WASTE MANAGEMENT
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2021
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IF 7.145
Zishang Tian,Xiaojie Shao,Jiaojiao Zhang,Lijuan Su,Yingxiong Wang,Tiansheng Deng,Yuqi Wang,Xianglin Hou
Poly-p-phenylene terephthamide (PPTA) is widely applied in bulletproof products and composite materials because of its high strength, high modulus, high temperature resistance and creep resistance. The PPTA molecule with highly symmetrical and regular structure is linear structure formed by the alternating connection of benzene ring and amide bond, and the amide bonds between the molecular chains form strong hydrogen bonds. Therefore, the dissolution and depolymerization of PPTA is very challenging. In this work, an efficient catalytic system was developed for the controllable degradation of waste PPTA, and the high-value added monomers terephthalic acid (TPA) and p-phenylenediamine (PPD) were recovered. The results show that the amide bonds of PPTA can be selectively cleaved by the strong Brönsted base catalysts in alcohols, especially in the NaOH/ n -butanol system. Under the optimal degradation conditions (5 wt% NaOH in n -butanol, 180 °C, 6 h), the percentage degradation of PPTA is 100%, and the yields of TPA and PPD are 92.0% and 91.5%, respectively. In addition, it is found that the wettability of n -alcohols on PPTA monofilament and the addition of a small amount of water have important influences on the degradation of PPTA. The work elucidates the degradation mechanism of PPTA, and reveals the important factors affecting the depolymerization of PPTA.
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INSTRUMENTATION SCIENCE & TECHNOLOGY
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2021
·
IF 1.584
Zhao-chan Liu,Li Yang,Rong-rong Xing,Xuan Chen,Xiao-hong Bai,Shuang Hu
This work describes three phase dispersive liquid-liquid microextraction based on reverse micelles for the determination of Q-markers of cinnamic acids (caffeic acid, p-hydroxycinnamic acid, ferulic acid, and cinnamic acid) in traditional Chinese medicine followed by high performance liquid chromatography (HPLC) analysis. The variables influencing the procedure were optimized separately. Enrichment factors from 110 to 189, linearities from 1.2 to 960 ng mL−1 with r2 exceeding 0.9943, detection limits from 0.1 to 0.6 ng mL−1, excellent precision with relative standard deviations below 5.6%, and good relative recoveries from 80.0% to 113.3% were achieved. In addition, the mechanism of the procedure was explored by comparison with conventional dispersive liquid-liquid microextraction at the optimum conditions. The results showed that the developed microextraction procedure improved the sensitivity and consumed less organic solvent and is a greener approach.
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CHINESE JOURNAL OF CATALYSIS
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2021
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IF 8.271
Dongdong Wang,Wanbing Gong,Jifang Zhang,Miaomiao Han,Chun Chen,Yunxia Zhang,Guozhong Wang,Haimin Zhang,Huijun Zhao
Catalytic hydrodeoxygenation (HDO) is one of the most promising strategies to transform oxygen-rich biomass derivatives into high value-added chemicals and fuels, but highly challenging due to the lack of highly efficient nonprecious metal catalysts. Herein, we report for the first time of a facile synthetic approach to controllably fabricate well-defined Ni-Co alloy NPs confined on the tip of N-CNTs as HDO catalyst. The resultant Ni-Co alloy catalyst possesses outstanding HDO performance towards biomass-derived vanillin into 2-methoxy-4-methylphenol in water with 100% conversion efficiency and selectivity under mild reaction conditions, surpassing the reported high performance nonprecious HDO catalysts. Impressively, our experimental results also unveil that the Ni-Co alloy catalyst can be generically applied to catalyze HDO of vanillin derivatives and other aromatic aldehydes in water with 100% conversion efficiency and over 90% selectivity. Importantly, our DFT calculations and experimental results confirm that the achieved outstanding HDO catalytic performance is due to the greatly promoted selective adsorption and activation of C=O, and desorption of the activated hydrogen species by the synergism of the alloyed Ni-Co NPs . The findings of this work affords a new strategy to design and develop efficient transition metal-based catalysts for HDO reactions in water.
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Nanoscale
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2021
·Vol. 14
·期 6
·2199-2209
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IF 7.79
Potao Sun,Fengqi Liu,Wenxia Sima,Tao Yuan,Ming Yang,Chen Liang,Mingke Zhao,Ze Yin
During the long-term operation of solid insulation materials, strong electric fields and mechanical stress cause electrical trees and cracks that are undetectable and irreversible, leading to the failure of electronic and electrical devices. A promising means of protecting against these problems is to endow the insulating materials with some self-healing capability alongside their excellent intrinsic properties. However, this has proved extremely challenging. In this paper, we describe an ultraviolet light, moisture, and magnetic field triple-response microcapsule that enables epoxy resin materials to heal themselves against various forms of damage without affecting the intrinsic performance of the matrix. In particular, microcapsules wrapped inside functional shells containing Fe3O4 nanoparticles are precisely controlled by a targeted magnetic field and distributed in the vulnerable area of the insulation materials, resulting in a high healing rate at low doping concentrations. Using the in situ ultraviolet light emitted by the electrical trees, artificial ultraviolet light, and moisture in the operating environment, it is possible to induce active or passive curing of the healing agent, thus realizing the intelligent, non-contact, and targeted self-healing of mechanical cracks and electrical tree damage. This method opens an avenue toward the development of self-healing insulation materials for electrical and electronic applications.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2021
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IF 2.694
Hao Wang,Nianzu Zhang,Xiaopo Wang
Densities and viscosities for the binary mixtures of n-nonane/1-heptanol, n-nonane/1-octanol, n-nonane/1-nonanol, and n-nonane/1-decanol were presented in this work. The measurements were carried out using an Anton Paar digital vibrating U-tube densimeter and an Ubbelohde capillary viscometer, and the entire composition range was investigated from 303.15 to 333.15 K at atmospheric pressure. In addition, the excess molar volumes and viscosity deviations of the mixtures were calculated and discussed. The Redlich–Kister equation was used to correlate the two derived properties. Furthermore, the viscosities of the studied mixtures were fitted to Eyring-type models.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2021
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IF 3.764
Shahid Hussain,Haifeng Dong,Yanqiang Zhang,Guoxiong Zhan,Shaojuan Zeng,Huifang Duan,Xiangping Zhang
The efficient capture of carbon dioxide (CO2) has industrial, economic, and environmental significance. Here, CO2 capture performance in terms of CO2/CH4 selectivity for the zeolitic imidazolate framework (ZIF-8) is enhanced by impregnation of 1-n-butyl-3-methylimidazolium dicyanide [BMIM][DCA]. The preparation of ionic liquids (ILs)/ZIF-8 composites, their comprehensive characterization, and the impact of IL impregnation are all investigated. The crystal structure and morphology of ZIF-8 remained intact even after the impregnation of ILs, according to X-ray diffraction and scanning electron microscopy studies. The infrared spectroscopy known as Fourier transform infrared spectroscopy determines the interaction between ILs and ZIF-8 in the composite. The isotherm fitting was also performed by dual site Langmuir models, which showed good agreement with the experimental results. The CO2/CH4 selectivity results demonstrated that the ideal selectivity for the IL-impregnated ZIF-8 composite has five times higher selectivity than pristine ZIF-8 at 0.05 bar which is the highest reported selectivity. The normalized selectivity of this type of IL/ZIF-8 composite is also higher. This study suggested that the IL/MOF composite with a tunable structure have a strong potential for enhanced acid gas separation performance to meet the environmental challenges.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2021
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IF 5.279
Yujiao Cheng,Guijie Li,Houjiu Wu,Linhua Huang,Hua Wang
Light-induced off-flavor compounds in Ponkan mandarin juice were investigated during its shelf-life by headspace solid-phase microextraction multidimensional gas chromatography–mass spectrometry/olfactometry (MDGC-MS/O) and a GC–MS/pulsed flame photometric detector (GC–MS/PFPD). A total of 34 aroma-active compounds with flavor dilution (FD) factors from 2 to 128 were tentatively identified by aroma extract dilution analysis-MDGC-MS/O. Among them, a light-induced off-flavor compound with a high FD factor, methional (cooked potato), was positively identified in the Ponkan mandarin juice at the end of the shelf-life. In addition, 11 volatile sulfur compounds (VSCs), including 6 screened shelf-markers (variable identification, VID > 0.80), were identified in Ponkan mandarin juice by a sulfur detector (PFPD). Four VSCs exhibited odor activity values exceeding 1. Three VSCs (methanethiol, dimethyl trisulfide, and methional) were confirmed as key light-induced off-flavor compounds in Ponkan mandarin juice based on addition/omission experiments. Furthermore, light irradiation accelerated the degradation of sulfur precursors (methionine and MMS) and the formation of these VSCs leading to an increase in off-flavor intensity.
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TALANTA
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2021
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IF 6.057
Hua-Ming Xiao,Shuai Zhao,Ru-Ting Fan,Dilshad Hussain,Xian Wang
Short-chain fatty alcohols (SCFAs) are one of the reactants for the production of biodiesels. The SCFA residues at the trace level have a significant impact on biodiesel quality. However, the analysis of SCFAs in aged biodiesels has not been reported so far, which is probably due to the unavailability of an appropriate analytical method for the simultaneous determination of SCFAs. Herein, we developed a novel analytical approach with high sensitivity and selectivity for the simultaneous identification and determination of SCFAs in seed oil and biodiesel samples during the simulated real-time aging by stable isotope labeling assisted liquid chromatography-mass spectrometry (SIL-LC-MS). A pair of isotope labeling reagents, pyridine (Py) and [ 2 H 5 ]pyridine ([ 2 H 5 ]Py), were used to label SCFAs in biodiesels and standards, respectively. The [ 2 H 5 ]Py labeled SCFAs were used as internal standards to compensate for the detection of variances. The simultaneous determination of SCFAs was performed by LC-MS with an improved detection selectivity and sensitivity. The limits of detection (LODs) values were ranged from 0.2 to 0.5 ng mL −1 for the investigated SCFAs. Good linearity was observed in the studied ranges (R 2 > 0.99) and good precision with relative standard deviations (RSDs) was in the range of 4.9–18.1%. Average recoveries were obtained in the range of 80.3%–115.4%. The matrix effects were in the range of 70.0–104.3%. The validated SIL-LC-MS method was applied to the simultaneous quantitative analysis of SCFAs in seed oil and biodiesel samples and the LC-MS analysis could be done within 3 min. The formation mechanism of SCFAs in aged oil and biodiesel samples was also investigated by this method. The results suggest that SCFAs were formed and their composition changed during the simulated real-time aging of long-chain fatty acid (LCFA), long-chain fatty acid methyl ester (FAME), seed oil, and biodiesels. Moreover, we found that the formation of 1-pentanol and 1-hexanol was associated with the number and position of double bonds in LCFAs and FAMEs .
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JOURNAL OF CHEMICAL THERMODYNAMICS
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2021
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IF 3.178
Xuemei Zhang,Feiyan Yang,Chungui Jian,Hongwei Wang,Wangxin Kong,Guangjin Shangguan,Meifang Xia
Liquid-liquid equilibrium (LLE) data for the ternary system of (2-methyl-2-butanol + water + n -octanol) were determined at 303.15 K, 313.15 K, and 323.15 K under atmospheric pressure. The Hand equation, the Othmer-Tobias equation, and the mass balance between the feed and the conjugated phases were used to test the reliability of the experimental LLE data. The results show that the correlation coefficients ( R 2 ) of the equations are close to 1, and the relative error of mass balance is less than 0.5%. The selectivity ( S ) was used to evaluate the capacity of n -octanol to extract 2-methyl-2-butanol from the water, which is much greater than 1. Furthermore, S decreases with the mass fraction of 2-methyl-2-butanol in the aqueous phase and increases with equilibrium temperature. The NRTL and UNIQUAC models were applied to correlate the experimental LLE data, and the binary interaction parameters were obtained. The root-mean square deviations (RMSDs) for the two models obtained are less than 1.1%.
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CANADIAN JOURNAL OF CHEMICAL ENGINEERING
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2021
·Vol. 100
·期 8
·1747-1754
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IF 2.007
Jing Li,Yanjun Jiao,Qin Luo,Weixin Hu,Shenwen Fang,Chunling Tang,Qiang Liu
During the exploitation of shale gas, there are many oil-based drill cuttings (OBDC) produced, which are hazardous waste. In this paper, the characteristics of OBDC were analyzed and 25 hydrophobic deep eutectic solvents (DESs) were prepared as extractants for treating OBDC. The results showed that the DES formed by lauric acid and thymol had the highest extraction efficiency. The significant parameters of the extraction process were studied by using total petroleum hydrocarbon (TPH) as an index and the rational extraction conditions were recommended as follows: 0.8:1 mole ratio of lauric acid to thymol, 10:1 mass ratio of DES to OBDC, and 1 h extraction time at 60°C. The TPH of OBDC can be decreased from 14.75 to 0.87 wt.% at this recommended condition. The high extraction efficiency was also confirmed by energy dispersive spectrum results of treated OBDC. In addition, the lauric acid/thymol DES can be recycled and the TPH was still smaller than 1% after three cycles. This research suggests that hydrophobic DES extraction is an effective technology for TPH removal from OBDC.
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Journal of Environmental Sciences
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2021
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IF 5.565
Qiongyang Zhou,Ying Wang,Xiaochen Wang,Yuanqi Bai
Aiming to investigate the impacts of n -octanol addition on the oxidation reactivity, morphology and graphitization of diesel exhaust particles, soot samples were collected from a four-cylinder turbocharged diesel engine fueled with D100 (neat diesel fuel), DO15 (85% diesel and 15% n -octanol, V/V ) and DO30 (70% diesel and 30% n -octanol, V/V ). All tests were conducted at two engine speeds of 1370 and 2150 r/min under a fixed torque of 125 N·m. The soot properties were characterized by thermogravimetric analyzer (TGA), transmission electron microscopy (TEM) and Raman spectroscopy (RS). The higher volatile organic fraction content, lower soot oxidation temperatures and lower activation energy from TGA results indicated that both the increasing n -octanol concentration and engine speed enhanced the soot oxidation reactivity. Additionally, quantitative analysis of TEM images showed that the soot derived from DO30 had the smallest primary particle diameters and fractal dimension, followed by those of soot produced by DO15 and D100. The RS results demonstrated that the n -octanol addition and higher engine speed led to a larger D1-FWHM (D1-full width at half maximum), A D1 /A T (area ratio of D1 band and the total spectral) and A D3 /A T (area ratio of D3 band and the total spectral) as well as a smaller L a (crystallite width), revealing a lower degree of graphitization. Furthermore, the correlations between characterization parameters of soot properties and reactivity were nonlinear.
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Journal of Cleaner Production
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2021
·
IF 9.297
Ya Gao,Tong Yue,Wei Sun,Dongdong He,Chenglong Lu,Xinzhuang Fu
Acid recovering and iron recycling from pickling waste acid are the desired goal of the steel mills for current ecological requirements and economic benefit. This study proposed a novel method to treatment the pickling waste acid using extraction separation of ferric chloride and hydrochloric acid , following by the spray pyrolysis of ferric chloride stripping liquor. Comparing the Ruthner method, the significant technical advantages of this method is the lower treatment load and operating costs for the spray pyrolysis process, attributing to the reuse of most hydrochloric acid without iron powder neutralizing. Different extractants (TBP, CYC, IA, OA, and PA) are compared to extract ferric ion from high-concentration hydrochloric acid solution and the optimum conditions are researched. Spectroscopic analysis is performed to characterize iron state in extractants. For the stripped solution, spray pyrolysis is employed to produce high-purity Fe 2 O 3 fine particles, meanwhile hydrochloric acid is recovered for following pickling procedure. The results showed that the effect of CYC under lower O/A ratio was better than that of TBP, and the opposite occurred at higher ratios. Three-stage extraction efficiency can reach over 80% at O/A = 2:1. The final O/A ratio of 1:1 was chosen for the stripping of iron-loaded extractants. Raman and UV–visible found that it was [FeCl 4 ] - anion that existed in Fe-loaded TBP and CYC. Spray pyrolysis at 1000 °C can obtain fine pure Fe 2 O 3 and hydrochloric acid. Eventually, a feasible technological process was put forward to recycle all chemicals and achieve zero emission of water and solid waste in the whole process.
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危险品化学品经营许可证（带存储）