CHEMICAL ENGINEERING SCIENCE
·
2019
·
IF 3.372
Tengda Wang,Jianxing Shan,Li Wang,Xiangwen Zhang,Guozhu Li
Aqueous-phase hydrogenation of 4-nitrophenol (4-NIP) by H 2 has been investigated in the presence of Pd nanoparticles (NPs) regulated by small biological molecules. Nucleosides and their derivatives were employed as capping agents of Pd NPs, and their effect on Pd activity was evaluated. All four kinds of nucleosides exhibited obvious promoting effect on the activity of Pd NPs in comparison to that without any capping agent. The general promoting effect sequence of nucleosides and their derivatives on the activity of Pd NPs was nucleoside ≥ nucleotide > deoxynucleoside > base > deoxynucleotide. The quantitative correlation between the activity promoting effect and the structure of nucleosides and their derivatives were also studied using the method based on poly-parameter linear free energy relationships. Moreover, the kinetic behaviors of 4-NIP hydrogenation over Pd NPs regulated by different nucleosides (adenosine, guanosine, cytidine, and β-thymidine) were studied systematically and different kinetic models were developed to fit the data. The obtained kinetic data fitted well to the Langmuir-Hinshelwood (L-H) model, where the surface reaction is the rate-controlling step. The apparent activation energy, adsorption enthalpy of 4-NIP, and dissociated adsorption enthalpy of hydrogen were calculated and compared for a better understanding of the mechanism. Pd NPs regulated by cytidine showed the lowest apparent activation energy of 43.66 kJ mol −1 .
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 29
·11636-11642
·
IF 3.069
Dongshun Deng,Xiuzhi Duan,Bao Gao,Chao Zhang,Xiaoxia Deng,Lei Gong
The hydrogen bond donor (HBD) glycerol (Gly) and hydrogen bond acceptors (HBA) selected among 1,2,4-triazole (Tri), imidazole (Im), tetrazole (Tz), 1-methyl-triazole (Tri-Me), 3-mercapto-1,2,4-triazole (Tri-SH), 3-amino-1,2,4-triazole (Tri-NH2), 3-cyano-1,2,4-triazole (Tri-CN), and 4-formalimidazole (Im-CHO) were paired to construct functional deep eutectic solvents (DESs) that were then utilized as ammonia (NH3) absorbents. The influences of the HBA in DESs, temperature, and partial pressure of NH3 on the NH3 absorption performance were systematically investigated. The results illustrated that all the DESs exhibited efficient and reversible absorption for NH3, and Tri–Gly possessed higher absorption capacity than Im–Gly, with the maximum absorption capacity of 0.115 gram NH3 per gram DES of Tri–Gly (1 : 3) at 313.15 K and 1.0 bar. The NH3-saturated DES could be easily recycled five times with a persistent absorption performance. The absorption mechanism was further deduced by the NMR and FTIR spectroscopy. These DESs acted as potential absorbents for NH3 due to their good absorption performance and reversibility.
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2019
·
IF 2.251
Pengbo Zhang,Sayyed Asim Ali Shah,Feng Gao,Hao Sun,Zhichao Cui,Jue Cheng,Junying Zhang
As a representative single component epoxy resin, diglycidyl ether of bisphenol A resin (DGEBA) is the most widely used matrix in adhesives. However, challenges are still remained including high curing temperature and short shelf life. Herein, bisphenol A (BPA), Tetrachlorobisphenol A (TCBPA), and Tetrabromobisphenol A (TBBPA) as latent curing agents and imidazole as accelerator were used in adhesives. Curing kinetics was studied by non-isothermal DSC, using a model-fitting Málek approach and a model-free advanced isoconversional method of Vyazovkin. Results indicated that curing temperature of EP-BPA, EP-TCBPA, and EP-TBBPA was reduced to 126 ℃, 94 ℃, and 106 ℃, respectively. Storage stability evaluated by DSC indicated the shelf life was up to five months. After curing, molecular weights of the as-prepared linear polymers (EP-BPA, EP-TCBPA, and EP-TBBPA) were 33,822 g/mol, 14,913 g/mol, and 18,846 g/mol, and their tensile strength and shear strength were more than 40.06 MPa and 13.64 MPa, respectively.
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2019
·Vol. 9
·期 1
·1-12
·
IF 4.011
Ren Li,Wang Mengjie,Lu Shaorong,Pan Lulu,Xiong Zhongqiang,Zhang Zuocai,Peng Qingyuan,Li Yuqi,Yu Jinhong
As a two-dimensional material, graphene has attracted increasing attention as heat dissipation material owing to its excellent thermal transport property. In this work, we fabricated sisal nanocrystalline cellulose/functionalized graphene papers (NPGs) with high thermal conductivity by vacuum-assisted self-assembly method. The papers exhibit in-plane thermal conductivity as high as 21.05 W m −1 K −1 with a thermal conductivity enhancement of 403% from the pure cellulose paper. The good thermal transport properties of NPGs are attributed to the strong hydrogen-bonding interaction between nanocrystalline cellulose and functionalized graphene and the well alignment structure of NPGs.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2019
·
IF 9.518
Qiuxi Wei,Chen Wang,Xue Zhou,Tsunghsueh Wu,Yanying Wang,Chunya Li,Nianjun Yang
Metal-organic framework nanocrystal (Zn-MOF) was synthesized by using 3,3'-{(propane-1,3-diyl)bis[1-(4-carboxybenzyl)-1H-imidazol-3-ium]} hexafluorophosphate ionic liquid as the functional monomer and Zn 2+ as the central metal ion under hydrothermal conditions. Spatially confined gold nanoparticles (Au-NP) were prepared by in-situ reduction of chloroauric acid in the nanopores of Zn-MOF using acetic acid as the reducing agent to fabricate [email protected] nanocomposites . [email protected] was further functionalized with 1H-imidazolium-1,3-bis(2-aminoethyl)bromide ionic liquid (IBABr) to prepare [email protected] nanocomposites. All abovementioned nanomaterials were thoroughly characterized by TEM , SEM, XPS , FTIR, and nitrogen-adsorption surface area analysis. [email protected] were then deposited onto a glassy carbon electrode and used as the photoactive element to fabricate a label-free photoelectrochemical (PEC) immunosensor by immobilizing anti-squamous cell carcinoma antigen (anti-SCCA). The PEC sensing principle is based on the photocurrent decline due to the blocking effect of SCCA on the electron and mass transfer after binding SCCA to anti-SCCA. The photocurrent variation related to the specific recognition of SCCA shows a linear relationship to the logarithm of SCCA concentration in the range of 5.0 pg mL −1 to 15.0 ng mL −1 . The detection limit is as low as 2.34 pg mL −1 . Such a signal-off PEC immunosensor is highly selective, sensitive, stable, and reproducible towards SCCA detection. Its performance is comparable to enzyme-linked immunosorbent assay from the studies on clinical samples. This immunosensor is promising for the label-free determining SCCA in clinical human serum samples.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 21
·期 14
·3891-3901
·
IF 9.405
Zhencai Zhang,Fei Xu,Hongyan He,Weilu Ding,Wenjuan Fang,Wei Sun,Zengxi Li,Suojiang Zhang
The utilization of renewable resources and carbon dioxide (CO2) has attracted extensive attention due to global warming and continuously declining petroleum-based resources. Herein, a novel synthetic approach of bio-based polycarbonates using isosorbide (ISB) and diphenyl carbonate (DPC), derived from the renewable resources glucose and CO2, respectively, was proposed, where an ionic liquid (IL) was used as a promising green catalyst; to overcome the poor activity of the endo-hydroxyl group (endo-OH) of ISB and achieve high-molecular weight polycarbonates, a new strategy was revealed that involved the activation of the endo-OH group via a series of efficient tetrabutylphosphonium-based IL catalysts. By designing the structures of cations and anions, most of the endo-OH groups have been activated and incorporated into the polymer chain, and the ratio of endo-OH/exo-OH at the end group of the polymer chain has been decreased to 0.25, which, to the best of our knowledge, is the lowest value reported to date. Among the prepared ILs, tetrabutylphosphonium acetate in a trace amount (1.5 × 10−6 mol) exhibited highest catalytic performance, and poly(isosorbide carbonates) (PICs) with the molecular weight of up to 66 900 g mol−1, Tg of 169 °C and better thermal stability than conventional polycarbonates were achieved. Mass spectrometry and density functional theory calculations provided a deeper understanding of the underlying cation–anion synergistic catalytic mechanism. Furthermore, copolymerization of ISB, diols and DPC was performed to modify the flexibility of PIC, resulting in copolycarbonates with the high molecular weight of 110 000 using 1,10-decanediol as a copolymer monomer.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Junhai Wu,Bihong Lv,Xiaomin Wu,Zuoming Zhou,Guohua Jing
A series of novel dual-functionalized ionic liquids (FILs) with the combinations of diethylenetriamine cation ([DETAH]+) and aprotic heterocyclic anion (AHA) are explored for efficient and reversible CO2 capture, which was distinguished from the traditional strategy by increasing the amino group number of ionic liquids. The structural features and the interactions between ions and CO2 were performed under the DFT method, at the B3LYP/6-311++G** level. The CO2 absorption loadings of [DETAH][Im], [DETAH][Py], and [DETAH][Tz] were 11.91, 11.36, and 10.10 mol CO2/ kg IL, respectively. After the fifth cycle, their regeneration efficiencies still kept above 90%. Based on the calculation and 13C NMR results, the reaction mechanisms of CO2 capture into [DETAH][AHA] solutions were clarified. The amino groups of [DETAH]+ reacted with CO2 to produce [DETAH]+-carbamates, which guaranteed the high absorption rate. Meanwhile, [AHA]− could also equimolecularly react with CO2 to form carbamate, which subsequently hydrolyzes into HCO3–/CO32–. Notably, the [AHA]− was protonated during the CO2 absorption process, and [AHA]-H could react with [DETAH]+-carbamates to produce [DETAH]+, which helped to recycle the active components of the absorbent and further increased the CO2 capacity and regenerability of the absorbent. The novel dual FILs present as an efficient candidate for CO2 capture.
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Ying Sun,Shuhang Ren,Yucui Hou,Kai Zhang,Weize Wu
In this work, we demonstrate an innovative strategy for efficient and sustainable absorption of NO in a series of ionic liquids (ILs) containing amine groups and azole groups. The results show that the ILs have low viscosities and high performance for NO absorption. For instance, [TEPA][Im] had a high absorption capacity of 6.79 mol NO per mol IL at 30 °C and ambient pressure. The absorbed NO was easily released by heat treatment, and the regenerated IL had significant reversibility. The results of 1H NMR, UV spectra, and FT-IR spectra of ILs before and after NO absorption indicated that the absorption of NO in the [TEPA][Im] mainly resulted from a chemical interaction. NO interacts with not only the secondary amine groups in the cation but also N-imidazole in the anion through the formation of NONOate, indicating [TEPA][Im] is a dual functional IL. By introducing this efficient and reversible absorption of NO by ILs, our work broadens the method of NO capture.
✓ 已验证
产品关联
DOI
高影响因子
ANALYST
·
2019
·Vol. 144
·期 18
·5624-5636
·
IF 4.019
Long Zhao,Zhanlin Zhang,Maohua Chen,Yuan Liu,Tao Wang,Xiaohong Li
Challenges remain in the facile, rapid and sensitive detection of substances at ultralow levels. In the current study, visual sensors of hydrogen peroxide (H2O2) and choline are developed via the integration of an ultrafine fibrous substrate and self-propagating and aggregation-induced emission (AIE) probes. Self-immolative probes (SIPs) composed of phenylboronic acid triggers and choline units are grafted on electrospun polyethylene terephthalate (PET) fibers, followed by electrostatic adsorption of tetraphenylethene derivatives (TPE-SO3) to obtain fluorescent PET-Ch/TPE fibers. Choline oxidase (ChOX) is immobilized on polystyrene-co-maleic anhydride (PSMA) fibers to obtain PSMA-ChOX, followed by assembly into PET-Ch/TPE@PSMA-ChOX composite mats. The presence of H2O2 initiates the cleavage of phenylboronic acid triggers in SIPs to release choline and choline/TPE complexes from PET-Ch/TPE fibers. The released choline is oxidized by PSMA-ChOX fibers to generate H2O2 that then activates a cascade of self-propagating reactions until the release of all choline/TPE complexes, leading to the alleviation of AIE effect and gradual fluorescence fading of fibrous mats. Thus, the hydrogen peroxide and choline concentrations can be read out from the fluorescence fading time of fibrous mats with a detection limit of 0.5 μM H2O2 within 30 min, providing potential self-test devices for a real-time, naked-eye and sensitive detection of bioactive substances.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Hao Guo,Taotao Sun,Liguo Yue,Ning Wu,Qi Li,Wenqing Yao,Wenhu Yang,Wu Yang
As a kind of energy storage device, supercapacitors have attracted the attention of researchers, and the development of high-performance electrode materials is also the focus of attention. In this paper, template synthesis and pyrolysis were combined to prepare high performance porous carbon electrode materials. The carbonized electrode material effectively increased the capacitance storage capacity and charge transfer rate. The results revealed that the derivative had a relatively low charge-transfer resistance and high specific capacitance of 1059 F·g −1 at a current density of 1.0 A·g −1 in a three-electrode system. To further exploring practical application, a device based on the derivative and hemp-activated carbon asymmetric supercapacitor was assembled in 0.1 M Na 2 SO 4 neutral electrolyte, which exhibited an energy density of 20.35 Wh·kg −1 at a power density of 400 W·kg −1 . Interestingly, it showed capability retention of nearly of 91.7% and columbic efficiency of 100% even after 10000 charging/discharging cycles in the neutral electrolyte.
✓ 已验证
产品关联
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2019
·
IF 3.031
Xiaodan Sun,Peisen Zhang,Yi Hou,Yingying Li,Xiaodan Huang,Zihua Wang,Lihong Jing,Mingyuan Gao
Photodynamic therapy that involves the photosensitizer transferring the absorbed energy to surrounding tissue oxygen has been used in clinical treatment of cancer. However, the clinically used porphyrin derivatives as PDT photosensitizers usually need high energy excitation light, which generally gives rise to limited tissue penetration depth and thereby limited photoactivation efficiency. Herein, protoporphyrin IX was chemically modified by jeffamines for improving the hydrophilicity and biocompatibility, and the resulting water-soluble porphyrin-jeffamine (PJ) was further covalently conjugated to the PEGylated upconversion nanoparticles (UCNPs) via “click” reaction, which is an efficient way to precisely control the resonance energy transfer from UCNPs to PJs. Our work demonstrates that, the probes can be effectively photosensitized to produce reactive oxygen species (ROS) under the excitation of 980 nm NIR light. When compared with the clinically used photosensitizer molecules, the probes exhibit a comparable capability for producing ROS. Besides, the probes present an outstanding ability in targeting tumor cells and high efficiency in inducing cell death through the photoactivation by 980 nm laser.
✓ 已验证
产品关联
DOI
高影响因子
PHYTOCHEMICAL ANALYSIS
·
2019
·Vol. 31
·期 2
·242-251
·
IF 1.963
Luwei Fang,Jinfeng Xie,Liangwen Lin,Minglei Tian,Kyung Ho Row
Introduction Ephedrine is a typical compound found in lots of plant species that is used in several medicines for the treatment of asthma and bronchitis. However, excess amounts are harmful to humans, so it needs to be removed. Objective This study developed a multi-phase extraction (MPE) method with a molecular imprinted polymer (MIP) coated ionic liquid (IL)-based silica (SiO 2 @IL@MIP) to simultaneously extract and separate ephedrine from Pinellia ternata , 10 medicines, and urine samples. Methods IL was immobilized on silica. Subsequently, the IL was combined with the functional monomer, followed by the addition of the crosslinker and template. The resulting sorbent was applied to the MPE, and the extraction, washing and elution solvents were evaluated. Results Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) confirmed the synthesis of SiO 2 @IL@MIP. A maximum adsorption amount of 5.76 mg/g was obtained at 30°C at a neutral pH. In MPE, 10.00 mL of methanol could extract all the ephedrine from Pinellia ternata . The interference was removed by washing with 4.00 mL of water, ethanol, and acetonitrile. Finally, 8.00 mL of methanol/acetic acid (99:1, v / v ) was applied as the elution solvent. The following were extracted: 5.50 μg/g of ephedrine from Pinellia ternata , 0.00–46.50 μg/g from the 10 herbal medicines, and 68.70–102.80 μg/mL in the urine samples. Conclusion The proposed method was applied successfully to the simultaneously extraction and separation of ephedrine from plants and medicines. These results are expected to provide important data for the development of new methods for the separation and purification of bioactive compounds.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）