RSC Advances
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2019
·Vol. 9
·期 23
·13234-13242
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IF 3.049
Peidong Li,Qiao Han,Xiaomin Zhang,Yangyang Yuan,Yanfei Zhang,Li Xu,Hongchen Guo,Lei Xu
The effect of the introduced base sites in CsX with alkali oxide modification towards side-chain alkylation of toluene with methanol was systematically investigated in the present work. A series of alkali oxide modified CsX with a base properties (base strength and amount) gradient were prepared by impregnating CsX with alkali metal hydroxide. Here, CsX with different base strengths were selected as the parent zeolite, which is favorable to clarify the different types of base site in the modified CsX. The base properties of the samples were elucidated based on the CO2-TPD results as well as with characterization by XPS and FT-IR of adsorbed CO2. It was revealed that the base strength of the oxygen atoms with negative charge (Oδ−) in the zeolite framework can be strengthened by the electron donating function of the alkali oxides in the supercage of CsX. Detailed analysis of the correlation between the reaction behaviors of side-chain alkylation reaction and the base properties of the indicated catalysts was carried out. It was found that the dehydrogenation of methanol to formaldehyde step was promoted by the increasing base properties of Oδ− in the CsX framework and that was the main reason for the promotion of the whole side-chain alkylation reaction. However, it was also found that the stronger base properties of the alkali oxide modified CsX would enhance the formation of active hydrogen atoms, which aggravated the unwanted styrene conversion to ethylbenzene.
研究领域:
催化
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化学工程
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材料科学
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DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
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2020
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IF 7.182
Ran Bi,Lin Yue,Sobia Niazi,Imran Mahmood Khan,Dan Sun,Bin Wang,Zhouping Wang,Qixing Jiang,Wenshui Xia
A new chitosan oligosaccharide derivative (COS-N-Ger), based on geraniol (Ger) modificated onto the NH 2 position of chitosan oligosaccharide (COS) via a facile method, was prepared and employed to evaluate in vitro antibacterial activity. The structures of COS-N-Ger derivatives were confirmed by FT-IR, 1 H, 13 C NMR, and elemental analysis. The characterization results showed successful synthesis of derivatives and the degrees of substitution (DS) of COS-N-Ger1-3 were from 0.260 to 0.283 with the yields up to 78 %. The in vitro antibacterial activity evaluation results presented a significant inhibition effect of COS-N-Ger1-3 derivatives on Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) as compared to COS. Moreover, their antibacterial activities were dose-dependent and more sensitive to S. aureus than E. coli . The results provide reliable theoretical supports for exploring the application of COS derivatives in the food industry as new potential antibacterial agents.
研究领域:
化学
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材料科学
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生物技术
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食品科学
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DOI
PubMed
高影响因子
CATALYSIS LETTERS
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2019
·Vol. 150
·期 5
·1373-1388
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IF 2.372
Ji Qinghua,Yu Xiaojie,Yagoub Abu El-Gasim A.,Li Mo,Fakayode Olugbenga Abiola,Yan Dong,Zhou Cunshan,Chen Li
Abstract The purpose of this study was to efficiently convert the sugary food waste (SFW) to 5-hydroxymethylfurfural (5-HMF) by ultrasound-[Bmim]Cl pretreatment in ionic liquids (ILs)-ion exchange resin system. The effect of ultrasonic pretreatment on SFW and the effect of ultrasonic frequency, ILs, acid resin and catalyst load on SFW conversion were studied. The kinetic curve and the relationship between products and intermediates were studied. In addition, the structure of SFW was also studied by FT-IR and SEM. The results indicated ultrasound-[Bmim]Cl pretreatment can significantly promote the dissolution of cellulose in SFW, and the optimal ultrasonic frequency, solvent and catalyst were 20 + 40 + 60 kHz, [Bmim]Cl and D001-cc resin, respectively; under the best reaction conditions, the maximum 5-HMF yields from the orange and apple wastes were 42.15 and 44.66 mol%, respectively. The kinetic studies showed that the early stage of 100 and 120 °C was mainly the hydrolysis reaction, and late stage was mainly isomerization and dehydration reaction; the early stage of 140 and 160 °C was a rapid hydrolysis and dehydration reaction, and the late stage was mainly the rehydration reaction of 5-HMF. The relationship between the intermediate precursors and 5-HMF showed that the rates of formation and rehydration of 5-HMF increased with the increase in temperature, and the formation reaction was mainly concentrated in zone II. The FT-IR and SEM results of degradation products showed that cellulose in SFW was more easily hydrolyzed at high temperature and long time. Graphic Abstract
研究领域:
化学工程
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环境科学
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催化
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废物管理
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DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2021
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IF 3.498
Biao Wu,Meng Yan,Fen Luo,Xiaoyan Shu,Yi Liu,Guilin Wei,Zhentao Zhang,Yi Xie,Xirui Lu
Spent nuclear fuel contains 129 I, which has deleterious effects on human health. This study focused on the immobilization of iodine waste forms via a novel preparation method with B 2 O 3 –Bi 2 O 3 –ZnO–SiO 2 glass at 500–600 °C. The XRD results manifest that the sample with 30 wt % iodine sintered at 550 °C exhibits an obvious amorphous phase. The density of the samples with different iodine contents increases with the temperature increasing, so does the amorphous fraction except for 25 wt %. The FT-IR results reveal the matrix is mainly composed of [BO 3 ], [BO 4 ], [SiO 4 ], and [BiO 6 ]. TGA analysis shows high water content in the prepared samples. SEM-EDS results present that at 550 °C one part of the iodine is chemically immobilized into the glass matrix, and meanwhile, the other physically packed by the vitrified bulk. Our findings demonstrate the potential of the new preparation method for the disposal of iodine waste forms.
研究领域:
核废料管理
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材料科学
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环境工程
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DOI
高影响因子
AAPS PHARMSCITECH
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2021
·Vol. 22
·期 5
·1-14
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IF 3.246
Luo Zheng,Liu Chao,Quan Peng,Zhang Yimeng,Fang Liang
Chemical penetration enhancers (CPEs) are commonly added into transdermal patches to impart improved skin permeation of drug. However, significant unexplained variability in drug release kinetics in transdermal patches is possible as a result of the addition of CPEs; investigations into the underlying mechanisms are still limited. In the present study, a diverse set of CPEs was employed to draw broad conclusions. Solubility parameters of CPEs and acrylate pressure-sensitive adhesive were calculated by molecular dynamics simulation and Fedors group contribution method to evaluate drug-adhesive miscibility. CPE-adhesive interaction was characterized by FT-IR study, 13 C NMR spectroscopy, and molecular docking simulation. Results showed that release enhancement ratio ( ER R ) of CPEs for zolmitriptan was rank ordered as isopropyl myristate > azone > Plurol Oleique ® CC497 > Span ® 80 > N -methylpyrrolidone > Transcutol ® P. It was found that solubility parameter difference (Δ δ ) between CPE and adhesive was negatively related with ER R . It was proved that hydrogen bonding between CPE and adhesive would increase drug release rate, but only if the CPE showed good miscibility with adhesive. CPE like isopropyl myristate, which had good miscibility with adhesive, could decrease drug-adhesive interaction leading to the release of drug from adhesive.
研究领域:
药剂学
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药学化学
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生物物理学
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材料科学
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DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
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2022
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IF 3.841
Rui Chen,Qiuyue Li,Kai Xu,Zhiwei Zhang,Tianhua Wang,Jinkang Ma,Yan Xi,Lifeng Cao,Bing Teng,Haitao Wu
In this present work, a chalcone derivative 1-(4-Chlorophenyl)-3-(4-ethoxyphenyl)-prop-2-en-1-one is investigated using the density functional theory. PES scan is used to find the most stable conformational structure of the title compound. The geometrical parameters, FT-IR and FT-Raman spectra are performed by the DFT method with B3LYP/6-311+G basis set, which are very comparable with the experimental results. UV-Vis spectrum, frontier molecular orbitals, global reactivity descriptors, molecular electrostatic potential surface, NLO parameters and Mulliken charge in the gas phase, various polar and non-polar solvents are performed to reveal solvents effect. Further, it is found that the electronic properties show a good correlation with the polarity of solvents. Hirshfeld Surface analysis demonstrates H···H contact is dominant in the crystal packing. By means of molecular reactivity descriptors such as natural bond orbital analysis, Fukui function and dual descriptor analysis, the chemical reactivity is theoretically estimated. ELF and LOL are used to access the energy density of electrons. Molecular docking illustrates ECC may be a potential inhibitor for 6R3K protein.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Ruibing Bai,Junfeng Wang,Daoguang Wang,Yanqiang Zhang,Junjie Cui
The high acidity of stripping is one of the major problems that hinder the industrialization of the tributyl phosphate (TBP) + FeCl 3 system for lithium extraction from the salt lake brines with high Mg/Li ratio. In this study, a novel solvent extraction system, trialkylmethylammonium di(2-ethylhexyl)orthophosphinate ([N 1888 ][P 507 ]) + TBP + FeCl 3 , was developed to significantly reduce the difficulty of stripping and simplify the extraction process. The conditions of extraction and stripping were systematically studied in the present work. The results showed that Li + extraction efficiency could reach 61% under the optimal extraction parameters and Li + stripping ratio was 90% with a relative mild conditions of O/A = 10:1, [HCl] aq = 1.5 mol·L –1 . Also, combined with experimental results, FT-IR analysis, and UV analysis, the possible mechanisms of lithium extraction and stripping were put forward. Li + was extracted from the aqueous phase through the formation of [Li·2TBP][FeCl 4 ] adduct, meanwhile [N 1888 ][P 507 ] was just slightly involved in the extraction step. In the stripping procedure, the interaction between [FeCl 4 ] − and [Li·2TBP] + might be destroyed, and new possible complexes, [Li·2TBP] + , and [FeCl 4 ·TBP·P 507 ] 2− /[FeCl 4 ·P 507 ] 2− were formed in the organic phase. Additionally, the extraction efficiency of Li + remained above 70% while the organic phase was reused for six cycles. Compared with the traditional system, the addition of [N 1888 ][P 507 ] resulted in a slight decrease of Li + extraction efficiency (about 5%), the stripping acidity significantly reduced from 6 mol·L –1 HCl to 1.5 mol·L –1 HCl. This new extraction system showed a promising performance in selective extracting and easy stripping in lithium separation from the salt lake brines with high Mg/Li ratio.
研究领域:
化学工程
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材料科学
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环境化学
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无机化学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·
IF 2.7
Qihong Xue,Zhikui Jiang,Chao Wang,Xian Kan,Jiaming Wang,Jiangang Chen
13-Ni/ZrO2, 13-Ni3P/ZrO2, 13-Ni/SiO2, and 13-Ni3P/SiO2 catalysts were used in the hydrogenation of diethyl oxalate (DEO) to ethyl glycolate (Egly) to investigate the modulating effect of phosphorus. XRD, TEM and FT-IR results show that phosphorus act as a divider of Ni metallic particle and shows a segregation effect. The presence of P transformed the linkage of surface metals from the original -Ni-Ni-Ni-Ni- to the P-Ni-P-Ni-P state, and FT-IR shows that the former adsorbed CO in a combination of linear and bridging adsorption mode, whereas the latter predominantly in CO linear adsorption. Bridging adsorption is via dual sites and makes the preliminary hydrogenation products less likely to detach from the catalyst surface thus facilitating deep hydrogenation, while linear adsorption facilitates partial hydrogenation by a rapid detachment of intermediate product like Egly. The various loading Ni3P/SiO2 catalysts show incomplete phosphorylation with increasing nickel loading, giving rise to a state of coexistence of Ni and Ni3P crystalline phases. This may lead to a coexistence of surface -Ni-Ni-Ni-Ni- and P-Ni-P-Ni-P and the corresponding assort of adsorption, e.g. bridging/linear ones, making deep hydrogenation occur partially besides stepwise hydrogenation.
研究领域:
催化
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材料科学
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化学工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Wei Zhou,Wenwei Zhang,Xueqin Ma,Haichen Lai,Xingguang Zhang
Metal-zeolites catalysts are of great importance in selective organic conversions. Zeolites possess features of highly-ordered porous network, adjustable acidic properties (Brønsted/Lewis), spatial nanoconfinement effects, unique shape selectivity and the strong (hydrothermal-) stability. The role of zeolite hydroxyl (z-OH) groups, such as bridging ones in Si-O(H)-Al (B acids) and terminal ones in Al-OH and Si-OH (silanols), in catalysis is an interesting topic, particularly when they are not catalytic active sites, while they affect the catalytic performances. This study comprehensively investigated series of Au/USY catalysts in the selective oxidation of benzyl alcohol to benzaldehyde and clarified the dominating contributions of Al-associated z-OH groups to affecting catalytic conversions and selectivity via altering the Si/Al ratio and reducing z-OH groups by amorphous silica species derived from diethoxydimethylsilane under high-temperature calcination. The catalysts were characterized by XRD, BET, TEM, XPS, UV/Vis, FT-IR and in-situ DRIFT to investigate crystal structures, textural properties, morphologies, size distribution, chemical state of gold, acidity, and adsorptive properties. The experimental results proved that zeolites with a higher amount of z-OH groups tuned by Si/Al ratios or by diethoxydimethylsilane silylation exhibited higher catalytic activity because of the adsorption effect. Finally, a possible mechanism was discussed based on the experimental results and literature.
研究领域:
催化
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材料科学
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化学工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2021
·
IF 4.527
Debao Liu,Baolu Shi,Chenqi Wang,Zeshuai Li,Xianbo Wang,Baosheng Xu,Lijie Qu
Herein, the SiC ceramic aerogels with in-situ growth of SiC nanowires (SiC w /SiC CAs) have been synthesized by polymer‐derived ceramics (PDCs) method. The morphology, microstructure, and phase composition of the as-prepared samples were systematically investigated through SEM, XRD , TEM , Raman spectrum, FT-IR spectrum, and XPS spectrum techniques. The results showed that the as-obtained SiC w has a diameter of about 80 nm and a length of 1–3.5 μm. In addition, the formation mechanism and evolution process of growth SiC w were systematically studied using a VLS growth mechanisms. The way in this work could be expanded to synthesize other Si-based porous ceramic aerogel nanostructed with nanowires.
研究领域:
材料科学
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纳米技术
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陶瓷
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2018
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IF 3.927
Qiang Wu,Mingyan Liu,Xiong Wang
A new type of absorbent was synthesized by grafting N-methyl-D-glucamine (MG) onto the surface of chitosan beads to separate boron element. The physicochemical properties of modified chitosan beads (CTS-MG) were examined by FT-IR and SEM analyses. The results indicated that MG had grafted on chitosan beads (CTS) successfully. Compared to surface of pure CTS, CTS-MG had a rougher surface. While the pH value ranged 3–8, CTS-MG would have a high efficiency of adsorption to boron. The characteristics of the adsorption process were evaluated by Langmuir and Freundlich adsorption isotherms , and the maximum adsorption capacity of CTS-MG was 20.36 mg·g −1 . When mass of absorbent was not lower than 0.1 g, the concentration of 10 ml boron solution would decrease from 50 to 0.5 mg/L. This absorption process fit to the pseudo-second-order kinetic model. CTS-MG had a comparatively high selectivity because general competing ions had little influence on the absorptive ability of CTS-MG. After 5 times adsorption-desorption cycles, absorptive capacity of CTS-MS did not decrease obviously. CTS-MG was hopefully used in the process of boron desorption in salt lake brine.
研究领域:
材料科学
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环境化学
·
水处理
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2017
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IF 3.359
Qihua Shi,Yimin Zhang,Jing Huang,Tao Liu,Hong Liu,Luyao Wang
New extractant and an extractant system are attractive for liquid-liquid extraction. To improve the extraction efficiency and selectivity, the binary extractant system consisting of bis-2-ethylhexyl phosphoric acid (D2EHPA) and 2-ethylhexylphosphonic mono-2-ethylhexyl (PC88A) was explored to separate vanadium (V) via synergism from multi-element sulphuric acid leaching solution in this study. The optimal proportion and concentration of extractant was investigated and results demonstrated that the maximum synergistic co-efficient was 1.52 by adjusting the volume ratio to 14:6 (D2EHPA/PC88A) when the extractant concentration was 20% (v/v). Next, the selectivity of the mixture was investigated at different pH values and contact time, which demonstrated better separation of vanadium from primary impurities compared with extraction by D2EHPA or PC88A alone. Furthermore, the Fourier Transform Infrared (FT-IR) spectra were employed to analyse the mechanism of extraction. The results suggested that the cation exchange (P OH bands) and coordination reaction (P O bands) contribute to vanadium extraction, and the structure of extracted complex was proposed. The formation of a dimer between D2EHPA and PC88A was demonstrated. Finally, after multi-stage counter-current extraction and stripping, V 2 O 5 product with a high purity of 99.07% was obtained by oxidation, precipitation and calcination.
研究领域:
化学工程
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环境科学
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）