CARBOHYDRATE POLYMERS
·
2011
·Vol. 85
·期 4
·832-837
·
IF 3.463
Dongke Zhao,Jun Huang,Sheng Hu,Jianwei Mao,Lehe Mei
Chitosan was prepared by alkaline N -deacetylation of squid cartilage β-chitin and carboxymethylated derivatives with different degrees of substitution (DS) were synthesized. The DS of the derivatives calculated by pH titration were 0.64, 0.81, 1.0, 1.33 and 1.59. The antioxidant properties and bile acid binding capacity of the derivatives were studied in vitro . The carboxymethylation of chitosan caused enhancement of bile acid binding capacity. At 1 mg/mL, carboxymethyl chitosan (CMCS) showed a stronger scavenging effect than chitosan towards DPPH radicals. The CMCS scavenging effect on superoxide radicals was stronger than that of chitosan, and EC 50 values were below 5.6 mg/mL. The effectiveness of reducing power correlated with the DS of CMCS. At 1.2 mg/mL, the ability of CMCS to chelate ferrous iron was 100%, whereas that of chitosan was only 22.34%. This suggested that carboxymethylation is a possible approach to obtain chitosan derivatives with desirable biological properties.
研究领域:
生物化学
·
海洋生物技术
·
食品科学
·
高分子化学
·
功能生物材料
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ACS Applied Nano Materials
·
2023
·
IF 5.9
Zhiqian Yao,Suqiong Xu,Xianke Zhang,Jujun Yuan,Chuicai Rong,Zuzhou Xiong,Xiurong Zhu,Yi Yu,Huajun Yu,Shuying Kang,Fangguang Kuang
Metal–organic frameworks (MOFs) have come into the limelight in the field of microwave absorption since they can be developed into porous carbon-based MOF derivatives with a variety of features, such as controlled defects, tunable structures, and variable compositions. In this paper, Cu3[Co(CN)6]2 Prussian blue analogue (CuCo-PBA) precursors with a regular cubic morphology were synthesized by a simple co-precipitation method and converted into CuCo nanocube/N-doped carbon nanotube (CuCo/NCNT) derivatives by annealing them in argon. It was found that when the annealing temperature was 850 °C, the minimum reflection loss (RLmin) of CuCo/NCNT could reach −54.13 dB with an effective absorption bandwidth of 4.01 GHz. The excellent microwave absorption properties were attributed to the mutual synergy of conduction loss, interfacial polarization, magnetic resonance loss, and eddy current loss. Therefore, this work provides an effective preparation method for the design of lightweight carbon-based microwave-absorbing materials with heterogeneous interfaces using Prussian blue.
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Small
·
2023
·Vol. 19
·期 40
·2302095
·
IF 13.3
Yuqun Du,Yiwei Liu,Jangwei Li,Yanyun He,Yanbin Li,Hongxia Yan
Nonconventional luminogens with high quantum yield (QY) possess very potential applications in various fields. However, the preparation of such luminogens remains a great challenge. Herein, the first example of piperazine-containing hyperbranched polysiloxane exhibiting blue and green fluorescence is reported under the irradiation of different excitation wavelength and a high QY of 20.9%. The density functional theory (DFT) calculations and experimental results revealed that the through-space conjugation (TSC) within the clusters of N and O atoms is produced via the induction of multiple intermolecular hydrogen bonds and flexible Si O units, which is accountable for the fluorescence. Meanwhile, the introduction of the rigid piperazine units not only rigidifies the conformation, but also enhances the TSC. In addition, the fluorescence of both P1 and P2 shows concentration-, excitation-, and solvent-dependent emission, especially exhibits significant pH-dependent emission and obtains an ultrahigh QY of 82.6% at pH 5. The synthetic luminogens show excellent applications in fluorescence detection for Fe 3+ and Co 2+ , information encryption, and fluorescent film. This study provides a novel strategy to rationally design high-efficiency nonconventional luminogens.
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PubMed
高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Yan Gu,Ya Ru Pei,Ming Zhao,Guo Yong Wang,Chun Cheng Yang,Qing Jiang
Potassium-ion batteries (PIBs) have gained tremendous attention to compete with lithium-ion batteries (LIBs), especially for storing energy on a large scale, due to their dominance in the geographical distribution of K resources and similar energy storage mechanisms. Herein, using an electrospinning method, we synthesized a unique material of carbon nanonecklaces with a high content of N-doping (N-CNN). The N-CNN-700 anode (N-CNN annealed at 700 °C) shows outstanding durability in PIBs, delivering 173 mAh g–1 after 1000 cycles at 1 A g–1. The unique characteristics of ultrahigh pyrrolic/pyridinic-N doping and hollow necklace-like structures account for excellent performance, which can enable fast electrolyte diffusion, increase active sites for K+ insertion, and enhance K+ adsorption ability. This object demonstrates a clever strategy to design a structure for improved energy storage technologies.
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Materials Letters-X
·
2021
·
IF 0
Yan-Ming Chen,Jie Gao
Zinc oxide (ZnO) nanoparticles were synthesized by solution chemistry method with n-hexanol as solvent. The synthesized ZnO nanoparticles were characterized by Ultraviolet–visible spectroscopy, transmission electron microscope and X-ray powder diffraction, and the growth kinetics was studied by Lifshitz, Slyozov and Wagner model. The effects of temperature, the addition of deionized water and the concentration of zinc acetate dihydrate on the synthesis of ZnO nanoparticles were investigated. The results show that the nucleation and growth of ZnO nanoparticles were promoted by the addition of small amount of water, and the size of synthesized ZnO nanoparticles could be controlled by changing the amount of water addition and the concentration of zinc acetate dihydrate.
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DIAMOND AND RELATED MATERIALS
·
2020
·
IF 2.65
Yahui Mo,Juan Du,Haijun Lv,Yue Zhang,Aibing Chen
Due to the characteristics of thin thickness, rich active sites and short diffusion distance, the carbon nanosheets have been widely used as electrodes for energy storage in supercapacitors . Herein, N-doped mesoporous carbon nanosheets (N-MCS) were prepared by using cheap mica powder as template and resorcinol-formaldehyde (RF) resin as carbon precursor. The ethyl orthosilicate (TEOS) was introduces as porogen to create rich mesopores and to increase surface area. The ethylenediamine can be used not only as catalyst for TEOS hydrolysis and RF resin polymerization, but also as nitrogen dopant . The N-MCS faithfully replicated the template morphology, exhibiting sheet-like morphology, porous and N-doping characteristics, which can effectively improve the electrochemical performance .
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Journal of Materials Chemistry B
·
2020
·Vol. 8
·期 37
·8599-8606
·
IF 5.344
Zhen Lin,Linlin Zheng,Wensong Yao,Shijun Liu,Yemei Bu,Qi Zeng,Xiaomin Zhang,Haohua Deng,Xinhua Lin,Wei Chen
Nanozymes have emerged as enzyme-mimicking nanomaterials to overcome the low stability and high cost of some natural enzymes. The design and fabrication of nanozymes with superior performance to natural enzymes are in urgent demand. Single-atom catalysts offer the unique characteristics of maximum atomic utilization, and are an excellent candidate for nanozymes. However, most of the reported synthesis methods for single-atom catalysts require the preparation of supports for single-atom catalysts in advance, which requires multiple steps and calcination in a high temperature atmosphere. Herein, Cu–N–C single-atom nanozymes (Cu–N–C SAzymes) were successfully designed via a one-pot solvothermal method. Cu–N–C SAzymes exhibited excellent peroxidase-mimicking activity that is superior to some other related nanoparticles. The mechanism study revealed that H2O2 was catalyzed by Cu–N–C SAzymes to generate reactive oxygen species. Furthermore, based on the excellent peroxidase-mimicking activity of the Cu–N–C SAzymes, a simple and sensitive detection method for H2O2 and glucose has been developed.
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PubMed
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Yi-meng Huang,Guang Li,Mingzhen Li,Jijie Yin,Na Meng,Di Zhang,Xiao-qiang Cao,Fan-ping Zhu,Ming Chen,Lin Li,Xian-jun Lyu
N-doped carbon materials have been proven to be effective catalysts for activating peroxymonosulfate (PMS). Marine algae biomass is rich in nitrogenous substances , which can reduce the cost of N-doping process and can obtain excellent N-doped catalysts cheaply and easily. In this study, kelp biomass was selected to prepare N-doped kelp biochar (KB) materials. The high defect degree, high specific surface area, and participation of graphite N make KB have excellent catalytic degradation ability. The KB degraded 40 mg/L ofloxacin (OFL) close to 100% within 60 min, applied with PMS. Through quenching experiments and electron paramagnetic resonance spectroscopy, the degradation process dominated by non-radical pathways was determined. At the same time, O 2 ·- and 1 O 2 were closely related, and a significant impact of quenching O 2 ·- on the reaction was observed. The non-radical approach made the system excellent performance over a wide pH range and in the presence of multiple anions. The experiments of reusability confirmed the stability of the material. Its catalytic performance was restored after low-temperature pyrolysis . This research supports the use of endogenous nitrogen in biomass. It provides more options for advanced oxidation process application and marine resource development.
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Journal of Physical Chemistry C
·
2019
·
IF 4.309
Hao Feng,Ni Tang,Meng An,Rulei Guo,Dengke Ma,Xiaoxiang Yu,Jianfeng Zang,Nuo Yang
The thermal switch is a device that can modulate the heat flux and create a huge gap between the “On” and “Off” state, which has been widely used in many applications. However, owing to weak biocompatibility and complicated structures, most of existing thermal switch devices mostly are difficult to use in some emerging mobile health areas, such as soft electronics and biomedical applications. Herein, it is reported that a poly(N-iopropylacrylamide) (PNIPAm) hydrogels-based thermal switch featuring good biological compatibility and a simple preparation process. The thermal conductivity of the PNIPAm hydrogels at temperatures from 30 to 40 °C has been measured using the transient hot wire method. Interestingly, the thermal conductivity drops from 0.51 to 0.35 Wm–1 K–1 when the hydrogel is heated above the lower critical solution temperature. Its thermal resistance ratio Roff/Ron, an important criterion to evaluate the performance of the thermal switch, reaches up to 3.6. Furthermore, the effective medium approach is used to evaluate the thermal conductivity of hydrogels with different water content, and molecular simulation analysis reveals that the hydrogen-bonding network among water molecules mainly contributes to heat conduction of the hydrogels. The proposed thermal responsive hydrogel-based thermal switches contribute to the development of non-mechanical-assist devices and show a promising potential in biomedical science due to their biocompatibility.
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JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY
·
2019
·Vol. 95
·期 3
·207-213
·
IF 1.429
Fan Ying,Gao Ruihan,Jiang Yangming,Bian Bing,Tao Zhu,Wei Gang,Xiao Xin
In this work, we report a conceptual strategy for preventing pesticide degradation using cucurbit[n]uril to encapsulate pyroquilon (Pyn). The host–guest inclusion complexes of pyroquilon (Pyn) with CB[7] and CB[8] were prepared and characterized using 1 H NMR spectroscopy, quadrupole-time of flight mass spectrometry (Q-TOF), isothermal titration calorimetry (ITC) and UV absorbance spectrophotometry. The experimental results revealed that the entire Pyn molecule resides within the cavities of CB[7] and CB[8], forming 1:1 inclusion complexes between CB[n] and Pyn. Our study on the release of Pyn demonstrated that CB[n]@Pyn exhibit sustained- and slow-release properties. Moreover, CB[8] can effectively shield UV irradiation and thereby protect the Pyn from photodegradation. Therefore, CB[7]@Pyn and CB[8]@Pyn have great potential to be used as slow-release agents.
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ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Ying Han,Jihe Wang,Jun Li,Zhonglin Chen,Weiwei Li,Beibei Jiang,Jie Yao
Copper corrosion products (Cu(OH)2, Cu2O, CuO and Cu2CO3(OH)2) were applied to catalyze the reduction of N-Nitrosodimethylamine (NDMA) with iron. All the copper corrosion products showed catalytic abilities. Lower pH values and DO concentrations facilitated NDMA reduction in most cases. 1,1-dimethylhydrazine (unsymmetrical dimethylhydrazine, UDMH) and dimethylamine (DMA) formed during the degradation of NDMA. There were also some undetected products. Catalytic hydrogenation was proposed as the mechanism. The catalytic systems did not promote the formation of hydrogen atoms. The dissolved copper ions in these systems were too sparse to enhance the reaction. The smooth iron surface and formation of Cu2O in each catalytic system explained the enhancement of NDMA removal. Different surface morphologies and states of Cu2O accounted for the differences in NDMA removal and kinetics between the reaction systems. This technique could be an alternative for NDMA reduction and could broaden the application of copper corrosion products.
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MACROMOLECULAR RESEARCH
·
2012
·Vol. 21
·期 6
·681-686
·
IF 1.153
Xu Yewei,Tang Jie,Chang Guanjun,Zhu Fanghua,Luo Xuan,Zhang Lin
Poly( N -arylenebenzimidazole ketone ketone)s (PNABIKKs) consisting of m - and p -phenylene linkages have been synthesized by nucleophilic aromatic substitution from bis(benzimidazolyl) derivatives containing sulfonyl, carbonyl, and ether groups with activated aromatic difluorides in sulfolane at 210 °C in the presence of anhydrous potassium carbonate. The structures of the polymers were characterized by means of Fourier tramsfom infrared (FTIR), proton nuclear magnetic resonance ( 1 H NMR) spectroscopy, and elemental analysis, and the results were largely consistent with the proposed structure. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) measurements demonstrated that polymers had high glass transition temperatures ( T
g
>220 °C) and good thermal stability with high decomposition temperatures ( T
D
>480 °C). These novel polymers also showed good solubility.
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危险品化学品经营许可证（带存储）