JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 29
·e54063
·
IF 3
Huan Wang,Zhengzai Cheng,Lesly Dasilva Wandji Djouonkep,Linfeng Wang,Shuanpu Cai,Mario Gauthier
A novel biphenyl monomer, diethyl 6,6′-dimethoxy-[1,1′-bipheny]-3,3′-dicarboxylate (DDBD), was synthesized from 4-hydroxybenzaldehyde, a phenolic compound derived from lignin. A series of polyesters were prepared by polycondensation of the biphenyl monomer with hydroquinone bis(2-hydroxyethyl) ether and aliphatic diacids via a two-step melt polycondensation method. It was shown that the properties of the polyesters can be tuned by varying the length and the structure of the spacer in the aliphatic diacid monomers. Structure–property relations for these materials were investigated by Fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. GPC analysis showed that the weight-average molecular weight ( M w ) of the samples varied from 4.2–5.0 × 10 4 g/mol, while thermal analysis yielded T g values of 51–120°C, and 5% decomposition temperatures ( T d,5% ) of 327–389°C. All the samples exhibited a high yield strength (56–87 MPa). After 30 weeks of degradation in soil, the copolyesters had mass losses of up to 4.4%, and an investigation of the ecotoxicity of the copolyesters with Eisenia fetida yielded a survival rate of over 80% after 14 days for the different copolyesters, suggesting low toxicity in the environment. Overall, these copolyesters have good properties and would be suitable to replace petroleum-based commercial poly(ethylene terephthalate) packaging materials.
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International Journal of Electrochemical Science
·
2023
·
IF 1.5
Chengyi Zhu,Jianxiong Liu,Xiaohua Yu,Yingjie Zhang,Xiaodong Jiang,Peng Dong,Yannan Zhang
4-Bromoanisole (4BA) is recommended for LiNi0.6Co0.2Mn0.2O2 (NCM 622) cathode materials as a safety electrolyte additive. The effect of anti-overcharge on NCM 622 cathodes are analyzed by cyclic voltammetry, constant current charge and discharge, AC impedance and scanning electron microscopy (SEM) measurement. The overcharge test results show that 4BA can be effectively electropolymerized at 4.45 V (vs. Li/Li + ), which can consume the overcharge current and protect the working electrode from voltage runaway. The time for the voltage rising to the overcharge state is availably delayed from about 16 hours to about 37 hours. The strategy can block off further oxidation of the active material and electrolyte, and finally promote the overcharge tolerance of the Li-ion batteries. Moreover, it is also found that the use of 4BA as a safety electrolyte additive does not obviously effect the electrochemical performance of NCM 622 and can effectively improve its cycle stability at high cut-off voltage (4.7 V).
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ENVIRONMENTAL MONITORING AND ASSESSMENT
·
2023
·Vol. 195
·期 6
·1-15
·
IF 3
Wang Yan,Han Xue,Zhang Jie,Zhou Meng-Xuan,Liu Ai-Lin
Biological effect-based monitoring is essential for predicting or alerting to a possible deterioration in drinking water quality. In the present study, a reporter gene assay based on oxidative stress–mediated Pgst-4::GFP induction in the Caenorhabditis elegans strain VP596 (VP596 assay) was assessed for its applicability in evaluating drinking water safety and quality. This assay was used to measure the oxidative stress response in VP596 worms exposed to six ubiquitous components (As 3+ , Al 3+ , F − , NO 3 − -N, CHCl 3 , and residual chlorine) in drinking water, eight mixtures of these six components designed through orthogonal design, ninety-six unconcentrated water samples from source to tap water in two supply systems, and organic extracts (OEs) of twenty-five selected water samples. Pgst-4::GFP fluorescence was not induced by Al 3+ , F − , NO 3 − -N, and CHCl 3 , and was significantly enhanced by As 3+ and residual chlorine only at concentrations higher than their respective drinking water guideline levels. Pgst-4::GFP induction was not detected in any of the six-component mixtures. Induction of Pgst-4::GFP was observed in 9.4% (3/32) of the source water samples but not in the drinking water samples. However, a notable induction effect was revealed in the three OEs of drinking water, with a relative enrichment factor of 200. These results suggest that the VP596 assay has limited utility for screening drinking water safety by testing unconcentrated water samples; however, it offers a supplemental in vivo tool for prioritizing water samples for an enhanced quality assessment, monitoring pollutant removal performance by drinking water treatment plants, and evaluating water quality in water supplies.
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Micromachines
·
2023
·Vol. 14
·期 4
·739
·
IF 3.4
Mingjie Han,Yong Xie,Ri Wang,Yang Li,Chao Bian,Shanhong Xia
As a highly toxic heavy metal ion, mercury ion (Hg2+) pollution has caused serious harm to the environment and human health. In this paper, 4-mercaptopyridine (4-MPY) was selected as the sensing material and decorated on the surface of a gold electrode. Trace Hg2+could be detected by both differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) methods. The proposed sensor displayed a wide detection range from 0.01 μg/L to 500 μg/L with a low limit of detection (LOD) of 0.002 μg/L by EIS measurements. Combined with molecular simulations and electrochemical analyses, the chelating mechanism between Hg2+and 4-MPY was explored. Through the analysis of binding energy (BE) values and stability constants, 4-MPY showed an excellent selectivity for Hg2+. In the presence of Hg2+, the coordination of Hg2+with the pyridine nitrogen of 4-MPY was generated at the sensing region, which caused a change in the electrochemical activity of the electrode surface. Due to the strong specific binding capability, the proposed sensor featured excellent selectivity and an anti-interference capability. Furthermore, the practicality of the sensor for Hg2+detection was validated with the samples of tap water and pond water, which demonstrated its potential application for on-site environmental detection.
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ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Yinghua Xu,Tingjie Ge,Hongxing Ma,Xufen Ding,Xiaoyong Zhang,Qi Liu
Hydrodefluorination (HDF) is the key step in fluoroaromatic pollutant (FAP) degradation, making the search for efficient HDF catalysts and the determination of the corresponding mechanism a matter of great importance. In this study, we developed an efficient HDF catalyst (a Rh-Pd alloy) and investigated the underlying catalytic reaction mechanism , using 4-fluorophenol (4-FP) as a model FAP. Specifically, the rapid aqueous-phase HDF of 4-FP at pH 3 was achieved on a Rh-Pd alloy-modified Ni foam electrode, which was followed by ring hydrogenation (RH) of the HDF product (phenol) to afford cyclohexanone and cyclohexanol . Inductively coupled plasma optical emission spectrometer (ICP-OES) and thermodynamic analyses showed that, in addition to those supplied by the applied current, the electrons involved in the HDF of 4-FP and the RH of phenol were largely provided by the oxidative dissolution of the Ni foam support. Hydrogenation and cyclic voltammetry experiments indicated that the HDF of 4-FP probably follows an indirect mechanism (featuring adsorbed H atoms as the direct reductant) and that the strength of 4-FP adsorption onto the surface of the catalyst significantly influences its HDF activity.
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NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 14
·12205-12211
·
IF 3.201
Qin Wang,Jianling Zhang,Yuyan Yu,Yi Dan,Long Jiang
Aiming to develop a visible-light-driven polymeric photocatalyst that can be fabricated by an easy-to-scale-up polymerization method, a porous polyimide (PPI) with a specific surface area (SBET) of 79.3 m2 g−1 was synthesized by a facile polycondensation of 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) with 4,4′,4′′-triaminotriphenylamine (TPA). UV-vis diffused reflection spectroscopy (DRS), electrochemical analysis, valence band X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculation results reveal that the prepared PPI possesses a narrow band gap (2.04 eV) with the valence band (VB) located at 1.26 V (vs. NHE) and the conduction band (CB) edge at −0.78 V (vs. NHE), clearly indicating the visible light activity of PPI. The photocatalytic performance for the degradation of methylene blue (MB) in water was studied, and the results demonstrate that PPI possesses excellent photocatalytic activity under visible light irradiation. Electron paramagnetic resonance (EPR) and photo-current analyses were used to study the photocatalytic mechanism, which show that PPI has a lot of single electron trapped oxygen and more light-generated electrons. This work may provide a cost-effective, potentially scalable strategy to design and develop a polymeric photocatalyst with continuously tunable photoelectrical properties.
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TISSUE & CELL
·
2024
·
IF 2.7
Lei Zhu,Qingxin Cai,Gang Li,Xiaoming Zou
Objective Gastric precancerous lesions (GPL), characterized by intestinal metaplasia and dysplasia, marks a pivotal juncture in the transformation from gastritis to gastric cancer. Research on GPL could offer fresh perspectives on preventing cancer occurrence. Methods This study employed 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) to establish GPL rat models and knocked BRD4 down in vivo to assess its impact on the lesions and macrophage morphology. Following that, the impacts of BRD4 knockdown on the malignant phenotypes of human gastric epithelial GES-1 cells were determined. Moreover, conditioned medium from macrophage was gathered and used for GES-1 cell culture. The involvement of macrophage polarization in the BRD4 regulatory mechanism in GES-1 cells was assessed. Results This study elucidated that MNNG induced an increase level of BRD4 in the rat models. BRD4 knockdown reduced lesions based on pathological sections and immunohistochemistry to detect proliferative antigens. Western blotting and immunofluorescence showed that BRD4 knockdown suppressed epithelial-mesenchymal transition and macrophage M2 polarization. In in vitro experiments, BRD4 knockdown inhibited the malignant phenotype of GES-1 cells and the differentiation of THP-1 cells into M2 macrophages, respectively. The conditioned medium from M2 macrophages with BRD4 knockdown was co-incubated with GES-1 cells, which attenuated the malignant phenotypes compared with the medium from M2 macrophages. Conclusion: Through in vivo and in vitro experiments, BRD4 upregulation was found to already occur during GPL, affecting macrophage polarization and epithelial cell cancerization. This finding provides an experimental basis for strategies targeting BRD4 inhibition at this critical stage.
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JOURNAL OF FOOD SCIENCE
·
2015
·Vol. 80
·期 6
·C1162
·
IF 1.696
Hai-wei Jiang,Hong-yan Li*,Cheng-wei Yu,Ting-ting Yang,Jiang-ning Hu,Rong Liu,Ze-Yuan Deng*
en Isobolographic analysis was used to assess the antioxidant interactions (synergism, addition, and antagonism) of 4 common vegetables (tomato [T], carrot [C], eggplant [E], and purple potato [P]). The lipophilic (L) extracts of T and C (main carotenoids), the hydrophilic (H) extracts of E and P (main phenolics) were mixed by the certain ratios (1:9, 3:7, 1:1, 7:3, 9:1, w/w) and their antioxidant activities were investigated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radical scavenging assays, respectively. Most of the binary mixtures (LC-HE, LC-HP, HE-HP, LT-HE, and LT-HP combinations) showed the synergistic antioxidant effects. In DPPH assay, the greatest antioxidant activity of vegetable combinations was 1:9 LT-HP (EC 50 : 2.45 ± 0.13 mg/mL), followed by 9:1 HE-HP (EC 50 : 3.62 ± 0.12 mg/mL) and 1:9 LC-HE (EC 50 : 3.74 ± 0.47 mg/mL). In ABTS assay, the greatest antioxidant activity of vegetable combinations was 9:1 HE-HP (EC 50 : 4.20 ± 0.10 mg/mL), followed by 7:3 HE-HP (EC 50 : 4.41 ± 0.63 mg/mL) and 1:1 HE-HP (EC 50 : 5.35 ± 0.85 mg/mL). Among these combinations, 1:1 LC-HE combination showed the highest synergistic antioxidant effects in DPPH assay (synergistic rate: 87.4%), and 7:3 LC-HE combination showed the highest synergistic antioxidant effects in ABTS assay (synergistic rate: 87.0%). The mixtures of phenolics and carotenoids with suitable ratios in vegetables effectively enhanced the synergistic antioxidant effects. Practical Application pt In this study, the results indicate that the combination of different vegetables with suitable ratios could improve the antioxidant activities through synergistic effects of phytochemicals. Also, isobolographic analysis could be well used in evaluating the antioxidant interactions between antioxidants.
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JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2016
·
IF 3.652
Shiliang Wu,Dekui Shen,Jun Hu,Huiyan Zhang,Rui Xiao
The pyrolytic characteristics of cellulose, cellobiose and glucose were examined by TG-FTIR combined with Py-GC–MS, in order to gain the effect of β -O-4 glycosidic bond on the pyrolysis process. In TG-FTIR analysis, two mass loss peaks were observed for cellobiose and glucose, indicating dehydration in low temperature stage and consequently intensive cracking of glycosidic bond and fragments for cellobiose. The samples were tested in Py-GC–MS at the temperature of 300, 500 and 900 °C according to their mass loss characteristics from TG-FTIR. Formation of furans from cellobiose, which involved the cracking of β -O-4 glycosidic bond, was prominent over other products, compared to that of cellulose and glucose. Four possible chemical pathways for the cleavage of β -O-4 glycosidic bond have been proposed with regard to the formation of furans and anhydrosugars from cellulose. Besides, another two reaction pathways leading to the formation of levoglucosan were also suggested.
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RSC Advances
·
2017
·Vol. 7
·期 45
·28476-28482
·
IF 3.108
Xiuqin Cai,Yunhua Xu,Rong Yang,Hui Yang
A novel calix[4]arene-based tetracholesteryl derivative was synthesized, and its gelation behaviours in 30 organic solvents were studied. It showed that 1 gelled long chain alkane, some of alcohol, kerosene, ethyl acetate benzene and toluene. Interestingly the gel of 1/kerosene possessed special property, which was that the mixture solution of the compound 1/kerosene heating for a while was put on the flat contact heater and formed a gel film at 25 °C and 65 °C. Unlike ordinary film, gel film had higher strength and toughness at 65 °C, by contrast other was fragile and broken easily at 25 °C, this phenomenon was few reported before. In order to explore the phenomenon, the mechanism of the gel of 1/kerosene was discussed by Scanning Electron Microscope (SEM), High Nuclear Magnetic Resonance (H NMR), Fourier Transform Infrared Spectrometer (IR) and micro-rheology. SEM revealed that the xerogel of 1/kerosene assembled network through some long and thick fibers at 65 °C, with concentration reducing fibers become thin and its networks were clearly observed. In contrast the morphology of xerogel was porous at low concentration and was a bulk at high temperature system. According to EI data in micro-rheology, the gelation process could be divided into three stages at 65 °C and they could be that some cholesterol segments in the gelator interacting with each other formed some small aggregation in the first stage, and other cholesterol section of the gelator sufficiently were cross-linked with time and assembled into large assembly in the second plateau. In the final moment the large assembly build gel network and the system of gel tended to stable. But there are two stages at low temperature and could be some cholesterol segments that didn't take part in assembly, which may be the cause that the performance of gel was fragile.
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Materials Research Express
·
2016
·Vol. 3
·期 7
·075024
·
IF 0.968
Shiben Liu,Yingjie Chen,Lifeng Dong
Hybrid nanostructures can be multifunctional and even possess enhanced properties. Ag–Fe2O3 nanocomposites and Ag nanoparticles (NPs) were fabricated and applied to catalyze the reduction of 4-nitrophenol. Compared with Ag NPs, Ag–Fe2O3 nanocomposites demonstrated enhanced catalytic activities. Furthermore, due to their magnetic properties, Ag–Fe2O3 nanocomposites could be easily separated from the reaction mixture and recycled through an external magnetic field. These findings will help us design hybrid nanostructures with catalytic activity and explore other potential applications of magnetic nanocomposites.
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BIORESOURCE TECHNOLOGY
·
2016
·
IF 4.917
Danlian Huang,Xingmeng Qin,Piao Xu,Guangming Zeng,Zhiwei Peng,Rongzhong Wang,Jia Wan,Xiaomin Gong,Wenjing Xue
A composting study was performed to investigate the degradation of 4-nonylphenol (4-NP) in river sediment by inoculating Phanerochaete chrysosporium ( Pc ). Pc was inoculated into composting Reactor A, C and D, while Reactor B without inocula was used as control. The results showed that composting with Pc accelerated the degradation of 4-NP, increased the catalase and polyphenol oxidase enzyme activities in contaminated sediment. The dissipation half-life (t 1/2 ) of 4-NP in Reactor A, C and D with inocula of Pc were 2.079, 2.558, 2.424 days, while in Reactor B without inocula of Pc it was 3.239 days, respectively. Correlation analysis showed that the contents of 4-NP in sediment in Reactor A and D were negatively correlated with the actives of laccase, whereas no obvious correlation was observed in Reactor B and C. All these findings also indicated that Pc enhanced the maturity of compost, and the best composting C/N ratio was 25.46:1.
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