ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Chao Liu,Min Wei,Jia Wang,Junming Xu,Jianchun Jiang,Kui Wang
Directional depolymerization is a critical step for the integrated utilization of waste lignocellulosic biomass resources to produce value-added biofuels and biochemicals. Herein, we demonstrate an efficient and environmentally benign liquefied process for converting cellulose and waste lignocellulosic residues into levulinic acid (LA) in a polar aprotic solvent using a low-cost sulfate as catalyst. Due to the synergistic effect between the γ-valerolactone (GVL) and an active acid center derived from sulfate, more than 77 mol % and 61 mol % of biochemicals were obtained from cellulose and bamboo meal wastes in GVL/H2O (m/m = 9:1) solvent at 200 °C for 2 h, respectively. A combination of 27Al NMR spectroscopy and electrospray quadrupole time-of-flight tandem mass spectrometry (ESI-Q-TOF-MS/MS) revealed that the [Al(OH)2(aq)]+ species significantly contributed to cellulose depolymerization under cationic polarization of polar aprotic solvents. Besides, the existence of an appropriate amount of water was believed to be responsible for promoting the destruction of cellulose and the restraint of humin formation. Notably, all solvents and byproducts could be efficiently retrieved during this process, which shed light on its considerable industrial application prospects and facilitated the high value-added utilization of waste biomass resources.
研究领域:
生物质化学
·
可再生资源工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Yitong Wang,Huazong Liu,Yan Chu,Jiyu Yang,Ganlu Li,Kequan Chen,Hui Li
Protein aggregates are extremely useful in fields such as bioseparation, biocatalysis, and bioadhesives. The development and use of protein aggregates, however, are in their infancy. In this study, emerging protein aggregates were developed through protein self-assembly using polar aprotic solvents coupled with halides. The polar aprotic solvent molecules, including dimethyl sulfoxide (DMSO), were inserted into the hydration shell of proteins such as ovalbumin (OVA), bovine serum albumin, and whey protein to partially exchange water molecules via van der Waals and electrostatic interactions to alter the surface polarity of the protein. Then, the halide ions were allowed to bind to proteins via electrostatic interactions and cause the self-assembly of proteins into aggregates. Under optimal conditions, the yield of OVA-DMSO protein aggregates reached 91.2 ± 1.52 %. OVA-DMSO-EDC/NHS-CA showed excellent enzymatic properties, and the production of calcium carbonate reached 7.1 ± 0.4 mg at 37 °C for 10 min. Additionally, other enzymes, such as L-TA, had high activity after being fixed with OVA-DMSO. These innovative protein aggregates are highly valuable for developing biomaterials.
研究领域:
生物化学
·
生物材料科学
·
酶工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2022
·
IF 4.432
Caihong Zhang,Weijie Wang,Pengfei Zhang,Shuguang Yang
Rigorous thermodynamic analysis of polymer complexation is challenging due to the possible kinetically frozen state, complicated chain conformation, and slow chain relaxation. In this work, we study the complexation of poly(acrylic acid) (PAA) with poly(vinylpyrrolidone) (PVPON), poly(2-ethyl-2-oxazoline) (PEOX) and poly(ethylene oxide) (PEO) in acidic water and in organic solvents , including protic solvents (methanol (MeOH), ethanol (EtOH)), and aprotic solvents ( N, N -dimethylformamide (DMF), N, N -dimethylacetamide (DMAC), 1-methyl-2-pyrrolidone (NMP), and dimethyl sulfoxide (DMSO)) with isothermal titration calorimetry (ITC). In DMF, complexation of PAA and PVPON has moderate heat releasing and the effect of kinetically frozen structure is negligible, and the ITC data meet the basic standard to be used for analyzing and estimating thermodynamic parameters, and enthalpy, entropy and Gibbs free energy are calculated to be −1.5 kJ/mol, 45 J/(mol⋅K), and −15 kJ/mol respectively. Furthermore, the effects of temperature, chain length contrast, and concentration on the complexation of PAA with PVPON in DMF are studied. The work provides a theoretical method how to evaluate the ITC dada of hydrogen-bonding polymer complexation for thermodynamic analysis and strengthens the understanding of polymer complex.
研究领域:
高分子化学
·
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
Bioresources and Bioprocessing
·
2023
·Vol. 10
·期 1
·1-12
·
IF 4.6
Dai Mohan,Xu Binpeng,Guo Qing,Wan Junfen,Cao Xuejun
Ursodeoxycholic acid (UDCA) is not only safer than chenodeoxycholic acid in the treatment of hepatobiliary diseases, but also has a wide range of applications in Acute Kidney Injury and Parkinson’s Disease. The purpose of this experiment is to improve the conversion rate of 7-ketocholic acid (7K-LCA) and the yield of ursodeoxycholic acid in aprotic solvents during electrochemical reduction process. Three aprotic solvents were investigated as electrolytes. 1,3-Dimethyl-2-imidazolidinone (DMI) has a stable five-membered ring structure, and 7K-LCA has undergone two nucleophilic reactions and “Walden” inversion, the 7K-LCK was stereoselectively reduced to UDCA. Hexamethylphosphoramide (HMPA) and 1,3-methyl-3,4,5,6-Tetrahydro-2(1 H )-pyrimidinone (DMPU) can be attacked by chloride ions to produce by-products. Molecular orbital theory-based simulations were conducted to study the reducibility of three aprotic solvents [hexamethylphosphoramide (HMPA), 1,3-methyl-3,4,5,6-Tetrahydro-2(1 H )-pyrimidinone (DMPU), and 1,3-Dimethyl-2-imidazolidinone (DMI)] in combination with experiments. Choose the best solvent based on the simulation results, the electrolysis reaction can be carried out by applying current and voltage when lithium chloride is used as electrolytes. Calculations using Materials Studio showed that Cu, Pb, Hg–Cu, and Ni exhibited the highest binding energies to the substrate in this system. Using Cu as the electrode when the solvent is a 1:1 mix of DMI and HMPA, the conversion rate of 7-ketocholic acid (could reach 98%, the yield of ursodeoxycholic acid was up to 80%. Under the same conditions, linear voltammetry was performed on the electrochemical workstation to study the electrolysis behavior, and the obtained results were consistent with the experiment. Graphical Abstract
研究领域:
药理学
·
有机化学
·
生物化学
✓ 已验证
DOI
高影响因子
Nano-Micro Letters
·
2024
·Vol. 16
·期 1
·1-12
·
IF 31.6
Wu Shuilin,Yang Yibing,Sun Mingzi,Zhang Tian,Huang Shaozhuan,Zhang Daohong,Huang Bolong,Wang Pengfei,Zhang Wenjun
A novel aqueous/aprotic electrolyte with low salt concentration (i.e., 0.5 m Zn(CF 3 SO 3 ) 2 +1 m LiTFSI) demonstrated an expanded electrochemical window, which can simultaneously stabilize Zn metal anode and increase the operation voltage of Zn-ion hybrid supercapacitors.
The coordination shell of the electrolyte induced by acetonitrile and LiTFSI can not only suppress the Zn corrosion and hydrogen evolution reaction but also promote the cathodic stability and ion migration, which is depicted by the density functional theory simulations together with experimental characterizations.
The Zn-ion hybrid supercapacitor based on the developed electrolyte can operate within 0–2.2 V in a wide temperature range with an ultra-long lifespan (> 120,000 cycles).
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
Nanoscale Advances
·
2020
·Vol. 2
·期 7
·2943-2949
·
IF 0
Li Gao,Datong Wu,Wensheng Tan,Fei Pan,Jiale Xu,Yongxin Tao,Yong Kong
In this study, a facile synthesis of two ionized carbon dots (CDs-2 and CDs-3) is reported, in which different ionic pairs are formed at the surface of the carbon core. In contrast to CDs-3, the accumulation of carbon core can be clearly observed in the TEM image of CDs-2. This is due to the linkage of the dibromine alkyl group. Compared with naked CDs in the absence of the ionic pair, the maximum emission wavelength undergoes a red-shift of nearly 60 nm. Moreover, protic solvents (water, ethanol and N,N′-dimethyl formamide) have an apparent effect on the emission intensities of CDs-2 and CDs-3. The time-resolved average lifetimes of CDs-2 and CDs-3 are calculated as 56.34 ns and 54.50 ns, respectively. Furthermore, they both have much better fluorescence stability in the solution with pH ranging from 2 to 11 due to the presence of the imidazolium cation. It is interesting to see that CDs-2 and CDs-3 have much different responses towards Cu2+ and Fe2+. The CDs-3 solution generates clear fluorescence quenching when treated with Fe2+. In brief, we believe that these findings can inspire more research developments in the synthesis and further application of functional CDs.
研究领域:
材料科学
·
分析化学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Yake Luo,Shanshan Ma,Bo Sui,Luyang Zhang,Ajuan Yu,Jiaheng Zhang,Yanhao Zhang,Wuduo Zhao,Gangfeng Ouyang
Perfluorooctanoic acid (PFOA) has aroused global attention due to its persistence, biotoxicity and bioaccumulative properties. Monitoring PFOA levels in biological samples could give significant insights into its toxicity mechanism and health risk evaluation. Herein, to explore the distribution of PFOA in biological tissues, an indirect quantitation strategy for PFOA in biological samples was proposed based on fluorescence spectroscopy. F - ion was produced through highly efficient degradation of PFOA in polar aprotic solvent, and then F - ion was detected with highly selective F - ion fluorescent probe, which enabled the indirect quantitative detection of PFOA in biological samples. The sensitivity for PFOA was exhibited with limit of detection of 3.55 μM. The method’s accuracy and precision were validated by spiked biological sample experiment, with recovery rate ranging from 93.2 % to 105.5 % and relative standard deviation below 9.2 %. The content of PFOA was successfully detected in rats livers, kidneys and lungs tissues. Density function theory was employed to explore defluorination pathway, indicating that heating, alkaline and water conditions played a crucial role in the degradation of PFOA to produce F - ion. Thus, this novel strategy is suitable for quantitative analysis of PFOA in biological samples with high selectivity, sensitivity, recovery ratio, and simple sample preparation, which also provides a strategy for evaluating the levels of per- and polyfluoroalkyl substances in biological samples.
研究领域:
分析化学
·
环境科学
·
毒理学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
CHROMATOGRAPHIA
·
2019
·Vol. 82
·期 10
·1523-1529
·
IF 1.552
Zhang Wei,Fang Sheng,Liang Xianrui
A relatively new application of natural deep eutectic solvents (NADESs) as eco-friendly dilution mediums in static headspace gas chromatography (SHS-GC) was further studied. The partition coefficients of twelve organic solvents in NADESs were determined by SHS-GC. Eight NADESs were prepared with choline chloride and carboxylic acids, polyols and urea in different molar ratios. The twelve organic solvents included four haloalkanes, four aprotic solvents, two alcohols, and two alkanes. The partition coefficients ( K ) of each solvent in different NADESs were determined and discussed. The log K values of alkanes and aprotic solvents in NADESs were low, while the log K of haloalkanes and alcohols was high. That is, alkanes and aprotic solvents in NADESs had better headspace efficiency, indicating that the interaction between the solvents and the NADESs played an important role. The relationship between the log K and the properties of NADESs and organic solvents was further discussed. As an example, the method was applied to determine the residual solvents in paroxetine by SHS-GC with appropriate NADES. This study is beneficial for the selection of suitable NADESs as green mediums for the detection of residual solvents in pharmaceuticals.
研究领域:
分析化学
·
药学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Cheng Yang,Maoshuai Li,Weikang Dai,Jie Wei,Qi Yang,Yi Feng,Wanxin Yang,Jie Ding,Ying Zheng,Mei-Yan Wang,Xinbin Ma
The homogeneous catalytic hydroformylation of formaldehyde to glycolaldehyde is a key intermediate step for one-step synthesis of ethylene glycol from syngas. The effect of solvent nature on the catalytic response and mechanistic pathway has been rarely studied. A group of parameters (e.g., ε r , μ, α, β) describing the solvent electronic features were achieved for a descriptor database and correlated with the hydroformylation activity. The net electron donating ability has been found to govern the selectivity to glycolaldehyde. The DFT calculation demonstrates the stronger electron-donating solvents serve to lower the energy required for the dissociation of Rh-H to form the anionic rhodium species, which induces the anion mechanism that preferentially facilitates the glycolaldehyde generation. The polar aprotic solvents can be protonated in the dissociation of Rh-H to the anionic species and participate in the HCHO activation through the proton transfer from solvent molecules to HCHO, resulting in the formation of hydroxymethyl species.
研究领域:
催化
·
化学工程
·
物理化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Feng Li,Ru Meng,Wenjuan Wang,Wei Wang,Baokang Jin
The electrochemical degradation of p-nitrochlorobenzene in aprotic media containing CO2 is reported. Little is known about the effects of electron-donating groups on electrochemical degradation of aromatic nitro compounds. Accordingly, electrochemical behavior of nitrobenzene (NB), para-nitrotoluene (PNT), and para-nitroanisole (PNA), in an aprotic solvent containing CO2, was investigated by cyclic voltammetry (CV), in situ Fourier transform infrared (FT-IR) spectroscopy, and potenstiostatic electrolysis. It was established that their electrochemical reduction was an irreversible four-electron transfer process. Based on cyclic voltabsorptometry (CVA), derivative cyclic voltabsorptometry (DCVA), and chronoamperometry (CA), a mechanism of electroreduction of aromatic nitro compounds in the presence of CO2 was proposed. The products of potenstiostatic electrolysis, in the presence of CO2, were characterized by X-ray single-crystal diffraction, 13C NMR, and 1H NMR. NB and PNT gave only the corresponding azo compound with a 99% conversion rate. However, the conversion rate of PNA was lower (78%) due to the effect of the strong electron-donating methoxy group. The intermediate reduction product 4,4′-dimethoxyazoxybenzene was formed along 4,4′-dimethoxyazobenzene. In the process, CO2 was converted to CO32–. This constitutes a new way of carbon sequestration.
研究领域:
电化学
·
环境科学
·
分析化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2014
·Vol. 49
·期 14
·5141-5150
·
IF 2.305
Zhuo Longhai,Kou Kaichang,Wang Yiqun,Yao Pan,Wu Guanglei
We report the design and synthesis of a novel pyridine-containing triamine monomer, 2,6-bis(4-aminophenyl)-4-(4-aminophenoxy)pyridine (BAAP), through combining the nucleophilic aromatic substitution with modified Chichibabin reaction and hydrazine hydrate reduction. Based on it, a novel three-step route was applied in order to obtain a series of new polyimides, containing phthalimide as pendent group and pyridine moieties in main chains. The three-step route consisted of terminating the triamine by incorporating phthalic amic acid as pendant, ring-opening polymerization to form poly(amic acid)s and further chemical imidization to acquire polyimides. Nuclear Magnetic Resonance Spectroscopy ( 1 H-NMR) was used for chemical structural characterization, and the results indicated the various forms of BAAP and branched structure units in the obtained polyimides. The morphology structures of the polyimides were evaluated by X-ray diffraction patterns, and the d -spacing values were found in the range of 4.14–4.65 Ǻ. Most of the resulting polyimides were soluble in polar aprotic solvents, such as NMP, DMF, DMAc, DMSO, and so on. Meanwhile, the polyimides exhibited excellent thermal stability, with the decomposition temperature at 5 and 10 % weight loss temperatures in the ranges of 399.1–461.1 °C and 481.1–566.9 °C, respectively. The polyimides, based on 6FDA, possessed the best comprehensive thermally stable and soluble performance.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）