POLYMER SCIENCE SERIES B
·
2019
·Vol. 61
·期 2
·124-131
·
IF 0.907
Guanghong Lin,Xiang Hongping,Xi Lu,Wen Zhixia,Wang Zhaowei,Yu Junwei,Liu Xiaoxuan
Abstract A tricomponent catalyst comprising titanium tetrachloride, triisobutyl aluminum and diphenyl ether is developed for the highly cis -1,4-selective polymerization of isoprene. The influence of the content of diphenyl ether and its complexation order on polymerization, microstructure and performance of polyisoprene are studied. The polyisoprene synthesized presents high monomer conversion (91–99%). With the increasing of diphenyl ether content, intrinsic viscosity and viscosity-average molecular weight of polyisoprene increase. The molar percentage of cis -1,4-unit is almost unaffected by diphenyl ether and different complexation sequence. The polyisoprene reveals comparable T g (–61.31°C) and mechanical strengths (11.14 MPa, 667%) to commercially available LHIR-80 synthesized with neodymium. However, the viscosity and viscosity-average molecular weight of the former are lower than that of the latter, which avails the processability and maintains excellent mechanical properties.
研究领域:
高分子化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2015
·Vol. 22
·期 12
·9224-9232
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IF 2.828
Qin Li,Feng Mingbao,Zhang Xuesheng,Wang Liansheng,Wang Zunyao
Polychlorinated diphenyl ethers (PCDEs) are a group of halogenated aromatic compounds and serious environmental pollutants. In the present study, sediment and water samples from eight sites in Nanjing section of the Yangtze River were characterized with 15 congeners of PCDEs. Concentrations and distributions of these PCDEs in water phase and sediments were analyzed by GC/MS. Results demonstrated that ∑PCDE concentrations were higher in the low water period (1.15–1.80 μg/L) than those in the high water period (0.73–1.30 μg/L) in water phase. Moreover, ∑PCDE concentrations were higher in the low water period (1.58–3.98 μg/kg) than those in the high water period (1.24–3.48 μg/kg) in sediments. A significant linear relationship existed between the ∑PCDE concentrations and TOC contents in sediments, but a poor linearity was found between ∑PCDE concentrations and DOC contents in water phase. Furthermore, the comparison of the percentage compositions in sediments and in water phase showed that CDE-30 (2,4,6-tri-CDE) was the predominant congener in the studied sites, and higher chlorinated congeners accounted for a larger proportion in sediments than those in water phase. In conclusion, the present study demonstrated the prevalent contamination by PCDEs in sediments and water from the Nanjing section of the Yangtze River.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 62
·39089-39095
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IF 3.108
Ying-Ying Shao,Wei-Dong Ye,Chun-Yan Sun,Chu-Lin Liu,Qi Wang
As typical persistent organic pollutants, polybrominated diphenyl ethers (PBDEs) have aroused high environmental concern because of their toxicity and recalcitrant degradation. Here we report the visible-light-induced degradation of PBDEs with AgI–TiO2 (>420 nm). A series of nano-structured AgI–TiO2 particles were synthesized by a deposition–precipitation method and characterized by SEM, TEM, XRD, XPS, BET and UV-Vis-DRS. The AgI–TiO2 hybrids showed high efficiency for degradation of PBDEs and excellent photostability in cyclic run experiments. The absorbance intensity and absorption ability of AgI–TiO2 hybrids and the properties of the solvents were found to greatly influence the efficiency of degradation of PBDEs. The 0.2-AgI–TiO2 (the mass ratio of Ag to P25 was about 20%) in CH3OH solution presented the highest reaction rate with 0.29 ± 0.02 h−1. Most interestingly, mechanistic pathways in the degradation of PBDEs were different under UV and visible light. Unlike the common single-electron transfer in the UV-TiO2 system, the debromination mechanism in the visible light/AgI–TiO2 system showed multi-electron transfer. The analysis of products showed that many different lower brominated congeners simultaneously appeared under visible light rather than being stepwise formed under UV. This implies that the special structure of AgI–TiO2 performs remarkably enhanced electron transfer, multi-electron transfer, and results in high photocatalytic activity. This research may provide a green and efficient method to remove halogenated pollutants by using visible light.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2015
·Vol. 22
·期 21
·16914-16926
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IF 2.828
Wang Sheng,Bai Naling,Wang Bing,Feng Zhuo,Hutchins William C.,Yang Ching-Hong,Zhao Yuhua
Commonly used flame retardants, such as polybrominated diphenyl ethers, are extremely persistent in the environment, causing serious environmental risks. Certain strains of bacteria are able to degrade several low brominated congeners of PBDEs aerobically. However, the aerobic degradation pathway is not yet well understood, particularly at the genetic level. In this study, we isolated Cupriavidus sp. WS from the environment that could degrade diphenyl ether (DE), 4-bromodiphenyl ether, and 4,4′-bromodiphenyl ether. DE was completely degraded in 6 days without any detectable end-product. Using transposon mutagenesis, several DE degradation-deficient mutants were obtained. Knocking out bphA1 , bphA2 , and bphA3 eliminated the ability of the Cupriavidus sp. WS bacterium to degrade DE, indicating that the bph genes play a crucial role in DE degradation by this strain. The specific roles of bphA , bphB , and bphC were identified by systematically expressing these genes in Escherichia coli . The dihydrodiol product of BphA was dehydrogenated into 2,3-dihydroxydiphenyl ether by BphB. 2,3-Dihydroxydiphenyl ether was then decomposed into phenol and 2-pyrone-6-carboxylic acid by BphC. Thus, BphA, BphB, and BphC act sequentially in the aerobic degradation of DE, 4-bromodiphenyl ether, and 4,4′-dibromodiphenyl ether by the Cupriavidus sp. WS bacterium.
研究领域:
环境微生物学
·
分子生物学
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污染治理
✓ 已验证
DOI
PubMed
高影响因子
Jove-Journal of Visualized Experiments
·
2019
·
IF 1.108
Weixiang Guan,Chuang Li,Xiao Chen,Xiao-Ying Lu,Chi-Wing Tsang,Haoquan Hu,Hongxu Qi,Changhai Liang
We herein present a method for the synthesis of HNbWO6, HNbMoO6, HTaWO6 solid acid nanosheet modified Pt/CNTs. By varying the weight of various solid acid nanosheets, a series of Pt/xHMNO6/CNTs with different solid acid compositions (x = 5, 20 wt%; M = Nb, Ta; N = Mo, W) have been prepared by carbon nanotube pretreatment, protonic exchange, solid acid exfoliation, aggregation and finally Pt particles impregnation. The Pt/xHMNO6/CNTs are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and NH3-temperature programmed desorption. The study revealed that HNbWO6 nanosheets were attached on CNTs, with some edges of the nanosheets being bent in shape. The acid strength of the supported Pt catalysts increases in the following order: Pt/CNTs < Pt/5HNbWO6/CNTs < Pt/20HNbMoO6/CNTs < Pt/20HNbWO6/CNTs < Pt/20HTaWO6/CNTs. In addition, the catalytic hydroconversion of lignin-derived model compound: diphenyl ether using the synthesized Pt/20HNbWO6 catalyst has been investigated.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2024
·
IF 6.7
Zi-Chun Fan,Zhuang Li,Xiang Bai,Xian-Yong Wei,Yierxiati Dilixiati,Qian-Qian Kong,Ji Zhao,Yong-Hui Feng,Zhi-Min Zong,Jun-Long Wang
The catalytic hydroconversion (CHC) of benzyloxybenzene (BOB) and oxydibenzene (ODB), two typical lignite-related model compounds (LRMCs) representing α-Ο-4 and 4-O-5 model linkages , have been investigated using uniformly dispersed Ni 15 /HY prepared by a three-step method. The cleavage of >CH-O- bridged bonds in BOB and partial hydrogenation of ODB are considered as a crucial first step, and the target reactions in this work are to produce complete hydrodeoxidized ring saturation products. Through the exploration of reaction mechanism, H + /H - and biatomic active hydrogen, as the main hydrogen species involved in the reaction, play an important role in the CHC of BOB and ODB. Herein, the synergic effect between the hydrogenation of nickel nanoparticles and the acidic function of Y -type zeolite improves the CHC performance, resulting in Ni 15 /HY displaying proficient catalytic activity and selectivity for the CHC of BOB and ODB. Under the optimal reaction conditions, BOB and ODB can be completely converted to cyclanes over Ni 15 /HY, and the main products are dicyclohexylmethane (57.6 %) and cyclohexane (92.4 %), respectively. The developed Ni 15 /HY can not only promote the hydroconversion of BOB and ODB to produce ring-saturated products, but also undergo the rearrangement reaction to produce two- or three-ring cyclanes, which is desirable to upgrade LRMCs to high-density hydrocarbon fuels .
研究领域:
化学工程
·
燃料化学
✓ 已验证
产品关联
DOI
高影响因子
ChemElectroChem
·
2018
·Vol. 5
·期 11
·1509-1515
·
IF 4.446
Hong Yun Yue,Zhan Li Han,Liang Liang Tao,Yao Fa Zhang,Lan Wang,Xiang Nan Li,Yan Hong Yin,Wei Guang Yang,Shu Ting Yang
Graphical Protective additive : Diphenyl ether (DPE) is investigated as a film-forming additive to improve the cyclic stability of LiNi 0.5 Mn 1.5 O 4 at high voltage and elevated temperature (55 °C). A robust and uniform film is generated on the LiNi 0.5 Mn 1.5 O 4 surface, alleviating the subsequent electrolyte decomposition and protecting LiNi 0.5 Mn 1.5 O 4 from transition metal dissolution and structural destruction. Diphenyl ether (DPE) is investigated as a film-forming additive to improve the cyclic stability of LiNi 0.5 Mn 1.5 O 4 at high voltage and elevated temperature (55 °C). Addition of DPE in the baseline electrolyte significantly improves the capacity retention of LiNi 0.5 Mn 1.5 O 4 at elevated temperature. Its capacity retention increases from 41.2 % at the baseline electrolyte to 90.5 % after 0.1 vol% DPE is added to the baseline electrolyte in 100 cycles. Calculations demonstrate that DPE is oxidized preferentially to the baseline electrolyte. The experimental results show that a robust and uniform film is generated on the LiNi 0.5 Mn 1.5 O 4 surface, alleviating the subsequent electrolyte decomposition and protecting LiNi 0.5 Mn 1.5 O 4 from transition metal dissolution and structural destruction.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2021
·
IF 10.588
Kaibo Huang,Jiahao Liang,Chad T. Jafvert,Qiuyue Li,Sishuo Chen,Xueqin Tao,Mengyao Zou,Zhi Dang,Guining Lu
The effects of ferric iron on the photo-treatment of simulated BDE-47 (2,2′,4,4′- tetrabromodiphenyl ether)-Brij35 (Polyoxyethylene lauryl ether) washing waste were studied to evaluate the influences of ferric iron on BDE-47 removal and Brij35 recovery. The results show that Fe 3+ accelerated BDE-47 degradation at lower concentrations (<0.5 mM) but attenuated it at higher concentrations (0.5–5 mM) and that Brij35 loss was increased with increasing Fe 3+ . These results likely are caused by changes in the rate of •OH production due to the ferric ion, association of Fe 3+ and electron transfer from Brij35, and light attenuation at high concentration. The BDE-47 and Brij35 had different degradation rates at different pH values and at different dissolved oxygen concentrations. The BDE-47 products were identified by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). The results indicated that BDE-47 transformed into mainly lower-brominated products, a few bromodibenzofurans, some rearrangement products, and some hydroxylated polybrominated diphenyl ethers . A series of Brij35 oxidization products were detected by ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS), including hydroxylation products, carboxylation products, and some hydrophilic chain-breaking products. Brij35 was mainly oxidized by Fe 3+ and/or reactive oxygen species (ROS) with the final products of CO 2 and H 2 O. The iron ions apparently cycled from ferric to ferrous ions in the micelles such that the Fe 3+ -Brij35 complex dominated the main redox reaction, leading to both BDE-47 and Brij35 degradation. It appears that in any applied soil washing system, the ferric ions in the washing waste need to be removed because of the adverse effects on BDE-47 removal and eluate reuse.
研究领域:
环境科学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 29
·期 3
·4461-4473
·
IF 4.223
Shao Jiang,Zhang Yi,Liu Zongtang,Fei Zhenghao,Sun Yufeng,Chen Ziyan,Wen Xiaoju,Shi Weizhong,Wang Dandan,Gu Chenggang
Organic palygorskite (OP)–supported Pd/Fe nanoparticles composite (OP-Pd/Fe) was prepared by stepwise reduction method. The removal capacity of 4,4′-dibrominated diphenyl ether (BDE15) by OP-Pd/Fe was compared with other various materials. For better understanding the possible mechanism, the synthesized and reacted OP-Pd/Fe materials were characterized by TEM, SEM, XRD, and XPS, respectively. The effects of major influencing parameters on the degradation of BDE15 were also studied. Benefit from the synergistic effect of the carrier and bimetallic nanoparticles, BDE15 could be completely debrominated into diphenyl ether (DE) under suitable conditions. A two-stage adsorption/debromination removal mechanism was proposed. The degradation of BDE15 with OP-Pd/Fe was mainly stepwise debromination reaction, and hydrogen transfer mode was assumed as the dominated debromination mechanism. The removal process fitted well to the pseudo first-order kinetic equation. The observed rate constants increased with increasing Pd loading and OP-Pd/Fe dosage while decreased with increasing initial BDE15 concentration, the tetrahydrofuran/water ratio, and the initial pH of the solution. The work provides a new approach for the treatment of PBDEs pollution.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Yating Jia,Fan Hu,Yuancai Lv,Yuancai Chen,Yongyou Hu
Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants and challenges for water treatment due to their persistence and toxicity. In this study, the reduction of 2′2′4′4′-tetrabromodiphenyl ether (BDE-47) was investigated in a nano-bio-integrated system. Results showed that the introducing of P. putida could markedly accelerate the demineralization of BDE-47 in nZVI/Pd- P.p system; the continuous generation of acidic metaboliates by P. putida could decrease pH, which could alleviate the surface passivation to some extent, resulting in the releasing of Fe 2+ and high generation of H 2 O 2 , the shift in reactive oxygen species from Fe(IV) to •OH. The BDE-47 was firstly debrominated to the DE by the highly reductive [Pd·2H] generated by nZVI/Pd, then oxidized to bromophenol and phenol, catechol as well as hydroquinone via the P. putida strain and the Fenton-like system. The toxicity assays confirmed the combined system could avert generation of nocuous intermediates, and could be an alternative strategy for complete remediation of recalcitrant POPs.
研究领域:
环境科学
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微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PLoS One
·
2015
·Vol. 10
·期 8
·e0135400
·
IF 3.234
Mei Wang,Huili Wang,Rongbo Zhang,Meiping Ma,Kun Mei,Fang Fang,Xuedong Wang
To date, no report was concerned with participation of reactive oxygen species in waters during photolysis of low-brominated diphenyl ethers (LBDEs). Herein, we found that electron spin resonance (ESR) signals rapidly increased with increasing irradiation time in the solution of LBDEs and 4-oxo-TMP solutions. But this phenomenon did not occur in the presence of NaN 3 ( 1 O 2 quencher) demonstrating generation of 1 O 2 in process of LBDEs photolysis. The indirect photolytic contribution rate for BDE-47 and BDE-28 was 18.8% and 17.3% via 1 O 2 , and 4.9% and 6.6% via ·OH, respectively. Both D 2 O and NaN 3 experiments proved that the indirect photolysis of LBDEs was primarily attributable to 1 O 2 . The bimolecular reaction rate constants of 1 O 2 with BDE-47 and BDE-28 were 3.12 and 3.64 × 10 6 M -1 s -1 , respectively. The rate constants for BDE-47 and BDE-28 (9.01 and 17.52 × 10 −3 min -1 ), added to isopropyl alcohol, were very close to those (9.65 and 18.42 × 10 −3 min -1 ) in water, proving the less indirect photolytic contribution of ·OH in water. This is the first comprehensive investigation examining the indirect photolysis of LBDEs in aqueous solution.
研究领域:
环境科学
·
化学
·
毒理学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Sciences
·
2019
·
IF 3.556
Meiqian Wang,Hua Yin,Hui Peng,Mi Feng,Guining Lu,Zhi Dang
The degradation of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) by Pycnoporus sanguineus was investigated in order to explore the impact of the heavy metal Cu 2+ on BDE-47 decomposition and the subsequent formation of metabolites, as well as to further elucidate the degradation mechanism of BDE-47. An increase in degradation rate from 18.63% to 49.76% in the first four days and its stabilization at (51.26 ± 0.08)% in the following days of BDE-47 incubation were observed. The presence of Cu 2+ at 1 and 2 mg/L was found to promote the degradation rate to 56.41% and 60.79%, respectively, whereas higher level of Cu 2+ (≥ 5 mg/L) inhibited the removal of BDE-47. The similar concentration effects of Cu 2+ was also found on contents of fungal protein and amounts of metabolites. Both intracellular and extracellular enzymes played certain roles in BDE-47 transportation with the best degradation rate at 27.90% and 27.67% on the fourth and third day, individually. During the degradation of BDE-47, four types of hydroxylated polybrominated diphenyl ethers (OH-PBDEs), i.e., 6′-OH-BDE-47, 5′-OH-BDE-47, 4′-OH-BDE-17, 2′-OH-BDE-28, and two bromophenols, i.e., 2,4-DBP and 4-BP were detected and considered as degradation products . These metabolites were further removed by P. sanguineus at rates of 22.42%, 23.01%, 27.04%, 27.96%, 64.21%, and 40.62%, respectively.
研究领域:
环境科学
·
微生物学
✓ 已验证
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）