RSC Advances
·
2015
·Vol. 5
·期 125
·103203-103209
·
IF 3.84
Qin Zhang,Po Yang,Yuyuan Deng,Chengxi Zhang,Rongqi Zhu,Yi Gu
This work aims to search the key starting materials and the key step of benzoxazine synthesis using primary amine, phenol and formaldehyde as the starting materials. The reaction kinetics were investigated by gas chromatography. The kinetic parameters of benzoxazine formation, such as reaction order, rate constant and activation energy, were found to approximately equal those of phenol consumption, which revealed that phenol was the key starting material and played an important role in the synthesis of benzoxazine. Furthermore, step 2, the reaction between formaldehyde–amine derivatives and phenol for the production of a mannich base was the controlling step. This improved insight into the benzoxazine synthesis is expected to help researchers explore novel benzoxazines and control their synthesis.
研究领域:
化学
·
材料科学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2022
·Vol. 24
·期 17
·10394-10407
·
IF 3.945
Jing Xiao,Cong Wang,Bai-Qi Feng,Tian-Yu Liu,Shao-Yi Jia,Hai-Tao Ren,Yong Liu,Song-Hai Wu,Xu Han
Although synthesis of oligoaniline (OANI) by persulfate and aniline has been investigated in the recent years, the impact of phenol on the synthesized soluble OANI is still not clear. In this study, our results indicate that phenol and pH mediate the production of the blue water-soluble OANI (OANIblue) in the reaction between sodium persulfate (SPS) and aniline under alkaline conditions, and the yields of OANIblue increase with increasing concentrations of phenol and pH values. Quenching experiments rule out the contributions of SO4˙− and ˙OH to aniline oxidation and imply that the non-radical activation of SPS is an important pathway in the formation of OANIblue. MALDI-TOF-MS analysis indicates that phenol apparently inhibits the polymerization degree of aniline in that the molecular weights of OANIblue gradually decrease from 1586.4 to 684.6 when phenol is increased from 0 to 2.0 mM. FTIR and Raman analyses confirm the structure of aniline oligomers in OANIblue and indicate that phenol inhibits the phenazine-like structure in OANIblue and facilitates the transformation of benzenoid rings to quinoid rings in the oxidation products. However, simultaneous activation of SPS by phenol and aniline is likely to occur in the reaction system with the formation of PhNH˙, as indicated by DFT calculations. The high scavenging reactivity of phenol towards both PhNH2˙+ and PhNH˙ implies that PhNH2˙+ and PhNH˙ are not the intermediates in the formation of OANIblue. DFT calculations also reveal that apart from the one-electron transfer pathway between aniline and SPS, the two-electron transfer pathway is also likely to occur in the presence of phenol, resulting in the formation of PhNH+/PhN˙˙ without producing PhNH2˙+ and PhNH˙. The produced PhNH+/PhN˙˙ intermediates then couple with aniline, PhNH+, aminophenyl sulfate and its hydrolysate to form dimers, trimers, oligomers, and eventually OANIblue. This study not only describes a novel method to prepare water-soluble OANI, but also gives new insight on the importance of phenol in the production of OANIblue.
研究领域:
化学
·
材料科学
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DOI
PubMed
高影响因子
BIOTECHNOLOGY & BIOTECHNOLOGICAL EQUIPMENT
·
2021
·
IF 1.632
Bo Wang,Feng Gao,Jing Xu,Jianjie Gao,Zhenjun Li,Lijuan Wang,Fujian Zhang,Yu Wang,Yongsheng Tian,Rihe Peng,Quanhong Yao
Biological treatment is a cost-effective and environmentally friendly technique for treating toluene. However, this process is limited by the type and quantity of toluene degraders that can be applied to different environments and methods. It is a feasible solution to constructing new genetic engineering organisms for toluene degradation through biotechnology. To facilitate genetic manipulation and improve gene expression, the toluene/o-xylene monooxygenase locus from Pseudomonas stutzeri was reconstructed and artificially synthesized. All six genes were optimized and driven with a monocistronic transcriptional pattern by T7 promoter and terminator to be expressed at a high level. The engineered bacteria can hydroxylate toluene to a mixture of o-, m- and p-cresol, which are then further oxidized to 3- and 4-methylcatechol. Benzene can also be oxidized to phenol, catechol and pyrogallol successively. The negative effects of toluene can be removed by the engineered bacteria via proteomics analysis. Overall, the artificial gene clusters established in this study can be used to construct different toluene and benzene degradation organisms for bioremediation.Supplemental data for this article is available online at https://doi.org/10.1080/13102818.2021.1996267 .
研究领域:
生物技术
·
环境微生物学
·
基因工程
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DOI
高影响因子
ANALYST
·
2011
·Vol. 137
·期 4
·944-952
·
IF 3.913
Yanli Quan,Zhonghua Xue,Haicai Shi,Xibing Zhou,Jie Du,Xiuhui Liu,Xiaoquan Lu
A novel idea on the basis of 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (THPP) functionalized carbon nanotubes (CNTs) film was developed to simulate the chromatographic separation, which was able to rapidly and simultaneously detect dihydroxybenzene isomers based on their different oxidation potentials and corresponding currents. The mechanism involved in the recognition and isolation of the dihydroxybenzene isomers was explored and confirmed by UV spectra and density functional theory. It was proven that the current method for simultaneously detecting and isolating dihydroxybenzene isomers was ascribed to the priority of porphyrin film to induce oxidation of the three kinds of isomers, and the priority depends to a large extent on the different tendencies of dihydroxybenzene to interact with the peripheral hydroxyl group and with the extended π-conjugated ring of porphyrin. Most important of all, porphyrin functionalized CNTs film allows for the formation of well-defined interface and provides an advantageous and high-performance platform for the simultaneous determination and isolation of dihydroxybenzene isomers.
研究领域:
分析化学
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电化学
·
纳米材料
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环境监测
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药物分析
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Yucheng Zi,Dong Chen,Guochen Wang,Yuhong Ma,Wantai Yang
A simple strategy is proposed to offer styrene (St) copolymer with intrinsic and catalyst-free upcycling capability by incorporating α -methylstyrene (AMS) units into the copolymer poly(AMS -co- St) (PAS). Compared to polystyrene (PS), the PAS is more susceptible to depolymerizing into St and AMS monomers with higher yields at relatively lower temperature. The yield of liquid chemicals of PAS-4 (26.1 mol% AMS) is up to 93 wt% at 380°C, whereas that PS as control is 78 wt%. The reclaimed liquid chemicals of PAS-4 contain 58.4 wt% St and 37.7 wt% AMS, while the chemicals of PS contain 81.8 wt% St and 4.1 wt% AMS. The introduction of AMS units in PAS leads to a reduction in the liquid chemicals other than St and AMS monomers. The blends of PS and PAMS do not demonstrate the synergistic effect regarding facilitating the PS depolymerization. In addition, the properties of the new PASs prepared with the reclaimed monomers are comparable with those of the virgin PASs. This work proves the concept that recycling efficiency could be boosted by incorporating liable structural units into the copolymer chains and demonstrates a closed-loop of PS up-cycling.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
CHEMICAL PAPERS
·
2017
·Vol. 72
·期 1
·51-56
·
IF 1.258
Wei Mengyi,Qian Chao,Chen Xinzhi
Based on the recycling of NO
x
, the Cu(I)- and HNO 3 -catalyzed oxidation of 2-chloro-4-(methylsulfonyl)toluene to 2-chloro-4-(methylsulfonyl)benzoic acid has been developed with an excellent yield of 84.2% and a purity of 99.7%. The optimized reaction conditions (160 °C, oxygen pressure 1.5 MPa, HNO 3 concentration 25 wt%, HNO 3 : substrate 0.5:1) use 1.0 mol% CuI as catalyst. The dosage of HNO 3 in the new process is only 25% of the stoichiometric amount and 12.5% of the amount of the traditional process. The NO
x
emission is 5% amount of the traditional process. The oxidation of several additional toluene derivatives with comparable yields demonstrates the generality to these reaction conditions.
研究领域:
化学
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环境科学
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DOI
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Weitao Wang,Kang Wang,Huan Wang,Jiaqi Zhu,Zhen-Hong He,Zhao-Tie Liu
Selective oxidation of benzyl alcohol to benzaldehyde with molecular oxygen is a typical oxidation in synthetic chemistry. In present, Mn-Cu bimetal oxide spinel catalyst was prepared and characterized. The content of surface oxygen vacancies can be adjusted by the molar ratio of Cu to Mn during the preparation process and oxygen vacancies were found positively related to the activity of entitled reaction. The solvent effect on the reaction is investigated. The reaction conditions of the entitled reaction were optimized and the conversion of benzyl alcohol can reach 98.5 % with 100 % selectivity to benzaldehyde at 70°C for 8 h. The catalyst is stable and can be reused for 5 times without any significant decrease in its catalytic performance. In addition, the reaction was studied from the aspect of kinetic to reveal the reason of high selectivity.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2025
·
IF 3.2
Xiang Chen,Shaohua Chen,Pengxin Liu,Chaodan Pu
We report the efficient C–C coupling between benzyl alcohol and benzaldehyde to hydrobenzoin using CdSe/CdS quantum dots as visible-light photocatalysts and sodium oxide as a cocatalyst. The optimized conditions resulted in a reaction with a selectivity of hydrobenzoin >95%, an apparent quantum yield of 23.6% under the excitation by 520 nm LED, and a turnover frequency of 56.8 mmol g–1 h–1. Reactant concentration-dependent experiments demonstrated that benzaldehyde can process fast proton-coupled electron transfer, improving the utilization of photogenerated electrons. Photoluminescence quenching experiments and reactions with deuterated benzaldehyde confirmed that due to the in situ produced hydrogen ions, the hydroxymethyl radicals would process efficient reverse conversion from hydroxymethyl radicals to benzyl alcohol, resulting in noneffective charge transfer. Formation of sodium benzyloxide can eliminate the in situ produced hydrogen ions around the hydroxymethyl radical, suppressing this reverse conversion and improving the utilization efficiency of transferred holes and electrons.
研究领域:
化学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2018
·
IF 2.196
Shuyu Ning,Weifeng Chen,Teng Pan,Youwei Cheng,Lijun Wang,Xi Li
Solubilities of isophthalic acid in ternary mixtures of acetic acid + water + benzoic acid were determined by the static analytical method. The temperature range was from 292.55 to 372.10 K, the mass ratios of water to acetic acid were 0, 1:9, and 1:4, and the mass fractions of benzoic acid in initial solvent ranged from 0 to 20.1%. The experimental results indicated that the solubility of isophthalic acid increased with the introduction of benzoic acid to the binary solvents of acetic acid and water, and that could be explained by Hansen’s three-dimensional parameters and like-dissolves-like rule. Then the experimental solubilities were correlated by the nonrandom two liquids (NRTL) model, and the model parameters were regressed. The values calculated by the NRTL model showed good agreement with the experiment data.
研究领域:
化学工程
·
物理化学
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DOI
高影响因子
Materials Today Physics
·
2021
·
IF 9.298
Feichong Yao,Wenhao Xie,Ming Yang,Hang Zhang,Hongbo Gu,Ai Du,Nithesh Naik,David P. Young,Jing Lin,Zhanhu Guo
With the purpose of ameliorating the electrical property, permittivity and magnetoresistance of polyaniline (PANI) nanofibers , three types of phenylenediamine (PDA), including o -PDA, m -PDA, and p -PDA, and different contents of PDA have been incorporated into the PANI polymer backbone by the interfacial copolymerization of aniline with PDA. The results demonstrate that different types and contents of PDAs could disclose the distinct effects on the chemical structures , crystalline structures, and morphologies for copolymers of aniline with PDA affirmed by Fourier transform infrared (FTIR) spectroscopy, solid-state 13 C nuclear magnetic resonance ( 13 C NMR), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The molecular weight of all copolymers is reduced by several orders of magnitude relative to pure PANI nanofibers confirmed by gel permeation chromatography (GPC). The resistivity variations for the copolymers of aniline with different types of PDAs are well explained from the point view of their molecular structures based on the first-principle simulations (i.e. intrachain electrical conductivity) and degree of crystallinity gained from XRD (i.e. interchain electrical conductivity). A tunable room-temperature magnetoresistance (MR) and a controllable negative permittivity are discovered in the copolymers of aniline with different types and contents of PDAs. This work provides a new insight for the manipulation of electrical transport for PANI nanofibers and helps seek the new applications of conductive polymer .
研究领域:
材料科学
·
化学
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 15
·50190
·
IF 2.52
Haonan Cheng,Yunjie Yin,Bo Wang,Junrong Zhu,Chaoxia Wang
Fabrication of highly conductive poly(styrene)/poly(aniline) (PS/PANI) microspheres has been considerably explored. Improving the adsorption efficiency of aniline on the PS microspheres is still a challenge by facile methods. To overcome this problem, poly(styrene-co-methacylic acid) (poly(St-co-MAA)) is firstly synthesized for capturing anilinium ions, and then the in-situ polymerization of aniline is implemented to obtain highly conductive poly(St-co-MAA)/PANI microspheres. The prepared poly(St-co-MAA) microspheres bearing an average particle size of 238 nm possess a low polymer dispersity index (PDI, 0.082) and high zeta-potential, which guarantee no agglomeration and deposition of microspheres latex after 30 days at room temperature. After the in-situ polymerization of aniline, the conductive disc based on poly(St-co-MAA)/PANI microspheres presents a superior electrical conductivity of 14.6 S m −1 at an inferior PANI loading of 5.74 vol% and a relatively low electrical percolation threshold (EPT < 0.16 vol%). The results indicate that the carboxylic microspheres for preparing high polymer/PANI microspheres is effective. Meanwhile, poly(St-co-MAA)/PANI microspheres show a great potential in manufacture of conductive composites due to their excellent electrical conductivity.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
Molecular Catalysis
·
2021
·
IF 5.062
Chang Bai,Yong Liu,Cong Wang,Xiao-Cong Zhang,Jia-Xuan Wu,Hai-Tao Ren,Xu Han
Although the oxidation processes mediated by persulfate (PS) and peroxymonosulfate (PMS) attract more attention in the degradation of various recalcitrant contaminants, the high concentrations of oxidants required for the low concentrations of contaminants always limit their large-scale applications. In this work, aniline can be effectively oxidized by CuO and PS under pH-neutral and alkaline conditions. The increased observed rate constant ( k obs ) values with increasing pHs indicate that the oxidation of aniline is facilitated by solution OH − . Meanwhile, the low ratios between the removed PS and aniline (1.19 at pH 7.0 and 1.68 at pH 12.0) indicate the high catalytic oxidation efficacy of the CuO-PS system. The insignificant contributions of SO 4 − , OH, 1 O 2 and O 2 − to aniline oxidation in quenching experiments and EPR analysis suggest that PS is likely activated on the surface of CuO via the non-radical pathway. The presence of carbon-centered radicals (CCRs), as well as UV and GC MS analysis, indicates the important intermediates of PhNH 2 + and PhNH radicals during the oxidation process, revealing that separate transfer of an electron from aniline to the activated PS, followed by subsequent abstraction of a H + by OH − to form PhNH are two important steps in the oxidation process. Further coupling of PhNH radicals results in the formation of insoluble polyaniline polymers at pHs 7.0 and 12.0. The high thermal stability and ideal pseudo-capacitive properties of the insoluble products indicate that the polyaniline produced from aniline wastewater can be used for high-temperature-resistant materials or capacitors. This study provides an efficient alternative to turn aniline waste to polyaniline polymers.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
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