PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2024
·
IF 5.3
Qilong Fang,Jun Fang,Yi Zhang,Jianguo Zhang,Tianyou Lian,Wei Li,Yuyang Li
Oxymethylene ethers (OMEs) have received great attention due to their carbon-neutral nature and advantageous properties as alternative transportation fuels or fuel additives. Previous studies focused on the combustion of linear OMEs with the chemical formula of CH 3 O(CH 2 O) m CH 3 ( m ≥ 0), while a deep understanding of the combustion of branched OMEs with the chemical formula of CH 3 OCH 3- n (OCH 3 ) n (0 ≤ n ≤ 3) is still absent. In this work, the flow reactor pyrolysis of dimethoxymethane (DMM, n = 1), trimethoxymethane (TMM, n = 2), and tetramethoxymethane (TeMM, n = 3) is investigated using gas chromatography, with special attention given to the multi-sidechain effects on the pyrolysis chemistry. A pyrolysis model of branched OMEs is developed and validated against the new pyrolysis data. Modeling analysis is performed to provide insights into the pyrolysis chemistry of the three branched OMEs and the multi-sidechain effects. Unimolecular decomposition and H-abstraction reactions are found to be two major types of fuel decomposition pathways, with the former dominating TMM decomposition, the latter dominating DMM decomposition, and both contributing almost equally to TeMM decomposition. Sensitivity analysis shows that C O bond dissociation is the most sensitive reaction to fuel decomposition in DMM pyrolysis, while methanol elimination is the most sensitive reaction in TMM and TeMM pyrolysis. Among the three fuels, DMM has the lowest pyrolysis reactivity and produces the least abundant methanol. In contrast, TMM is observed with the highest pyrolysis reactivity and produces the most abundant methanol. Theoretical calculations reveal that TMM and DMM have the lowest and highest energy barriers of methanol elimination reactions, which determines the order of their pyrolysis reactivities and methanol formation trends. As a result, DMM pyrolysis occurs at higher temperature regions where the C O bond dissociation and H-abstraction reactions are preferred, while TMM pyrolysis occurs at lower temperature region where methanol elimination dominates.
研究领域:
能源科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2022
·Vol. 12
·期 10
·1278
·
IF 4.501
Ying Wang,Huilin Xie,Kunming Liu,Jinhui Li,Jin-Biao Liu
Herein, we report a copper-catalyzed C-O cross-coupling of N-methoxy amides and arylboronic acids for the synthesis of aryl-N-methoxy arylimides. The fully selective O-arylation of the N-methoxy amides is found to be greatly prompted by the inexpensive and commercially available CuI. The reaction conditions tolerate a variety of functional groups and promote different reactivities depending on the electronic and steric properties of the distorted substrates.Keywords:copper catalyzed;N-methoxy amides;selective C-O cross-coupling;aryl-N-methoxy arylimides
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2022
·
IF 3.682
Heyi Mao,Yidan Zhang,Lei Wang,Anduo Zhou,Shanfeng Zhang,Jing Cao,Huang Xia
The mortality rate of cardiovascular diseases is the highest among all mortality rates worldwide. Allotransplantation and autotransplantation are limited by rejection reaction and availability. Tissue engineering provides new avenues for the treatment of cardiovascular diseases. However, the current small-diameter (<6 mm) vascular tissue-engineered scaffolds have many challenges, including thrombosis, stenosis, and infection. Small-diameter vascular scaffolds have structural and compositional requirements such as biocompatibility, porosity, and appropriate phase separation. We used liquid-crystal cyclopeptide（CYC）to modify β-cyclodextrin and mixed it with γ-glycerol methoxytrimethoxysilane (GPTMS) to prepare CYC-β-cyclodextrin (βCD)/GPTMS film by sol-gel. The chemical structure of CYC-βCD was confirmed by Fourier transform infrared spectroscopy and 1H-nuclear magnetic resonance. The chemical characterization of CYC-βCD/GPTMS film was performed by differential scanning calorimetry, X-ray diffraction, and small-angle X-ray scattering. The surface morphology and phase separation microstructure of the film were determined by scanning electron microscopy and atomic force microscopy, and the image of polarizing microscopy showed the liquid-crystal structure of the film. Cell culture experiments showed that CYC-βCD/GPTMS film had good cytocompatibility and induced growth and proliferation of cells. These results indicated the potential applications of CYC-βCD/GPTMS film in tissue engineering scaffolds.
研究领域:
生物材料学
·
心血管医学
·
组织工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2020
·Vol. 34
·期 11
·e5925
·
IF 3.14
Jie Yao,Yan Wang,Suleiman Sabo Bello,Guangwen Xu,Lei Shi
As it is well known, Brønsted acid sites in 8-MR of H-MOR (mordenite) are selective for dimethyl ether (DME) carbonylation to methyl acetate, whereas those in 12-MR are more prone to methanol to olefin reaction. Interestingly, we observed that the Brønsted acid sites in 12-MR of H-MOR are highly active for dimethoxymethane (DMM) carbonylation to methyl methoxyacetate (MMAc), whereas those in 8-MR led to the formation of DME. A series of modified H-MOR catalysts with accurate regulation of Brønsted acid sites in 12-MR or 8-MR were successfully synthesized by selective Na + exchange or pyridine (Py) adsorption. Fourier-transform infrared (FT-IR) spectra, NH 3 -temperature-programmed desorption, Py-FT-IR, and inductively coupled plasma analyses suggested that Na + first occupied Brønsted acid sites in 8-MR and then replaced those in 12-MR. All Na + -exchanged catalysts exhibited significant acceleration on MMAc selectivity, and the ratio of Brønsted acid amount in 12-MR/total had a positive correlation with MMAc selectivity. The MMAc selectivity (78%) of H-MOR-0.15Na was nearly 2.5 times more than that of untreated H-MOR (31%). However, H-MOR-Py showed almost no carbonylation activity (<1% MMAc) and a highest DME selectivity (98%), indicating that Brønsted acid sites in 12-MR were the only active sites for DMM carbonylation, whereas those in 8-MR tended to accelerate DMM disproportionation to DME.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2025
·
IF 3.1
Xinran Cui,Yongbin Wang,Yan Zhan,Xiaoyan Chen
Dimethoxyethyl phthalate (DMEP) is an industrial phthalates reagent exposed to human body. Its hydrolytic metabolite ethylene glycol methyl ether (EGME) and further oxidative metabolite methoxyacetic acid (MAA) have reproductive and developmental toxicity, and the latter is more toxic than the former. However, due to the lack of sensitive and reliable analytical method, the in vivo clearance and biotransformation of EGME and MAA is poorly understood. In order to evaluate their toxicokinetic profiles, a precolumn derivatization liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of EGME and MAA in rat plasma. After a simple protein precipitation procedure, the sample was derivatized with p -toluene sulfonyl isocyanate (PTSI) and 4-bromo- N -methylbenzylamine (4-BNMA), separated by gradient elution on HSS T3 column, and detected by electrospray ionization (ESI) source in positive multiple reaction monitoring (MRM) mode. The results of the method validation showed that EGME had good linearity in the range of 2.00–400 ng/mL and MAA in the range of 5.00–1000 ng/mL. The intra- and inter-day accuracy and precision were within acceptable limits ( ± 15 %) at all concentrations. This validated method was successfully applied to characterize the toxicokinetics of EGME and MAA in rats following a gavage administration of 50 mg/kg DMEP.
研究领域:
分析化学
·
毒理学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 3
·467
·
IF 5.3
Bingjie Ma,Yingying Cheng,Peiying Hu,Dan Fang,Jin Wang
Silica aerogels are one of the most widely used aerogels, exhibiting excellent thermal insulation performance and ultralow density. However, owing to their plenitude of Si-O-Si bonds, they possess high infrared emissivity in the range of 8–13 µm and are potentially robust passive radiative cooling (PRC) materials. In this study, the PRC behavior of traditional silica aerogels prepared from methyltrimethoxysilane (MTMS) and dimethyldimethoxysilane (DMDMS) in outdoor environments was investigated. The silica aerogels possessed low thermal conductivity of 0.035 W/m·K and showed excellent thermal insulation performance in room environments. However, sub-ambient cooling of 12 °C was observed on a clear night and sub-ambient cooling of up to 7.5 °C was achieved in the daytime, which indicated that in these cases the silica aerogel became a robust cooling material rather than a thermal insulator owing to its high IR emissivity of 0.932 and high solar reflectance of 0.924. In summary, this study shows the PRC performance of silica aerogels, and the findings guide the utilization of silica aerogels by considering their application environments for achieving optimal thermal management behavior.Keywords:silica aerogel;methyltrimethoxysilane;dimethyldimethoxysilane;thermal insulation;radiative cooling;thermal management
研究领域:
材料科学
·
热能工程
·
能源材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 19
·10948-10957
·
IF 3.049
Lukai Wang,Junzong Feng,Yonggang Jiang,Liangjun Li,Jian Feng
Native silica aerogels are fragile and brittle, which prevents their wider utility. For designing more durable and stronger silica aerogels, polyvinylmethyldimethoxysilane (PVMDMS) polymers as effective and multifunctional reinforcing agents were used to strengthen methyltrimethoxysilane based silica aerogels (MSAs). The PVMDMS polymer, which was composed of long-chain aliphatic hydrocarbons and organic side-chain methyl and alkoxysilane groups, was integrated into silica networks via a simple sol–gel process. Compared with MSAs, PVMDMS reinforced MSAs (PRMSAs) display many fascinating characteristics. PRMSAs exhibit improved hydrophobic properties (water contact angle of 136.9°) due to abundant methyl groups in the silica networks. Benefiting from the fine integration of PVMDMS polymers into MSAs, PRMSAs show a perfectly elastic recovery property, the compressive strength of which ranges from 0.19 to 1.98 MPa. More importantly, PVMDMS polymers have successfully suppressed the growth of secondary particles. Homogeneous silica networks formed by nanoscale particles give PRMSAs a high surface area of 1039 m2 g−1. Moreover, optimized PRMSAs also exhibit a low thermal conductivity of 0.0228 W m−1 K−1 under ambient conditions, and their thermal stability reaches up to 222.3 °C in air. All the results obtained from this paper will help us to design silica aerogels.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2023
·Vol. 136
·期 2
·771-786
·
IF 1.8
Su Haitang,Yang Zhixiu,Xiao Guomin,Gao Lijing,Wei Ruiping,Zhang Jin
A series of cost-effective (X) K 2 CO 3 /γAl 2 O 3 catalysts for efficient conversion of vinyltrimethoxysilane (VTMOS) to vinyltris(β-methoxyethoxy)silane (VTMOEOS) were synthesized. The microstructure and active site of the synthesized catalysts were analyzed by BET, XRD, FT-IR, SEM, and CO 2 -TPD. The results showed that the synthesized catalysts formed K–O–Al strong basic sites while maintaining the original structure, which greatly improved the basic strength of the catalysts. It was found that the 60%K 2 CO 3 /γAl 2 O 3 possessed the highest the catalytic activity under the activation temperature of 600 °C by optimizing the preparation conditions of K 2 CO 3 /γAl 2 O 3 . Moreover, the optimal reaction process conditions were also determined by optimizing the experimental reaction temperature, reaction time, catalyst dosage, and reactant molar ratio under (60%, 600 °C) K 2 CO 3 /γAl 2 O 3 catalysis. Under the optimal reaction conditions, the conversion of VTMOS was 92.5% and the yield of VTMOEOS was 65%. Meanwhile, the 60%K 2 CO 3 /γAl 2 O 3 catalyst was satisfactorily reusable and maintained a high catalytic activity after four cycles of catalytic reactions.
研究领域:
材料化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Jing-Jing Luo,Ming-Shuai Sun,Boyuan Tang,Yan Zhou,Wen-Ting Chen,Wen-Qiang Gong,Song Han,Fei-Feng Mao,Zhang-Min Li,Duan-Jian Tao
Solvent-controlled hydrogenation of vanillin to 4-hydroxymethyl-2-methoxyphenol (HMP) or 2-methoxy-4-methylphenol (MMP) is an attractive topic in the field of bio-oil utilization. Herein, a nickel-based catalyst supported on a N-doped carbon material (Ni-N-C) was prepared by facile ball milling mixing and subsequent high-temperature calcination. The as-prepared Ni-N-C800 catalyst showed more than 99% MMP yield and good stability using pure H2O as a solvent under the given conditions. By using the mixed solvent H2O/ethyl acetate with a volume ratio of 1:5, the hydrogenation was conveniently tuned to produce the intermediate product HMP. Density functional theory (DFT) calculations further showed that the intermolecular forces of HMP interacting with ethyl acetate were much stronger than those interacting with H2O. Ethyl acetate could raise the energy barrier to keep vanillin hydrogenation in the intermediate HMP stage, and H2O reduced the energy barrier to accelerate the final product MMP formation.
研究领域:
催化化学
·
可再生资源利用
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 34
·e202403054
·
IF 1.9
Yifei Wang,Ze Wang,Pengfei Qin,Songgeng Li
Graphical Reactivities of 2-methylphenol, 2-methoxyphenol, 4-methylphenol and 4-methoxyphenol with formaldehyde, and the thermal stabilities of the resoles are investigated. The reactivity of ortho phenol is found higher than that of para phenol. The resole of para phenol has a higher thermal stability than that of ortho phenol. The resole of methylphenol generally has a higher thermal stability than that of methoxyphenol. Bio-oil formaldehyde resole (BFR) can be used as adhesive in plywood industry. However, the BFR has a lower thermal stability, and the reason is still unclear. Herein, the reactivities of four representative phenolic compounds in bio-oil, including two ortho phenols (2-methylphenol, 2-methoxyphenol) and two para phenols (4-methylphenol and 4-methoxyphenol), as well as the thermal stabilities of the prepared resoles are investigated. The results show that the reactivity of an ortho phenol is higher than that of a para phenol. The resole prepared from a para phenol has a higher thermal stability than that of an ortho phenol. The resole of an ortho phenol decomposes even when heated at the low temperature of 100 °C. The resole of a methylphenol generally has a higher thermal stability than that of a methoxyphenol. Based on the results, the reason for the low reactivity of bio-oil and the low thermal stability of BFR are speculated.
研究领域:
化学
·
材料科学
·
生物能源
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2023
·Vol. 24
·期 7
·6172
·
IF 5.6
Tianxiao Sun,Haihua Li,Yan Zhang,Guixin Xiong,Yuerun Liang,Fang Lu,Rong Zheng,Qi Zou,Jiejie Hao
Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease characterized by lung inflammation and excessive deposition of extracellular matrix components. Transforming growth factor-β1 (TGF-β1) induced epithelial–mesenchymal transformation of type 2 lung epithelial cells leads to excessive extracellular matrix deposition, which plays an important role in fibrosis. Our objective was to evaluate the effects of 3-cyclopropylmethoxy-4-(difluoromethoxy) benzoic acid (DGM) on pulmonary fibrosis and aimed to determine whether EMT plays a key role in the pathogenesis of pulmonary fibrosis and whether EMT can be used as a therapeutic target for DGM therapy to reduce IPF. Firstly, stimulation of in vitro cultured A549 cells to construct EMTs with TGF-β1. DGM treatment inhibited the expression of proteins such as α-SMA, vimentin, and collagen Ⅰ and increased the expression of E-cadherin. Accordingly, Smad2/3 phosphorylation levels were significantly reduced by DGM treatment. Secondly, models of tracheal instillation of bleomycin and DGM were used to treat rats to demonstrate their therapeutic effects, such as improving lung function, reducing lung inflammation and fibrosis, reducing collagen deposition, and reducing the expression of E-cadherin. In conclusion, DGM attenuates TGF-β1-induced EMT in A549 cells and bleomycin-induced pulmonary fibrosis in rats.Keywords:IPF;A549;EMT;TGF-β1/Smad;ECM
研究领域:
药理学
·
呼吸医学
·
细胞生物学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Gaoyin He,Liping Wang,Midong Shi,Qingsong Li,Yunfang Wang
This work reveals experimental liquid–liquid equilibria (LLE) for ternary systems of (2-methoxyethanol + water + solvents) with methyl tert-butyl ether, ethyl acetate, and trichloromethane at 313.15 K and dichloromethane as solvent at 298.15 K under 101 kPa. The extraction capacity of the aforementioned solvents has been tested when it comes to the distribution ratio and separation factor according to the experimental data. The calculation results demonstrate that trichloromethane is an available solvent for extraction applications. Simultaneously, the reliability of the experimental LLE data was checked by Othmer–Tobias and Hand correlations, and all of the linear correlation coefficients were greater than 0.98. The experimental LLE values were regressed to obtain binary interaction parameters with both NRTL and UNIQUAC activity coefficient models. Both models shows satisfactory agreement with all of the root-mean square deviation values below 0.50.
研究领域:
化学工程
·
热力学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）