INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Peng Cui,Changtong Song,Xianhong Zhang,Dong Chen,Yuhong Ma,Wantai Yang
The controlled radical polymerization (CRP) of vinyl chloride monomer (VCM), a low activity monomer with high radical reactivity, is still a true challenge. In this study, a novel CRP of VCM with high monomer conversion at 45 °C with xanthene-9-thione (XT) as mediator and bis(4-tert-butylcyclohexyl)peroxydicarbonate (TBCP) as initiator is achieved. The Mn of the produced poly(vinyl chloride) (PVC) increases slightly with increasing monomer conversion and could be mediated in the range from 6k to 12k by simply changing the molar ratio of TBCP/XT while the dispersity maintains around 2.0. The fidelity of XT dormant groups of PVC-XT is about 60–80% and depends on the ratio of TBCP/XT. With the as-prepared PVC-XT as macroinitiator, block copolymerizations of methyl methacrylate (MMA), n-butyl acrylate (BA), and styrene (St) are carried out and the PVC-b-PMMA, PVC-b-PBA, and PVC-b-PSt block copolymers have been synthesized successfully.
研究领域:
高分子化学
·
材料科学
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Yangyi Wu,Lijun Fan,Changtong Song,Xianhong Zhang,Dong Chen,Yuhong Ma,Wantai Yang
The copolymers of vinyl chloride (VC) with acrylates are widely used as special resins in multiple fields such as coatings, adhesives, and polymer processing aids. Nevertheless, the controllability in the copolymer composition is still a challenge owing to the big gap in reactivity ratio. In this paper, we conducted the nonaqueous copolymerization of VC with methyl acrylate (MA) in a mixed organic solvent (hexane/ethanol) without any suspending agent or emulsifier and intended to regulate the copolymer composition by dropping MA in a continuous mode. The promising results showed that a powdery vinyl chloride-co-methyl acrylate (PVMA) with ultralow number-average molecular weight (Mn, 9000–11 000) and submicrometer size (0.2–0.5 μm) is synthesized successfully, which is highly different from those of conventional aqueous polymerizations such as suspension and emulsion. More interestingly, varied PVMAx (x represents the actual mass fraction of MA in the copolymer) with relatively uniform and narrow dispersity in copolymer compositions (x = 1.7 ± 0.4, 3.2 ± 0.5, 5 ± 0.7, and 8.2 ± 0.4%) are obtained during the whole polymerization stage. In the batch process, the content of MA units in the copolymer decreased significantly with the increase of monomer conversion. Subsequently, the PVMA copolymers were employed as processing aids in rigid PVC and exhibited unique features. Stemming from its low Mn and the excellent compatibility with PVC matrix, the addition of PVMA can improve the plasticization efficiency significantly and thereby further enhance the mechanical performance. For instance, addition of 3 phr PVMA8.3 in the rigid PVC system can shorten the plasticization time from 104 to 52 s, enhance the tensile strength from 65 to 74 MPa, and increase the elongation at break 2-fold in comparison to the controlled PVC. In summary, this study provides a novel polymerization technique and strategy for the preparation of a vinyl chloride based copolymer resin with a low Mn and further composition control.
研究领域:
高分子化学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Xueyi Zheng,Qiaochen Feng,Liangqia Guo
The exposure of micro- and nanoplastics (MNPs) via medical device is still unknown to us. Herein, a visual quantitative detection of polyvinyl chloride (PVC) MPs and a fluorescent quantitative detection of PVC NPs were developed. To overcome the aggregation of PVC NPs, sodium dodecylbenzene sulfonate was used as the stabilizer of PVC NPs. The brand-new disposable PVC infusion tubes were found to carry PVC MPs with the average total number (ATN) of 931.4 particles and PVC NPs with the average mass of 0.040 μg, respectively. For four typical infusion fluids such as 0.9% sodium chloride, 5% glucose, 5% sodium bicarbonate , hydroxyethyl starch 40 sodium chloride, the released PVC MPs and NPs were ranged from 1003.6 ∼ 3494.6 particles and 0.042 ∼ 0.087 μg, respectively in stimulating normal infusion scenario (room temperature 4 h). The released PVC MPs and NPs were also increased with the infusion duration and temperature. The released PVC MPs are mainly in granular form, accounting for 38 ∼ 49% of the total PVC MPs. Our findings indicate PVC MNPs can enter the blood vessel directly with the infusion fluids during intravenous infusion and the PVC MNPs exposure risk towards patients deserves more attention.
研究领域:
医学
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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
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Fei Miao,Yanfeng Liu,Mingming Gao,Xin Yu,Pengwei Xiao,Mei Wang,Shuguang Wang,Xinhua Wang
Nowadays, microplastic pollution has been brought into focus for its hazards to aquatic life. However, researches on the electrocatalytic treatment for efficient degradation of microplastics are still insufficient. Herein, an electro-Fenton like (EF-like) technology based on TiO 2 /graphite (TiO 2 /C) cathode was put forward to degrade polyvinyl chloride (PVC), a typical microplastic in water. It exhibited a remarkable performance on PVC degradation via cathodic reduction dechlorination and hydroxyl radical (O H) oxidation simultaneously. Besides, the effects of reaction temperature and initial PVC concentration were investigated. Under optimal conditions, the dechlorination efficiency of PVC reached 75 % after potentiostatic electrolysis at -0.7 V vs. Ag/AgCl for 6 h. The intermediate products were explored during the degradation of PVC microplastics. The surface morphologies and molecular weight of PVC changed accordingly. Based on these results, a possible degradation process for PVC was proposed. This work demonstrated that such a heterogeneous EF-like technology using TiO 2 /C cathode was hopefully to provide an eco-friendly method for microplastic wastewater treatment.
研究领域:
环境科学
·
材料科学
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2017
·Vol. 24
·期 21
·17598-17605
·
IF 2.741
Wang Na,Jia Daqing,Jin Yaoyao,Sun Sheng-Peng,Ke Qiang
The present study investigated the degradation of trichloroethylene (TCE) in sand suspensions by Fenton-like reaction with magnetite (Fe 3 O 4 ) in the presence of various chelators at circumneutral pH. The results showed that ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) greatly improved the rate of TCE degradation, while [S,S]-ethylenediaminedisuccinic acid (s,s-EDDS), malonate, citrate, and phytic acid (IP6) have minimal effects on TCE degradation. Quenching tests suggested that TCE was mainly degraded by hydroxyl radical (HO · ) attack, with about 90% inhibition on TCE degradation by the addition of HO · scavenger 2-propanol. The presence of 0.1–0.5% Fe 3 O 4 /sand ( w / w ) contributed to 40% increase in TCE degradation rates. In particular, the use of chelators can avoid high concentrations of H 2 O 2 required for the Fenton-like reaction with Fe 3 O 4 , and moreover improve the stoichiometric efficiencies of TCE degradation to H 2 O 2 consumption. The suitable concentrations of chelators (EDTA and NTA) and H 2 O 2 were suggested to be 0.5 and 20 mM, respectively. Under the given conditions, degradation rate constants of TCE were obtained at 0.360 h −1 with EDTA and 0.526 h −1 with NTA, respectively. Enhanced degradation of TCE and decreased usage of H 2 O 2 in this investigation suggested that Fenton-like reaction of Fe 3 O 4 together with NTA (or EDTA) may be a promising process for remediation of TCE-contaminated groundwater.
研究领域:
环境科学
·
化学工程
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产品关联
DOI
PubMed
高影响因子
Catalysts
·
2019
·Vol. 9
·期 5
·408
·
IF 3.444
Chao Wang,Wenchao Hua,Guangtao Chai,Chuanhui Zhang,Yanglong Guo
Co3O4catalysts of cube and sphere shapes were prepared by one-step hydrothermal synthesis with different controlled amounts of Co(NO3)2·6H2O and NaOH. The morphological effects on both physicochemical properties and catalytic activities of vinyl chloride oxidation were investigated by material characterization and performance evaluation. The obtained results showed that the morphology, resulting in the exposure difference of crystal planes, significantly affected the catalytic property. The catalytic activity for vinyl chloride oxidation followed a descending order of Co3O4cube (Co3O4-c) > Co3O4sphere (Co3O4-s) > Co3O4commercial (Co3O4-com). The cube-shaped Co3O4presented higher catalytic activity and stability than Co3O4spheres despite their similar crystallographic structures as well as physicochemical and redox properties. Accordingly, the different catalytic behaviors should be attributed to a morphological effect. The Co3O4cube with a preferential exposure of (001) plane presented higher abundance of surface Co2+cations and adsorbed oxygen species, which acted as the active sites responsible for the improvement of its catalytic activity.Keywords:Co3O4;morphological effect;crystal plane;catalytic oxidation;vinyl chloride
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED COMPOSITE MATERIALS
·
2025
·
IF 2.3
Zhiwei Cai,Jing Sun,Ning Jiang,Chao Chen,Yanzi Lin,Yimin Shen,Minmin Ge,Guanglin Fang,Corinne Boudon,Yaokang Lv,Laurent Ruhlmann
Novel Ce/TiO2 were synthesized using a solution-based method involving two types of Ce(III)-doped polyoxotitanium cages, namely ([Ti28O38(OEt)38CeCl(EtOH)1.4] and [Ti8O7(OEt)21Ce(EtOH)]). This novel material was used to coat the surface of polyvinylidene chloride (PVDC)/polyvinyl chloride (PVC) film, resulting in a homogeneous CeO2/TiO2@PVDC/PVC film. Remarkably, the CeO2/TiO2@PVDC/PVC film exhibited notable hydrophobicity and UV absorption capacity. Furthermore, the UV absorption capacity of the films was significantly improved with increasing CeO2/TiO2 content. The incorporation of CeO2/TiO2 also led to a substantial improvement in the barrier properties of the film, particularly in terms of water vapor permeability. These modified films hold great potential and offer a wide range of applications in the pharmaceutical packaging and food packaging industries.
研究领域:
材料科学
·
纳米技术
·
高分子科学
·
包装工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL ENGINEERING
·
2021
·Vol. 148
·期 1
·04021072
·
IF 1.86
Ting Su,Xiaoning Wang,Xinan Chen,Yan Cheng,Zhenkai Wang,Zhangxiong Wu,Winston Duo Wu,Sheng-Peng Sun
The ferric-nitrilotriacetate (Fe3+-NTA)-catalyzed homogenous Fenton-like reaction (i.e., Fe3+-NTA/H2O2) has received increasing interest for environmental applications, but its potential in degrading trichloroethylene (TCE) in groundwater still is not well known. The results of this study showed that Fe3+-NTA/H2O2 was more effective than other Fe3+-chelate/H2O2 processes (e.g., including ethylenediaminetetraacetate, ethylenediamine-N,N′-disuccinate, citrate, malonate, and tartrate) in degrading TCE in groundwater at natural pH (∼8.0). The effects of important parameters including the ratio of NTA∶Fe3+, and the dosages of Fe3+-NTA and H2O2 were investigated. Greater than 98% degradation efficiency of TCE in actual groundwater was obtained after 60 min of reaction time under the given conditions of NTA∶Fe3+=1.5∶1, 0.1 mM Fe3+-NTA, 5 mM H2O2, and pH 8.0. Hydroxyl radical (HO•) was responsible for the degradation of TCE, and the by-products were identified as formic acid and chloride ion (Cl−). Greater than 90% degradation efficiency of TCE in a sand column was achieved under dynamic conditions [0.5 mM Fe3+-NTA (1∶1.5), 4 mM H2O2, and hydraulic retention time of 4 h], resulting in stoichiometric ratios of ΔCl−∶ΔTCE and ΔTCE∶ΔH2O2 of ∼3∶1 and 4%, respectively. Compared with iron mineral (e.g., magnetite)-catalyzed Fenton-like processes, Fe3+-NTA/H2O2 led to much smaller consumption of H2O2 (at least 1 order of magnitude smaller). In addition, the buffering capacity of bicarbonate anions (HCO3−) in groundwater had a positive effect on the degradation of TCE by Fe3+-NTA/H2O2.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2021
·
IF 5.565
Weilai Wang,Fan Zhang,Yunfei Zhang,Lei Xu,Yuansheng Pei,Junfeng Niu
Hydrodechlorination is a promising technology for the remediation of water body contaminated with trichloroethylene (TCE). In this work, the liquid-phase hydrogenation of TCE by Raney Ni (R-Ni) and Pd/C under an open system have been studied, in which nascent H 2 (Nas-H 2 ) generated in situ from the cathode acted as a hydrogen source. Experimental results showed that TCE was completely eliminate from the solution through the synergistic effects of hydrodechlorination and air flotation due to the formation of continuous micro/nano-sized Nas-H 2 bubbles from the cathode. Furthermore, the effects of inorganic anions and organic solvents on R-Ni and Pd/C hydrogenation activity were investigated, respectively. The results showed that NO 3 − and acetonitrile can form a competitive reaction with TCE; Sulfur with lone-pair electrons will cause irreversible poisoning to these two catalysts, and have a stronger inhibitory effect on Pd/C. This work helps to realize the separation of volatile halogenated compounds from water environment and provides certain data support for the choice of catalyst in the actual liquid-phase hydrogenation system.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Jingjing Zhan,Mengxue Ma,Xiujuan Zhang,Minghui Li,Yiwen Zhang,Hao Zhou,Tianxiang Wang
Sulfidated nanoscale zero-valent iron (S-nZVI) particles have demonstrated great potential in the remediation of trichloroethylene (TCE) due to their high reactivity and electron selectivity . However, very few studies have been carried out to investigate their application in salinity water or seawater. In this work, two kinds of S-nZVI particles were prepared through different methods including the chemical reduction method (CH-S-nZVI) and the bioprecipitation method (BP-S-nZVI), and then their performances in TCE remediation in seawater environment were thoroughly compared. The results suggested that the TCE removal by CH-S-nZVI particles in seawater is reduced compared to that in fresh water. However, the difference is negligible for BP-S-nZVI particles. It indicates that the seawater has a relatively strong inhibitory effect on the TCE degradation by CH-S-nZVI, but the inhibition for BP-S-nZVI is very weak. Furthermore, this work verified that sodium chloride and organic matters have obvious inhibitory effects on the TCE dichlorination, while coexisting ions such as NO 3 - , SO 4 2- and Mg 2+ are helpful to the degradation of TCE. The research proved that the performance of BP-S-nZVI particles in seawater is superior to CH-S-nZVI particles, providing a suitable candidate for the treatment of polluted aquifers in coastal and near-shore areas.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xuqing Zou,Yizhou Feng,Min Hu,Daohui Lin,Kun Yang,Wenhao Wu
Biochars was widely employed to immobilize chlorinated aliphatic hydrocarbons (CAHs) in groundwater. Biodegradation of adsorbed CAHs may be able to regenerate biochars, but was scarcely explored. In this study, therefore, biodegradation of trichloroethylene (TCE) adsorbed on a biochar prepared at 700 °C (WBC700) by Dehalococcoides mccartyi 195 ( Dhc 195) was investigated. Aqueous TCE was completely degraded to ethene by Dhc 195 within 28 days, while 87.5 % of WBC700-adsorbed TCE was degraded to ethene within 63 days. The slower biodegradation of WBC700-adsorbed TCE could be attributed to its lower accessibility to Dhc 195 caused by the steric effects of WBC700. The adsorption capacity of WBC700 for TCE remained 80.4 % after five adsorption-bioregeneration cycles, indicating that the microbial degradation could be a highly efficient method to regenerate biochars. The microbial degradation was mainly through the electron transfer from Dhc 195 to TCE mediated by biochars as electron conductor or shuttle, but was not assisted by desorption or extracellular redox active species. Compared with biodegradation of aqueous TCE, the biodegradation of WBC700-adsorbed TCE by Dhc 195 had a wider pH tolerance and required more VB 12 , due to the buffer effect and adsorption of WBC700, respectively. The obtained results could provide a cost-effective method of biochar regeneration for CAHs removal in groundwater.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 16
·15733-15742
·
IF 2.8
Fu Xiaori,Dionysiou Dionysios D.,Brusseau Mark L.,Zaman Waqas Qamar,Zang Xueke,Lu Shuguang,Qiu Zhaofu,Sui Qian
This study presents a performance comparison of Fe(II)-catalyzed sodium percarbonate (SPC), Fe(II)-EDDS-catalyzed SPC, and of the innovative hydroxylamine hydrochloride (HA)-Fe(II)-EDDS-catalyzed SPC for the degradation of trichloroethylene (TCE) in water. TCE degradation was greater in the Fe(II)-EDDS-catalyzed SPC system compared to the Fe(II)-catalyzed SPC system, indicating the effectiveness of adding EDDS as an enhancement factor for the removal of TCE. Moreover, TCE degradation was faster in the HA-Fe(II)-EDDS-catalyzed SPC system compared to the Fe(II)-EDDS-catalyzed SPC system, illustrating that HA can play a synergistic role in TCE degradation. Analysis of iron distribution in the three systems demonstrated that EDDS addition maintained iron in soluble form, and that the generation of soluble ferrous from ferric iron was expedited with addition of HA. Studies using nitrobenzene and carbon tetrachloride probes provided insights on the generation of hydroxyl radical (HO • ) and superoxide anion radical (O 2 •− ) in the three systems. A gradual increasing contribution of O 2 •− to TCE removal in Fe(II)-catalyzed SPC, Fe(II)-EDDS-catalyzed SPC, and HA-Fe(II)-EDDS-catalyzed SPC systems was verified through free-radical scavenger tests. Finally, monitoring of Cl − concentrations manifested the complete dechlorination of TCE. A possible mechanism of TCE degradation involving two pathways of HO • oxidation and O 2 •− reaction was proposed.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）