SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2014
·
IF 2.129
Na Li,Jiang-Kun Dai,Hong-Tao Du,Mao-Sen Yuan,Ji-Wen Zhang,Jun-Ru Wang
A novel sensing system based on the β -carboline core has been designed and synthesized for Hg 2+ detection in water. We have demonstrated that a straight forward methodology can provide rapid, sensitive and selective recognition (cross-contamination experiments) for Hg 2+ over a wide pH range. The vivid fluorescence change from blue to colorless can be clearly discriminated by the naked eye. Furthermore, there is a good negative correlation between the fluorescent intensity and the concentration of Hg 2+ in the range 1.0 × 10 −6 M–7.0 × 10 −6 M. β -Carboline as a fluorophore synthesized via this route also provides a new strategy for the design of novel fluorescence probes and fluorochromes.
研究领域:
分析化学
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环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
HIGH PERFORMANCE POLYMERS
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2020
·
IF 1.568
Ke Li,Hua Yin,Kun Yang,Pei Dai,Ling Han,Riwei Xu
Designing novel low-melting, high-rigidity phthalonitrile resin is of great significance in the current context of development. In this study, rigid spirocycle acetal structure was introduced into phthalonitrile to reduce the melting point and maintain their thermal stability. The chemical structure of resins was confirmed by nuclear magnetic resonance (NMR) spectrometry, matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and Fourier-transform infrared (FTIR) spectroscopy. The curing behaviors were studied by differential scanning calorimetry (DSC). Thermal stability and mechanical properties of the cured resins were investigated by dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The processability was studied by rheological analysis. The results indicated the three monomers had a low melting temperature, wide processing windows and low viscosities. These polymers did not exhibit Tg from room temperature to 400°C, exhibited superb dynamic mechanical property and thermal stability.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Zhongke Li,Jing Yang,Xiande Yang,Hongxi Zhang,Liang Wei
Lignin is a promising alternative to fossil resources due to its abundance of benzene ring monomers. However, the stability of the C α C β bond in lignin has hindered its efficient depolymerization. Electrochemical methods for breaking this bond are not well-studied. This paper presents a novel approach for catalytic depolymerization of lignin to produce acetals under mild conditions, without the need for additional catalysts. Under room temperature and in an air atmosphere, the combination of tetrabutylammonium tetrafluoroborate (TBABF 4 ) as an auxiliary electrolyte and methanol (MeOH) as a solvent has shown high selectivity in catalyzing the cleavage of C α C β bonds in lignin. Over 90.0 % of the resulting products are acetals, with the optimal conditions being a substrate concentration of 0.02 M, TBABF 4 concentration of 0.008 M, a constant current of 30 mA, and a reaction time of 3 h. This led to a substrate conversion rate of 95.8 % and a product yield of 98.0 % for benzaldehyde dimethyl acetal (Bda). The mechanism study reveals that the tributyl ammonium radical cation decomposed by TBABF 4 is adsorbed on the electrode surface. Subsequently, the adsorbed O 2 is activated to form superoxide anion radical active species through single electron transfer, which plays a crucial catalytic role. TBABF 4 acts as both an auxiliary electrolyte and a catalyst in this process. This research introduces a novel approach for electrocatalytic depolymerization of inert C α C β bonds in lignin, leading to the selective conversion into acetal chemicals.
研究领域:
生物质化学
·
电催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
·
2024
·
IF 5.1
Nianzhao Gao,Yanglei Zheng,Jianan ShangGuan,Haoran Sun,Junyi Jiang,Shuangfei Xiang,Shujun Zhao,Feiya Fu,Xiangdong Liu
The development of sustainable composites necessitates biobased epoxy resins that are highly recyclable and degradable; however, the integration of mechanical, reprocessing, and rapid degradation properties into a single epoxy resin remains a significant challenge. The present study proposes a straightforward approach to overcoming the problem by combining two labile covalent bonds into an epoxy resin. The combination of acetal and disulfide bonds demonstrates a synergistic effect on the degradation performance of epoxy resin, leading to an ultrafast degradation of the epoxy polymer. The carbon fiber-reinforced composite with the epoxy resin matrix shows a tensile strength exceeding 630 MPa, but the epoxy resin degrades completely within just 8 min, while the recovered carbon fibers display nondestructive characteristics similar to those of the original material. Moreover, the epoxy resin that we designed shows good self-healing and reprocessing ability. Scratches on the resin surface can be completely self-healed by heating, while the powdered resin can be reshaped under a hot press. These findings offer a new approach to the preparation of sustainable composites, highlighting the significant importance of the development of thermosetting polymers.
研究领域:
材料科学
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可持续发展
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 30
·18039-18049
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IF 10.733
Qiong Li,Songqi Ma,Sheng Wang,Wangchao Yuan,Xiwei Xu,Binbo Wang,Kaifeng Huang,Jin Zhu
Dynamic covalent networks offer the favorable features of cross-linked polymers as well as the functions of reprocessing, recycling, self-healing, reshaping, and welding; however, it is a challenge to design readily monomer-recovery, highly malleable, catalyst-free, dynamic materials. Here we report the first design of acetal dynamic networks to address this challenge. Acetal dynamic networks were built via the catalyst-free “click” addition of polyol and a commercial divinyl ether without releasing small molecules. Small-molecule model compounds demonstrated thermally-induced acetal exchange without a catalyst. There are two mechanisms for the dynamic exchange of acetal: one is the metathesis of acetal, another is transacetalization. Acetal dynamic covalent networks exhibited excellent malleability and recyclability. They presented rapid stress relaxation at high temperatures. Hot press recovery can be achieved in 10 min at 150 °C. Meanwhile, the starting material was recovered with 92% recovery in 1 h under hot water treatment at 100 °C, and could be recross-linked with a commercial divinyl ether to obtain an acetal network. The acetal networks recovered by the two methods maintained the original structure and performance. An acetal dynamic linkage will open up a new way for the development of catalyst-free dynamic covalent networks and enrich acetal chemistry.
研究领域:
材料科学
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有机化学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
·
2020
·Vol. 5
·期 3
·539-546
·
IF 3.441
Guangcai Zhang,Lu Zhang,Xuesong Wang,Aicheng Chen,Qinhui Zhang
This work presented microfluidic processing of zeolite films in a capillary microreactor and its potential application for biomass conversion. Uniform and continuous HZSM-5 zeolite films were fabricated under a continuous flow hydrothermal system in which the film thickness could be precisely tuned by flow rate and synthesis time. The catalytic performance of this acidic HZSM-5 film capillary microreactor was evaluated by the continuous flow acetalisation reaction of glycerol with acetone, affording ∼62.61% solketal yield under mild and solvent free conditions. No deactivation was observed even after 100 h, indicating the excellent stability of this HZSM-5 film capillary microreactor. This microfluidic processing strategy provided an extended applicability in the fabrication of zeolite film-based capillary microchannels with a high length-to-diameter ratio or other chip-based microchannel devices.
研究领域:
化学工程
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生物质转化
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微流控技术
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 47
·41404-41409
·
IF 3.289
Wei-Hong Zhang,Shan-Shan Liu,Ping Liu,Jie Xu,Bing Xue,Xian-Yong Wei,Yong-Xin Li
Chitosan immobilized with an acidic ionic liquid (CS–VImPS–PW) was fabricated via a radical addition reaction of N-vinylimidazoliumpropane sulfonate and chitosan, followed by acidification with a heteropolyacid. It was characterized by a Fourier transform infrared spectrometer, solid-state 13C nuclear magnetic resonance spectrometer, thermogravimetric analyzer, elemental analyzer, and Hammett indicator. Some acetalization reactions were investigated to evaluate the catalytic activity of CS–VImPS–PW. The results show that CS–VImPS–PW is highly active for the acetalization reactions in high acetal yields ranging from 83.2 to 96.2% and can be reused 8 times without noticeable loss of activity.
研究领域:
化学工程
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材料科学
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有机化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yushan Li,Qingqing Xie,Mengyu Wang,Zhenyang Wang,Jiefeng Liu,Yiyao Du,Dongpei Zhang,Mengyuan Liu,Guangyu Zhang,Xin Jin,Chaohe Yang
Solketal is known as a promising non-BPA plasticizer . However, fast and robust synthesis of solketal from bio-oxygenates remains a grand challenge, as strong surface polarization often deactivates acidic catalysts. We proposed and validated a dual designing strategy, involving (1) Fe 3+ modified Bronsted acidity and (2) chlorotrimethylsilane (CTS) altered hydrophilicity for enhanced activity and stability of NaY catalysts. As one of the key findings, Fe 3+ exchanged NaYs display an unusual shortened Si-OH bond and electronically reconfigured Fe 3+ sites for a 4-fold activity enhancement. Furthermore, CTS modified FeY materials further alleviate surface passivation of glycerol and water, leading to an 18-fold activity improvement and better durability for acetalization of glycerol. CTS modified FeY catalysts display remarkable stability against varies impurity molecules. The dual modification methodology provides useful information on rational design of durable catalysts for synthesis of various other non-BPA derivatives.
研究领域:
催化化学
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绿色化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
·
2024
·
IF 2.5
Fumeng Yin,Shan Hu,Shuwei Zhu,Shifeng Xing,Hongjun Zhu
Graphical Using mesoporous graphitic carbon nitride (mpg-C 3 N 4 ) as a metal-free heterogeneous photocatalyst was developed for thiocyanation of alkenes under visible light irradiation with oxygen as green oxidant and without any other additives. The present protocol has excellent functional group tolerance and the desired tetrasubstituted alkenyl thiocyanides were obtained in moderate to good yields. Moreover, the recyclable mpg-C 3 N 4 catalyst could be used at least 6 times without significant loss of activities. Using mesoporous graphite carbon nitride (mpg-C 3 N 4 ) as metal-free heterogeneous catalyst, the thiocyanation of ketene dithioacetals was achieved under visible light irradiation with oxygen as green oxidant and without any other additives. The present protocol has excellent functional group tolerance and the desired tetrasubstituted alkenyl thiocyanides were obtained in moderate to good yields. Moreover, the recyclable mpg-C 3 N 4 catalyst could be used at least 6 times without significant loss of activities. A series of mechanistic validation experiments indicated that the reaction involves a radical process.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2024
·
IF 9.3
Xinyue Sun,Junjie Ni,Yuhan Lou,Peng Zhao,Yanyan Yu,Yilin Li,Qi Tang,Haipeng Yu,Yongzhuang Liu
Solvents with integrated functions enable directional lignin valorization for producing value-added chemicals or lignin polyols. In this study, a solvent-triggered directional lignin valorization process was developed based on the design of a biphasic deep eutectic solvent/dichloromethane (DES/DCM) system. The designed solvents exhibit a combined feature of chemical stabilization from ethylene glycol-based-DES and physical stabilization from a biphasic system. By establishing the DES/DCM, lignin was effectively functionalized into lignin polyols with high yield. Furthermore, by implementing a simple recycling procedure of the DCM phase, the reaction pathway was switched, leading to depolymerization and stabilization of the stabilized lignin polyols. This process resulted in an almost threefold increase in monomeric acetal yields. The effect of biphasic DES on functionalization or switched depolymerization of lignin was confirmed through model compound studies. Our findings demonstrate a directional lignin valorization route using the designed biphasic DES system, which offers potential applications in the production of value-added aromatic chemicals or potential intermediates for polymers.
研究领域:
化学工程
·
生物质能
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2023
·
IF 5.7
Huiling Tang,Shuang Xu,Mingjie Li,Liqin Wu,Chenghao Duan,Huiming Luo,Biao Zhou,Mumin Rao,Yongcai Qiu,Guangxu Chen,Keyou Yan
Biomass ethanol is regarded as a renewable resource but it is not economically viable to transform it to high-value industrial chemicals at present. Herein, a simple, green, and low-cost CuCl2–ethanol complex is reported for ethanol dehydration to produce ethylene and acetal simultaneously with high selectivity under sunlight irradiation. Under N2 atmosphere, the generation rates of ethylene and acetal were 165 and 3672 μmol g–1 h–1, accounting for 100% in gas products and 97% in liquid products, respectively. An outstanding apparent quantum yield of 13.2% (365 nm) and the maximum conversion rate of 32% were achieved. The dehydration reactions start from the photoexcited CuCl2–ethanol complex, and then go through the energy transfer (EnT) and ligand to metal charge transfer (LMCT) mechanisms to produce ethylene and acetal, respectively. The formation energies of the CuCl2–ethanol complex and the key intermediate radicals (e.g., ·OH, CH3CH2·, and CH3CH2O·) were validated to clarify the mechanisms. Different from previous CuCl2-based oxidation and addition reactions, this work is anticipated to supply new insights into the dehydration reaction of ethanol to produce useful chemical feedstocks.
研究领域:
催化
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绿色化学
·
有机转化
·
光化学
·
生物质转化
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Na Lu,Qiong Li,Songqi Ma,Binbo Wang,Xiwei Xu,Sheng Wang,Jiale Ye,Jianfan Qiu,Jin Zhu
Covalent adaptable networks (CANs) were rapidly developed to address the recycle issue of thermosets; however, facile and scalable synthesis of CANs is still a challenge. Here, we report the preparation of the acetal-based CANs with commercially available raw materials by a one-pot method without solvent, which can achieve zero atom loss over the whole process. The CANs were synthesized through a radical copolymerization of styrene (or 2-ethylhexyl methacrylate) and 2-hydroxyethyl methacrylate and an addition reaction of the hydroxyl from 2-hydroxyethyl methacrylate and a divinyl ether in one pot. The CANs could be recycled by hot-press reprocessing, and could also be degraded and regenerated into networks to achieve closed-loop recycling. In addition, the thermal and mechanical properties could be readily regulated by changing the monomers for the preparation. This work provides a scalable method to prepare acetal-based CANs, which will shorten the scientific research of CANs to industrialization.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）