Molecular Catalysis
·
2024
·
IF 3.9
Tao Liu,Youcai Zhu,Yue Mu,Xindi Feng,Zhen Liu
CO 2 -based polyols have a unique terminal hydroxyl group structure that makes them suitable for the production of high-performance polyurethane foams. Zn-Co double metal cyanides (DMC) are an important class of catalysts for the copolymerization reaction of CO 2 with propylene oxide (PO). In the DMC-catalyzed CO 2 /PO copolymerization to produce CO 2 -based polyols, the crucial role of chain transfer agents (CTAs) is emphasized. In this work, a high-performance composite CTA (c-CTA) was successfully developed by investigating various dicarboxylic acids and polypropylene glycol (PPG-400) as CTAs. This system combines the high reaction rate of the DMC/PPG-400 system with the high CO 2 insertion rate of the DMC/sebacic acid (SA) system, achieving 2-3 times higher activity than that of single CTA (PPG-400 or SA), reaching 0.5 kg/g. The molecular characteristics of the CO 2 -based polyols synthesized by different DMC/CTAs systems were analyzed by FTIR and 1 H NMR. The reasons for the high catalytic activity of the DMC/c-CTA system were elucidated by analyzing the hydrogen bond distribution in each DMC/CTA systems. Overall, this work provides a theoretical guidance for the development of novel CO 2 -based materials with high industrial application value.
研究领域:
化学工程
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Yuanhang Jin,Yu Xie,Haipeng Zhu,Jiangpu Nan,Fenjuan Xiangli,Gongping Liu,Wanqin Jin
Separation of azeotropic mixtures is a typical energy-intensive process in chemical industry, in which pervaporation membrane process shows great potential in energy efficiency. However, the performance of commercial membranes such as polydimethylsiloxane (PDMS) is unattractive for practical application. Henein, for the first time, we employed microporous MAF-6 as a new filler incorporating into PDMS membrane for pervaporation separation of DMC/methanol azeotropic mixture. The resulting MAF-6/PDMS mixed-matrix membrane with the optimal filler size of 300 nm and filler loading of 12 wt% exhibited highly DMC permeability (651–811.5 Barrer) and selectivity (10.1–10.4) during 31 days continuous separation process, which fairly exceeds the state-of-the-arts membrane performance. A pervaporation-distillation coupled process was further proposed for the purification of DMC/methanol mixtures, showing 55.7 % of energy-saving compared with conventional distillation process.
研究领域:
化学工程
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2021
·
IF 2.262
Li Chao,Haiwang Wang,Xinfang Wei,Jinlong Li,Cheng Ji,Xiwei Qi
At present, the polymer flocculation technology has been widely used in the treatment of oil sand tailings. However, the current composite flocculant still has the problems of low flocculation efficiency and serious secondary pollution after using. In this article, cationic composite flocculant SiO2-TiO2-P(AM-DMC) with self-degrading characteristics was prepared by the surface photoinitiated polymerization technique. Above all, in order to study the synthesis process of SiO2-TiO2-P(AM-DMC), cationic composite flocculant was characterized by FTIR, TG, TEM, XPS, etc. Furthermore, the central composite design (CCD) and response surface methodology (RSM) were used to optimize the preparation parameters of the cationic composite flocculant. And the optimization results of preparation parameters of cationic composite flocculant showed that the optimal preparation parameters of SiO2-TiO2-P(AM-DMC) were as follows: mDMC: mAM = 5, monomer concentration was 35% and reaction time was 100 min. Ultimately, the flocculation parameters of SiO2-TiO2-P(AM-DMC) were optimized by CCD and RSM. Moreover, the optimization results of flocculation parameters of cationic composite flocculant showed that the optimal flocculation parameters of SiO2-TiO2-P(AM-DMC) were as follows: pH = 5, flocculant dosage was 30 ppm, kaolin concentration was 1.36%. In summary, this work had greatly enriched the knowledge of oil sand tailings treatment, and had the extremely important reference significance for realizing the parameter regulation of high-efficiency flocculation of oil sand tailings.
研究领域:
环境科学
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材料科学
·
化学工程
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产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2024
·Vol. 35
·期 1
·e6277
·
IF 3.1
Anqi Ming,Xiaoxiao Li,Jun Sun,Yanyan Liu,Xingyou Tian,Hua Wang,Lin Chen,Yuxiang Cao,Yun Yuan
The cationic water-soluble polymers, which are widely used in many areas such as papermaking and separation process, are typically synthesized through polymerization of cationic monomers represented by quaternary ammonium salt. In this work, the polymerization reaction kinetics of three typical quaternary ammonium salt cationic monomers including acryloyl oxygen ethyl trimethyl ammonium chloride (DAC), methyl acryloyl oxygen ethyl trimethyl ammonium chloride (DMC), and methyl acrylamide propyl trimethyl ammonium chloride (MAPTAC) was examined by using the dilatometer method. The results showed that the polymerization rate of all three monomers increased with the increase of initiation temperature, monomer concentration, and initiator concentration. Under the same conditions, the polymerization activity of the three monomers followed the order: DAC > DMC > MAPTAC. The activation energies for the polymerization reaction under the specified conditions were E aDAC = 138.97 kJ/mol, E aDMC = 141.24 kJ/mol, and E aMAPTAC = 226.97 kJ/mol, respectively. The polymerization rate equations were R pDAC = k 1 [ M ] 4.25 [ I ] 0.51 , R pDMC = k 2 [ M ] 3.77 [ I ] 0.50 , and R pMAPTAC = k 3 [ M ] 3.30 [ I ] 0.49 . The polymerization activity of the monomers may be influenced by electronic effects and steric hindrance of the monomer structure. This work has provided a theoretical and experimental foundation for the actual work of structural design and preparation of cationic water-soluble polymers.
研究领域:
高分子化学
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材料科学
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产品关联
DOI
高影响因子
MOLECULES
·
2021
·Vol. 26
·期 6
·1735
·
IF 4.412
Fucan Zhang,Ping Liu,Kan Zhang,Qing-Wen Song
The effective separation of dimethyl carbonate (DMC) from its methanol mixture through simple, inexpensive and low energy-input method is a promising and challenging field in the process of organic synthesis. Herein, a reversible adsorption strategy through the assistance of superbase and CO2for DMC/methanol separation at ambient condition was described. The process was demonstrated effectively via the excellent CO2adsorption efficiency. Notably, the protocol was also suitable to other alcohol (i.e., monohydric alcohol, dihydric alcohol, trihydric alcohol) mixtures. The study provided guidance for potential separation of DMC/alcohol mixture in the scale-up production.
研究领域:
化学工程
·
分离科学
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DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Chenxu Wang,Kangying Guo,Beibei Liu,Yue Gao,Qinyan Yue,Haijiao Xie,Baoyu Gao
The efficient removal of antibiotics and its combined pollutants is essential for aquatic environment and human health. In this study, a lignin-based organic flocculant named PRL-VAc-DMC was synthesized using pulp reject as the raw material, with vinyl acetate (VAc) and methacryloxyethyltrimethyl ammonium chloride (DMC) as the grafting monomers. A series of modern characterization methods were used to confirm the successful preparation of PRL-VAc-DMC and elucidate its polymerization mechanism. It was found that the Ph-OH group and its contiguous carbon atoms of lignin served as the primary active sites to react with grafting monomers. Flocculation experiments revealed that PRL-VAc-DMC could react with tetracycline (TC) through π-π* interaction, hydrophobic interaction, hydrogen bonding, and electrostatic attraction. With the coexistence of humic acid (HA) and Kaolin, the aromatic ring, hydroxyl, and amide group of TC could react with the benzene ring, hydroxyl group, and carboxyl group of HA, forming TC@HA@Kaolin complexes with Kaolin particles acting as the hydrophilic shell. The increase in particle size, electronegativity, and hydrophily of TC@HA@Kaolin complexes facilitated their interaction with PRL-VAc-DMC through strong interfacial interactions. Consequently, the presence of HA and Kaolin promoted the removal of TC. The synergistic removal mechanism of TC, HA, and Kaolin by PRL-VAc-DMC was systematically analyzed from the perspective of muti-interface interactions. This paper is of great significance for the comprehensive utilization of pulp reject and provides new insights into the flocculation mechanism at the molecular scale.
研究领域:
环境科学
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化学工程
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材料科学
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Na Li,Yuping Fan,Xianshu Dong,Qingxia Liu,Xiaomin Ma,Ruxia Chen
In this study, in order to improve the flocculation efficiency of natural organic flocculant in coal mine wastewater, guar gum (GG) and [2-(methacryloyloxy) ethyl] trimethyl ammonium chloride (DMC)were used to synthesize a type of graft copolymer of GG with DMC (GG-g-DMC) with flocculating function by free radical polymerization under ultraviolet (UV) light initiation conditions. Performance testing and structural characterization of the composites including FTIR, NMR, XRD, SEM, TG, and XPS were conducted to verify the synthesis of the graft polymer. The GG-g-DMC was applied to treat coal mine wastewater, according to the sedimentation index and the optimal flocculation solution was determined, and the flocculation settling mechanism was studied using focused beam reflectance measurement (FBRM), Zeta potentiometer and adhesion force meter. The results indicated that GG-g-DMC synthesis by UV-initiated polymerization was feasible and the settling effect increased significantly; 0.5 mg/g (s) GG-g-DMC 4 was excellent in all aspects, its sedimentation speed reached 20.64 cm/min, the light transmittance was 95.00%, and the compression layer thickness was 1.89 cm; the mechanism is mainly the synergy of charge neutralization, bridging, and improve hydrophobicity.
研究领域:
环境科学
·
高分子化学
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产品关联
DOI
高影响因子
ACS Sensors
·
2023
·
IF 8.9
Huajing Wang,Rui Xiong,Zhou Cui,Jie Wan,Baisheng Sa,Xiao Wu,Wulin Song,Xiaoxia Wang,Dawen Zeng
The problems of lithium-ion battery (LIB) failure have attracted growing attention since flammable and explosive electrolyte leakage might lead to serious consequences. However, due to the redox-neutral and volatile nature of main electrolyte components, such as dimethyl carbonate (DMC), trace leakages are difficult to detect. Therefore, research on LIB electrolyte sensors is urgent and lacking. Herein, sensors based on rare-earth Nd-doped SnO2 nanofibers are reported for detecting DMC vapor in LIB. The excellent sensitivity (distinct response to 20 ppb DMC), high response (∼38.13–50 ppm DMC), and superior selectivity and stability of 3%Nd-SnO2 suggest that it should be a promising candidate for LIB safety monitors. Meanwhile, it also shows clear and rapid response during the LIB-leakage real-time detection experiment. The doping of Nd endows SnO2 with more oxygen vacancy defects. In addition, the highly active Nd sites greatly enhanced the adsorption energy of DMC on SnO2. All of these features contribute to the improvement of DMC-sensing performances.
研究领域:
材料科学
·
传感器技术
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DOI
PubMed
高影响因子
Nanoscale Research Letters
·
2019
·Vol. 14
·期 1
·1-15
·
IF 3.159
Protsak Iryna S.,Morozov Yevhenii M.,Dong Wen,Le Zichun,Zhang Dong,Henderson Ian M.
Abstract Three poly(organosiloxanes) (hydromethyl-, dimethyl-, and epoxymethylsiloxane) of different chain lengths and pendant groups and their mixtures of dimethyl (DMC) or diethyl carbonates (DEC) were applied in the modification of fumed silica nanoparticles (FSNs). The resulting modified silicas were studied in depth using 29 Si, 1 H, and 13 C solid-state NMR spectroscopy, elemental analysis, and nitrogen adsorption-desorption (BET) analysis. The obtained results reveal that the type of grafting, grafting density, and structure of the grafted species at the silica surface depend strongly on the length of organosiloxane polymer and on the nature of the “green” additive, DMC or DEC. The spectral changes observed by solid-state NMR spectroscopy suggest that the major products of the reaction of various organosiloxanes and their DMC or DEC mixtures with the surface are D (RR’Si(O 0.5 ) 2 ) and T (RSi(O 0.5 ) 3 ) organosiloxane units. It was found that shorter methylhydro (PMHS) and dimethylsiloxane (PDMS) and their mixtures with DMC or DEC form a denser coverage at the silica surface since S BET diminution is larger and grafting density is higher than the longest epoxymethylsiloxane (CPDMS) used for FSNs modification. Additionally, for FSNs modified with short organosiloxane PMHS/DEC and also medium organosiloxane PDMS/DMC, the dense coverage formation is accompanied by a greater reduction of isolated silanols, as shown by solid-state 29 Si NMR spectroscopy, in contrast to reactions with neat organosiloxanes. The surface coverage at FSNs with the longest siloxane (CPDMS) greatly improves with the addition of DMC or DEC. The data on grafting density suggest that molecules in the attached layers of FSNs modified with short PMHS and its mixture of DMC or DEC and medium PDMS and its mixture of DMC form a “vertical” orientation of the grafted methylhydrosiloxane and dimethylsiloxane chains, in contrast to the reaction with PDMS/DEC and epoxide methylsiloxane in the presence of DMC or DEC, which indicates a “horizontal” chain orientation of the grafted methyl and epoxysiloxane molecules. This study highlights the major role of solid-state NMR spectroscopy for comprehensive characterization of solid surfaces. Graphical abstract
研究领域:
材料科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Jie Wan,Chengao Liu,Xiaoxia Wang,Huajing Wang,Lu Tang,Zhenming Du,Wulin Song,Dawen Zeng
Safety problem caused by the leakage of electrolyte in lithium-ion batteries (LIB) have become a critical hot issue. However, since the main components of LIB electrolyte, such as dimethyl carbonate (DMC), are volatile or redox, trace electrolyte leakage is difficult to detect. Therefore, in order to realize early detection of electrolyte leakage and real-time monitoring of LIB health, here we report a success of DMC gas detection by MOS sensor based on Co/Pd-doped SnO 2 nanomaterial for LIB health monitoring. In detail, the sensor showed high response to DMC when compared to interfering gases. Especially, the sensor could detect DMC down to the ppb level (the response value of the 500 ppb DMC is about 1.6). The response and recovery time for 1 ppm DMC were about 66 s and 240 s, respectively. The response of the sensor was obvious even when the leakage levels were as low as only 0.1 μL electrolyte. Furthermore, in the simulated electrolyte leakage via LIB penetration experiment, the sensor successfully exhibited an instant response, which proved that this work effectively provides a new approach for LIB real-time health and safety monitoring.
研究领域:
材料科学
·
传感器技术
·
电池安全
✓ 已验证
DOI
高影响因子
Green Energy & Environment
·
2017
·Vol. 3
·期 2
·138-146
·
IF 0
Meng Li,Yulong Wang,Xiaobang Hou,Xia Wan,Hui-Ning Xiao
Novel cellulose based flocculants C-g-P (DMC) with various chain architectures are synthesized through a situ graft copolymerization. The cationic ammonium chloride group (DMC) is grafted onto cellulose by two separate inverse emulsion polymerization with γ-methacryloxypropyl trimethoxy silane (KH-570) and double bond addition reactions, which is a new and simple method to employ KH-570 as a bridge for the connection of cellulose matrix and DMC group. The effects of pH, flocculant dose, standing time on turbidity of kaolin suspensions and particle sizes have been studied systematically. In addition, the response surface methodology (RSM) study confirms that PAC and C-g-P (DMC) have synergy in turbidity removal with a higher removal efficiency of 98.32%. Moreover, C-g-P (DMC) 1 has higher removal efficiency with 96.5% at a low dosage of 0.6 mg L −1 and better floc properties than C-g-P (DMC) 2 and C-g-P (DMC) 3 , suggesting that the length and quantity of cationic branch chains play a crucial role in Kaolin flocculation due to their dramatically enhanced bridging effects.
研究领域:
环境科学
·
高分子化学
·
水处理
·
材料科学
✓ 已验证
DOI
Molecular Catalysis
·
2026
·
IF 4.3
Zhendong Pan,Ying Liu,Yong Li,Yifan Liu,Zifeng Yang
PILs@ZnOx nanocatalyst was constructed via in-situ self-assembly of pyrrolium-based PILs and ZnO, featuring tailored oxygen vacancies for potentially relieving the entrainment phenomenon of reactive distillation, dual alkaline sites and unique interfacial microenvironment to facilitate transesterification. • The catalyst exhibited outstanding activity and good stability for room-temperature synthesis of DMC from CO 2 -derived cyclic carbonate, far superior to metal oxide catalyst. • Multiple characterizations combined with in-situ spectroscopy elucidated the synergistic catalysis of dual basic active sites at the catalyst interface. Pyrrolium-based polymeric ionic liquids-functionalized ZnO nanocatalysts (PILs@ZnO) with an oxygen-vacancy-enriched interface were fabricated via in-situ oxidative polymerization to resolve the entrainment phenomenon in reactive distillation process of producing DMC. The unique interfacial microenvironment effectively modulates the electronic structures and enhances the synergistic catalysis, which could lower the reaction temperature of transesterification between ethylene carbonate and dimethyl carbonate to ambient conditions, and performed the results of EC conversion with 86.7% and DMC selectivity with over than 99.0%. Physicochemical characterizations including FTIR, XRD, XPS and HRTEM were combined with in-situ FTIR and NMR to reveal the structure-activity relationship and further proposed its probably real-time catalytic process. At room temperature, the designed PILs@ZnO x catalyst behaved multiple functional active sites, including strongly basic OH - , pyrrolium-N + cations and Lewis-basic ZnO nanoparticles with a newly constructed oxygen-vacancy microelectronic interface to potentially relieve the entrainment phenomenon in reactive distillation process of producing DMC. Benefiting from the synergistic effect of these multifunctional moieties, PILs@ZnO x exhibits outstanding catalytic performance for the synthesis of DMC from cyclic carbonate. Its catalytic activity is far superior to the pristine ZnO, pure PPY + OH - , and other corresponding PILs-supported metal oxide (PPY + OH - @MgO, PPY + OH - @Al 2 O 3 , PPY + OH - @CaO and PPY + OH - @ZrO 2 ). Download: Download high-res image (327KB) Download: Download full-size image
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DOI
高影响因子
危险品化学品经营许可证（带存储）