ADVANCED MATERIALS
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2024
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IF 27.4
Yafei Ding,Qingqing Cheng,Jing Lyu,Zengwei Liu,Ruizhe Yuan,Fengguo Ma,Xuetong Zhang
Microfluidic deprotonation approach is proposed to realize continuous, scalable, efficient, and uniform production of aramid nanofibers (ANFs) by virtue of large specific surface area, high mixing efficiency, strong heat transfer capacity, narrow residence time distribution, mild laminar-flow process, and amplification-free effect of the microchannel reactor. By means of monitoring capabilities endowed by the high transparency of the microchannel, the kinetic exfoliation process of original aramid particles is in situ observed and the corresponding exfoliation mechanism is established quantificationally. The deprotonated time can be reduced from the traditional several days to 7 min for the final colloidal dispersion due to the synergistic effect between enhanced local shearing/mixing and the rotational motion of aramid particles in microchannel revealed by numerical simulations. Furthermore, the cascade microfluidic processing approach is used to make various ANF colloidal aerogels including aerogel fibers, aerogel films, and 3D-printed aerogel articles. Comprehensive characterizations show that these cascade-microfluidic-processed colloidal aerogels have identical features as those prepared in batch-style mode, revealing the versatile use value of these ANFs. This work achieves significant progress toward continuous and efficient production of ANFs, bringing about appreciable prospects for the practical application of ANF-based materials and providing inspiration for exfoliating any other nano-building blocks.
研究领域:
材料科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
ACS Catalysis
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2025
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IF 13.1
Chenyang Xia,Bowen Lu,Qi Xu,Nanxin Shen,Qiancheng Liao,Jiyun Cui,Baiyang Wang,Yueyang Sun,Changjiang Dong,Fei Gan
The discovery and engineering of prenyl diphosphate C-methyltransferases have facilitated the understanding and expansion of terpenoid diversity. Here, we report the structural and mechanistic characterization of a methyltransferase variant HumMT W197G that produces unconventional C11 prenyl diphosphates through an unusual dual deprotonation mechanism. Through protein engineering, we expanded the substrate-binding pocket of Micromonospora humi methyltransferase (HumMT) by W197G substitution, converting the substrate specificity from DMAPP and IPP (C5) to GPP (C10). Notably, HumMT W197G exhibits both C4 and C2 deprotonation, producing both iso-2-methyl-GPP and 2-methyl-GPP. Using cryogenic electron microscopy (cryo-EM), we solved the structures of apo-HumMT W197G, HumMT W197G-SFG, and HumMT W197G-SFG-Mg2+-GPP complexes to resolutions of 3.14, 2.97, and 2.3 Å, respectively. Through structure-guided engineering, molecular docking, and molecular dynamics simulations, we identified E168 as a catalytic base facilitating deprotonation at both the C2 and C4 positions. Additionally, we discovered W197Y as a critical mutation that discriminates between IPP and DMAPP substrates, leading to the identification of a natural methyltransferase from Micromonospora echinospora that produces noncanonical C7 prenyl diphosphates 2,2-dimethyl-IPP and 2,4-dimethyl-DMAPP. Our findings expand the understanding of methyltransferase catalytic mechanisms and demonstrate successful structure-based protein engineering to modulate carbocation intermediate deprotonation, providing implications for expanding terpenoid diversity.
研究领域:
生物化学
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结构生物学
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合成生物学
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酶工程
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2022
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IF 7.392
Dandan Zhou,Youxi Wang,Yuniu Sun,Jiefu Zhang,Dan Wang,Zhenyu Li,Xiang Shao
The details of catechol interacting with the ZnO surfaces are critical for understanding how the organic chromophores anchor on and hence functionalize the ZnO materials. In this work, we apply low-temperature scanning tunneling microscopy (LT-STM) in combination with density functional theory (DFT) calculations to investigate the adsorption state and interface charge transfer of catechol on a ZnO(10-10) surface. For the molecules deposited at liquid nitrogen temperature, the fully-protonated (FP) status prevails in the isolated molecules despite the synergistic formation of half-protonated (HP) and fully-deprotonated (FD) ones. However, annealing to elevated temperature drives all the molecules to assemble into either linear or a c(2 × 2) superstructure composed of only FD catechols. Such spontaneous deprotonation of catechol is different from the predicted water-assisted process and plays critical roles in switching the catechol from electron acceptors to electron donors relative to the ZnO surface. These results may bring new insights into the design of optoelectronic and biomedical applications of the ZnO-organic compositional system.
研究领域:
材料科学
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表面化学
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产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
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2025
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IF 4.7
Yi Wu,Anqi He,Da Li,Limin Yang,Yizhuang Xu,Yukihiro Ozaki,Isao Noda
This study investigates single-crystal structures of Lu3+/erythritol and nine rare earth–glycerol complexes, revealing deprotonation of normally inert OH groups via μ2-bridging (so-called DIOμ2 phenomenon). The pH drops upon alditol addition correlate with the deprotonation extent, showing increased deprotonation with decreasing lanthanide ionic radius (lanthanide contraction) and exceptionally high deprotonation for Sc3+. In all the rare earth/alditol complexes with the DIOμ2 phenomenon, two μ2-bridges merge into an M2O2 cluster (M is a rare earth ion) that is not very stable due to the Coulombic repulsion between two M3+ and between two O–. To stabilize the M2O2 cluster, the formation of more auxiliary five- and six-membered chelating rings between rare earth ions and alditol ligands is needed. Increment of the number of auxiliary five- and six-membered chelating rings favors the DIOμ2 reaction. This is the reason why the DIOμ2 reaction shows a progressively enhanced tendency when the alditol ligands change from myo-inositol to glycerol to erythritol and galactitol. The reaction is endothermic, as an increased temperature enhances deprotonation. The above results may be useful in the rational design of catalysts that efficiently activate inert OH bonds and facilitate related chemical processes.
研究领域:
无机化学
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配位化学
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晶体学
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物理化学
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催化
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产品关联
DOI
PubMed
高影响因子
Journal of Water Process Engineering
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2024
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IF 6.3
Yang Li,Shuijing Wang,Hengming Huang,Jiahui Kou,Chunhua Lu,Zhongzi Xu,Jinhua Ye
Faster OH − transfer for efficient adsorption on catalysis is key to accelerating the oxygen evolution reaction (OER). The diffusion of OH − in electrolyte mainly involves two mechanism which is dependent on the water coordination number (CN): Grotthuss diffusion (4 CN) and vehicular diffusion (5 CN). The Grotthuss diffusion is much faster but the vehicular diffusion of OH − is predominant in the electrolyte. Herein, negatively charged kaolin, which are simply dispersed in the electrolyte, are utilized to provide surface electrostatic attraction to H 2 O and repulsion to OH − to reduce the OH − CN from 5 to 4 for rapid Grotthuss diffusion. This contributes to the accelerated OH − adsorption which facilitates the charge transfer, the formation and the deprotonation of *OOH leading to enhanced OER performance. The OH − CN recovery from 4 to 5 is proved quite slow after leaving the kaolin surface, breaking the limitation that kaolin must be on the catalyst surface. This strategy exhibits universality for various electrocatalysts with reduced overpotential by 10–246 mV at 10 mA cm −2 . We provide a clean, simple and low-cost way to promote the industrial development of alkaline water electrolysis.
研究领域:
电化学
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材料科学
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催化
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能量转换
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产品关联
DOI
高影响因子
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