最新刊期
卷 55 ， 期 10 ， 2024
- 摘要：Maleic anhydride/maleimide copolymers and their derivatives have realized industrial production and application with the advantages of easy functionalization, low cost, tunability and biocompatibility, long before their fluorescence properties were discovered. In recent years, the self-stable precipitation polymerization method of maleic anhydride/maleimide copolymer were developed to realize the polymerization and separation of olefin raw materials in the petrochemical industry. The resulting copolymer microspheres also have important industrial value, and can be used in many fields such as light diffusion, wood bonding, and light transfer. As a new typical class of non-conjugated photoluminescence polymers, maleic anhydride/maleimide copolymers and their derivatives could exhibit the following advantages: (1) The electron-deficient maleic anhydride and maleimide monomers could easily form copolymers with electron rich monomers such as styrene, α-methyl styrene, stilbene, vinyl acetate, etc., to achieve special photoluminescence caused by spatial conjugation. Such polymers showed strong molecular designability and variable structures; (2) Based on the reactivity of maleic anhydride/maleimide units, such copolymers can achieve functional group grafting, ionic modification, amidation/imide transformation, removal reaction, etc. Therefore, the study of the photoluminescence properties of maleic anhydride/maleimide copolymers is also convenient to provide a systematic basis for the photoluminescence mechanism of non-conjugated polymers. Besides, their fluorescence properties of these copolymers could be adjusted according to practical applications. However, the photoluminescence properties, mechanism and related applications of maleic anhydride/maleimide copolymers and their derivatives are still lacking. Based on the fluorescence molecular modification, polymerization regulation, acid-base modification and heat treatment of maleic anhydride/maleimide copolymers and their derivatives, combined with their preparation methods, structural characteristics and fluorescence mechanism, the latest research progress of this kind of non-conjugated polymers in the field of photoluminescence is briefly reviewed in this paper. Maleic anhydride/maleimide copolymers and their derivatives exhibit high industrial potential in kinds of applications such as light-emitting diode (LED), chemical sensing, drug delivery, cell imaging, ink-free anti-counterfeiting printing.关键词：non-conjugated polymers;Photoluminescence;maleic anhydride/maleimide copolymers and derivatives;space conjugation;cluster luminescence
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发布时间：2024-11-15
Review
- 摘要：We utilized a low-cost polymer donor P(Cl) with a simple non-fused ring acceptor 2BTh-2F as the active layer material for device preparation. Through careful selection and optimization of additives, the microstructure and interfacial interactions of the device were significantly enhanced, resulting in an excellent power conversion efficiency (PCE) of 14.21%. The device achieves an open-circuit voltage (VOC) as high as 0.861 V, a short-circuit current density (JSC) of 23.18 mA/cm², and a fill factor (FF) of 71.21%, which exceed the performance of the control without additives (12.51%). It is noteworthy that this efficiency value is one of the highest achieved to date based on the pairing of a simple polymer donor material with a simple non-fused ring acceptor material. Our work not only demonstrates the great potential of low-cost materials in the preparation of high-performance devices, but also proves that dual low-cost, high-efficiency devices with polymer donors and small-molecule acceptors can be realized by finely tuning the morphology of the blended film and deeply studying the film-forming process. This work opens up a new path for the future development of low-cost and high-performance photovoltaic devices, which is of great scientific significance and practical application value.关键词：Organic solar cell;Simple donor;Non-fused ring acceptor;Photovoltaic conversion efficiency
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发布时间：2024-11-15 - 摘要：Diphenyl silicone raw rubbers were efficiently prepared by anionic ring-opening copolymerization of cyclosiloxanes using CTPB as catalyst. The vulcanized silicone rubbers with different diphenylsiloxane contents were then prepared for studies of damping and other properties. The results showed that the mechanical properties of silicone rubbers first increased and then decreased with the diphenylsiloxane contents increasing from 5 mol% to 50 mol%. Accordingly, the damping loss peak moved to high temperature when the glass transition temperature increased, affording the widened effective damping temperature range. Among which, the silicone rubber with 40 mol% diphenylsiloxane and 50 phr silica exhibited best balance in mechanical and damping properties, with tensile strength of 7.0 MPa and elongation at break of 376%. The effective damping temperature range of this silicone rubber reached 113 ℃ (-31 ℃ to 82 ℃) with the maximum loss peak (tanδmax) of 0.7. In addition, replacing the traditional silica filler with carbon black K90 and graphene sheet further enhanced damping performance, affording tanδmax value of 1.2 and 0.7 and broad effective damping temperature range of 127 ℃ (-27 ℃ to 100 ℃) and 133 ℃ (-33 ℃ to 100 ℃), respectively. This paper provided a novel method for preparing high damping silicone rubbers with wide temperature range, which have great potential for the industrialized application.关键词：Phenyl silicone rubber;Silicone rubber;Damping;Organocatalysis;Ring-opening polymerization
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发布时间：2024-11-15 - 摘要：Based on polymerized thermally activated delayed fluorescence (TADF) small molecules, a series of single white-emitting polymers named P010-P075 have been designed and synthesized by using acridine- benzophenone-carbazole (AcBPCz) as the sky-blue TADF moiety, acridine-naphthalimide-carbazole (AcNICz) as the orange TADF moiety and tetramethylbenzene as the linker between them. After a modulation of the AcNICz content in the range of 1%-7.5%, a part energy transfer can happen from AcBPCz to AcNICz. Consequently, P010-P075 all display a dual spectral profile in the photoluminescence (PL): the sky-blue emission peaked at 482-492 nm is from AcBPCz, while the orange emission peaked at 590-602 nm is from AcNICz. And the ratio of sky-blue to orange emission together is found to be decreased gradually with the increasing content of AcNICz. The corresponding solution-processed OLEDs achieve a bright white electroluminescence (EL), revealing a maximum current efficiency of 5.4-16.8 cd·A-1 and a maximum external quantum efficiency of 3.0%-6.4%. Noticeably, the EL is obviously dependent on the AcNICz content, consistent with the PL counterparts. Ongoing from P010 to P075, the Commission Internationale d'Eclairage (CIE) coordinates are shifted from (0.32, 0.50) to (0.47, 0.44) and the correlated color temperature (CCT) is reduced from 5910 K to 2797 K. The obtained cold white EL for P010 and warm white EL for P075 are believed to be applicable for different lighting scenes.关键词：Organic light-emitting diode;Thermally activated delayed fluorescence polymers (TADF);Single white-emitting polymers;Polymerized TADF small molecules;Emissive color
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发布时间：2024-11-15 - 摘要：Two styrene derivatives 2,2,2-trifluoro-1-(4'-vinyl-[1,1'-biphenyl]-4-yl)ethan-1-one-O-(3-methylbenzoyl) oxime (OXE-P) and 2,2,2-trifluoro-1-(4'-vinyl-[1,1'-biphenyl]-4-yl)ethan-1-one-O-thiophene-2-carbonyl oxime, OXE-S) modified by photosensitive oxime ester group were synthesized. They were characterized by 1H nuclear magnetic resonance (1H-NMR) spectroscopy and high-resolution mass spectrometry (HRMS). New polymers (POXE-P and POXE-S) were prepared by the reversible addition-fragmentation transfer (RAFT) polymerization, and were further characterized by gel permeation chromatography (GPC), giving molecular weights (Mw) of 8.3 kDa and 7.2 kDa, and polydispersites (Đ) of 1.1. Both polymers possess good solubility, thermal stability and film-forming capability, which meet the requirements of resist materials. The polymers were dissolved separately in the propylene glycol methyl ether acetate (PGMEA) to form nonchemically-amplified resists (n-CARs). The lithographic performance of the POXE-P resist was examined by e-beam lithography, giving a 50 nm HP (half-pitch) lithographic pattern. The mechanism of POXE-P resist during exposure was investigated by Fourier transform infrared spectrometer (FTIR) and in situ outgassing analysis. It showed that the oxime ester group decomposed during exposure to form carbonyl compounds, CO2, and other small molecules. The cleavage of side chains and the possible crosslinking led to the solubility switch of the polymer, resulting in negative lithographic patterns.关键词：Nonchemically-amplified resist;Reversible addition-fracture chain transfer (RAFT) polymerization;Oxime ester;Electron beam lithography;Mechanism
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发布时间：2024-11-15 - 摘要：A soluble polyimide (PI) was synthesized in a high-temperature one-step process using fluorinated dianhydride 4,4'-(hexafluoroisopropylidene)bis(phthalic anhydride) (6FDA) and reactive carboxyl-containing diamine 3,5-diaminobenzoic acid (DABA) as monomers, with the self-enhancing photosensitive cinnamoyl group grafted on the carboxyl group of the PI through the esterification reaction. Three kinds of photosensitive polyimide resins with different molecular weights, PI95, PI97.5 and PI100, were synthesized by controlling the molar ratio of 6FDA to DABA. The photolithographic process parameters of the three kinds of photosensitive polyimides with different molecular weights were systematically explored, and the PI97.5 sample was preferred according to the quality of the photolithographic pattern. The sensitivity of the PI97.5 sample is 785 mJ/cm2, the resolution is up to 7 μm, and the line width is up to 14 μm. The 5% weight loss temperature of the cured film is higher than 340 ℃, and the glass transition temperature is up to 274.2 ℃, which shows good mechanical properties. The results provide a research basis for the development of new negative photosensitive polyimide photoresists.关键词：Photosensitive polyimide;Cinnamoyl group;Self-photosensitive;Photolithography process;Photosensitive properties
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发布时间：2024-11-15 - 摘要：A regioselectively substituted cellulose derivative with bulky pendants at the 6-position, that is the cellulose-[2,3-(3,5-dimethyl)-6-(4-(4-(3-(9-ethyl-9H-carbazole-3)ureido)benzyl))]phenylcarbamate (Cel-1), was successfully synthesized using cellulose as substrate by 6-position-protection method and carbamoylation. The 1H-NMR spectrum and elemental analysis data indicated that the cellulose derivative was structurally regular with almost complete substitution as expected. The fluorescent recognition property of Cel-1 was then evaluated in detail based on twelve metal ions. The results indicated that the bulky cellulose derivative (Cel-1) could realize excellent dual-mode recognition to both Fe3+ and Cu2+ with high sensitivity and high selectivity in the DMSO/H2O system, together with high anti-counterfeiting ability to the other ten metal ions tested in the study. Especially, the limits of detection of Cel-1 for Fe3+ and Cu2+ in both fluorescence and UV-visible modes were lower than the maximum acceptable concentrations of the two ions in drinking water as defined by the United States Environmental Protection Agency (EPA). It demonstrated that the obtained bulky cellulose derivative possessed high-efficient and specific fluorescent recognition ability for Fe3+ and Cu2+, which could be used as chemosensors for the rapid recognition and detection of the two metal ions. In addition, the fluorescent ink prepared based on Cel-1 could not be observed under natural light, whereas emitted bright blue fluorescence under ultraviolet light, suggesting its potential in the anti-counterfeiting related field.关键词：Fluorescent sensing;Bulky pendants;Cellulose derivatives;Metal ion recognition;Dual mode detection
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发布时间：2024-11-15 - 摘要：Polycaprolactone polyurethane (PCL-PU) has excellent mechanical properties, good biocompatibility and biodegradability, which is widely used in biomedical materials and other fields. However, the domestic production capacity of polycaprolactone diols is unable to meet the production demand of the polyester-based polyurethane industry. The search for alternatives with comparable properties to polycaprolactone-based polyurethanes is of great research importance. Therefore, in this study, three polycaprolactone (PCL-diol) and polycarbonate (1,4-butanediol) ester polyols (PC-diol) with different relative molecular masses were prepared using Lewis pair-catalyzed controlled ring-opening polymerization, respectively. The structures of the two polyester diols were characterized by nuclear magnetic resonance hydrogen spectrometry (1H-NMR) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis (MALDI-TOF MS). PCL-PU and polycarbonate polyurethane (PC-PU) were synthesized by the reaction of two polyester diols with 2,4-toluene diisocyanate (TDI) and chain extender 1,4-butanediol (BDO), respectively. The thermal properties, crystalline behaviors, and mechanical properties of the two polyurethanes were further investigated in a comparative manner by thermogravimetric analysis, differential scanning calorimetry analysis, and stress/strain test. The results show that PC-PU has similar thermal stability and thermal decomposition process as PCL-PU, and the initial decomposition temperature of both polyurethanes is higher than 260 ℃, and both of them have two thermal decomposition stages. PCL-PU has a faster crystallization rate, while PC-PU has a slower crystallization rate. Compared to PCL-PU, PC-PU has higher elongation at break (>1200%) and breaking strength (>45 MPa). This paper provides a scientific basis and rationale for the creation of PC-PU with comparable properties of PCL-PU, and provides impetus for the development of the polyurethane industry.关键词：Polycaprolactone;Polycarbonate;polyester diols;Ring-opening polymerization;Polyurethane
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发布时间：2024-11-15 - 摘要：Low-foaming nonionic Gemini surfactants are widely used in industrial cleaning and photoresist development. In this study, three low-foaming nonionic Gemini surfactants are synthesized by using 2,5-di-tert-pentylbenzene-1,4-diol and ethylene oxide as raw materials via ring-opening reaction under alkali-catalyzed conditions. The surfactants, named P1, P2, and P3, have different polyoxyethylene chain lengths of 6, 7, and 8, respectively. The surface tension, critical micelle concentration (CMC), wettability, emulsifying, and foaming properties of the three Gemini nonionic surfactants are carefully investigated. The surface tension of P1, P2, and P3 decreases with increasing concentration and remains unchanged when CMC is reached. While at the same concentration, the surface tension increases with the increase of polyoxymethylene chain length due to increased hydrophilicity. The CMC of P1, P2, and P3 are 1.225 mmol/L, 1.016 mmol/L, and 0.700 mmol/L, respectively, decreasing with the increment of polyoxymethylene chain length. The contact angle of P1, P2, and P3 decreases with increasing concentration and remains unchanged when the concentration is higher than CMC. The contact angle increases with the increase of polyoxymethylene chain length at the same concentration. The emulsion stability of P1, P2, and P3 increases with increasing concentration and it increases with the increasement of the polyoxyethylene chain length at the same time. The initial foaming volume of P1, P2, and P3 increases with increasing concentration and the chain length of polyoxymethylene at the same concentration. In particular, P1 has the lowest initial foaming volume, which is 1% of the conventional nonionic surfactant Tween-80, exhibiting excellent low-foaming properties. P2 and P3 also show good low-foaming ability, with less than 20% of the foaming ability of conventional surfactant Tween-80. Overall, the three Gemini surfactants offer excellent low-foaming properties while reducing surface tension, making them well-suited for real-world applications such as industrial cleaning and developer fluids.关键词：Nonionic Gemini surfactants;Low-foaming;Surface tension;Wettability;Emulsifying property
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发布时间：2024-11-15 - 摘要：The aramid fiber reinforced polyurethane composites (AF@PU), which exhibit high strength and lightweight characteristics, have attracted widespread concerns for advanced personal protective systems. However, the interface has consistently been the scientific issue that permeates composite research and is frequently overlooked. In this work, polydopamine and γ-aminopropyltriethoxysilane modified SiO2 (m-SiO2) were used to optimize the interfacial properties, and the effects on ballistic performance and ballistic damage mechanism of composites were deeply investigated. Attributing to the strong bonding strength between fibers and polymer resins improved by them at the interface, the interfacial peeling strength of m-SiO2/PDA/AF@PU is increased by 244.1% (4.68 N/cm); the interlaminar shear strength is increased by 30.7% (6.09 MPa); the tensile, flexural and compressive strength of is maximally increased by 5.0%, 91.4% and 69.5%, respectively. Notably, because the introduction of abundant m-SiO2 enhances the interface roughness, m-SiO2/PDA/AF@PU demonstrates the maximal energy absorption value; the ballistic limit velocity is improved from 449.8 m/s of AF@PU to 481.9 m/s of m-SiO2/PDA/AF@PU. This work highlights the optimization of interfacial properties and provides an efficient guideline for the design of next-generation fiber reinforced polymer resin composites.关键词：Composites;Interfacial modification;Polydopamine;Nano silica;Ballistic performance
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发布时间：2024-11-15 - 摘要：Polypropylene (PP) has the advantages of low cost, thermoplastic processing and good biocompatibility, and is widely used in the fields of household appliances and medical devices. However, it has rarely been used in the preparation of capacitive pressure sensors. In this research, thermoplastic polyurethane (TPU)/PP blends were prepared by melt blending, and then the blends were foamed by supercritical carbon dioxide batching foaming. The microstructure and mechanical properties of the TPU/PP blends and their foams were characterized. Based on this, the effects of the TPU on the mechanical and foaming properties of the blends, and thus on their pressure sensing performances were analyzed. The SEM images of the blends showed that the TPU droplets were uniformly distributed in the PP matrix. And the mechanical results suggests that the deformation abilities of the blends were significantly improved by these TPU droplets. Thus, the pressure sensors with the blends as dielectric layers show higher sensitivity (S). It is also found that, the melt strengths of the blends were improved by the TPU. And thus the cellular structures of the TPU/PP foams were improved: the solid area and wormlike-connected cellular structure in the TPU/PP foams were significantly reduced or even disappeared. Therefore, the deformation abilities of the TPU/PP blends were improved by foaming. And the values of S for the sensors with TPU/PP foams were higher than those with the TPU/PP blends. For example, for the blend with 30 wt% TPU, the values of S in elastic bending and buckling regions were increased by 4.1 and 0.4 times, respectively, after foaming. The application testing results show that the sensor with the PP-based cellular materials as dielectric layers reveals good application prospect in detecting human movements, such as walking, sitting and grasping.关键词：Polypropylene;Supercritical carbon dioxide foaming;Mechanical properties;Pressure sensing performance
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发布时间：2024-11-15 - 摘要：As the display industry evolves, the research and development of colorless transparent polyimide (CPI) films for use in flexible display covers have become increasingly prominent. This study leverages commercial anhydrides and diamine monomers to fine-tune the main chain structure, fluorine content, and intermolecular hydrogen bonding, thereby achieving an equilibrium among transparency, dimensional stability, thermal resistance, and mechanical strength of the films. The produced CPI-2-TF film showcases exceptional optical average transmittance (Tav>88%), along with minimal coefficients of thermal expansion (CTE) (<1.3×10-5 K-1), elevated glass transition temperatures (Tg) (≥380 ℃), and superior mechanical properties. These attributes establish a robust foundation for the commercialization and mass production of CPI. Moreover, this study specifically examines the bend-durability of CPI-2-TF. After 2×105 bending cycles, the film maintained over 99% of their original average transmittance (Tav) and exhibited a mere 4% decrease in mechanical properties. Upon extending the bending to 400k cycles, the films retained virtually unchanged optical performance and over 92% of their mechanical integrity, demonstrating high potential for applications in folding screen smartphones and similar devices.关键词：Colorless transparent polyimide;Bend-Durable;Flexible Display Covers;High Temperature-resistance
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发布时间：2024-11-15 - 摘要：The self-assembly behavior of three regio-isomers, namely the ortho-, meta-, and para-isomers, formed by double chains grafted at different vertices of cage-like molecules, was simulated using the dissipative particle dynamics (DPD) method. The results indicate that a long the varying length of the grafting chains the three regio- isomers exhibit inconsistent regulation of the emergence and stability of self-assembled structures. Specifically, when the grafting chains are relatively short, the curvature of the ordered structures self-assembled by the tail chains increases in the order of ortho-, meta-, and para-isomer. In contrast, when the grafting chains are longer, the cage-like molecules in different isomers tend to stack into distinct bicontinuous structures. The simulation results also predict that the temperature of the order-disorder transition (TODT) for the three regio-isomers decreases in the order of ortho-, meta-, and para-, and this trend is consistent with the TODT of the combined regio-isomers. The diverse phase behaviors in the regio-isomers can be understood from the different conformation of the chains and packing of the cage molecules. This study clarifies that the tiny differences in the structural unit can profoundly impact the self-assembled structures, which offers new insights into exploring unconventional order structures self-assembled in soft matters.关键词：Cage-like molecule;Block copolymer;Dissipative particle dynamics (DPD);Self-assembly
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发布时间：2024-11-15 - 摘要：This research comprehensively examines the thermodynamic behavior and conformational changes in polyethylene (PE) and its blends with supercritical carbon dioxide (scCO2) under shear flow conditions using non-equilibrium molecular dynamics (NEMD) simulations, which uncovers the influence of scCO2, acting as a plasticizer, on the thermodynamic and conformational properties of PE. The study reveals that scCO2 diminishes intermolecular forces and shear stress within the system, leading to a reduction in viscosity and alterations in the conformational parameters of PE molecular chains. These changes result in an increased free volume and curling of the molecular chains, with a notable decrease in molecular orientation alignment under shear, thereby, enhancing the system's dynamic properties and thermal stability. By analyzing parameters such as stress (τxy and σv)-strain(γ) curves, mean square end-to-end distance (Rete), radius of gyration (Rg), orientation parameters (P2θ), and the autocorrelation function of the relaxation process under three shear flow, the peak shear stress τxy decreased from 0.18 in the PE system to 0.068 in the PE+scCO2 system at
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发布时间：2024-11-15 - 摘要：The technologies for harvesting green electricity from the ubiquitous moisture in the environment have garnered significant attention in recent years. This study proposed a facile approach for fabricating the n-type and p-type polymer composite membranes containing thermal redox couples, enabling a n-p type moisture-heat induced electricity generator (n-p-MHEG) for generating electricity from the chemical potential of moisture and low-grade heat in the environment. It reveals that temperature and moisture gradients synergistically enhance the ionic migration and capability of power generation of n-p-MHEG. The introduction of thermal redox couples further improves the conversion of thermal energy in the environment into electricity. The power density of n-p-MHEG can reach 17 μW·cm-2 under a temperature difference of 20 ℃ at 80% RH. By integrating nine such devices, it is possible to generate high voltages of 4-8 V from the moisture and thermal energy of the human skin. This type of flexible device with rapid response to environmental stimuli, excellent environmental adaptability, lightweight and eco-friendliness has potential applications in self-powered wearable electronics, sensing, and human health monitoring.关键词：Moisture-heat induced electricity generator;Polymer composite membrane;Temperature gradient;Moisture gradient;Power generation
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发布时间：2024-11-15
Research Article
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