JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Changchun Wang,Xingming Jie,Lixin Li,Guodong Kang,Dandan Liu,Yiming Cao,Yi Wei,Lina Wang
Thermally rearranged (TR) polymers are well known for their exceptional gas permeability and have been considered as promising candidates for hollow fiber membranes in natural gas purification. However, the conventional TR process requires temperatures above 400 °C, which often compromises both gas transport performance and mechanical integrity. In this study, we developed Claisen thermal rearrangement (CTR) hollow fiber membranes derived from allyl-functionalized copolyimides under mild thermal conditions. By exploiting the [3,3]-sigmatropic rearrangement, the required rearrangement temperature was reduced to 160 °C. The resulting CTR membranes demonstrated a CO 2 permeance of 281.57 GPU with a CO 2 /CH 4 selectivity of 25.37 after thermal treatment at 200 °C. Notably, CTR fibers exhibited excellent resistance to CO 2 plasticization up to 2.0 MPa, markedly superior to their precursor membranes. Furthermore, the elastic modulus of CTR hollow fiber membranes increased by more than an order of magnitude, reaching 1.56 GPa. Overall, this work presents an energy-efficient strategy based on [3,3]-sigmatropic rearrangement for fabricating high-performance hollow fiber membranes, holding great potential for application in natural gas purification.
研究领域:
材料科学
·
膜分离技术
·
高分子化学
·
气体分离
·
能源化工
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Qin Zhang,Guo-Rui Zhu,Xiang-Xin Xiao,Min Jiang,Feng-Ming He,Xin Li,De-Ming Guo,Hai-Bo Zhao,Ze-Yong Zhao,Li Chen,Bo-Wen Liu,Yu-Zhong Wang
With the increasing public awareness of safety and the ongoing global legislation on the use of flame retardants, the development of eco-friendly flame-retardant methods has become an urgent issue. In this study, we utilized the room-temperature hydrogen-bonding effect and the high-temperature rearrangement inherent in the functional hydroxyl-containing phenylimide structure to engineer a flame-retardant, high-performance aliphatic polyamide. Remarkably, the obtained polyamide copolymer was exclusively composed of the elemental constituents inherent to polyamide itself, i.e., carbon, hydrogen, oxygen, and nitrogen. As expected, the high-temperature rearrangement along with the corresponding char-forming and end-group-capturing effect significantly improved the flame retardancy of the copolymer, characterized by an UL-94 V-0 rating with great anti-dripping performance, 41% reduction in peak heat release rate and 50% reduction in total heat release. The room-temperature hydrogen bonding largely mitigated the deterioration of the chain symmetry and regularity caused by the incorporation of the monomer, thus resulting in substantial preservation of mechanical properties. Furthermore, the copolymer exhibited low dielectric properties and high heat resistance, thereby broadening its potential application domains. This work presented a novel flame-retardant-free strategy for achieving both flame retardancy and high performance in polymeric materials, meeting the increasingly stringent demands for environmental protection and safety.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2024
·Vol. 14
·期 1
·36
·
IF 3.8
Min Zheng,Xiangzhou Li,Dulin Yin,Steven R. Kirk,Hui Li,Peng Zhou,Yanhong Yang
Carveol is a rare fine chemical with specific biological activities and functions in nature. The artificial synthesis of carveol from plentiful and cheap turpentine is expected to further improve development of pharmaceutical and industrial applications. A new green catalytic system for the preparation of high-value carveol from α-epoxypinane is presented. A novel ammonium salt solid acid (AC-COIMI-NH4PW) was obtained from phosphotungstic acid bonded with imidazole basic site on nitrogen-doped activated carbon which, after ammonia fumigation, presented an excellent catalytic performance for the selective rearrangement of α-epoxypinane to carveol in DMF as solvent under mild reaction conditions. At 90 °C for 2 h, the conversion of α-epoxypinane could reach 98.9% and the selectivity of carveol was 50.6%. The acidic catalytic sites exhibited superior durability and the catalytic performance can be restored by supplementing the lost catalyst. Based on the investigation of catalytic processes, a parallel catalytic mechanism for the main product was proposed from the rearrangement of α-epoxypinane on AC-COIMI-NH4PW.
研究领域:
化学工程
·
材料科学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 32
·25365-25371
·
IF 3.84
Yang Li,Kai Wang,Kang Qin,Tao Wang
As an important green synthesis technology of caprolactam, the Beckmann rearrangement reaction of cyclohexanone oxime using high temperature and pressure water as the reaction media was carefully studied with a microreactor. An important byproduct – acetamide was confirmed with a selectivity higher than 40% in the subcritical water, which was more serious than the reported cyclohexanone. The effects of phase state and operating conditions, such as reaction temperature, pressure, flow rate ratio and reactant residence time, on the cyclohexanone oxime conversion and caprolactam selectivity were carefully analyzed, and the results showed that keeping the reaction close to the supercritical state was critical for the preparation of caprolactam.
研究领域:
化学工程
·
绿色化学
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Tong Zhou,Qingqing Chai,Man Zhang,Heping Cui,Ahmad Mohammad,Khizar Hayat,Xiaoming Zhang,Chi-Tang Ho
Exogenous xylose (Xyl) could promote 2-furfural formation but inhibit pyrazines generation during its co-heating with alanine (Ala)-Xyl Amadori rearrangement product (AX-ARP). The activation energy of AX-ARP formation from Ala and Xyl was considerably lower than that of pyrazine formation from Ala and glyoxal (GO). Accordingly, the preferential interaction of exogenous Xyl with regenerated Ala triggered a continuous cycle of consumption and regeneration of Ala in AX-ARP-Xyl model. In this way, functioning as a catalyst, regenerated Ala facilitated the continuous conversion of AX-ARP into deoxyxylosones (DXs). However, exogenous Xyl accelerated the pH drop during the thermal treatment of AX-ARP, which favored the conversion of DXs into 2-furfural while limiting the transformation of their α-dicarbonyl fragments into pyrazines. Model reactions of AX-ARP-[ 13 C 5 -Xyl] further confirmed that exogenous Xyl was progressively converted into 2-furfural, while its downstream products, such as GO and methylglyoxal (MGO), did not exhibit an enhanced tendency to form pyrazines.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2021
·Vol. 26
·期 19
·5736
·
IF 4.412
Chunhua Wang,Zhiquan Yu,Yuhao Yang,Zhichao Sun,Yao Wang,Chuan Shi,Ying-Ya Liu,Anjie Wang,Karen Leus,Pascal Van Der Voort
Upgrading furfural (FAL) to cyclopentanone (CPO) is of great importance for the synthesis of high-value chemicals and biomass utilization. The hydrogenative ring-rearrangement of FAL is catalyzed by metal-acid bifunctional catalysts. The Lewis acidity is a key factor in promoting the rearrangement of furan rings and achieving a high selectivity to CPO. In this work, highly dispersed Pd nanoparticles were successfully encapsulated into the cavities of a Zr based MOF, UiO-66-NO2, by impregnation using a double-solvent method (DSM) followed by H2reduction. The obtained Pd/UiO-66-NO2catalyst showed a significantly better catalytic performance in the aforementioned reaction than the Pd/UiO-66 catalyst due to the higher Lewis acidity of the support. Moreover, by using a thermal treatment. The Lewis acidity can be further increased through the creating of missing-linker defects. The resulting defective Pd/UiO-66-NO2exhibited the highest CPO selectivity and FAL conversion of 96.6% and 98.9%, respectively. In addition, the catalyst was able to maintain a high activity and stability after four consecutive runs. The current study not only provides an efficient catalytic reaction system for the hydrogenative ring-rearrangement of furfural to cyclopentanone but also emphasizes the importance of defect sites.Keywords:Pd/UiO-66-NO2;furfural;hydrogenative ring-rearrangement;cyclopentanone;double-solvent method
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Ji Liu,Yuan-gu Xia,Meng-fan Liu,Bin Hu,Hong-jin Zhang,Ji-hong Li,Zhen-xi Zhang,Qiang Lu
Nitrogen oxides are the major pollutants in solid fuel/waste combustion processes, which can be reduced by unburned or additive chars. The surface char–NO reaction is significantly influenced by CO 2 , whereas the impact mechanism is far from conclusive. Herein, fixed-bed experiments and computational methods were adopted to elucidate the role of CO 2 on char–NO reaction. Experimentally, CO 2 exhibited an inhibitive impact on NO reduction at 873 K but a promotive influence at 1023 K and 1173 K. According to the detection of outlet CO, characterization of char, and density function theory (DFT) calculations, CO and gasified char derived from char–CO 2 gasification are both responsible for the promotive effect at 1173 K, which offers a clear image of the gasification mechanism conjectured in previous work. More importantly, a CO 2 -mediated oxygen rearrangement (CO 2 -MOR) mechanism has been found and confirmed for the first time, which can well explain the experimental results observed at 873 K and 1023 K. The adsorbed CO 2 can intervene in the oxygen rearrangement on the char surface to alter the NO reduction behaviors. The present study offers a comprehensive insight into the roles of CO 2 in the heterogeneous reduction of NO on char surface.
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Wei Huang,Huifang Wu,Xin Yan,Jiaxing Zhang,Zhaochi Feng,Miao Yang,Peng Tian,Xinwen Guo,Limin Ren
Nine-membered-ring (9-MR) STT zeolites hold immense potential in studying the impact of pore structure on catalytic performance. However, synthesizing pure-phase STT zeolites with tunable acid sites has been challenging. This study presents a rational approach for the rapid synthesis of STT zeolites from lamella Si-MWW zeolite via a chain rearrangement process, leveraging their structural similarities and the flexibility in manipulating MWW’s layer structure. Both zeolites share a common chain comprising ordered arrangements of 4-, 5-, and 6-membered rings, facilitating robust and rapid (10 h) STT growth, with a broad Si/Al ratio range. The resulting Al-STT zeolites exhibited an olefin product distinct from the 8-MR CHA and 10-MR MFI zeolites in the methanol-to-olefin reaction, underscoring the pivotal role of 9-MR pore structure. The findings not only advance the understanding of zeolite synthesis but also demonstrate the potential of tailoring pore structures to enhance the catalytic efficiency in industrially relevant processes.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Han Zhang,Heping Cui,Xue Xia,Shahzad Hussain,Khizar Hayat,Xiaoming Zhang,Chi-Tang Ho
Exogenous xylose exhibited a significant temperature-dependent regulatory effect on the furans and pyrazines formation during the degradation of dual-glycated Amadori rearrangement product of lysine (Lys), N α ,N ε -di(1-deoxy- d -xylulos-1-yl)lysine ( N α ,N ε -di-Xul-Lys ARP). At 100 °C, xylose primarily enhanced the dehydration pathway of deoxypentosone. This significantly increased furans yield, while delaying lysine release by interacting with mono-glycated Lys-ARPs, thereby inhibiting the early formation of pyrazines. 120 °C accelerated the dehydration and retro-aldolization of deoxypentosone, markedly boosting furans formation and further promoting the substantial production of α -dicarbonyl compound with extra-added xylose. Additionally, xylose buffered the rapid pH decline, enhancing the α -aminoketones electrophilicity and facilitating pyrazines formation in N α ,N ε -di-Xul-Lys ARP. At 140 °C, xylose hindered furans formation but notably increased methylpyrazine levels during 30–60 min. Furthermore, increasing the xylose concentration to 60 mmol/L at 120 °C markedly enhanced glyoxal and methylglyoxal production, yielding the highest pyrazine concentration of 98.04 μg/L within 60 min.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2017
·
IF 2.895
Jin-Pei Huang,Fu-Ning Sang,Guang-Sheng Luo,Jian-Hong Xu
In this paper, a microreaction system was developed to intensify the synthesis process of Gabapentin. Due to the high mass and heat transfer performance, Hofmann rearrangement can be achieved continuously by one-step microreaction process at relatively high temperature (40–45 °C) with a residence time (5–7 min) much shorter than the conventional 4–5 h in batch reactors. By studying the effects of concentration and temperature on the reaction rate, an apparent kinetic model was developed to help understanding the whole process deeply and optimizing the operation conditions.
研究领域:
化学工程
·
制药工程
✓ 已验证
产品关联
DOI
高影响因子
Reactions
·
2024
·Vol. 5
·期 4
·812-822
·
IF 2.2
Joseph Dean,Natalia Buckler Reinoso,Francesco Spiedo,Carola Romero Fernández,Bhaven Patel
Flow chemistry has shown significant versatility over the last two decades, offering advantages in efficiency, scalability, and sustainability. In this study, the continuous stirred tank reactor (CSTR) was used to optimise the synthesis of α-hydroxyphosphonates via the Pudovik reaction and their subsequent conversion to phosphates through the phospha-Brook rearrangement. The study highlights that using CSTRs allows for better control over reaction parameters, leading to reduced reaction times and improved yields compared to traditional batch methods. The optimised conditions successfully facilitated a range of organophosphates, including electron-rich and electron-poor derivatives, with high efficiency. Additionally, a one-pot tandem process combining the Pudovik reaction and the phospha-Brook rearrangement was developed, reducing reaction times to two hours while maintaining comparable yields. This work demonstrates the potential of CSTRs in flow chemistry for synthesising complex organophosphorus compounds, achieving higher reaction yields and shorter reaction times, highlighting the effectiveness of continuous flow methodologies.
研究领域:
有机化学
·
合成化学
·
流程优化
✓ 已验证
DOI
高影响因子
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY
·
2017
·Vol. 53
·期 3
·459-461
·
IF 0.603
Liu X. J.,Yan Y. N.,Wang S. Q.,Li X.,Liu X. G.
A new synthetic route to 4-methoxyisophthalic acid, the key intermediate in the synthesis of Picotamide, is reported. The new protocol starts from commercially available and cheap 4-methylphenol and includes four steps: esterification, Fries rearrangement, methylation, and oxidation; the overall yield is 49%. Unlike the traditional Blanc chloromethylation/oxidation scheme, the proposed procedure avoids using volatile and corrosive hydrochloric acid.
研究领域:
有机化学
·
药物化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）