看更多>>摘要：The incessant escalation of global energy consumption undeniably has led fossil fuel reserves to their verge of I depletion. So, the need for an unlimited source of energy has led researchers to explore solar energy as the alternate energy reserve. Especially, dye-sensitized solar cells (DSSC) have received considerable attention, since they allow low-cost photovoltaic energy conversion which is sustainable as well as capable of fulfilling the global energy demand. The molecular design of the sensitizers is one of the several indispensable aspects for achieving high power conversion efficiencies. Quinoxaline scaffold represents one such versatile building block that has been significantly utilized for the synthesis of materials for optoelectronic applications especially, organic bulk heterojunction photovoltaic materials as well as DSSC's. The structural versatility of quinoxaline as well as its I easy accessibility and electron-withdrawing ability has resulted in the development of several quinoxaline-based optoelectronic materials. However, there exist no reports which have elaborated the role of quinoxaline and the design strategies involving quinoxaline in maneuvering the power conversion efficiencies of the organic sensitizers for DSSCs. Therefore, the review article aims at offering a comprehensive overview of die diverse approaches to build quinoxaline-based sensitizers for organic DSSC's as well as enlightening readers with ideas about designing sensitizers utilizing other electron-deficient heterocyclic scaffolds as well.
查看更多>>摘要：With available different solar cell technology, adequate conversion efficiency is a major concern with reference to important parameters like energy payback time, inexpensive to fabricate: Production cost, lightweight, customizable, flexible, less adverse environmental effects. Such solar cells are developed using a modem version of dye synthesized solar cells and progress in nanotechnology known as quantum dot sensitized solar cells (QDSCs). QDSCs attracted researchers due to their high absorption coefficient, tunable bandgap, multiple exciton generation, and fabrication method, and energy payback time. Currently in the laboratory achieved efficiency of QDSCs is 18.1% in comparison to theoretical limits. This review article presents a comprehensive overview of the efficiency of QDSC and its status under the effect of photoanode and Quantum Dot sensitizers.
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