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Synthesis of a Novel Fluorescent Cyanide Chemosensor Based on Photoswitching Poly(pyrene-1-ylmethyl-methacrylate-random-methyl methacrylate-random-methacrylate spirooxazine)
摘要： The photoswitching poly(pyrene-1-ylmethyl-methacrylate-random-methyl methacrylate-random-methacrylate spirooxazine) was synthesized via atom transfer radical polymerization and characterized by proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, and differential scanning calorimetry (DSC). The obtained copolymer exhibited the capability of erasable and rewritable photo-imaging, making it a potential candidate for optical data storage materials. Moreover, the copolymer also showed the sensing ability for cyanide anions effect in aqueous solutions.
关键词： spirooxazine,chemosensor,photoswitching polymers,atom transfer radical polymerization
更新于2025-09-23 15:21:01
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Charge Transfer Complex of Thioxanthonephenacyl Sulfonium Salt as Visible Light Photoinitiator for Free Radical and Cationic Polymerizations.
摘要： A new double chromophoric sulfonium salt photoinitiator possessing both thioxanthone and phenacyl groups, namely 2-isopropylthioxanthonium phenacyl hexafluoroantimonate (ITXPhenS) was synthesized and characterized. ITXPhenS can form charge transfer complex (CTC) with the donor N, N-dimethyl aniline (DMA) with absorption characteristics in the visible range as confirmed by spectral analysis, cyclic voltammetry (CV) and density functional theory (DFT). The extension of the absorbance shift can be controlled by the ITXPhenS to DMA ratio. The ability of the CTC to initiate free radical and cationic polymerization reactions of various monomers under visible and natural sunlight is demonstrated. The proposed mechanism assumes the generation of radical and ionic species by the heterolytic and/or homolytic cleavage of ITXPhenS within the CTC followed by electron transfer reactions.
关键词： photochemistry,density functional calculations,cyclic voltammetry,polymerization,charge transfer
更新于2025-09-23 15:21:01
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Photo-controlled RAFT polymerization mediated by organic/inorganic hybrid photoredox catalysts: enhanced catalytic efficiency
摘要： Photo-controlled RAFT polymerization mediated by organic/inorganic hybrid photoredox catalysts: enhanced catalytic efficiency. Metalloporphyrins (MTPPs) play an important role in the conversion of light energy to initiate photo-induced electron transfer–reversible addition–fragmentation chain transfer (PET-RAFT) polymerization, in which zinc tetraphenylporphyrin (ZnTPP) has attracted a high degree of attention. However, the self-aggregation effect of porphyrins in some organic solvents such as dimethyl sulphoxide (DMSO) leads to quenching of the excited state of the MTPPs and reduces their photocatalytic capacity in a concentration-dependent manner. In this study, a ZnTPP–POSS organic/inorganic complex was fabricated by linking a polyhedral oligomeric silsesquioxane (POSS) to ZnTPP. The aggregation of the photocatalyst was efficiently depressed in a PET-RAFT polymerization which was catalyzed by ZnTPP–POSS under green light (λmax = 515 nm, 3 mW cm?2). Compared to ZnTPP, the reactions using ZnTPP–POSS as the photocatalyst were well controlled for different monomers with accelerated reaction rates. Well-defined block copolymers were successfully achieved by the chain-extension reaction which demonstrates the high-end fidelities of this polymerization approach.
关键词： Photo-controlled RAFT polymerization,PET-RAFT polymerization,organic/inorganic hybrid photoredox catalysts,block copolymers,ZnTPP–POSS
更新于2025-09-23 15:19:57
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Evaluation of solution processable polymer reduced graphene oxide transparent films as counter electrodes for dye-sensitized solar cells
摘要： This paper reports the synthesis of reduced oxide (RGO) coated polyaniline (PANi) nanocomposites via in-situ emulsion polymerization and its application as counter electrode for dye sensitized solar cells (DSSCs). The synthesized nanocomposites were systematically characterized through Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform resonance infra-red (FTIR) and Raman spectroscopy indicating the uniform intercalation of polyaniline with reduced graphene oxide. The synergy between RGO and PANi chains owing to the co-doped SDS and H2SO4 leads to the enhanced solubility and improved electrocatalytic activity, that was further confirmed through electrochemical measurements to satisfy the criteria for application as cost effective counter electrode material for scalable DSSC. The fabricated CE was highly transparent and reached the conversion efficiency which is comparable to that of Platinum with a current density of (12.58 mA. cm-2) and (13.11 mA. cm-2) respectively under an illumination of AM 1.5 G (100 mW. cm-2) simulated solar light with an overall photo conversion efficiency of 3.9 %. Thus PANi/RGO based nanocomposites could therefore serve as efficient alternative material to Pt. free CE in DSSC.
关键词： In-situ emulsion polymerization,PANi,DSSC,counter electrode,reduced graphene oxide
更新于2025-09-23 15:19:57
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Preparation of molecularly imprinted fluorescence sensor based on carbon quantum dots via precipitation polymerization for fluorescence detection of tetracycline
摘要： A facile and effective method was proposed to prepare the molecularly imprinted fluorescence sensor with carbon quantum dots, which were modified vinyl groups by acrylic acid on the surface. The obtained fluorescence composite material was investigated by transmission electron microscope and Fourier transform infrared spectra. After the experimental conditions were optimized, a linear range of 1.0–60 μmol L?1 was obtained and the detection limit was 0.17 μmol L?1. The novel fluorescence sensor can be successfully used to detect tetracycline in real samples. This study provides a convenient strategy for selective recognition and rapid detection of tetracycline in the complex environment.
关键词： precipitation polymerization,tetracycline,carbon quantum dots,molecularly imprinted polymers,fluorescence detection
更新于2025-09-23 15:19:57
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Electrochemical Polymerization: An Emerging Approach for Fabricating High-Quality Luminescent Films and Super-Resolution OLEDs
摘要： Currently, the fabrication of high-resolution OLEDs remains great limitations. Electrochemical polymerization is an efficient way to fabricate conducting polymer films. However, the control of the structures and dedoping of films is difficult, thus making the films rough and incapable with flat-panel devices. In this review, the molecular design and the fabrication of high-quality electrochemical polymerization films and super-resolution RGB displays are introduced. Inspired by the unique electrochemical features of N-alkyl carbazoles, highly luminescent precursors are designed with the spatially separated emissive cores and side carbazoles. The films with low doping levels, high luminescent efficiencies and smooth morphology are prepared by optimizing potential windows, electrolyte solutions, scan rates and post-washing process. The luminous efficiency of OLEDs where the films as light-emitting layers exceeds that of most OLEDs prepared by conventional methods. Then electrocopolymerization and multilayer electropolymerization techniques are developed, in which the components and thickness of films can be precisely controlled, endowing the films and OLEDs with superior stability. Finally, RGB active-matrix OLEDs and super-resolution displays of 2822 ppi are achieved. The above works demonstrate electrochemical polymerization is an emerging technique in RGB super-resolution displays and has great commercial potential.
关键词： OLEDs,Electrochemical polymerization,RGB,N-alkyl carbazoles,super-resolution displays
更新于2025-09-23 15:19:57
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Bicarbazole-based oxalates as photoinitiating systems for photopolymerization under UV-Vis LEDs
摘要： Photoinitiators are critical to initiate chain reactions in photopolymerization. For such applications, the absorption of photoinitiator must be compatible with the emission of light sources and enables the fast manufacturing of three-dimensional network or structures. Light-emitting diode (LED) is a new kind of energy-saving and environmental protection light source, exhibiting a substantial response in the near UV and visible range to replace the traditional mercury lamp and other light sources in photopolymerization. Here, we introduce methyl oxalate into bicarbazole chromophore (BiCz). By variation of the single or double substituents in the BiCz, we demonstrate that the absorption spectra can be adjusted and redshift to visible range and show good absorption in the near UV and visible range (365–475 nm). We explore their photochemistry based on experimental results and theoretical calculations and the mechanism of photoreactions have been verified. The super photostability by themselves and good hydrogen abstraction ability from amine co-initiator make them as excellent near UV and visible light active photoinitiators. Critically, the photoinitiation of the free-radical polymerization of acrylate monomers with low content (0.1% concentration) upon LED irradiation at 365–475 nm, exhibits excellent application potential in light curing and other fields.
关键词： free-radical polymerization,high efficiency,photoinitiators,UV–visible LEDs
更新于2025-09-23 15:19:57
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Xanthene Dye-Functionalized Conjugated Porous Polymers as Robust and Reusable Photocatalysts for Controlled Radical Polymerization
摘要： Photoinduced electron/energy transfer?reversible addition?fragmentation chain transfer (PET?RAFT) polymerization represents a versatile and highly e?cient method for polymerizations of wide-ranging monomer variances upon solar energy harvesting. Although signi?cant progress has been achieved, several drawbacks are still associated with existing photocatalysts, such as toxicity of transition metals, high cost, poor stability, and unavoidable puri?cation procedures because of the photobleaching e?ect, to name a few. Herein, 1,4-diethynylbenzene-linked xanthene dye-conjugated porous polymers (CPPs) have been established as potential heterogenous photocatalysts of PET?RAFT polymerization. With this two-dimensional planar architecture, we demonstrate dual-stimuli toggling of RAFT polymerization using two di?erent external physical manipulations: light “ON”/“OFF” and solution pH “LOW”/“HIGH”. In addition, these CPPs endowed radical polymerizations with various impressive features such as compatibility of diverse monomer formulations, unique oxygen tolerance, and ppm-level catalyst dosage. Demonstrations of chain extension and catalyst recycling further highlight the robustness and performance of this CPP catalyst. Through the study of structure?property relationship using the experimental analyses, we envisage that a series of xanthene dye-functionalized CPPs can be developed as visible light-absorbing organocatalysts rivaling transition-metal photocatalysts.
关键词： PET?RAFT polymerization,visible light-absorbing organocatalysts,xanthene dye-functionalized conjugated porous polymers,dual-stimuli toggling,heterogeneous photocatalysts
更新于2025-09-23 15:19:57
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Controlled Synthesis of PdII and PtII Supramolecular Copolymer with Sequential Multiblock and Amplified Phosphorescence
摘要： Supramolecular copolymers constitute a fundamental new class of functional materials attracting burgeoning interest, but examples that display phosphorescence and long-lived excited states are rare. Herein, we describe the synthesis of sequential phosphorescent multi-block supramolecular copolymers in one and multiple dimensions using pincer PtII and PdII complexes as building blocks by manipulating out-of-equilibrium self-assemblies via the living supramolecular polymerization approach. Doping a small amount of PtII complexes (2 mol %) into the PdII assemblies significantly boosted the emission efficiency and radiative decay rate constant (Fem = 3.7%, kr = 1.8 3 104 s?1 in PdII assemblies; Fem = 76.2%, kr = 58.6 3 104 s?1 in PtII-PdII co-assemblies), which is ascribed to an external heavy-atom spin-orbital coupling effect arising from the doped PtII complex with a delocalized 3[ds*/p*] excited state. The findings on PtII and PdII supramolecular copolymers with controlled sequences and greatly enhanced phosphorescence efficiencies open the door to new photofunctional and responsive luminescent metal-organic supramolecular materials.
关键词： Living supramolecular polymerization,PtII and PdII complexes,Phosphorescence,External heavy-atom effect,Supramolecular copolymers
更新于2025-09-23 15:19:57
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Stereoregular polymers with pendant carbazolyl groups: Synthesis, properties and optoelectronic applications
摘要： The most recent results concerning the stereospecific synthesis and the microstructural, chemico-physical and optical characterization of polymers containing pendant carbazolyl groups are reviewed for the first time. Stereoregular poly(N-alkenyl-carbazole)s, poly(4-(Ncarbazolyl) methyl styrene), poly(ω-(N-carbazolyl)alkyl acrylate)s and poly(ω-(N-carbazolyl)alkyl metacrylate)s are considered in this review, with a particular focus on the influence of polymer stereochemistry on photophysical behavior. Potential applications of these materials in light-emitting diodes (LEDs), electrochromic devices, electrophotography and holographic memories are also discussed. Among these, we show the appealing results of our experiments, concerning the color tuning in organic LEDs based on poly(N-pentenyl-carbazole) by means of the polymer chain stereoregularity.
关键词： Organic light emitting diode,Carbazole,Optical properties,Stereospecific polymerization
更新于2025-09-23 15:19:57