Journal of CO2 Utilization
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2022
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IF 8.321
Fei Chen,Wensheng Wei,Yunsheng Gao,Yuxin Wang,Zizhen Yan,Zhanguo Zhang,Haiming Yu,Guangwen Xu,Lei Shi
Ionic liquid 1-ethyl-3-methylimidazolium ([Emim]IM) with high thermal stability and strong basicity was successfully synthesized. Using [Emim]IM as catalyst, dimethyl carbonate (DMC) was directly synthesized from epoxy propane (PO), CO 2 , and methanol under mild reaction conditions. A continuous two-stage DMC synthesis process was developed. The cycloaddition of CO 2 and PO was first conducted to produce propylene carbonate (PC), and then methanol was introduced into the system to synthesize DMC. During the cycloaddition process, 97.40% PO conversion and 97.40% PC yield were achieved with TON of 99.49. In the subsequent transesterification stage, DMC yield attained 83.63% with selectivity higher than 99% and TON of 70.15. [Emim]IM was reused for seven times without obvious deactivation, exhibiting good stability. The effects of reaction temperature, reaction time, the initial pressure of CO 2 , and catalyst weight on cycloaddition and transesterification reactions were systematically investigated. The kinetic study showed that the activation energies (E a ) of cycloaddition and transesterification reactions were 28.02 and 38.53 KJ·mol −1 , respectively, much lower than those of catalysts reported in the literatures. In addition, [Emim]IM displayed superior catalytic activity for the cycloaddition of CO 2 with various epoxy compounds .
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Materials Today Communications
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2022
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IF 3.662
Yipeng Zhang,Jianping Zhang,Zechun Liu,Yanjun Huang,Xiaopeng Xiong
Beta-cyclodextrin (β-CD) has promising applications in many fields based on its hydrophobic cavity at the central of the cyclic molecule, which can form inclusion complex with specific molecule via a host-guest interaction. However, the water solubility of β-CD limits its application. Herein, attempts have been made to graft β-CD onto two kinds of solid particles while retaining the function of β-CD, so as to expand its application. First, SiO 2 nanoparticles were modified with silane coupling agent KH-560 to offer epoxy groups. Then, the epoxy groups of the modified SiO 2 and the hydroxyl groups of β-CD were simultaneously esterified by a dicarboxylic acid of succinic acid in a non-toxic solvent medium to obtain the β-CD modified SiO 2 (SiO 2 @β-CD). On the other hand, microcrystalline cellulose (MCC) particles were also modified with β-CD (MCC@β-CD) through co-esterification of their hydroxyl groups with succinic acid. The syntheses were monitored by Fourier transform infrared (FT-IR) spectroscopy, and the obtained materials were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The degrees of β-CD modification for the particles have been measured and analyzed to optimize the synthesis conditions. The results indicate that the degree of β-CD modification for the SiO 2 @β-CD is relatively low, but the material exhibits over 60 ºC elevation of the thermal stability. In comparison, the degree of β-CD modification for MCC@β-CD reached as high as 422 mg/g. Due to the much higher content of β-CD, the synthesized MCC@β-CD was employed to load a flavor compound of D -limonene, and its sustained release was investigated to suggest the potential of the β-CD modified particles.
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JOURNAL OF PHYSICS D-APPLIED PHYSICS
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2022
·Vol. 55
·期 48
·485202
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IF 3.409
Kun Liu,Xiaohan Zhang,Xiongfeng Zhou,Xinming Huo,Xiaohao Wang,Kostya (Ken) Ostrikov
This work reported an air atmospheric pressure plasma jet served as an ion source for nonvolatile solid analysis, which allows a unique capability to achieve thermal desorption and ionization simultaneously without complex devices, inert gas, or solvents. Owing to precise amount of heat generated by plasma jet, nonvolatile analytes were thermally released from solid surfaces without the assistance of secondary desorption equipment. According to the mass spectra and Fourier transform infrared spectrum, [M + H]+ and [M + NO3]− ions were the major analyte ions in the positive-ion and negative-ion modes, respectively. The applied voltages, discharge currents, and gas temperatures of plasma jet were measured, and found to be positively correlated with the mass spectra signal intensity of the samples, while the added resistances and gas flow rate were negatively correlated with the signal intensity. The influence mechanisms of analytes natures coupling physical parameters of plasma jet on detection performance were revealed. The prospect of quantitative testing was confirmed by the linear relationship between the peak intensity and sample mass.
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INDUSTRIAL CROPS AND PRODUCTS
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2022
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IF 6.449
Guangchuan Tang,Xin Huang,Anbang Xu,Zhongqing Yang,Changlei Qin,Jingyu Ran
Pyrolysis of cellulose produces substantial anhydrosugars, particularly levoglucosan (LGA), as the main product. In this study, liquid-phase continuous conversion of LGA was carried out over SO 3 H functionalized resin for the production of levogluosenone (LGO), which is a bio-renewable platform for fine and commodity chemicals. Factors including solvent, reaction temperature, catalyst dosage, initial LGA concentration and total flow rate were investigated on the influence of LGO yield, which was obtained with the highest yield of 38.4 % at 94.8 % LGA conversion at the optimized conditions. In addition, a stable catalytic performance without losing LGO yield was observed for 10 h long test. The use of glucose as substrate led to a decrease of LGO yield to 33.5 %, nevertheless, the use of bio-oil, derived from cellulose pyrolysis, as the substrate promoted LGO yield to 55.4 % due to the presence of other anhydrosugars. Density functional density calculations revealed that the free energy barrier was significantly decreased to 168 kJ/mol with the SO 3 H functionalized resin compared to that of 258 kJ/mol without catalyst.
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JOURNAL OF POLYMER RESEARCH
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2022
·Vol. 29
·期 11
·1-13
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IF 3.061
Xu Jingmei,Meng Lingxin,Shi Qingyuan,Ren Qiang,Wang Zhe
In this study, sulfonated poly (ether ketone sulfone)s polymers with long sulfonic acid alkyl side chains and amino groups were prepared by free radical and polycondensation reaction. Poly (ether ketone)s with carboxyl groups were used for macromolecule crosslinking agent to prepare cross-linked membranes by amidation reaction. This series of membranes were characterized by FT-IR and 1 H NMR. Meanwhile, cross-linked composite membranes possessed excellent mechanical properties, methanol resistance performance and thermal stability. The highest proton conductivity of 0.096 S cm −1 was observed for APD-3/CP at 80 °C. The range of methanol permeation coefficients for the prepared membranes (2.89 × 10 −7 cm 2 s −1 —4.95 × 10 −7 cm 2 s −1 ) was far lower as compared to that of Nafion 117 (24.1 × 10 −7 cm 2 s −1 ). The results of morphology, swelling ratio and proton conductivity showed that the hydrophilic-hydrophobic phase separation structure effectively improved the properties of the membrane namely water uptake, dimensional stability and proton conductivity. Long-side chains functionalized cross-linked sulfonated poly (ether ketone sulfone)s proton exchange membranes had good candidate for application in fuel cells.
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ACS Sustainable Chemistry & Engineering
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2022
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IF 9.224
Lei Zhang,Jingyu Wang,Renliang Huang,Mei Cui,Wei Qi,Zhimin He,Rongxin Su
Cellulose nanocrystals (CNCs) are renewable and multifunctional plant-based nanoparticles that are industrially produced by controlled sulfuric acid hydrolysis, resulting in a large amount of acid–sugar mixture, which has potential to be recovered and concentrated for reuse. However, the removal of sugar from the acid–sugar mixture, which was produced by cellulose biomass hydrolysis, is essential before acid recycling. In this study, the acid–sugar mixture was separated from the CNC hydrolysate, and then, a combination process of diffusion dialysis (DD) using anion-exchange membranes and electrodialysis (ED) was used to remove the sugar from the acid–sugar mixture. The operation parameters were optimized and Fenton oxidation (FO) was applied to degrade sugar with a decrease in the chemical oxygen demand (CODCr) in the wastewater. As a result, 98.8% sulfuric acid was totally recovered in a practical process, with 92.2% recovery by diffusion dialysis and 87.1% by electrodialysis, and more than 90% sugar was rejected. CODCr in the wastewater decreased to <500 mg/L by FO treatment. Furthermore, CNCs prepared with the recovered sulfuric acid showed a crystallinity, surface charge, and morphology similar to that prepared with fresh acid. Therefore, this combination process of DD and ED is a green and economic feasible way for acid recycling for sustainable CNC production.
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CHEMISTRY OF MATERIALS
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2022
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IF 10.508
Shengda Wang,Hanqing Jiang,Ronghua Yu,Shenghui Lou,Li Ma,Jie Liu,Tao Tang
A series of epoxy resins containing aromatic imine are synthesized via the Duff reaction by using various bisphenols, which show significantly reduced heat release capacity (HRC) and total heat release (THR) after curing. Compared to diglycidyl ether bisphenol A/4,4-diaminodiphenyl methane (DGEBA/DDM), the HRC and THR of phenolphthalein-based epoxy resin containing aromatic imine/DDM (BPP-E/DDM) are reduced by 87% (464 J/g K vs 58 J/g K) and 62% (30.2 kJ/g vs 11.4 kJ/g), respectively. Furthermore, the BPP-E/DDM exhibits a UL-94 V-0 rating (1.6 mm) and a limiting oxygen index of 48% (3.2 mm). Compared to DGEBA/DDM in the cone calorimeter test, the peak heat release rate, THR, peak smoke produce rate, and total smoke production of BPP-E/DDM were reduced by 91% (1006 kW/m2vs 87 kW/m2), 51% (89 MJ/m2vs 44 MJ/m2), 89% (0.36 m2/s vs 0.09 m2/s), and 79% (38 m2vs 8 m2), respectively. The influences of aromatic imine and the chemical structures between two benzene rings in the bisphenols on HRC and THR of the resultant epoxy thermosets are investigated. The mechanism studies show that the presence of aromatic imine in the epoxy resins completely changes the decomposition process to generate the products containing aromatic N-heterocycle, which contributes greatly to the improved char-forming ability and flame retardancy. Meanwhile the thermosets bearing carbonyl, 3-phthalidylene, and sulfonyl between two benzene rings in the bisphenols show better char-forming ability and flame retardancy among the resultant epoxy resins containing aromatic imine, due to more polycyclic aromatic hydrocarbons produced in the condensed phase.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2022
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IF 3.898
Sihan Huang,Yaohan Chen,Xue Wang,Jing Guo,Yonggang Li,Lei Dai,Shenghai Li,Suobo Zhang
The past few decades have witnessed rapid gains in our demands of antifouling membranes such as water purification membranes and hemodialysis membranes. A variety of methodologies have been proposed for improving the antifouling performance and the hemocompatibility of the membranes. In this study, a series of copolymers (PSF-PESSB) containing polysulfone (PSF) and poly(arylene ether sulfone) bearing pendant zwitterionic sulfobetaine groups (PESSB) were prepared via one-pot polycondensation . Subsequently, the ultrafiltration (UF) membranes were prepared from different zwitterion-containing copolymers. The prepared membranes showed high thermal stability and mechanical properties. Besides, it also displayed attractive antifouling performance and blood compatibility. Compared with the original PSF membrane, the amount of protein absorption on the modified membrane was reduced; the flux recovery ratio and the resistance to blood cells were significantly improved. The results of this work suggest that PSF-PESSB membranes are expected to be applied in blood purification. The introduction of zwitterion-containing polymers to membranes paves ways for developing advanced hemodialysis technologies for crucial process.
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Journal of Chemistry
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2022
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IF 3.241
Yan Jin,Xinyuan Wang,Ya-Ping Dong
The Yellow River is very important for human health and social development in China to require good water quality. This study selected the Ningxia section of the Yellow River as the study area to investigate the water quality variation in 2016–2020. A total of 9 water quality parameters were monitored, and 8 parameters including pH, dissolved oxygen, biological oxygen demand, chemical oxygen demand, total phosphate, fluoride, ammonia-nitrogen, and permanganate index were in the range of Class II standard requirement. Dissolved oxygen concentrations ranged from 7.5 to 9.4 mg/L. However, total nitrogen concentrations in 2018–2020 ranged from 1.87 to 2.8 mg/L to cause the pollution. Both the Nemerow index method and the contamination degree method showed that total nitrogen with high concentration exerted the water pollution. Principal component analysis also proved this. Stricter environmental management strategies for controlling total nitrogen should be taken in the future. The findings provided some useful information for water pollution of the Ningxia section of the Yellow River.
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SENSORS AND ACTUATORS A-PHYSICAL
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2022
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IF 4.291
Cheng Bai,Wen Zhou,Shifeng Yu,Tengfei Zheng,Chaohui Wang
Microfluidic mixing is a critical issue in the lab-on-a-chip system, which has been applied in various biomedical research. Recently, acoustic wave-based active micromixers have been applied to increase the mixing efficiency via acoustic streaming. However, along with the acoustic streaming, the acoustic thermal effect will generate additional heat to increase the temperature of the microfluid. In this work, we present an integrated thermal control unit applied to a surface acoustic wave (SAW)-assisted micromixer to address this problem. A metal microwire as the thermal resistance sensor is fabricated under the microchannel to measure the temperature in different conditions, together with the Peltier cooler beneath allowing the active temperature control of the microfluid. For characterization, neutralization reaction and alkaline phosphatase assay were successfully conducted on this device. It shows the integrated thermal control unit applied to a SAW-assisted micromixer is highly effective in temperature-sensitive biomedical research.
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Advanced Electronic Materials
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2022
·Vol. 9
·期 1
·2200414
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IF 7.633
Wen Huang,Tianxiong Ju,Ruipeng Li,Yajun Duan,Yanan Duan,Junji Wei,Lei Zhu
High energy density, high temperature, and low loss dielectric polymers have drawn increasing attention in research owing to their potential applications in power electronic and pulsed power devices. In this study, a new class of organo-soluble dipolar glass polymers (DGPs) are synthesized via polycondensation and post-functionalization of poly(aryl ether)s (PAEs) based on phenolphthalin. Due to the nonplanar backbone structure, the strongly dipolar side groups (-SO 2 CH 3 and -CH 2 CH 2 CN) can easily rotate in these PAEs. As a result, desirable physical properties are obtained: high dielectric constant (4.4–5.6), high glass transition temperature (155–180 °C), good mechanical property, and low dielectric loss (dissipation factor < 0.005). Among them, cyanolized poly(aryl ether nitrile) exhibit the highest discharged energy density of 8.6 J cm −3 at 650 MV m −1 and room temperature with a high discharged efficiency of 94.3%. At 100 °C, cyanolized poly(ether ether ketone) shows the highest discharged energy density of 7.3 J cm −3 at 600 MV m −1 with a discharged efficiency of 91%. Furthermore, these functionalized PAEs exhibit good mechanical toughness with a tensile strength at a break of 60-120 MPa and elongation at a break of ≈5%. Based on their thermal, mechanical, and dielectric properties, these phenolphthalin-based PAEs are promising for potential applications such as film capacitors.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
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IF 5.518
Yuqi Zheng,Yang Jin,Nan Zhang,Dong Wang,Yang Yang,Meng Zhang,Guohui Wang,Wenjuan Qu,Yuting Wu
MXene as a new member of 2D materials due to its metallic conductivity, rigid structure, hydrophilicity and functionalization has received extensive interests in the field of ion exchange membranes . Herein, different mass fractions of Ti 3 C 2 T X MXene were mixed into polyvinylidene fluoride (PVDF) by blending method to obtain cation exchange membranes (CEMs), and the electrodialysis (ED) properties of these membranes were characterized to determine the possibility of their application. With the addition of MXene, the anti-fouling ability of the membrane was effectively improved and the membrane resistance was reduced, and the overall performance reached the best when the content of MXene was 3%wt. The ED process results showed that the modified CEMs can reduce the energy consumption and improve the mass transfer capacity, and 3%wt MXene/PVDF CEM had better performance than other prepared CEMs. Furthermore, the improvement of mechanical and thermal stability of these membranes were attributed to the formation of strong interaction between PVDF and MXene. The preparation strategy of MXene/PVDF CEMs provides basic information for the rational design of separation membrane with high comprehensive performance and opens up a good prospect for the application of MXene in the field of electrodialysis.
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