CATALYSIS TODAY
·
2023
·
IF 5.3
Wensheng Wei,Yuxin Wang,Zizhen Yan,Jiaxiang Hou,Guangwen Xu,Lei Shi
Three quaternary ammonium ionic liquids with strong nucleophilicity and distinctive structures were synthesized with high yield and purity based on the 1,2-propylene glycol anion (CH 3 CH 2 OHCH 2 O - ) derived from transesterification products. Dimethyl carbonate (DMC) was in turn produced via a one-step reaction among propylene oxide (PO), CO 2 , and methanol (MeOH) by using the synthesized ionic liquids. The involved two-stage catalytic reaction of PO-CO 2 cycloaddition and PC-MeOH transesterification was implemented without catalyst separation. Under mild conditions, the PO conversion reached 99.0%, with a PC yield of 99.0%, and a TON value of 119.5. Following the cycloaddition, MeOH was immediately introduced to achieve a PC conversion of 71.2%, a selectivity to DMC above 99%, and a TON value of 57.4 for the transesterification reaction. The influences of temperature as well as time for cycloaddition and transesterification were investigated. Cycloaddition of CO 2 with various epoxides was also examined and all showed good performance. By taking advantage of the decomposability of as-prepared ionic liquids and the recyclability of decomposition products, a new catalyst circulation process was designed to complete the full cycle without introduction of any impurities into the product system.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Nanjie Chen,Dongchu Chen,Jingshu Wu,Yuekun Lai,Dongyang Chen
Redox flow batteries (RFBs) are highly promising electrochemical systems for large-scale energy storage. To develop high energy density non-aqueous catholyte for RFBs, herein, two polar and bulky polyethylene glycol tails have been attached to the tetrathiafulvalene (TTF) core by ester exchange reactions. Such modification turns scarcely soluble TTF particles into viscous oils, which are totally miscible with the conventional organic electrolytes. The 4,4′(5′)-bis(2-(2-methoxyethoxy)ethyl)carboxylate -tetrathiafulvalene (TTF-BMEEC) with a mass-based specific capacity of 107.84 mAh g −1 is systematically evaluated in a hybrid RFB. When paired with a Li foil electrode and a permselective separator, the catholyte consisting of 1.0 M of TTF-BMEEC delivers two high discharge voltage plateaus of 3.55 and 3.88 V, a large volumetric capacity of 49.6 Ah L −1 , an outstanding energy density of 178.0 Wh L −1 , and a high cycling capacity retention of 91.5% after 100 cycles at the current density of 10 mA cm −2 . The excellent electrochemical stability of TTF-BMEEC is confirmed by UV–vis and 1 H NMR investigations and supported by density functional theory (DFT) calculations. These results demonstrate that molecular engineering has great potential for the development of high performance organic redox-active materials for RFBs.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2019
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IF 3.131
Rui Sun,Fangfang Ren,Dong Wang,Yufeng Yao,Zhenghao Fei,Huiwen Wang,Zongtang Liu,Rong Xing,Yukou Du
Design of high performance and low cost electrocatalysts for the oxidation of small organic molecules remains a great challenge for the practical application of direct fuel cells. Herein, a novel composite catalyst composed of PdAu nanoparticles (NPs) uniformly dispersed on the polydopamine functionalized MWCNTs (PDA-MWCNTs) has been synthesized. TEM images indicate that MWCNTs are successfully coated by PDA, and the as-prepared PdAu NPs are homogeneously dispersed on the PDA functional MWCNTs with smaller sizes than those on pristine MWCNTs. Electrochemical tests reveal that PDA-MWCNTs is a promising catalyst carrier for direct ethylene glycol fuel cell (DEGFC), and the PdAu(1:1)/PDA-MWCNTs catalyst displays the highest peak current density among all catalysts towards ethylene glycol oxidation reaction (EGOR) in alkaline medium, with mass activity of 1540.3 mA mg Pd −1 , which is 1.5, 2.6, 9.8, 13.4 and 2.0 times greater than those of PdAu(1:3)/PDA-MWCNTs, PdAu(3:1)/PDA-MWCNTs, Pd/PDA-MWCNTs, Pd/MWCNTs and commercial Pd/C catalysts, respectively. In addition, PdAu(1:1)/PDA-MWCNTs catalyst also exhibits the best stability. These findings are valuable for the development of advanced Pd-based catalysts, which will help promote the industrialization of direct fuel cell.
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COLLOID AND POLYMER SCIENCE
·
2019
·Vol. 297
·期 2
·249-260
·
IF 1.906
Zou Hongyun,Tang Dongyan,Wang Ning,Jia Shuyue,Sun Zhaojie,Yang Xu,Peng Jing
Molybdenum oxide, as one of the important transition metal semiconductor materials with photothermal property, has received increasing attention in the field of catalysis, sensing, energy storage, and clinical biomedicine. To improve its certain limitations such as poor biocompatibility and easy agglomeration during application as biomaterials and promote its performance as photothermal agent in biomedical fields, polyethylene glycol (PEG)–modified molybdenum oxide was synthesized and the synthesis conditions during the hydrothermal process, including the pH values and the amount of PEG added, were adjusted. Owing to the reduction function of PEG, as-obtained PEG-MoO x showed good photostability and colloidal stability, which were beneficial to its application in long-term clinical photothermal therapy. In addition, cell experiments indicated that PEG-MoO x particles exhibited low cytotoxicity and ability of photothermal killing for HeLa cells. With the increase PEG-MoO x particles in solution, the photothermal ablation ability of PEG-MoO x particles for the HeLa cells was enhanced under an 808-nm NIR laser irradiation. Hence, PEG-MoO x particles have great potential in the photothermal treatment of diseases.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 22
·22362-22371
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IF 2.914
Du Hongxue,Shi Shuyun,Liu Wei,Che Guangbo,Piao Mingyue
Polyethylene glycol diacrylate (PEGDA) hydrogel microsphere was synthesized by UV-assisted reverse emulsion polymerization as an efficient adsorbent for water purification. Optical microscopy and TEM proved its spherical and hollow structure, while XRD pattern proved that it was amorphous with limited crystallinity. Abundant oxygen-containing functional groups such as hydroxyl were detected by FTIR. The hydrogels exhibited low swelling capacities ranging from 0.19 to 0.77 g/g in water and would decrease in salty solutions. The effects of operation parameters on the bisphenol A (BPA) adsorption were studied, including the polymer composition between PEGDA and polyethylene glycol methacrylate (PEGMA), initial concentration of BPA, pH, and operation temperature. The resulting hydrogel, especially for PDM 2 (the ratio between PEGDA and PEGMA is 2), was able to effectively enrich BPA in water. The adsorption capacity was nearly stable below pH 8.0 and decreased when beyond 8.0. Thermodynamic parameters reflected that BPA adsorbed by hydrogel was a spontaneous ( ΔG 0 < 0) and exothermic ( ΔH 0 < 0) progress. The adsorption capacity increased with the increase of the concentration of NaCl, exhibiting salinity-enhanced adsorption capacity driven by hydrophobic force. Excellent results were also achieved by applying hydrogel for spiked real surface waters, which accounted for more than 91% compared to simulated solution. As-prepared hydrogel was expected to be good candidate for treatment of endocrine disruptors with lower solubility in water.
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PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2019
·
IF 4.561
Xingchuan Yang,Huanxin Li,Chunmei Cao,Li Xu,Guoji Liu
Solubility and liquid-liquid equilibria data for dimethyl adipate +1,6-hexanediol + water or ethylene glycol ternary systems at T = 313.15K and 323.15K under atmospheric pressure were measured. The distribution coefficient and separation factors were calculated according to the tie-line data and water was considered to be the suitable solvent to extract 1,6-hexanediol. The Othmer–Tobias and the Bachman equations were used to test the reliability of the experimental data. Besides, the experimental data were correlated with the NRTL and UNIQUAC models. It turned out to be that the calculated results from the two models had good agreement with the experimental data.
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RSC Advances
·
2019
·Vol. 9
·期 46
·27050-27059
·
IF 3.049
Xia Wang,Wulan Zeng,Hongyan Zhang,Dan Li,Hongjing Tian,Xiude Hu,Qian Wu,Chunling Xin,Xiaoyu Cao,Wenjing Liu
To reduce the cost of CO2 capture, polyethylene polyamine (PEPA), with a high amino density and relatively low price, was loaded into MCM-41 to prepare solid sorbents for CO2 capture from flue gases. In addition, methoxypolyethylene glycol (MPEG) was codispersed and coimpregnated with PEPA to prepare composite sorbents. The pore structures, surface functional groups, adsorption and regeneration properties for the sorbents were measured and characterized. When CO2 concentration is 15%, for 30, 40 and 50 wt% PEPA-loaded MCM-41, the equilibrium adsorption capacities were respectively determined to be 1.15, 1.47 and 1.66 mmol g−1 at 60 °C; for 30 wt% PEPA and 20 wt% MPEG, 40 wt% PEPA and 10 wt% MPEG, and 50 wt% PEPA and 5 wt% MPEG codispersed MCM-41, the equilibrium adsorption capacities were respectively determined to be 1.97, 2.22 and 2.25 mmol g−1 at 60 °C; the breakthrough and equilibrium adsorption capacities for 50 wt% PEPA and 5 wt% MPEG codispersed MCM-41 respectively reached 2.01 and 2.39 mmol g−1 at 50 °C, all values showed a significant increase compared to PEPA-modified MCM-41. After 10 regenerations, the equilibrium adsorption capacity for codispersed MCM-41 was reduced by 5.0%, with the regeneration performance being better than that of PEPA-loaded MCM-41, which was reduced by 7.8%. The CO2-TPD results indicated that the mutual interactions between PEPA and MPEG might change basic sites in MCM-41, thereby facilitating active site exposure and CO2 adsorption.
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PubMed
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SEPARATION SCIENCE AND TECHNOLOGY
·
2018
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IF 1.2
Yajuan Li,Yanyang Wu,Kui Chen,Bin Wu,Lijun Ji,Jiawen Zhu
A polymer–salt aqueous two-phase system based on polyethylene glycol and sulfates was applied to explore the partition behavior of spiramycin. Binodal curves were measured by the turbidimetric titration method. The influence of temperature, salt concentration, and pH on the distribution behavior was investigated in detail by determining the partition coefficient and extraction efficiency. As pH and salt concentration increase, the partition coefficients increase accordingly. It was found that pH displays a significant influence on the partition behavior. The partition coefficient and extraction efficiency can reach 42.46 and 97.8%, respectively, at pH 9.0 and 15.80% (w/w) salt concentration.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Shaobo Cao,Ping Liu,Liangliang Zhang,Baochang Sun,Haikui Zou,Guangwen Chu,Yong Luo,Jianfeng Chen
To ensure steady operation of gas transmission lines and meet the utilization specification of downstream processes, gas dehydration is employed in offshore natural gas production, where urgent demands for space and size exist. In this work, a rotating packed bed (RPB) was used to intensify the triethylene glycol (TEG) dehydration process and the effects of operating variables on the overall volumetric mass transfer coefficient (Kya) and height of mass transfer unit (HTU) were investigated. The value of HTU in a RPB was measured to be 4.3–7.9 mm, which was at least an order of magnitude lower than that in conventional columns, indicating the significant reduction in the size of the dehydration apparatus. The predicted Kya matches well with the experimental data, and the mean relative error (MRE) is only 6.68%.
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Nano Research
·
2018
·Vol. 11
·期 5
·2436-2449
·
IF 7.994
Li Zhenglin,Li Zhuo,Chen Lei,Hu Ying,Hu Shaoshan,Miao Zhaohua,Sun Ye,Besenbacher Flemming,Yu Miao
Theranostic nanoagents that integrate the diagnoses and therapies within a single nanomaterial are compelling in their use for highly precise and efficient antitumor treatments. Herein, polyethylene glycol (PEG)-modified cobalt sulfide nanosheets (CoS-PEG NSs) are synthesized and unitized as a powerful theranostic nanoagent for efficient photothermal conversion and multimodal imaging for the first time. We demonstrate that the obtained CoS-PEG NSs show excellent compatibility and stability in water and various physiological solutions, and can be effectively internalized by cells, but exhibit a low cytotoxicity. The CoS-PEG NSs exhibit an efficient photothermal conversion capacity, benefited from the strong near-infrared (NIR) absorption, high photothermal conversion efficiency (∼33.0%), and excellent photothermal stability. Importantly, the highly effective photothermal killing effect on cancer cells after exposure to CoS-PEG NSs plus laser irradiation has been confirmed by both the standard Cell Counting Kit-8 and live-dead cell staining assays, revealing a concentration-dependent photothermal therapeutic effect. Moreover, utilizing the strong NIR absorbance together with the T2-MR contrast ability of the CoS-PEG NSs, a high-contrast triple-modal imaging, i.e., photoacoustic (PA), infrared thermal (IRT), and magnetic resonance (MR) imaging, can be achieved, suggesting a great potential for multimodal imaging to provide comprehensive cancer diagnosis. Our work introduces the first bioapplication of the CoS-PEG nanomaterial as a potential theranostic nanoplatform and may promote further rational design of CoS-based nanostructures for precise/efficient cancer diagnosis and therapy.
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PROGRESS IN ORGANIC COATINGS
·
2018
·
IF 2.955
Le Ma,Lina Song,Heng Wang,Leiqiao Fan,Baohua Liu
Waterborne polyurethanes (WPUs) with high solid contents were synthesized by using poly(propylene carbonate) glycol (PPC) as the soft segment, methylene-bis(4-cyclohexylisocyanate) (HMDI) and 1,4-butanediol (BDO) as the hard segments, 2,2-bis(hydroxymethyl)butyric acid (DMBA) and 2-[(2-aminoethyl) amino]-ethanesulfonic acid monosodium salt (AAS) as the donors of hydrophilic groups. For comparison, polypropylene glycol (PPG) and polytetramethylene ether glycol (PTMG) were also used as soft segments in the synthesis of WPUs (PPG-WPU and PTMG-WPU, respectively). The particle size and distribution of the emulsions were measured and analyzed by submicron particle size Zeta-potential analyzer and transmission electron microscopy (TEM). The storage stability, contact angle and viscosity of the emulsions were also tested. The structure, mechanical properties, acid and alkali resistance, water absorption and thermogravimetric analyses (TGA) of WPU films were also characterized. The results showed that the WPU emulsions exhibited narrow particle distributions, small particle dimensions, good appearance and excellent storage stability. The emulsion viscosity increased slowly at low solid contents and then showed an abrupt change when the solid content exceeded 52%. PPC-WPU films showed superior overall properties in terms of tensile properties, rubber hardness and T-peel strength relative to the PPG-WPU films or PTMG-WPU films. The water absorption rate of the PPC-WPU film was slightly lower than that of the PPG-WPU film but higher than that of the PTMG-WPU film. The hydrogen atom on the α-C atom and the special structure of bonds in the poly(propylene carbonate) glycol molecular chain resulted in excellent acid and alkali resistance but poor thermal stability at high temperature. Moreover, the crystallinity of the PPC-WPU film was lower than that of the PTMG-WPU film due to the irregular structure of poly(propylene carbonate) glycol.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 32
·47854
·
IF 2.188
Xiaotian Shan,Jing Mao,Miaomiao Long,Kamel S. Ahmed,Changling Sun,Lipeng Qiu,Jinghua Chen
Polyethylene glycol (PEG) and pH-sensitive polymers have been widely utilized in anticancer drug delivery systems due to their characteristics of prolonging circulation time and tumor-responsive drug release. However, the effect of PEG molecular weight on the delivery of anticancer drug-encapsulating pH-sensitive polymer micelles has been poorly studied. Therefore, a simple method was used to prepare pH-sensitive doxorubicin (DOX)-loaded micelles (DOX/POD) based on polyethylene glycol-2-(octadecyloxy)-1, 3-dioxan-5-amine (POD) polymers, and the influence of PEG molecular weights (1 K, 2 K, and 5 K) on in vitro drug release and antitumor effect was further studied. Interestingly, as the molecular weight increased, the release amount of DOX was augmented. While the cytotoxicity and cellular uptake were increased, the molecular weight was decreased. It is reasonable to speculate that the high molecular weight of PEG may promote the dissolution rate of DOX, and their micelles with uncompact structure are being prone to disassembly in an acid environment. However, the low molecular weight of PEG may contribute to the formation of compact POD micelles, which make it easier to be uptaken by tumor cells resulting in the enhanced antitumor effect. Taken together, the results indicate that pH-sensitive POD micelles with low molecular weight can achieve the efficient delivery of drugs, and PEG molecular weight in pH-sensitive nanocarriers may influence the antitumor effect. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47854.
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