SEPARATION AND PURIFICATION TECHNOLOGY
·
2017
·
IF 3.359
Ying Zhang,Ting-An Zhang,David Dreisinger,Weihua Zhou,Feng Xie,Guozhi Lv,Weiguang Zhang
In the current study, a novel chelating extractant Mextral 973H was employed to selectively extract V(V) from a low pH sulfuric acid solution containing high concentration of Fe (Ш). The extraction of V(V) is strongly dependent on solution pH, and the separation coefficient (β (V/Fe) ) between V(V) and Fe(Ш) can be greater than 720 when the solution pH < 0.5. A cation exchange between H and VO 2 + was proposed as the main extraction mechanism at pH < 1.5, while at pH > 1.5, a solvating reaction between the extractant and metal-oxo cluster anions took place. The effects of solution pH, acid medium types, contacting time and temperatures on the extraction and separation of V have been discussed. FT-IR and 1 HNMR were applied to confirm the extraction mechanism and also the degradation behavior of Mextral 973H in some extreme conditions. The loaded vanadium was effectively stripped using a diluted 0.2 M Na 2 CO 3 solution and a total stripping extent of 97% was achieved. The extraction process by Mextral 973H was finally simulated using Aspen Plus simulator comparing to traditional process, the results obtained were in good recovery efficiency and with the advantage of acid and alkali saving.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
·
2013
·
IF 1.233
Shunping Wang,Xiaodeng Yang,Qingquan Bai,Tianduo Li
A number of tertiary amines and organotin catalysts for the phenyl isocyanate- 1,2-propylene glycol reaction were investigated by using in situ FT-IR. The reaction rate of each hydroxyl group, which is defined as the ratio between the rate constant of the secondary hydroxyl group and the rate constant of the primary hydroxyl group, is described with a second-order equation. The influence of different catalyst concentrations as well as the reaction temperature is discussed. It is observed that the selectivity depends on temperature but not on concentration, and stannous octoate is the most effective catalyst. The thermodynamic parameters were determined for the catalyzed reactions, primary and secondary hydroxyl groups being differentiated.
研究领域:
化学工程
·
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
Polymers
·
2020
·Vol. 12
·期 6
·1318
·
IF 3.426
Ruitao Wang,Chunxiang Li,Zhaohua Jiang,Zhijiang Wang
The traditional two-component waterborne polyurethane coating system cannot effectively inhibit the undesirable side reaction between polyisocyanate and water during curing hardening. It is difficult to avoid the microbubbles formed by this reaction during the film formation process, which severely degrades the appearance and decreases the performance of the film. Therefore, the addition of an amphiphilic Linear-Dendritic carbosilane Block Surfactant (LDBS) to the hardener can physically separate the polyisocyanate emulsion from water through self-assembly. The bubble-free film thickness (BFFT) of the two-component waterborne polyurethane coating in this study is approximately 1.5-fold greater than commercial waterborne polyurethane coatings in today’s coating industry. Fourier transform infrared spectroscopy (FT-IR) varied the effectiveness of LDBS for inhibition of the undesirable side reaction. The successful application of the waterborne polyurethane coating with LDBS on the 600 km/h high-speed maglev train provides a technical solution for large-scale industrialization of waterborne polyurethane coating and complete replacement of solvent polyurethane coating.Keywords:linear−dendritic;self-assembly;polyurethane;waterborne coatings;FT-IR
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Yuning Meng,Xindian Wang,Feng Zhang,Zhibing Zhang,Youting Wu
Dual amino functionalized ionic liquid tetramethylammonium lysinate ([N1111][Lys]) was synthesized and mixed with 2-[2-(dimethylamino)ethoxy]ethanol (DMEE) to obtain a series of nonwater absorbents for CO2 capture. The density and viscosity of the IL hybrids were measured. Using dual-vessel absorption system, CO2 absorption capacity and rate were investigated over a wide range of IL mass fractions (5–100%) to evaluate the influence of DMEE content, and 20% was chosen for further studies including influences of temperature and regeneration performances. Mass transfer coefficients with constant absorption area were calculated from apparent absorption rate constant. Fourier transform infrared (FT-IR) and 13C NMR spectra were applied to indicate the absorption process and mechanism. This new nonwater mixed system was proved to have high absorption capacities and prominent regeneration efficiency under mild conditions (80 °C).
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Zhengyu Hu,Penghui Wang,Hongli Zhou,Yaping Li
Response surface methodology (RSM) combined with a Box–Behnken design (BBD) was used to optimize the hot-water extraction (HWE) conditions which were determined to be: liquid-solid ratio 29.25:1 mL/g, extraction time 1.66 h, extraction temperature 95 °C, the optimized yield of polysaccharides 0.47 ± 0.01% ( n = 3). Hot-water extraction polysaccharides (HWEP) and Microwave-assisted extraction polysaccharides (MAEP) both consist of Rha:Xyl:Ara:Fru:Glu with the molar ratio of 1.05:1.21:3.86:1:3.61:4.5 and 1:1.95:1.72:1.78:4.36:6.18, respectively. Ultrasound-assisted extraction polysaccharides (UAEP) consists of Rha:Xyl:Ara:Fru:Man:Glu with the molar ratio of 1:2.31:5.23:1.05:3.17:4.17:7.89. The molecular weight distribution of HWEP, MAEP and UAEP ranged from 16 kDa to 1698 kDa, 15 kDa to 913 kDa, and 17 kDa to 1118 kDa, respectively. The absorption peaks in FT-IR confirmed the skeletal modes of the pyranose ring in polysaccharides. The second derivative of FT-IR proved difference of polysaccharides obtained from different extraction methods. The antioxidant activity investigations shown all three polysaccharides extracts possess high scavenging activity of DPPH radicals, hydroxyl radical and ABTS+ radical. Polysaccharides from Carex meyeriana Kunth (CMKP) might be potentially used for various practical applications such as medical and food industries, and this paper provides a theoretical basis and reference for further study of CMK.
研究领域:
植物化学
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食品科学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Sustainability
·
2023
·Vol. 15
·期 15
·12057
·
IF 3.9
Won-Kyu Kim,Hanbai Park,Kazuei Ishii,Geun-Yong Ham
Microplastics can cause physical, chemical, biological, and structural problems in soil. In this study, microplastics were identified in the soil near two landfills where contamination by microplastics was expected. Pretreatment was performed to remove organic matter and to separate microplastics from the soil samples. FT-IR microscope analysis was performed to confirm the quantity and types of microplastics. The colors and shapes of microplastics in the soil were analyzed using a digital microscope. Averages of 73.4 MPs(ea)/kg and 97.8 MPs(ea)/kg of microplastics were identified in the soil at the two landfills. The main shapes of microplastics were fragments, fibers, and films, and it was confirmed that secondary plastics were found at a high rate. The major plastic types were identified as PP and PE, ranging from 62.5 to 65.3% in proportion, followed by PET, PS, nylon, PMMA, and PVC. As for the colors of microplastics, black had the highest percentage, while other microplastics were identified as being white, blue, transparent, gray, green, red, and yellow. These results can be taken as important data indicating that microplastics in the soil around landfills can be affected by landfill waste.Keywords:microplastics;soil;landfill;FT-IR;shape;color;composition
研究领域:
环境科学
·
生态学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
·
2013
·
IF 1.233
Shun
Ping Wang,Xiao
Deng Yang,Qing
Quan Bai,Tian
Duo Li
A comparative kinetic study of the urethane reactions of phenyl isocyanate and 1,2-, 1,3-, and 1,4-butanediol was carried out in dichloromethane solution with zirconium (IV) acetylacetonate as catalyst. In situ FT-IR was used to follow the kinetics of the reactions at a constant temperature of 15°–30°C. The rate constants for the reaction of the primary hydroxyl group and the secondary hydroxyl group were calculated as k
prim and k
sec, respectively. Analysis of the second-order rate constants of these systems indicated that k
prim follows 1,2-butanediol >1,3-butanediol >1,4-butanediol. The ratio of k
prim/k
sec in 1,2-butanediol was the highest and the order followed was the same as with the reaction rate. Activation energies and Eyring parameters were also determined for the urethane reaction of butanediols.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2023
·
IF 2.1
Junjie Zhou,Kangkang Guo,Fan Wang,Yaping Zhu,Huimin Qi
Herein, the catalytic effects of aromatic amines with different structures on the room temperature curing of bisphenol E cyanate (BECy) have been studied using differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopy. Our results revealed that the mixed amine comprised of aniline and N,N-dimethyl-p-phenylenediamine (AN/NNDPA) bearing primary amino groups in its structure was a highly effective catalyst for the room temperature curing of cyanate esters. When the cyanate ester and mixed amine were combined at a molar ratio of 100:5 and cured at room temperature for 5 days, the curing degree of BECy resin reached 79.7%. The room temperature curing mechanism of the BECy-AN/NNDPA system was investigated using pyrolysis gas chromatography-mass spectrometry (PY GC-MS). Our results showed that the formation reactions of the intermediate structure and cyclotrimerization reactions occurred during the room-temperature curing process. The activation energies of BECy and different aromatic amine systems at different heating rates were determined using non-isothermal DSC. The results further demonstrated the catalytic effect of AN/NNDPA on the cyanate ester curing reaction. BECy-AN/NNDPA cured at room temperature has suitable heat resistance and a 5% weight loss temperature (Td5) of 361°C.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 2.368
Qing Xu,Jianbo Guo,Chunmei Niu,Jing Lian,Zhenghao Hou,Yankai Guo,Shaoying Li
This study investigated the denitrification characteristics and practical applications of PET–CAs (chloroanthraquinones immobilised on polyethylene terephthalate), which are novel functional biocarriers. The PET–CAs were characterized using Fourier transform infrared spectroscopy (FT-IR) and energy dispersive spectrometry (EDS). Among the PET–CAs, PET-1,8-DCA (PET modified by 1,8-dichloroanthraquinone) was the best functional biocarrier for accelerating the denitrification process with approximately 0.14 mmol anthraquinone. The denitrification process was pseudo-zero order, with C NO3 − = 175.64–19.28 t and R 2 = 0.9715. The pH of the PET-1,8-DCA system increased and ultimately reached 9.7. The stabilized ORP value with PET-1,8-DCA was approximately 70 mV lower than that of the control with PET . This study explored a novel design concept for the immobilization of quinone.
研究领域:
环境生物学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2017
·
IF 3.671
Jun Yuan,Shuxian Chen,Liping Wang,Tingting Xu,Xu Shi,Yi Jing,Haijiang Zhang,Yange Huang,Ying Xu,Dong Li,Xing Chen,Jianhui Chen,Qingping Xiong
The aim of this paper was to prepare purified fractions of polysaccharides from Monetaria moneta Linnaeus and further compare their characteristics and antioxidant activities. Firstly, three novel purified fractions, named MM-P1, MM-P2 and MM-P3, were successfully prepared by a DEAE-Sepharose fast-flow column. Then, their characteristics were compared using chemical testing, FT-IR, GC and HPGPC. The results suggested that MM-P3 had higher molecular weights than MM-P1 and MM-P2. MM-P1 was consisted of glucose, MM-P2 was consisted of glucose and xylose, and MM-P3 was comprised of glucose, xylose and mannose. Differed from MM-P1 and MM-P2, MM-P3 had sulfuric radical and uronic acid groups. Finally, their antioxidant activities were also compared. We found that MM-P3 exhibited better antioxidant bioactivities than MM-P1 and MM-P2. The data demonstrated that three purified fractions derived from different adsorption capacity of DEAE-Sepharose fast-flow column possessed different structural characteristics and antioxidant activity.
研究领域:
生物化学
·
药理学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2014
·
IF 3.065
Lidan Lv,Jie Zhang,Chongpin Huang,Zhigang Lei,Biaohua Chen
The removal of dimethyl disulfide from model liquefied petroleum gas using metal salt impregnated zeolite as the adsorbent was studied in a fixed-bed adsorption equipment. Effects of different carrier, metal iron species and content of active component, mass space velocity, temperature, as well as adsorption selectivity and regeneration performance were all investigated by performing the breakthrough experiment. Among all these adsorbents, 5 wt.%Ag 2 O/NaY showed the highest breakthrough sulfur capacity. The adsorption selectivity of Ag 2 O/NaY was studied by the infrared spectra. It was found that the direct S–Ag(I) interaction was the essential reason for the evidently improved adsorption ability and selectivity of Ag 2 O/NaY for removing disulfide from solutions containing olefin . Regeneration study indicated that the saturated adsorbent was regenerated under the temperature of 550 °C for 8 h in the air atmosphere. After five times regeneration, the adsorbent Ag 2 O/NaY still shows high breakthrough sulfur capacity.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED MICROBIOLOGY
·
2025
·
IF 3.2
Zhang Chuhan,Qin Lijun
AimsTo determine the optimum conditions for extracting Eucommia ulmoides gum (EUG) from Eucommia ulmoides leaves during fermentation by Coprinellus disseminatus. At the same time, the EUG characteristics were characterized.Methods and resultsThe ability of C. disseminatus to secrete degrading enzymes, including enzyme activity and lignocellulose content, was observed by culturing C. disseminatus on a medium with different formulations. Based on the optimal formula, the fermentation conditions were determined by an orthogonal test and EUG was extracted. After that, the characteristic parameters of EUG were determined by FT-IR, 1H-NMR, SEM, POM, DSC, XRD and GPC. The results showed that the lignin and hemicellulose contents in Eucommia leaves decreased significantly with the increase of fermentation days, and C. disseminatus mediated fermentation had an obvious damage effect on the tissue of Eucommia leaves. At the same time, At the same time, xylan can be used as an initiator to induce the expression of degradation-related enzymes. The extraction yield of EUG from Eucommia ulmoides leaves after fermentation was 3.06%, which was significantly improved. The optimum fermentation conditions were 4% inoculum, 28°C fermentation temperature, and pH = 5. The results of infrared FT-IR and 1H-NMR showed that the extract had typical characteristics of EUG, and the surface and quenching part of the EUG were smooth, as observed by SEM. In addition, DSC and XRD analysis show that there are two crystal types, α and β, in the crystallization process of molten EUG. The main crystallization type of EUG extracted from fermented leaves was β type.ConclusionThe ability of C. disseminatus to produce degrading enzymes can effectively improve the extraction rate of EUG under optimal fermentation process. The method can maintain the integrity of gutta-percha better. EUG has the characteristics of good crystallinity, many β crystal types and high molecular weight.
研究领域:
生物技术
·
生物化学
·
材料科学
·
植物学
✓ 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）