Asian Journal of Organic Chemistry
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2017
·Vol. 6
·期 11
·1612-1619
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IF 2.788
Zhengmin Cheng,Feifei Xing,Yue-ling Bai,Yongmei Zhao,Shourong Zhu,Mingxing Li
Graphical A colorful exchange : A neutral, water-soluble, PEG-substituted perylene bisimide (PEPBI) was synthesized and its concentration-, solvent- and temperature-dependent visible and fluorescence spectra were measured. PEPBI exists as a dimer in aqueous solution but can be dispersed as monomers with an anionic surfactant. In organic solvents the monomer predominates. The reduction of PEPBI and the resulting aggregate forms was also investigated. A polyethylene-glycol-functionalized perylene bisimide (PEPBI) was synthesized. Its concentration-, solvent- and temperature-dependent visible spectra were measured and its aggregation states were analyzed. PEPBI exists as an aggregate dimer in aqueous solution or predominantly as a monomer in organic solvents. The anionic surfactant sodium dodecylbenzenesulfonate (SDBS) can disperse PEPBI as a monomer in aqueous solution. The fluorescence of these solutions depends on the concentration of PEPBI and SDBS. The reduction of aggregated PEPBI with Na 2 S is slow and the monoanion radical as well as dianion species are the main forms of monomer. PEPBI exists predominantly as monomers in DMF and reacts with Na 2 S much faster. Interestingly, the anionic radical species exist in H-aggregate form at low PEPBI concentrations and J-aggregation occurs at high concentration. The dianion species is EPR-silent and its color highly depends on its concentration in DMF.
研究领域:
化学
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材料科学
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产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
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2011
·
IF 3.463
Jing Han,Fa Cheng,Xiangguo Wang,Yuping Wei
In this work, the interactions between cationic cellulose (PQ-10) and anionic surfactant (SDBS) in aqueous media were investigated by turbidity, electric conductivity, steady-state fluorescence, shear rheology and transmission electron microscopy (TEM) analyses. Results indicated that precipitation appeared near the charge neutrality point, and the size of precipitation region widened with increasing PQ-10 concentration (0.57–1.72 mM for 0.05% PQ-10, and 2.30–17.22 mM for 0.5% PQ-10). The specific conductivity values of SDBS in the presence of PQ-10 were higher than that of pure SDBS over the whole concentration range under current experimental conditions. The aggregation number of SDBS kept constant in the flat region of the micropolarity curve (0.86 mM–1.43 mM). The structural transformation of the mixtures was monitored visually by TEM . As SDBS concentration increased, the morphologies of the mixtures changed gradually from branched wormlike aggregates to interconnected networks, finally the networks collapsed.
研究领域:
化学
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材料科学
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DOI
高影响因子
Nano Research
·
2019
·Vol. 13
·期 1
·52-60
·
IF 8.515
Yan Fanyong,Jiang Yingxia,Sun Xiaodong,Wei Junfu,Chen Liang,Zhang Yuyang
Multicolor emissive carbon dots (M-CDs) have tremendous potential applications in manifold fields of bioimaging, biomedicine and light-emitting devices. Until now, it is still difficult to produce fluorescence tunable CDs with high quantum yield across the entire visible spectra. In this work, a type of M-CDs with concentration-tunable fluorescence and solvent-affected aggregation states was synthesized by solvothermal treatment of citric acid (CA) and 1-(2-pyridylazo)-2-naphthol (PAN) and the formation mechanism was monitored by different reaction time and raw material ratio. The fluorescence spectra of M-CDs in organic solvents can range from 350 to 750 nm by adjusting the concentration. M-CDs possess different aggregation states in water and organic solvents, accompanied by different fluorescence emission, which is attributed to the different surface states of various component CDs in M-CDs. Moreover, the obtained products can be uniformly dispersed into polymethylmethacrylate (PMMA) solutions as well as epoxy resins to fabricate transparent CDs/PMMA films and CDs/epoxy composites, which can effectively prevent the aggregation and produce multicolor and white light-emitting diodes (WLED). In addition, the prepared WLED with Commission Internationale de L’Eclairage (CIE) of (0.29, 0.31) by using M-CDs/epoxy resin as packages, demonstrating the M-CDs exhibit potential applications for light-emitting devices.
研究领域:
材料科学
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光学
·
生物成像
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光电子器件
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DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2025
·
IF 7
Long-Qi Yang,Xiao-Ming Jiang,Guo-Cong Guo
Luminescent organic materials play an indispensable role in various aspects of human life and modern society; however, their photophysical processes in the aggregated state remain inadequately understood. Here, we introduce an experimental scheme to monitor in situ the evolution of charge density and noncovalent interactions in aggregated molecules under dark conditions and 360 nm laser irradiation. Application to 9,10-diphenylanthracene (DPA) crystals reveals an unexpected light-induced molecular shift and rotation. Topological analysis of the in situ charge density indicates that the overall molecular shift within DPA crystals strengthens intermolecular C–H···π interactions while weakening π···π interactions. Moreover, significant rotation of the phenyls occurs upon light exposure, resulting in a change in the dihedral angle between their plane and the anthracene core from 66.621 to 66.344°, which enhances the intramolecular conjugation across the entire molecule. This structural evolution leads to a reduction in excitation energy and an increase in the radiative transition rate, as demonstrated by theoretical calculations, ultimately resulting in the observation of strong emission. The motion-induced enhancement mechanism uncovered in this study addresses the long-standing debate surrounding photophysical processes in traditional luminescent aggregates, providing a foundation for the development of novel luminescent materials with improved performance and versatility.
研究领域:
有机化学
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物理化学
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材料科学
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DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
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2025
·
IF 7.4
Li Yang,Jie Xu,Ping Wang,Jiacheng Ling,Xinyun Hu,Wenxiu Liu,Yiyang Zhou,Tian Cao,Guilin Li,Jin Liu,Shaojie Feng
Improving the flame-retardant performance of polydicyclopentadiene (PDCPD) while maintaining mechanical properties has remained a technical challenge. In this study, a novel synchronous enhancement strategy for intrinsic flame retardancy and reinforcement based on frontal ring-opening metathesis polymerization (FROMP) was proposed, in which the newly synthesized phosphorus-containing norbornene flame retardant (NB-DPPC) and 5-norbornene-2-carboxylic acid (NB-COOH) were embedded into the cross-linked networks of PDCPD. The effects of NB-COOH and NB-DPPC on the thermodynamics and kinetics of the polymerization, as well as the crosslinked structure, mechanical properties, and flame retardancy of the copolymers, were systematically investigated. The results showed that by introducing NB-COOH into the PDCPD system improved the mechanical properties and flame resistance of the material. Specifically, the tensile strength and elongation at break of the specific copolymer reached 71.81 MPa and 123.62%, which were 50.07% and about 12 times higher than those of PDCPD, respectively. Meanwhile, the maximum limiting oxygen index (LOI) of the material reached 30.2%, resulting in an increase of 51.76%. According to the carbon layer structure and combustion gas composition, the flame retardant mechanism was further investigated. This work established a efficient method for the preparation of intrinsic flame retardant PDCPD and provided a strategy for constructing PDCPD materials with excellent comprehensive performance.
研究领域:
高分子材料科学
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阻燃材料
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功能高分子
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聚合物化学
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材料物理与化学
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DOI
高影响因子
Biomaterials Science
·
2024
·
IF 5.8
Hao Fu,Yongxin Zhang,Cheng Wang,Zhencheng Sun,Shuyi Lv,Minghui Xiao,Kaiyu Wu,Linqi Shi,Chunlei Zhu
Photothermal therapy (PTT) has emerged as a promising approach for treating bacterial infections. However, achieving a high photothermal conversion efficiency (PCE) of photothermal agents (PTAs) remains a challenge. Such a problem is usually compensated by the use of a high-intensity laser, which inevitably causes tissue damage. Here, we present a universal strategy to enhance PCE by regulating the molecular aggregation states of PTAs within thermoresponsive nanogels. We demonstrate the effectiveness of this approach using aggregation-induced emission (AIE) and aggregation-caused quenching (ACQ) PTAs, showing significant enhancements in PCE without the need for intricate molecular modifications. Notably, the highest PCEs reach up to 80.9% and 64.4% for AIE-NG and ACQ-NG, respectively, which are nearly 2-fold of their self-aggregate counterparts. Moreover, we elucidate the mechanism underlying PCE enhancement, highlighting the role of strong intermolecular π−π interactions facilitated by nanogel-induced volume contraction. Furthermore, we validate the safety and efficacy of this strategy in in vitro and in vivo models of bacterial infections at safe laser power densities, demonstrating its potential for clinical translation. Our findings offer a straightforward, universal, and versatile method to improve PTT outcomes while minimizing cytotoxicity, paving the way for enhanced treatment of bacterial infections with safe PTT protocols.
研究领域:
纳米技术
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生物医学工程
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材料科学
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治疗学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）