Heliyon
·
2022
·
IF 3.776
Xiang Liu,Yongliang Wang,Li Xiao,Licheng Ma,Peiwei Han,Shufeng Ye
Gold is a valued, critical element whose chemical activation or extraction is challenging. Non-cyanide extraction of gold is now the focus, and N-bromosuccinimide(NBS) is attracting attention. Herein, new insights into the possible mechanism are deeply revealed through comprehensive analysis and detection of the reaction by using elementary gold and gold bearing ore. Experiments on gold foil indicate that Au can be activated in NBS solution to perform a satisfactory dissolution. Application of NBS in gold extraction from ore show a high yield of 86.24% under optimal conditions of NBS dosage 0.05 M, liquid-solid ratio 4:1, stirring speed 400 rpm, pH 8, 25 °C and leaching for 20 h, while yields of other coexisting metals are nearly negligible. The process leads to direct, efficient, one-pot conversion of gold, into simple water-soluble salts. Characterizations show that the framework of NBS are not destroyed, only bromine separates from the framework. The oxidation of neutral gold atom to trivalent Au (III) occurs in a mild, clean and room-temperature chemistry, which converts gold to [AuBr 4 ] - , and the framework to succinimide. The active bromine and radical Br (Br•) generated from in-situ autocatalysis of NBS are responsible for this. The systematic results herald a green procedure for preparation of gold derivatives and gold extraction industry.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
RUSSIAN JOURNAL OF GENERAL CHEMISTRY
·
2025
·Vol. 95
·期 3
·644-653
·
IF 0.8
Wang J.,Zhou Y.,Wu X.,Zhou X.,Sun Y.,Wu W.,Wang X.
Discovering super-efficient herbicides with novel structures is one of the effective ways to solve the increasingly severe weed resistance problem and meet ecological requirements. In this work, a series of novel bromo- p -hydroxybenzamides were designed based on the molecular hybridization strategy, and rapidly synthesized by one-step amidation reaction, and then characterized by 1 H NMR, 13 C NMR and HRMS. The herbicidal activity assay indicated that most of the target compounds exhibited good-to-excellent inhibition effects on seed germination of two model plants. At a concentration of 100 mg/L, the inhibition rate of 3,5-dibromo- N -(4-bromo-3-chlorophenyl)- p -hydroxybenzamide reached up to 98 and 96% on the roots and stalks of the monocotyledonous barnyard grass ( E. crus-galli ), respectively. 3,5-Dibromo- N -(2-bromophenyl)- p -hydroxybenzamide showed excellent inhibitory activity on the roots and stalks of dicotyledonous rape ( B. napus ) at 100 mg/L, with an inhibitory rate of more than 90%. Furthermore, the concentration was reduced to 1 mg/L, the inhibitory rate of 3,5-dibromo- N -(2-bromophenyl)- p -hydroxybenzamide on the roots of B. napus was still as high as 90%. This work provides a novel molecular scaffold for the development and research of new super-efficient herbicides.
研究领域:
农药化学
·
植物生理学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 73
·59286-59291
·
IF 3.84
Shifeng Li,Min Xing,Haiyan Wang,Li Zhang,Yiman Zhong,Lei Chen
In this work, water-soluble ZnS quantum dots (QDs) modified with 3-mercaptopropionic acid (MPA), L-cysteine (L-Cys) and thioglycolic acid (TGA) were synthesized. The nanostructure and optical properties were characterized by X-ray powder diffraction (XRD), Transmission electron microscopy (TEM), UV-Vis absorption spectrum and fluorescence spectrum. Through the study of the ZnS QDs effects on the chemiluminescence (CL) system of luminol, we found that ZnS QDs could obviously enhance the CL of the luminol–N-bromosuccinimide (NBS) system in an alkaline medium. At the optimal experimental conditions, we researched the impact of 17 kinds of amino acids on this system. It was found that L-tryptophan (Trp) and L-tyrosine (Tyr) had significantly inhibitory effects on luminol–NBS–ZnS QDs CL. Based on the inhibitory effects, a novel CL method with a wider linear range and lower detection limit for determination of Trp and Tyr was developed. The detection limits were 1.5 × 10−11 g mL−1 and 2.0 × 10−10 g mL−1, respectively. The possible CL reaction mechanism was also discussed briefly.
研究领域:
分析化学
·
生物化学
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2015
·Vol. 7
·期 4
·951-957
·
IF 5.52
Titao Jing,Liyi Fu,Le Liu,Lifeng Yan
A new bromine substituted near infrared (NIR) cyanine Br2-IR808 has been synthesized, and the heavy atom effect makes it an efficient photosensitizer with NIR fluorescence properties, and it can be used as both a photosensitizer and a fluorescent dye synchronously. An intelligent reduction-sensitive polypeptide nanogel has also been synthesized, and it worked as the nano-carrier for the Br2-IR808 dye. The as-prepared NIR nanogel showed imaging guided PDT properties for in vitro studies, and the reduction-induced disassembly of the nanogel could promote the delivery of the hydrophobic cyanine dye inside the cell, and it also enhances the efficiency of the photosensitizer release, which makes the nanogel potential for application in NIR theranosis of cancer. In addition, only 2 μM photosensitizer Br2-IR808 is required for efficient PDT here while 30 μM IR808 is required solely as reported.
研究领域:
生物医学工程
·
肿瘤学
·
材料科学
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Fu Li,Pengfei Fei,Bowen Cheng,Jianqiang Meng,Liang Liao
In order to improve the antibacterial efficiency and spectrum of cellulose acetate reverse osmosis membrane (CA–RO), both quaternary ammonium and bromoacetyl groups were introduced into cellulose diacetate under mild conditions forming CA–RO with bi-antibacterial groups for seawater desalination. Bromoacetyl bromide and a series of tertiary amine were chosen as the modification agents respectively. The characterization results showed that both two antibacterial groups were successfully introduced with a certain density. The obtaining membrane had a less hydrophilic but more electronegative surface as well as improved mechanical property. The flux values increased firstly and decreased subsequently after twice modifications while the salt rejection rose. The membrane modified with N,N- dimethyloctylamine (DMOA) had the optimal comprehensive performance of flux and salt rejection. The antibacterial testing results indicated that the resulting RO membranes showed high antibacterial efficiency and broad-spectrum. Their bactericidal rates against gram-negative Escherichia coli ( E. coli ) and gram-positive Staphylococcus aureus ( S. aureus ) were more than 99.9%.
研究领域:
材料科学
·
环境工程
·
生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Hengxuan Zhao,Lu Wang,Deyang Kong,Yuefei Ji,Junhe Lu,Xiaoming Yin,Quansuo Zhou
Peroxymonosulfate (PMS), a widely used in situ chemical oxidation agent, has attracted increasing attention in ground water/soil remediation. PMS is relatively stable with lifetime from months to even years in subsurface. The residual PMS can react with various of organics or inorganics species in environment, which may pose long term environmental effects. In this study, reaction between PMS and bromide (Br − ) in water, and thus to the transformation of triclosan (TCS), an antibiotic agent, was studied. We found that TCS cannot be degraded by PMS alone but was efficiently removed in the presence of both PMS and Br − . This was due to the formation of free bromine upon the oxidation of Br − by PMS. Formation of bromine radical (Br ) in PMS/Br − system was unlikely according to quenching tests. Reaction between free bromine and TCS generated brominated TCS intermediates which underwent further degradation to brominated disinfection byproducts (DBPs), of which bromoform (CHBr 3 ) and dibromoacetic acid (DBAA) were the most prominent ones. Their yields reached 1.31 µM and 0.49 µM in 24 h, respectively, when 1 mg/L TCS was treated with 100 µM PMS and 100 µM Br − . Presence of humic acid (HA) remarkably enhanced the formation of monobromoacetic acid (MBAA), DBAA, and bromochloroacetic acid (BCAA) but inhibited the formation of CHBr 3 and dibromochloromethane (CHClBr 2 ). Thus, even though certain phenolic contaminants like TCS can be effectively removed in PMS/Br − system, formation of free bromine and DBPs makes it not a good treatment strategy. Particular attention should be paid when Br − is presented in PMS-based oxidation process.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
NORDIC PULP & PAPER RESEARCH JOURNAL
·
2020
·Vol. 36
·期 1
·149-156
·
IF 0.775
Rina Wu,Qiuyu Wang,Huayu Liu,Gaosheng Wang,Peng Lu
Cellulose bromo-isobutyl ester was prepared using filter paper as raw material through esterification reaction with 2-Bromoisobutyryl bromide (BIBB) in N, N-Dimethyl-formamide (DMF). Cellulose esters with different degree of substitution were obtained. FTIR result indicated the successful introduction of bromo isobutyryl group in cellulose to obtain cellulose ester (Cell-Br). The surface of modified filter paper become rough and grooves could be observed by SEM. The thermal stability of the cellulose ester decreased in comparison with unmodified filter paper. Besides, the hydrophobicity of the filter paper was improved and the water contact angle increased from 73.4° to 116.5° with increasing degree of substitution. The water vapor barrier property was improved by 26 %. Furthermore, it was also found the modified filter paper possessed antibacterial activity against S. aureus bacteria. The modified filter paper obtained could be potentially used in food packaging fields and the results provide a simple method to prepare functional filter paper.
研究领域:
材料科学
·
食品科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2018
·
IF 6.434
Qiongfang Wang,Yisheng Shao,Naiyun Gao,Wenhai Chu,Juxiang Chen,Xian Lu,Yanping Zhu,Na An
UV/persulfate (UV/PS) has been as an efficient method to remove many organic contaminants in water. However, little is known about the impact of UV/PS pretrement on the formation of disinfection byproducts (DBPs) during chlorination of 2,4-Di-tert-butylphenol (2,4-D). This research evaluated that UV/PS preoxidation of 2,4-D greatly decreased the DBPs generation during following chlorination. In the 2,4-D solution without any treatment system (O system), trichloromethane (TCM) as the only detected DBP increased with the increase of chlorine dosage. While the formation of TCM declined with the increase of PS dosage in the PS and UV/PS preoxidation systems and decreased the estimated toxicity accordingly. And it was found the residual PS in system could combine free chlorine to further oxidize 2,4-D. And intermediate products were analysed by high-performance liquid chromatography combined with triple quadrupole mass spectroscopy analysis. In the presence of bromine, the bromodichloromethane augmented first and then slowly decreased while dibromochloromethane and tribromethane increased both in O and UV/PS systems with the increase of [Br − ]. Bromine substitution was decreased by preoxidation of UV/PS. UV/PS could decrease the total-DBPs formation when used in the real water matrix contained 100 μg/L 2,4-D.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2017
·
IF 5.099
Man Ren,Hao Zeng,Ping-An Peng,Hui-Ru Li,Cai-Ming Tang,Jian-Fang Hu
Polybrominated dibenzo- p -dioxins (PBDDs) and hydroxylated polybrominated diphenyl ethers (OH-PBDEs) can be formed from bromophenols (BPs) by thermal degradation , biosynthesis or phototransformation. However, it is unknown whether PBDDs and OH-PBDEs can be formed during the chemical production processes that utilize BPs as raw materials. 2,4,6-tribromophenol (2,4,6-TBP) is an important raw material for the synthesis of 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), a novel brominated flame retardant . In this study, PBDDs, polybrominated dibenzofurans (PBDFs) and OH-PBDEs have been identified and quantified in commercially available BTBPE and 2,4,6-TBP. Furthermore, their formation as unintentional by-products during the laboratory synthesis of BTBPE from 2,4,6-TBP and 1,2-dibromoethane in the presence of sodium carbonate has also been investigated. 2,3,7,8-substituted PBDDs and PBDFs (2,3,7,8-PBDD/Fs) were undetectable in commercial samples of BTBPE and present in low levels (nanogram per gram) in 2,4,6-TBP. Two tetrabrominated dibenzo- p -dioxins (TeBDDs), namely 1,3,6,8- and 1,3,7,9-TeBDD, and three hydroxylated pentabrominated diphenyl ethers (OH-pentaBDEs), namely 4′-OH-BDE121, 2′-OH-BDE121, and 6′-OH-BDE100, were identified or tentatively identified, and quantitatively estimated to be at concentrations in the range of undetectable to several thousands of nanograms per gram in commercial BTBPE and 2,4,6-TBP. TeBDDs and OH-pentaBDEs were formed as by-products from 2,4,6-TBP during BTBPE synthesis. Further studies need to be conducted in order to determine whether PBDD/Fs and OH-PBDEs are also formed during the industrial synthesis of other chemical compounds that utilize BPs as raw materials or intermediates.
研究领域:
环境科学
·
毒理学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Lirong Lv,Sheng Wang,Ya Ding,Lei Zhang,Yang Gao,Shudong Wang
CH 3 Br catalytic oxidation as the probe reaction was investigated over Ru supported on TiO 2 with different crystalline phases. 1% Ru/anatase TiO 2 (a-TiO 2 ) exhibited superior stability at 240 °C after a 180 h time-on-stream run. And there was an induced activation for 1% Ru/a-TiO 2 during the initial 60 h reaction. Then the activity sustained stable. To elucidate the intrinsic mechanism, a series of characterizations were performed such as XRD, CO-Pulse, H 2 -TPR, XPS and NH 3 -TPD etc. Results showed that the Ru particle size increased and the Ru 0 content decreased as the reaction proceeded, which were not conductive to the reaction. It was assumed that the catalytic activity was strongly dependent on other factors. In combination with NH 3 -TPD and Py-FTIR measurements, it was confirmed that the enhanced activity and stability was strongly associated with the surface acidity, especially moderate strong Lewis acid (L acid). The increase of the acid amount and acidity strength was led by the generation and adsorption of HBr, Br 2 and RuO x Br y during the reaction, among which HBr and Br 2 was easier to desorb at 250 °C. While moderate strong L acid was sourced from the formation of RuO x Br y . The addition of transition metal (Ce, Co, Mn, Nb and Ni) further validated that the moderate strong L acid played a decisive role in the CH 3 Br catalytic oxidation.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2024
·
IF 8.1
Xintong Li,Baocheng Qu,Jingyao Wang,Hongxia Zhao
Tetrabromobisphenol A bis (allyl ether) (TBBPA-BAE) represents an extensively used brominated flame retardant (BFRs) in the production of many fields and their phototransformation in natural water is still unclear. The environmentally persistent free radicals (EPFRs) with preserved activities could exist in the environment for a long time and involve in the phototransformation of many organic pollutants. Here, the photodegradation of TBBPA-BAE with the degradation rate constant ( k = 0.060 h −1 ) under simulate sunlight and the promoting effect of EPFRs on TBBPA-BAE photodegradation ( k = 0.135 h −1 ) were investigated. According to the detected photogenerated electrons (e − ) and singlet oxygen ( 1 O 2 ) rather than hydroxyl radicals (•OH) by the electron paramagnetic resonance (EPR), the effect mechanism may not be related to the typical •OH induced by EPFRs. The possible transformation pathways of the ether cleavage, hydrolysis and hydroxylation of propenyl bond and the debromination were proposed by the primary byproducts identified by UPLC-Q-Exactive Orbitrap MS. EPFRs caused a further debromination and ether cleavage and probably be due to EPFRs directly providing electrons to TBBPA-BAE which promoted the photodegradation of TBBPA-BAE, and their reaction mechanism needed further attention. Overall, this study provided useful information to understand the role of EPFRs on phototransformation of TBBPA-BAE in water.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 30
·30160-30169
·
IF 2.8
Ding Jiafeng,Long Gaoyuan,Luo Yang,Sun Runze,Chen Mengxia,Li Yajun,Zhou Yanfang,Xu Xinhua,Zhao Weirong
Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) are ubiquitous and highly toxic emerging endocrine disruptors found in surface and subsurface soils and clay deposits. Seriously, they could be easily transformed to the more toxic dioxins (PBDD/Fs) in photochemical processes and incineration, but the spontaneous formation of PBDD/Fs has rarely been reported. This study focused on the formation of 1,3,8-tribromodibenzo- p -dioxin (1,3,8-TrBDD) and 2,4,6,8-tetrabromodibenzofuran (2,4,6,8-TeBDF) from 2′-OH-BDE-68 and 2,2′-diOH-BB-80 under the oxidization of iron and manganese oxides (goethite and MnO x ). Approximately 0.09 μmol/kg (2.33%) and 0.17 μmol/kg (4.15%) were transformed to 1,3,8-TrBDD and 2,4,6,8-TeBDF by goethite in 8 days and a higher conversion 0.15 μmol/kg (3.77%) and 0.23 μmol/kg (5.74%) were observed for MnO x in 4 days. However, the formation of PBDD/Fs, probably proceeding via Smiles rearrangements and bromine elimination processes, was greatly inhibited by the presence of water. Transformation of OH-PBDEs by goethite and MnO x was accompanied by release of Fe and Mn ions and the possible pathways for the formation of reaction products were proposed. In view of the ubiquity of OH-PBDEs and metal oxides in the environment, oxidation of OH-PBDEs mediated by goethite and MnO x is likely an abiotic route for the formation of PBDD/Fs.
研究领域:
环境科学
·
毒理学
✓ 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）