POLYMERS FOR ADVANCED TECHNOLOGIES
·
2021
·Vol. 32
·期 8
·2908-2915
·
IF 3.665
Shuai Wen,Qiang Liu,Wentian Liang
The linear benzyl chlorine-free poly(4-acetoxystyrene) (PSTO) with low polydispersity ( M w / M n = 1.3) is obtained through anisole quenching of the living polymerization of 4-acetoxystyrene initiated with the St–Cl/SnCl 4 /n-Bu 4 NBr system in CH 2 Cl 2 . The alkylation reaction rate increases with increasing anisole concentration and temperature. With a 4-fold excess of anisole over the initiator, end-chlorine groups are completely capped by anisole in 30 minutes at −15°C through adding extra SnCl 4 prior to the alkylation reaction. In addition, by using 2-methylanisole and 2,6-dimethylanisole as capping agents, it is verified that both para- and ortho-positions substitution of living PSTO cations to the anisole occur during alkylation reactions.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2020
·
IF 3.023
Hong-Yi Wang,Jia-Wei Tang,Peng Peng,Hai-Jun Yan,Fu-Li Zhang,Shao-Xin Chen
We first developed a novel and efficient chemoenzymatic process to prepare (S)-1-(pyridin-4-yl)-1,3-propanediol, a vital HepDirect prodrug intermediate, from inexpensive and commercially available isonicotinic acid. Through this process, we provide a creative way to obtain the key chiral intermediate, β-hydroxyester, with ketoreductase (KRED) EA. After optimization of the process, we performed the reaction on a 100 g scale with a substrate concentration of up to 150 g/L, a yield of 93%, and an ee value of up to 99.9%. Additionally, we used a simple and effective NaBH4/MgCl2 reduction system to obtain (S)-1-(pyridin-4-yl)-1,3-propanediol with >99.9% ee and an 80% yield. This novel chemoenzymatic process has the potential to be a cost-effective and environmentally friendly process suitable for industrial use.
研究领域:
生物化学
·
制药工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Jie Liu,Zhiwei Zhao,Penghui Shao,Fuyi Cui
Heterogeneous catalysts with low cost, little hazardous, high effective and facile separation from aqueous solution are highly desirable. In this study, magnetic Fe 3 O 4 –MnO 2 core–shell nanocomposites with various Fe/Mn weight ratios were synthesized through a facile one pot method and then characterized. These as-synthesized solids were applied to activate the peroxymonosulfate (PMS) for 4-chlorophenol degradation. The sample 3 with a Fe/Mn molar ratio of 4:1, which can be separated conveniently through external magnetic field, exhibited higher activity than other Fe 3 O 4 –MnO 2 nanocomposites, pure MnO 2 and physical mixture of Fe 3 O 4 and MnO 2 . The effects of operational parameters on the catalytic activity of sample 3, including initial Oxone and pollutant dosage, pH and catalyst dosage, were assessed. The catalyst had high stability and good reusability according to five successive repeated reaction. The reactive radicals generated in the PMS/Fe 3 O 4 –MnO 2 nanocomposites system were sulfate radical (SO 4 − ) and hydroxyl radical ( OH). The enhancement of the nanocomposites may be attributed to the interaction of Fe 3 O 4 with MnO 2 on the basis of the in situ ATR-FTIR analysis and XPS spectrum.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2013
·Vol. 15
·期 44
·19422-19426
·
IF 3.829
Weiming Wu,Rui Lin,Lijuan Shen,Ruowen Liang,Rusheng Yuan,Ling Wu
CdS photocatalysts with tunable band gaps (2.17–2.32 eV) were successfully prepared by a solvothermal method. Photocatalytic hydrogenation of 4-nitroaniline over the obtained samples was evaluated in the presence of HCO2NH4 as a hole scavenger upon purging with N2 under visible light irradiation (λ ≥ 420 nm). The CdS sample prepared by CdCl2 and sulfur powder in ethylenediamine showed excellent catalytic activity, giving 100% of 4-nitroaniline conversion and 95% of p-phenylenediamine selectivity after 35 min of visible light irradiation. The results of electron spin resonance revealed that its photoexcited holes could efficiently react with HCO2− ions within HCO2NH4 molecules to produce ˙CO2− radicals with strong reductive abilities. Furthermore, photoexcited electrons of the obtained sample exhibited relatively strong reductive abilities as compared to other CdS samples. Therefore, this sample showed the highest catalytic activity among the CdS samples for the photocatalytic hydrogenation of 4-nitroaniline.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 48
·25440-25446
·
IF 3.708
Yanlin Ren,Guangyin Fan,Weidong Jiang,Bin Xu,Fuan Liu
Magnetic palladium/reduced graphene oxide nanocomposites (Pd/rGO-Fe3O4) were prepared by depositing Pd nanoparticles on an rGO-Fe3O4 magnetic support. The as-prepared nanocomposites were investigated as catalysts for the hydrodechlorination of 4-chlorophenol in the aqueous phase. The complete conversion of 4-chlorophenol (with a concentration as high as 2.5 g L−1) to phenol was obtained in a reaction time of 40 min at room temperature and balloon hydrogen pressure without any additives. The excellent catalytic activity of the Pd/rGO-Fe3O4 can be attributed to the small particle size of Pd, and an electron-deficient state of Pd in the catalyst as a result of the strong interaction between the active sites and the oxygen of the oxygen-containing groups on the rGO-Fe3O4 support.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2015
·Vol. 38
·期 7
·1149-1155
·
IF 2.737
Ganghui Chu,Wensheng Cai,Xueguang Shao
To extract flavone glycosides efficiently, a new extraction material based on 4-butylaniline-bonded silica gel was prepared using a two-step grafting method including a ring-opening reaction and synchronous hydrolysis. Preparation of the silica-based material was easily achieved under mild conditions, and the material was characterized by Fourier transform infrared spectroscopy, elemental analysis, and scanning electron microscopy. The material was used in solid-phase extraction, and the extraction can be performed in neutral conditions without regard to ionic strength. Selectivity tests of 14 compounds on the extraction cartridge showed that the material has a high affinity to flavone glycosides in contrast to octadecyl silica, and the extraction yields for four flavone glycosides were found to be >93%. Selectivity tests further reveal that the adsorption on its surface is likely attributed to multiple interactions, including hydrophobic interactions, π–π interactions, and hydrogen bonding. To explore the applicability of 4-butylaniline-bonded silica gel, naringin and hesperidin from Simotang oral liquid were extracted, and the extraction yields were >90%, which is distinguished from <28% on octadecyl silica cartridge.
研究领域:
分析化学
·
药物分析
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2017
·Vol. 7
·期 10
·303
·
IF 3.553
Haijiao Lu,Jingkang Wang,Hongxun Hao,Ting Wang
With a large specific surface area, high reactivity, and excellent adsorption properties, nano zerovalent iron (nZVI) can degrade a wide variety of contaminants in wastewater. However, aggregation, oxidation, and separation issues greatly impede its wide application. In this study, MoS2/Fe3O4/nZVI nanocomposites were successfully synthesized by a facile step-by-step approach to overcome these problems. MoS2nanosheets (MNs) acted as an efficient support for nZVI and enriched the organic pollutants nearby, leading to an enhanced removal efficiency. Fe3O4nanoparticles (NPs) could not only suppress the agglomeration and restacking of MNs, but also facilitate easy separation and recovery of the nanocomposites. The synergistic effect between MNs and Fe3O4NPs effectively enhanced the reactivity and efficiency of nZVI. In the system, Cr(VI) was reduced to Cr(III) by nZVI in the nanocomposites, and Fe2+produced in the process was combined with H2O2to further remove 4-Chlorophenol (4-CP) through a Fenton reaction. Furthermore, the nanocomposites could be easily separated from wastewater by a magnet and be reused for at least five consecutive runs, revealing good reusability. The results demonstrate that the novel nanocomposites are highly efficient and promising for the simultaneous removal of Cr(VI) and 4-CP in wastewater.Keywords:nZVI;modification;nanocomposites;Cr(VI);4-CP;Fenton reaction;pollution treatment;recyclability;wastewater
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
Advanced Fiber Materials
·
2022
·Vol. 4
·期 5
·1069-1080
·
IF 12.958
Wang Caihong,Liu Ke,Wang Dong,Wang Guomin,Chu Paul K.,Meng Zheyi,Wang Xuefen
Hierarchical CuO–ZnO/SiO 2 (CZS) nanofibrous membranes are designed and fabricated to remove Congo red and 4-nitrophenol two common small molecular pollutants in water. The electrospun SiO 2 fibrous membrane is serves as the substrate for hydrothermal depositing CuO–ZnO nanosheets. The CZS nanofibrous membrane shows good adsorption characteristics for Congo red due to the hierarchical morphology and the adsorption kinetics where isotherm follows the pseudo-second-order model and Langmuir model, respectively. The maximum adsorption capacity for Congo red is 141.8 mg/g. Moreover, the membrane exhibits excellent catalytic reduction activity for 4-nitrophenol under mild conditions and over 96% of the pollutants are degraded within 90 s. The CZS nanofibrous membrane has promising prospects in applications in water treatment and environmental protection because of the good flexibility, easy fabrication, excellent adsorption, and catalytic activity. Graphical abstract
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2022
·
IF 4.177
Tongxin Xiao,Ying Chen,Yuning Liang
The photocatalytic conversion of CO2 into hydrocarbon fuels by utilizing abundant solar energy is a promising and eco-friendly approach to address the energy crisis and global warming. In this work, the sensitizer Ni(II) tetra(4-carboxylphenyl)porphyrin (NiTCPP) was successfully combined with TiO2 nanotube arrays (TiO2NTs) by three methods, and their performances in the photocatalytic reduction of CO2 under simulated solar irradiation were studied. The results showed that NiTCPP/TiO2NTs exhibit a greatly ameliorated photocatalytic activity, and the photocatalytic reduction activities of NiTCPP/TiO2NTs prepared by different methods were different. The catalyst prepared by the impregnation method displayed the highest photoreduction efficiency. The reduction rate of CO2 into CH4 was up to 33.89 μmol/cm2/h with a quantum efficiency of 0.65% (at 420 nm), about 5 times that of the bare TiO2NTs. The introduction of NiTCPP not only efficiently expands the light absorption range but also enhances the charge separation efficiency. Furthermore, a possible mechanism of its CO2 photoreduction performances was systematically presented.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Junlin Zhu,Xuan Zhang,Zhihui Qin,Lexin Zhang,Yuqu Ye,Meiwen Cao,Lili Gao,Tifeng Jiao
The development of functional hydrogel materials for applications in catalysis has attracted great research interest, especially in aqueous phase catalysis. However, preparation of new structural hydrogel catalysts with enhanced catalytic activity still remains a challenge. In this study, a series of Pd nanoparticles (PdNPs) doped chitosan (CS)-based composite hydrogels were successfully prepared by adding graphene oxide (GO), carbon nanotubes (CNTs) and layered double hydrotalcites (LDHs) to CS hydrogel with glutaraldehyde as a cross-linking agent and in situ growing PdNPs. The structure and morphology analysis indicated that chitosan-based composite hydrogels could be used as carriers to load PdNPs and effectively prevent the agglomeration of PdNPs. Subsequently, 4-nitrophenol (4-NP) catalytic reaction was used as a typical model to evaluate catalytic performances of chitosan (CS)-based composite hydrogel catalysts. The obtained chitosan-based composite hydrogel catalysts exhibited better catalytic activity than that of PdNPs doped CS hydrogel catalyst (CS-PdNPs) and reusability for the reduction of 4-nitrophenol in water. The catalytic process conformed to the pseudo-first-order kinetic equation. Moreover, chitosan-based composite hydrogel catalysts containing CNTs had the best catalytic performance since the particle size of PdNPs was the smallest among three kinds of chitosan-based composite hydrogel catalysts. This work provides new ideas for the preparation of stable and efficient precious metal nanoparticle catalysts for applications in aqueous phase catalysis.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2015
·Vol. 30
·期 5
·1098-1102
·
IF 0.399
Zhou Yong,Liu Fude,Wu Haiyan,Duan Lijie,Qu Boyang
One conjugated polymer consisting of carbazole and 3-hexylthiophene moiety, poly (N-Hexyl-2,7-di(2-(4-hexylthiophene)carbazole) (PNDC), has been synthesized by ferric chloride oxidative polymerization. The monomer N-Hexyl-2,7-di(2-(4-hexylthiophene)carbazole was synthesized and characterized by IR, 1 H-NMR, 13 C-NMR and MS. UV-vis absorption spectrum, fluorescence spectrum, photoluminescence spectrum and electrochemical properties of the polymer were investigated. Polymer PNDC shows maximum peak appearing at 394 nm in UV-vis absorption spectrum, strongest fluorescence-emission at 482 nm in fluorescence spectrum and maximum emission peak at 492 nm in photoluminescence spectrum. The band-gap ( E
g ), HOMO energy ( E
HOMO ), and LUMO energy ( E
LUMO ) of the polymer were obtained as 2.58, -5.32, and -2.74 eV, respectively.
研究领域:
材料科学
·
有机化学
✓ 已验证
DOI
高影响因子
Solar RRL
·
2021
·Vol. 5
·期 7
·2100181
·
IF 8.582
Yali Sun,Pengfei Qiu,Siyu Wang,Hongling Guo,Rutao Meng,Xiaowei Zhou,Li Wu,Wei Yu,Jianping Ao,Yi Zhang
Cu 2 ZnSn(S,Se) 4 are emerging as promising photovoltaic materials due to their outstanding photoelectrical performances, benign grain boundaries, and Earth-abundant constituent elements. However, there are largely distributed cation-disordering defects and defect clusters, which lead to an increase in recombination and a large open-circuit voltage deficit and thus deteriorate device performance. Herein, defect control for a high-efficiency Cu 2 ZnSn(S,Se) 4 solar cell by atomic layer deposition of aluminum oxide (ALD-Al 2 O 3 ) on the precursor film is reporter. Cu Zn defects and Sn-related deep defects are largely suppressed because of the decrease in Sn 2+ and the increase in Sn 4+ in the film by ALD-Al 2 O 3 on the precursor are found, and the crystallinity of absorber layer is improved from a double-layer structure to a completely single-layer structure. Furthermore, the carrier lifetime and recombination in the bulk and interface are significantly improved for devices with ultrathin Al 2 O 3 . Using this approach, the conversion efficiency increases from 8.8% to 11.0% and the open-circuit voltage deficit decreases from 0.621 to 0.577 V. Herein, a deep understanding of the relationship between Al 2 O 3 incorporation and high-efficiency Cu 2 ZnSn(S,Se) 4 devices and a new direction for controlling defects to further improve the performance of kesterite solar cells are provided.
研究领域:
材料科学
·
太阳能电池研究
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）