CELLULOSE
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2025
·
IF 4.8
Zhao Yao,Wang Xueping,Li Bowen,Si Tian,Gao Xin,Peng Lincai,Zhang Heng
The cellulose catalytic oxidation system mainly comprises inorganic ion-based oxidants. Hence, the selective oxidation of C 6- primary hydroxy groups (C 6 -OH) of cellulose, catalyzed by piperidine free radicals, was limited to the homogeneous cellulosic system containing protic solvents or heterogeneous system. In this work, the use of the catalytic system containing 4-acetamido-2,2,6,6-tetramethylpiperidine 1-oxyl (4-AcNH-TEMPO) was extended to the cellulosic solution in N, N-dimethylacetamide (DMAc) and combined with chlorine dioxide. Results showed that the carboxyl content was 0.832 mmol/g. Meanwhile, the degree of polymerization decreased from 900 to 489. This study provides an effective route for the homogeneous selective oxidation of primary hydroxy groups in cellulose and explored its oxidation mechanism in DMAc solvent. Furthermore, studies showed that the reactive chlorine species- ClO·, Cl·, and ClO 2 played a crucial role in the oxidation process. The methodology developed here displayed great potential to be utilized to various biomolecules in aprotic solvents homogeneous system based on 4-AcNH-TEMPO as oxidation catalysts.
研究领域:
化学工程
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材料科学
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高影响因子
CHEMICAL PAPERS
·
2018
·Vol. 72
·期 6
·1339-1345
·
IF 0.963
Li Bin,Chen Dan,Zhang Xiaoli,Dong Wenbo,Zhao Binxia
A catalyst comprised of 4-dimethylaminopyridine (DMAP) functionalized silica gel (SG-DMAP) was prepared via a convenient N-alkylation of 4-methylaminopyridine (MAP) with γ-chloropropylated silica gel promoted by potassium iodide. FT-IR, TG, SEM results illustrated that the DMAP was successfully immobilized on silica gel and the BET result suggested the pore structure was not altered after immobilization process. The highest immobilization amount of 0.75 mmol/g was obtained at 130 °C for 12 h. Activity test demonstrated that silica gel immobilized DMAP could be serve as a heterogeneous catalyst for the acylation with significant activity and stability.
研究领域:
有机化学
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催化材料
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DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2018
·Vol. 102
·期 3
·1414-1424
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IF 2.956
Yaowu Wei,Tao Zhang,Qi Zhang,Bingqiang Han,Nan Li
Improving the hydration resistance of CaO aggregates is the key to successful application of lime-based refractories in metallurgical industry. Additive Zr(OH) 4 and Al(OH) 3 were introduced in the preparation of CaO granules using granulation equipment and calcination method in this study. The results showed that the hydration resistance of CaO granules was improved significantly, especially for granules with 0.6 wt.% Zr(OH) 4 and 0.9 wt.% Al(OH) 3 , respectively. The shell of CaO granules was relatively dense after calcination and the volume of open pores of CaO granules decreased from 3.56 × 10 −2 to 1.80 × 10 −2 cm 3 /g when additive was introduced. Zr(OH) 4 and Al(OH) 3 have the opposite effect on the closed porosity of CaO granules, the closed porosity of CaO granules was decreased with Zr(OH) 4 addition, but increased with Al(OH) 3 addition.
研究领域:
材料科学
·
冶金工程
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DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
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2024
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IF 4.2
Jiali Chen,Peng Gao,Jie Liu,Yimin Zhu
Scheelite and calcite was firstly separated by new depressant Poly(sodium 4-styrenesulfonate) (PSS) with NaOL system. The recovery of scheelite was 87.18 % and the recovery of calcite was 5.57 % in single flotation experiments, the recovery and grade of WO 3 was 70.53 % and 61.08 % respectively in artificial mixed ore flotation under the optimal conditions of 10 mg/L NaOL, 10 mg/L PSS and pH of 8. Contact angle measurements, atomic force microscope (AFM) analysis, zeta potential analysis, fourier transforming infrared spectra (FT-IR) analysis and X-ray photoelectron spectroscopy (XPS) analysis were performed to uncover the reaction mechanism. The results showed that PSS could not adsorbed on scheelite by chemical reaction, and PSS had no impact on the further adsorption of NaOL onto the scheelite surface. Therefore, scheelite could still keep a high recovery with PSS. However, PSS could be strongly adsorbed on calcite by chemisorption between the Ca site of calcite and O site of PSS, which increased the hydrophilia of calcite and imped the further adsorption of NaOL. Therefore, it could selectively depress the flotation of calcite.
研究领域:
矿物加工工程
·
表面化学
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DOI
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Chuanxiang Cheng,Yujie Lei,Tiantian Min,Yushan Zhang,Jin Yue
4-Terpineol (4-TA), a typical monocyclic monoterpene essential oil compound with important biological activities, poor stability and solubility severely hamper its biological activities. To date, β-cyclodextrin (β-CD) encapsulating essential oil to form inclusion complexes (ICs) is considered as a satisfactory treatment. Nevertheless, the detailed inclusion mechanism of β-CD for 4-TA especially the behavior of 4-TA during inclusion formation have not available yet. Herein, 4-TA/β-CD ICs were successfully synthesized by the co-precipitation method, and hydrogen bonds and hydrophobic interactions played a key role in the formation of ICs, and the isopropyl of 4-TA entered the cavity through the wide rim of β-CD. Moreover, the release profile demonstrated that high RH (85 % and 99 %) triggered the release of TA from ICs. This study suggests the great potential of cyclodextrin inclusion strategy for improving the stability and sustained release of 4-TA in food preservation application.
研究领域:
食品科学
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化学
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DOI
PubMed
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Yiqi Liu,Gang Xue,Yaqian Ma,Lei Ding,Yanli Kong,Yang Gao,Zhonglin Chen
4-Nitrophenol (4-NP) removal using prepared molecular imprinting polymers (MIPs) as a specific adsorbent was investigated. On the basis of single-factor experiment, Box–Behnken statistical experiment design (BBD) and response surface methodology (RSM) were used to investigate the influence of MIPs dosage, initial concentration of 4-NP, pH and temperature of the solution, and their potential interaction effect on 4-NP removal. The quadratic polynomial regression model of response value Y (4-NP removal efficiency) was established based on the BBD experiment al results. The reasonable and reliable of regressive of the model was confirmed by the analysis of variance test and residuals analysis (R 2 = 0.9952). The RSM model indicates that all single-factors had a significant effect on 4-NP removal. The interaction effect between MIPs dosage and temperature, temperature, and pH were not significant but the other four interaction effects were significant. The regression model showed an optimum removal of 79.63%, while 78.39% removal was obtained from batch experiments at the optimum conditions suggested by the regression model, which reconfirmed the validity of the model. The results demonstrated that prepared MIPs possessed a strong adsorption ability for 4-NP removal, allowing a possible practical application in future water treatment.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Ming Chen,Linyang Li,Lanlan Zhong,Chuanbao Xiao,Nianbing Zhong,Quanhua Xie,Dengjie Zhong,Yunlan Xu,Haixing Chang
To effectively remove 4-fluorophenol from water, a novel optical fiber photocatalysis–biodegradation–ion-adsorption reactor, which is composed of photocatalytic optical fibers, algal–bacterial biofilm, and ion-adsorption functionalized glass fiber cloth, was developed. The photocatalytic optical fibers, i.e., polymeric carbon nitride and lanthanum-doped TiO 2 coated photocatalytic optical hollow fibers (POHFs), were located in the middle-layer of the reactor. POHFs have good ultraviolet–visible–near-infrared light absorption and photocurrent conversion capability and can rapidly oxidize 4-fluorophenol into biodegradable products. The S. obliquus biofilm was located on the top layer of the reactor and enriched by phototrophs ( Limnothrix and Gemmatimonas ) and heterotrophs ( Blastomonas and Roseococcus ), which continuously consume the photocatalytic products to accumulate biomass and provide dissolved oxygen through photosynthesis to generate advanced oxidation groups. The fluoride ion (F – ) absorption material, which is composed of amyloid fibril/ZrO 2 /activated carbon nanoparticles, was coated on the glass fiber cloth. The prepared fiber cloth was located on the bottom layer of the reactor and has good F adsorption (the adsorption rate approaches 27.8 μM/L), which enables it to effectively remove the F − in water to avoid F − poisoning of the biofilm. The results showed that the developed fiber reactor can perform complete and rapid removal of 4-fluorophenol (for 160 mL, 0.44 mM 4-FP, totally removed in 20 h) and increase biomass production (increase up to 18.0 mg/day). Hence, it provides a smart method for the effective removal and conversion of 4-fluorophenol in water.
研究领域:
环境科学
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生物技术
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材料科学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2014
·
IF 6.007
Qi Huang,Menghua Cao,Zhihui Ai,Lizhi Zhang
In this study, an environmentally benign polyaminocarboxylic ligand diethylenetriamine pentacetate (DTPA) was first used to promote the aerobic 4-chlorophenol (4-CP) degradation with Fe@Fe 2 O 3 core–shell nanowires, and then compared with the most used counterpart ethylenediamine tetraacetate (EDTA) of poor biodegradability. Although the 4-CP removal rate in the Fe@Fe 2 O 3 /DTPA/Air system was slower owing to the preferential degradation of DTPA, the total organic carbon removal rate in the Fe@Fe 2 O 3 /DTPA/4-CP/Air system was much faster than that in the Fe@Fe 2 O 3 /EDTA/4-CP/Air system. We interestingly found that hydroxyl radicals could more easily react with DTPA to produce DTPA radicals than with EDTA to produce EDTA radicals. Ligands (DTPA or EDTA) could significantly accelerate the hydroxyl radicals production with Fe@Fe 2 O 3 , while more hydroxyl radicals were generated in the Fe@Fe 2 O 3 /DTPA/Air system. We also employed gas chromatography-mass spectrometry and ion chromatography to detect organic intermediates and chloride ions to probe the 4-chlorophenol degradation pathways, and found its degradation pathways were dependent on the reactive oxygen species generated in the different systems. This study can clarify the roles of polyaminocarboxylic ligands on the molecular oxygen activation with nanoscale zero-valent iron, and also provide a green chlorophenols removal method.
研究领域:
环境科学
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化学
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DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2023
·
IF 8.3
Jian Zhang,Yanbo Zeng,Lifen Chen,Xiaoling Lei,Yiwen Yang,Zhidong Chen,Longhua Guo,Lei Li
A novel core-shell composite of PCN-222 and molecularly imprinted poly (ionic liquid) (PCN-222@MIPIL) with high conductivity and selectivity was prepared for electrochemical sensing 4-nonylphenol (4-NP). The electrical conductivities of some MOFs including PCN-222, ZIF-8, NH 2 -UIO-66, ZIF-67, and HKUST-1 were explored. The results indicated that PCN-222 had the highest conductivity and was then used as a novel imprinted support. PCN-222@MIPIL with core-shell and porous structure was synthesized using PCN-222 as support and 4-NP as template. The average pore volume of PCN-222@MIPIL was 0.085 m 3 g -1 . In addition, the average pore width of PCN-222@MIPIL was from 1.1 to 2.7 nm. The electrochemical response for PCN-222@MIPIL sensor for 4-NP was 2.54, 2.14, and 4.24 times that of non-molecularly imprinted poly (ionic liquid) (PCN-222@NIPIL), PCN-222, and MIPIL sensors, respectively, which result from superior conductivity and imprinted recognition sites of PCN-222@MIPIL. The current response of PCN-222@MIPIL sensor to 4-NP concentration from 1 × 10 −4 to 10 μM presented an excellent linear relationship. The detection limit of 4-NP was 0.03 nM. The synergistic effect between the PCN-222 supporter with high conductivity, specific surface area and shell layer of surface MIPIL results in the outstanding performance of PCN-222@MIPIL. PCN-222@MIPIL sensor was adopted for detecting 4-NP in real samples and presented to be a reliable approach for determining 4-NP.
研究领域:
分析化学
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环境科学
·
材料科学
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DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2024
·
IF 2.2
Yucong Song,Mingchuan Pang,Xiaoshu Ding,Guirong Wang,Xinqiang Zhao,Yanji Wang
The solubilities of 2,4-diaminotoluene (2,4-TDA), methyl 3-amino-4-methyl- N -phenyl carbamate (4-TMC) and dimethyl toluene-2,4-dicarbamate (2,4-TDC) in dimethyl carbonate (DMC) and di(2-ethylhexyl) phthalate (DOP) were determined by dynamic method at 298.15 ∼ 398.15 K under atmospheric pressure. The solubility data were correlated by the modified Apelblat equation, polynomial equation and simplified two-parameter equation. The modified Apelblat equation was more accurate than the others. In addition, the thermodynamic properties of the solution process, including the Gibbs energy, enthalpy and entropy were calculated by the modified Van't Hoff equation. The dissolution process of 2,4-TDC in DOP solvent is a non-spontaneous entropy reduction endothermic process. The dissolution processes of 2,4-TDA, 4-TMC and 2,4-TDC in DMC solvent and 2,4-TDA and 4-TMC in DOP solvent are all non-spontaneous entropy-increasing endothermic processes.
研究领域:
物理化学
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材料科学
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DOI
高影响因子
INORGANICA CHIMICA ACTA
·
2014
·
IF 2.041
Yong-Peng Xu,Jie Qin,Shi-Min Sun,Tong-Tong Liu,Xiao-Lin Zhang,Shao-Song Qian,Hai-Liang Zhu
Three novel complexes, [Ni II (dpp) 2 (L) 2 ] ( 1 ), [Ni II (eda) 2 (L) 2 ] ( 2 ) and [Ni II (deda) 2 (L) 2 ] ( 3 ) (L = 3-pyridinyl-4-amino-5-mercapto-1,2,4-triazole, dpp = 1,3-diaminopropane, eda = ethanediamine, deda = N,N-dimethyl ethylenediamine), were synthesized by reacting 3-pyridinyl-4-amino-5-mercapto-1,2,4-triazole with diamines and nickel(II) salt. The complexes were structurally determined by single-crystal X-ray diffraction. The inhibitory activity was tested in vitro against jack bean urease. Molecular docking was investigated to insert complexes into the crystal structure of jack bean urease at the active site to determine the probable binding mode. The experimental values and docking simulation exhibited that complexes 1 , 2 , 3 had better inhibitory activity than the positive reference acetohydroxamic acid, showing IC 50 values of 48.16, 32.35 and 15.22 μM, respectively. These complexes exhibited inhibitory activities as potent urease inhibitor.
研究领域:
配位化学
·
生物无机化学
·
药物化学
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DOI
高影响因子
CATALYSIS TODAY
·
2015
·
IF 3.893
Faheem Nawaz,Yongbing Xie,Hongbin Cao,Jiadong Xiao,YueqiuWang,Xihua Zhang,Mingjie Li,Feng Duan
Two series of α-MnO 2 materials were prepared via a similar method with surfactant cetyltrimethylammonium bromide (CTAB) and sodium dodecyl benzene sulfate (SDBS). The surfactants work both as shape directing agent and reduction initiator. The α-MnO 2 synthesized with 0.2 M of CTAB showed a mesoporous structure with high surface area of 387.7 m 2 /g. It is very active in catalytic ozonation of 4-nitrophenol (4-NP) and total organic carbon removal, with higher catalytic stability than commercial MnO 2 . Using tert -butanol and p -benzoquinone as scavengers of different oxidative species, we found that superoxide radicals, rather than hydroxyl radicals, were mainly responsible for the degradation of 4-NP.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）