FirePhysChem
·
2023
·
IF 0
Xinyi Li,Yuangang Xu,Jianxin Zhou,Tianyang Hou,Ze Xu,Pengcheng Wang,Ming Lu
As an important intermediate in the synthesis of most energetic pentazole compounds, the reaction system of sodium pentazole is complex and has many by-products, but there is no suitable HPLC analysis method. Based on the study of ultraviolet absorption peak of sodium pentazole aqueous solution, the HPLC purity analysis method of sodium pentazole was successfully established and its sensitivity, accuracy and repeatability were verified. When the detection wavelength was 192 nm, the chromatographic column was Agilent WondaSil C18 Superb (4.6 × 250 mm, 5 μm), the mobile phase was 95% water and 5% acetonitrile mixed solution, the flow rate was 0.8 ml/min, the analysis time was 8 min, the sample size was 1 μL and the column temperature was 40 °C, a liquid phase map of sodium pentazole was obtained. The analysis results showed that the retention time of pentazole sodium was 3.76 min, and showed a good linear relationship in the range of 0.3068–0.3288 g/L. The linear equation is y = -217447.64+835837.85 x , the correlation coefficient R 2 is 0.99997, and it has good sensitivity, accuracy and repeatability. In addition, three by-products from the synthesis of sodium pentazole were simply separated.
研究领域:
分析化学
·
有机合成
✓ 已验证
DOI
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
S.H.E.N. Ya-Qiang,L.I. Dong-Yun,X.U. Yang,G.E. Hong-Liang,X.U. Qiang,Y.A.N.G. Hui
High purity ultrafine alumina powders with different crystalline phases and morphologies were prepared by solid-phase sintering method. The influence mechanism of halides on the particle characteristics of alumina powders was studied. The results showed that NH 4 F additives induced the conversion of metastable alumina to α-alumina at high temperature, lowered the phase transformation temperature of α-alumina by about 300 °C, increased the α-alumina conversion rate by about 11.6%, reduced the sodium oxide content by about 72.3 wt%, and caused the alumina crystals to grow in a platelet shape manner. By comparison, NH 4 Cl additives had less effect on the transition temperature of α-alumina and the impurity content, and the particle morphology of alumina was a mixture of vermicular and platelet shapes. This study revealed the influence mechanism of two kinds of halides on the phase conversion, morphology evolution, and sodium removal of alumina powders from sintering mechanism and the theories of crystal structure, adsorption on the solid surface, and electronegativity of atoms.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Dan Wang,Yuanmin Gong,Meiting Yan,Jiaqi Chen,Xueping Tao,Yang Zhou,Yan Ma,Li Rao,Panpan Chen,Qifeng Fu
Carbon dots (CDs) hold great potential for chromatographic separations. However, their application in chromatographic stationary phases has been limited by two major synthetic challenges: (1) insufficient control over surface chemoselectivity caused by impurity co-adsorption, and (2) structural heterogeneity arising from uncontrolled solvothermal byproducts. To address these limitations, we developed a self-polymerization-driven strategy to synthesize high-purity hydrophobic CDs from 8-amino-2-naphthol (8N2OH) and 2,3-dihydroxynaphthalene (DHN). These CDs were incorporated into organic polymer monoliths via in situ copolymerization, yielding novel 8N2OH-CDs and DHN-CDs hybrid monolithic stationary phases for reversed-phase capillary liquid chromatography. The synthesized CDs were thoroughly characterized, with high purity confirmed by proton nuclear magnetic resonance. The resulting monolithic columns exhibited high permeability and uniformity, as demonstrated by field emission scanning electron microscopy, attributed to the excellent dispersion of the CDs. The chromatographic performance was evaluated using nine types of neutral, alkaline, and acidic compounds, as well as Tanaka standard test mixtures. Compared to unmodified columns, the CD-modified monoliths showed significantly enhanced retention strength and selectivity, supported by Tanaka tests revealing multifactorial retention mechanisms. This work demonstrates the potential of high-purity hydrophobic CDs as versatile modifiers for high-performance chromatographic stationary phases.
研究领域:
分析化学
·
材料科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Haibin Xu,Chang Xu,Yuting Zheng,Dezhi Zhang,Haomiao Zhang,Jingdai Wang,Yongrong Yang
We present a continuous flow strategy for synthesizing a high-purity primary explosive, silver acetylide-silver nitrate (SASN), using a 3D-printed acetylene bubble generator coupled with a vibration device and a coiled tubular reactor. The mass transfer enhancement by the active mixing provided by vibration and Dean vortices in the coiled reactor mitigates the deposition of SASN particles on the reactor walls. We obtain high-purity SASN products by optimizing the reactor configuration and process conditions. SEM analysis indicates bulbous-shape SASN particles with 150–300 nm size in acetonitrile; DSC analysis reveals three main peaks between 180–230 °C and facilitates the evaluation of activation energies using the Ozawa method. The as-synthesized SASN exhibits excellent sensitivities as compared with other primary explosives. This gas–liquid-solid flow approach is effectively and safely scaled up by increasing the volumetric flowrate under fixed reaction time and can be readily extrapolated to other continuous syntheses with solids generation.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Particuology
·
2024
·
IF 4.1
Chaofan Wu,Longjin Jiang,Wei Wang,Bin Dong,Zhidong Chang,Daixiang Wei,Hira Anwar,Minghui Zhang,Dekun Gao
Lithium carbonate (Li 2 CO 3 ) stands as a pivotal raw material within the lithium-ion battery industry. Hereby, we propose a solid-liquid reaction crystallization method, employing powdered sodium carbonate instead of its solution, which minimizes the water introduction and markedly elevates one-step lithium recovery rate. Through kinetic calculations , the Li 2 CO 3 solid-liquid reaction crystallization process conforms by the Avrami equation rather than shrinking core model, which means the dissolution rate of Na 2 CO 3 is the most important factor affecting the reaction process. The effects of reaction conditions such as temperature and stirring speed on the Li 2 CO 3 precipitation behavior were evaluated. The results indicated that temperature is a most essential parameter than other reaction conditions or stirring speed. The exceptional 93% recovery of Li 2 CO 3 at 90 °C with a remarkable purity of 99.5% was achieved by using 1.2 M ratio of Na 2 CO 3 /Li 2 SO 4 . This method provides a new idea for the efficient preparation of battery-grade Li 2 CO 3 .
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Ruizhuo Liu,Jian Cao,Zhongwei Zhao,Yongli Li
Solvent extraction with organophosphorus extractants has potential as a low-cost method for efficient Mo recovery for acidic leaching solutions. However, improved selectivity is required to obtain high-purity Mo products. In this study, various acidic organophosphorus extractants were compared, and 2-ethylhexylphosphonic acid mono-(2-ethylhexyl) ester (P507) was found to be optimal for efficient Mo extraction and Fe separation from acidic leaching solutions. Under the optimized conditions (40 vol% P507, 3:1 organic/aqueous, 20 °C, 5 min), the Mo and Fe extraction efficiencies reached 98.1 % and 35.2 %, respectively, with a separation factor of 90.1. The Mo/Fe separation efficiency was further improved using a two-stage countercurrent extraction method. The Mo extraction efficiency was attributed to coordination bonds (P = O → Mo) formed between Mo(VI) oxycations and P507 dimers, as well as covalent bonds (P O Mo) formed by substituting the hydrogen ions in P507. Increasing the H 2 SO 4 concentration in the leaching solution gradually transformed MoO 2 2+ into Mo 2 O 5 2+ dimers, which formed MoO 2 (HA 2 ) 2 and Mo 2 O 5 (HA 2 ) 2 metal complexes during the extraction process. HCl scrubbing of the loaded organic phase effectively removed Fe. For subsequent ammonia stripping of the HCl-scrubbed organic phase, the optimal ammonia concentration was 1.25 mol/L. Further increasing the ammonia concentration promoted the saponification reaction of ammonia with P507, thereby reducing the Mo stripping efficiency. In summary, using multistage countercurrent extraction, increasing the H 2 SO 4 concentration in the leaching solution, and scrubbing the loaded organic phase with HCl facilitate efficient Mo/Fe separation, providing a feasible approach for the preparation of high-purity ammonium molybdate with broad application prospects.
研究领域:
冶金化学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Han Sun,Zhiyi Wang,Jiming Su,Yingshuang Zhang,Chongqing Wang,Hui Wang,Hongru Jiang
Plastics offer considerable convenience in daily life and human health. However, a substantial amount of waste plastics is released into the environment without proper treatment, posing significant environmental challenges. Recycling and separating waste plastics is difficult due to their similar chemical and physical properties. This study introduces a novel method combining polymeric ferric sulfate (PFS) modification with flotation for efficient plastic separation. In order to achieve the optimal flotation conditions, single parameter experiments were used to confirm the key variables that have a close correlation with the flotation performance, namely PFS dose, temperature, time and pH value. PFS has different hydrophilic effects on polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS) and polyvinyl chloride (PVC) surfaces, whereas polyethylene terephthalate (PET) remains unaffected. For purpose of achieving the individual separation of the plastics, a stepwise flotation method was used. After the primary separation, PET and PC were discharged, while all plastics were individually separated and retained at high purity through the secondary separation process, resulting in 100% purity for both PET and PVC. PC and ABS can achieve 97.4% and 94.5% purity in triplicate validation tests, respectively. Surface modification mechanisms were investigated using X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FT-IR), and Scanning Electron Microscopy (SEM). Based on varying functional groups and surface potentials, PFS can adhere to different plastic surfaces for extended durations, creating the hydrophilicity difference. Nonhomogeneous adsorption of PFS on plastics surfaces was described by characterization and adsorption kinetics. The hydrophilization order and PFS adsorption capacity were consistent: PVC > ABS > PC > PET. The interaction between PFS and plastics was explained by density functional theory (DFT) simulations, the long-chain molecules and numerous hydroxyl groups primarily interact with the plastic surface through electrostatic forces and hydrogen bonds. Through optimization of the PFS treatment process, the consumption of the modification reagent was successfully reduced to 56.51 g/ton of waste plastic with the reuse of PFS. Our process optimization assessment highlights that PFS treatment is a highly effective method for recycling waste plastics.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2019
·Vol. 17
·期 2
·778-789
·
IF 1.074
Weihua Chen,Jiancheng Tang,Xingwang Shi,Nan Ye,Zhihao Yue,Xinghao Lin
High-purity titanium aluminum carbide (Ti 3 AlC 2 ) powders were synthesized by a microwave sintering method using different titanium sources as raw materials. The prepared products were characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated that the synthesized Ti 3 AlC 2 powders have high purity (97.5%) and even distribution of the grain size when using a 3TiH 2 /1.2Al/2C mixture as raw materials when the microwave sintering temperature and time were 1300°C and 30 minutes, respectively. The formation mechanism of the Ti 3 AlC 2 is described as proceeding via four stages. The solid-phase reaction between titanium and aluminum occurs below the melting point of aluminum and the main product is a Ti 3 Al phase, which is an observed intermediate compound for the formation of Ti 2 AlC and Ti 3 AlC 2 . Thus, this study provides a beneficial approach to low-temperature synthesis of high-purity Ti 3 AlC 2 materials.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
Royal Society Open Science
·
2019
·Vol. 6
·期 1
·
IF 2.515
Yujie Chen,Lili Zhang,Juan Yu,Yingzhao Lu,Bo Jiang,Yimin Fan,Zhiguo Wang
Deep eutectic solvents (DESs) have potential applications in biomass conversion and green chemicals due to their cost-effectiveness and environmentally friendly properties. This study reports on a feasible method of using DESs for lignin selective extraction from poplar wood meal. DESs obtained from various hydrogen-bond donors and acceptors were used to evaluate the dissolving capacity of lignin from poplar wood meal. Among the various DESs, lactic acid: choline chloride (9 : 1) exhibits the optimal extraction capacity, which is capable of selectively dissolving 95% of lignin from poplar wood meal at 120°C for 6 h. The purity of isolated lignin reaches 98% after regeneration in water. From Fourier Transform-IR, nitrobenzene oxidation and nuclear magnetic resonance analysis, the results demonstrate that the DESs can selectively cleave ether linkages and damage the non-condensation section of lignin, thereby facilitating lignin dissolution from wood meal. Thus, this study provides a promising route for the extraction of high-purity lignin from biomass materials.
研究领域:
林学
·
生物质化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Processes
·
2019
·Vol. 7
·期 6
·377
·
IF 1.963
Taotao Liang,Xiaogang Guo,Abdulmoseen Segun Giwa,Jianwei Shi,Yujin Li,Yan Wei,Xiaojuan Wang,Xuansong Cao,Xiaofeng Tang,Jialun Du
Methyl methacrylate (MMA) plays a vital role in national productions with broad application. Herein, the production of MMA is realized by the improved eco-friendly direct methylation method using Aspen Plus software. Three novel kinds of energy-saving measures were proposed in this study, including the recycle streams of an aqueous solution, methacrolein (MAL), and methanol, the deployment of double-effect distillation instead of a normal one, and the design of a promising heat-exchange network. Moreover, MMA with a purity of 99.9% is obtained via the design of a MAL absorber column with an optimal stage number of 11 and a facile chloroform recovery process by using the RadFrac model. Thus, the proposed green process with energy-conservation superiority is the vital clue for developing MMA, and provides a reference for the production of MMA-ramifications with excellent prospects.Keywords:MMA;double-effect distillation;energy conservation;MAL;purity
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
Bioresources and Bioprocessing
·
2014
·Vol. 1
·期 1
·1-8
·
IF 0
Ma Xiaolei,Cao Xuejun
Background Ursodeoxycholic acid is an important clinical drug in the treatment of liver disease. In our previous work, ursodeoxycholic acid was prepared by electroreduction of 7-ketolithocholic acid. The separation of ursodeoxycholic acid from the electroreduction product (47% ( w / w ) ursodeoxycholic acid) by silylation crystallization is described herein. Results N , N -dimethylformamide was used as the solvent, whereas hexamethyldisilazane was the reaction agent. The optimal material ratio of electroreduction product/ N , N -dimethylformamide/hexamethyldisilazane was found to be 1:10:2 ( w / v / v ). The reaction proceeded for 2 h at 60°C, and the corresponding silylation derivative was separated by crystallization and pure ursodeoxycholic acid was recovered by 5% acid hydrolysis at 50°C for 0.5 h. The maximum recovery and purity of ursodeoxycholic acid were 99.8% and 99.5%, respectively. Conclusion Ursodeoxycholic acid with high purity and high recovery can be prepared directly. The developed method offers a potential application for large-scale production of ursodeoxycholic acid.
研究领域:
药学
·
有机化学
✓ 已验证
产品关联
DOI
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
·
2013
·
IF 2.823
Jian-Yong Zheng,Jia-Yu Wu,Yin-Jun Zhang,Zhao Wang
The mycelium of Aspergillus oryzae WZ007 was successfully developed to kinetic resolution of ( R , S )-ethyl-2-(4-hydroxyphenoxy) propanoate (( R , S )-EHPP) for production of ( R )-ethyl-2-(4-hydroxyphenoxy) propanoate (( R )-EHPP). The key biocatalytic process parameters (pH, temperature, rotation speed and substrate concentration) were optimized. Under the optimum conditions, the optical purity of ( R )-EHPP was improved up to >99% when the conversion was above 49%. A. oryzae WZ007 whole-cell lipase exhibited high reaction capacity, enantioselectivity and good reusability. The tolerable substrate concentration was 0.5 mol/L, and dry mycelium of A. oryzae WZ007 maintains over 80% of its initial activity after eight repeating cycles. Therefore the enzymatic preparation of ( R )-EHPP route was suitable for industrial application.
研究领域:
生物化学
·
微生物学
·
制药工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）