JOURNAL OF MEMBRANE SCIENCE
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2023
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IF 9.5
Zhiguang Zhang,Xiaolong Ren,Guolong Huo,Shuanyan Kang,Zhenggong Wang,Nanwen Li
Fluorinated polyimides with biphenyl structure and –CF 3 with rigid chain structure exhibit great potential in membrane-based gas separation. However, the comprehensive separation performance of this type polyimides is not competitive as a gas separation material. Structure regulation is of great significance to improve the separation performance of polymer membrane. Few studies systematically investigated structure-property relationships in fluorinated polyimide structure. In this study, carboxylic groups are introduced into a fluorinated polyimide(6FDA-TFMB) via copolymerization with DABA diamine monomer . The hydrogen bond between –CF 3 group in TFMB and –COOH group in DABA is proposed to enhance chain segment rigidity and optimize polymer chain arrangement. WAXD results and FFV data indicate that inter-chain cavity of fluorinated polyimide could be finely tuned by adjusting molar ratio of TFMB and DABA in the copolyimide. The resulted copolyimide membranes thus demonstrate tunable gas permeation properties. Gas permeability of 6FDA-TFMB/DABA firstly increases and then decreases, and ideal gas selectivity continuously increases with increasing DABA molar ratio. Among the polyimides, 6FDA-TFMB/DABA(6:4) membrane demonstrated superior separation performance, e.g. CO 2 permeability of 135.6 Barrer and CO 2 /CH 4 ideal selectivity of 31.6, surpassing the commercial cellulose acetate and Matrimid membrane. Attributed to the optimized interchain interaction, the 6FDA-TFMB/DABA (6:4) membrane displays an optimized CO 2 plasticization resistance and physical aging in comparison with 6FDA-TFMB membranes. This study provides a guideline for controlling and optimize the performance of biphenyl fluorinated polyimide gas separation membrane .
研究领域:
材料科学
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膜分离技术
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DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
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2025
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IF 6.6
Anyi Sun,Chen Yu,Zhuoran Xing,Yujie Hao,Hongjuan Li,Yan Ren
A novel strategy for analyzing free fatty acids (FFAs) in edible oils was developed using isotope-coded derivatization reagents—4-(dimethylamino)benzoylhydrazine (DABA) and d 6 -4-(dimethylamino) benzoylhydrazine ( d 6 -DABA)—synthesized via a two-step process. These reagents selectively derivatized FFAs at 35°C in 30 min, considerably enhancing mass spectrometry sensitivity. Ultra-performance liquid chromatography–high-resolution mass spectrometry (UPLC–HRMS) enabled multidimensional identification via isotope ratio analysis, retention time prediction, isotope peak matching, and carbon count–based retention behavior, excluding 47.5% of initial proposals and identifying 42 FFAs. A relative quantification method using d 6 -DABA-derivatized pentadecanoic acid as the internal standard showed good linearity ( R = 0.9914–0.9993), precision, repeatability, and stability (relative standard deviation (RSD) ≤ 13.0%). The primary FFAs in five edible oils included palmitic, stearic, linoleic, arachidonic, and linolenic acids. Specifically, linoleic acid was predominant in rapeseed oil (117525.5 ng/mL) and peanut oil (525880.0 ng/mL), stearic acid was notable in soy oil (21255.2 ng/mL) and corn oil (29349.7 ng/mL), and palmitic acid was predominant in olive oil (97834.5 ng/mL). This method offers a sensitive analytical platform with excellent tolerance to substrate interference, facilitating the study of the composition and content of FFAs in edible oils.
研究领域:
分析化学
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食品科学
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脂质组学
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质谱分析
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色谱分析
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
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IF 5.518
Senyang Song,Xiaoyan Ma,Wenyue Li,Boyuan Zhang,Jing Sun,Chuyan Deng
In order to overcome the low capacitive performance of traditional metal organic frameworks (MOFs) applied to supercapacitors , a novel conjugated small molecule monomer(3,5-diaminobenzoic acid, DABA) with amino and carboxyl groups was used as a ligand, and Ni and Co ions as metal nodes to construct novel highly electroactive bimetallic MOF(DABA-MOF) materials through a simple one-step solvothermal method . The structure and capacitive performance of obtained DABA-MOF in three organic solvents with different polarities and degrees of deprotonation (methanol, ethanol, N,N-dimethylformamide) was investigated, and it was found that with the increase of solvent deprotonation degree, the morphology of DABA-MOF with the coexistence of amino and carboxyl groups gradually changes from a smooth rod-shaped solid structure to a rough hydrangea-like structure, and the corresponding capacitive performance of DABA-MOF is also gradually enhanced. In particular, DABA-MOF synthesized in DMF can reach a maximum specific capacitance of 621 C g −1 at 1 A g −1 , and the capacitance remains as high as 81.05% even after 5000 cycles, which exhibit excellent capacitance properties. This study shows that it has potential advantages to select the mixed coordination active MOF with amino and carboxyl groups as the electrode material for supercapacitor, and the deprotonation degree of solvent has a great influence on the structure and morphology of MOF with mixed active coordination sites.
研究领域:
材料科学
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电化学
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DOI
高影响因子
PRECAMBRIAN RESEARCH
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2026
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IF 2.7
Shixi Zhang,Yangchun Han,Kun Zheng,Yichi Zhang,Litao Hao,Kunli Luo
Five correlatable stone coal layers formed in the Ediacaran-early Cambrian succession. • Critical metals display pronounced spatial-stratigraphic heterogeneity. • Layer 3 hosts anomalous Se-Mo and significant Cd-V enrichment. • Metal enrichment was dominated by hydrothermal fluids and enhanced by algal activity. • Ga, V, Mo, and Cd indicate substantial critical-metal resource potential. The Qinling-Daba Mountains represent one of the major stone coal bearing areas in China, where multiple stone-coal layers occur within the Ediacaran-early Cambrian strata. These stone coal are commonly enriched in critical metals; however, their spatial and stratigraphic enrichment patterns remain poorly understood. In this study, we investigated the enrichment characteristics of 14 critical metals across three major belts (southern, central, and north) in the Qinling-Daba stone coal area. The results show that the Ediacaran-early Cambrian strata contain five regionally correlatable stone coal layers, three within the Ediacaran and two within the lower Cambrian. Critical metal enrichment exhibits pronounced spatial and stratigraphic pattern: the southern belt displays the strongest enrichment, whereas layer 3 ( Z 2 3 ) consistently hosts the highest enrichment of critical metals. Within this layer, Se and Mo reach anomalous enrichment levels (EF max > 100), and Cd and V are significantly enriched (EF max > 10) across all three belts. Four critical metals, Ga, V, Mo, and Cd, show significant mining potential. Inorganic and organic geochemical evidence indicates that hydrothermal input was the primary control on metal enrichment across the five layers, whereas the exceptionally high metal enrichment in layer 3 were further amplified by biogenic contributions, particularly from marine algae. These findings clarify the spatial and stratigraphic controls on critical metal enrichment in the Qinling–Daba stone coal area and provide new insights into hydrothermal–biological interactions and metalliferous sedimentation in Ediacaran-Cambrian basins. Download: Download high-res image (201KB) Download: Download full-size image
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高影响因子
ACS Applied Engineering Materials
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2026
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IF 3.5
Zehui Yao,Xinhai Zhang,Yi Wang,Xiaozu Wang,Zhaohui Wang,Zhaoliang Cui
Polyimide (PI) membranes face a trade-off between permeability and selectivity, limiting their gas separation applications. To address this, we synthesized 6FDA-DAM/DABA(DAM:DABA = 3:2) PI and two-dimensional COF-1 nanofillers, fabricating hollow fiber mixed matrix membranes (MMMs) via dry-jet wet-spinning. Under optimized conditions (25 cm air gap, 50 °C spinneret temperature, 30 °C NMP coagulation bath), the 10 wt % COF-1 incorporated membranes achieved optimal performance: tensile strength of 15.34 MPa; H2 and CO2 permeances of 79.3 GPU and 54.3 GPU, and ideal selectivities of 187.9 for H2/CH4 and 128.7 for CO2/CH4, respectively. The results demonstrate that the incorporation of COF-1 modifies solvent exchange during spinning, necessitating targeted optimization of spinning parameters to coordinate membrane structure and performance.
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DOI
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
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2021
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IF 4.556
Kangkang Wang,Meng Wang,Yuli Kou,Changyan Guo,Xin Ma,Bingren Tian,Ying Qi,Wei Wang,Jide Wang
A rapid and sensitive analytical method has been proposed to monitor simultaneously four nitrofuran metabolites (NFMs) in meat products by ultra-high performance liquid chromatography–fluorescence detection (UHPLC-FLD). These NFMs were derivatized by 4-( N,N diphenylamino)benzaldehyde (DABA) by thermostatic ultrasonication within 20 min. The results confirmed that the four NFMs derivatives had excellent fluorescence response at specific excitation (λ ex = 260 nm) and emission (λ em = 500 nm) wavelengths, and all NFMs derivatives could be separated entirely on the reversed-phase Syncronis C18 column within 10 min. The limits of detection (LOD) and quantitation (LOQ) in this new method were 0.21 to 0.28 and 0.69 to 0.92 μg/kg, respectively. The four NFMs displayed excellent linearity (R > 0.998), and the recovery rate was satisfactory, ranging from 91.6% to 104.0%. This method successfully determined the NFMs in fish, shrimp and chicken. The method is highly sensitive and accurate, therefore, it may have potential for detecting four NFMs residues in other foodstuffs.
研究领域:
分析化学
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食品科学
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药物分析
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DOI
高影响因子
GREEN CHEMISTRY
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2025
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IF 9.2
Jiahui Liu,Chuying Li,Yanwei He,Bo Deng,Haitao Huang,Siwei Liu,Yi Zhang
The widespread use of polyimide varnish in semiconductors, packaging, and flexible displays has created increasing demand for efficient and environmentally friendly preparation. Compared to polyamic acid varnish, polyimide varnish offers enhanced stability and significantly improved process control, as it eliminates the need for chemical reactions during subsequent production steps. However, traditional polyimide varnish synthesis involves the preparation of polyamic acid followed by chemical imidization, a complex and time-consuming process that includes precipitation, washing, and dissolution. This method is not only costly but also poses environmental and safety risks. In this study, we propose a high-temperature one-step process to prepare a colorless polyimide varnish using the environmentally friendly solvent 3-methoxy-N,N-dimethylpropanamide (MDMPA), and benzoic acid as a catalyst. The process requires only 4 h to obtain high molecular weight polyimide varnish without aftertreatment. The varnish can be easily converted into a transparent film through low-temperature drying. Additionally, by introducing a small amount of 3,5-diaminobenzoic acid (DABA) for copolymerization, polyimide synthesis can be successfully achieved without external catalysts. The resulting polyimide exhibits a higher imidization degree and significantly improved peel strength between the polyimide and copper foil. This one-step process not only maintains the superior properties of colorless transparent polyimides (CPI) but also reduces reliance on toxic solvents, enhances production efficiency, and provides an environmentally sustainable solution for the large-scale production of high-performance polyimides.
研究领域:
材料科学
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高分子化学
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绿色化学
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化学工程
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电子材料
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可持续制造
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）