JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Ziheng Li,Yuehu Guo,Jingbang Yu,Xuehua Ruan,Xiaobin Jiang,Yan Dai,Tiantian Li,Xiangcun Li,Wenji Zheng,Gaohong He
The fillers in asymmetric mixed matrix membranes (AMMMs) by phase inversion tend to distribute across the membrane, but less in the skin layer, resulting in limited enhancement of gas separation performance. In this work, an external gravity field is proposed to induce polystyrene-acrylate (PSA) modified hollow ZIF-8 nanospheres (PHZ) to settle and accumulate in the skin layer by the density difference between ZIF-8 and the polymer solution , then through phase inversion, the gravity induced AMMMs (GAMMMs) with improved ZIF-8 loading in skin layer is constructed. This is confirmed by the EDS analysis of the membrane cross-sections that more PHZ settle and accumulate in the skin layer, which enhances the filler loading by 330 % in comparison to the AMMMs without gravity sedimentation. Together with the hollow cavity of PHZ, the gas permeation can be improved greatly. Meanwhile, the PHZ can also guarantee the favorable interfacial compatibility by the hydrogen bonding interaction between the carboxyl groups in PSA with the PES polymer matrix , which is demonstrated by the slightly elevated Tg of GAMMMs over the ZIF-8/PES membrane. Consequently, the PHZ/PES GAMMMs can achieve high gas permeation while keeping sufficient selectivity at high filler loading in the skin layer. The PHZ-8d/PES GAMMM shows H 2 permeance of 29.11 GPU and H 2 /CH 4 of 83.04, which are 142.85 % and 5.99 % higher than those of ZIF-8/PES AMMM without gravity sedimentation, and exceeding the corresponding 2008 Robeson upper bound. This proposed GAMMM shows a great potential in the large-scale MMMs based gas separation.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2019
·
IF 15.548
Jiangwei Chang,Xuedan Song,Chang Yu,Huawei Huang,Jiafu Hong,Yiwang Ding,Hongling Huang,Jinhe Yu,Xinyi Tan,Zongbin Zhao,Jieshan Qiu
Integration/alternation of the short- and long-range order carbon species into one is always a trade-off between exposed armchair or zig-zag sites for enhancing the density of local charge states and electronic conductivity for fastening charge transfer. However, the strategies available now for coupling suffer from multiple/complicated steps, which makes the carbon-conjugated microstructure and electronic structure of the carbon as well as the process difficult to be controlled. Herein, surface coupling engineering mediated by external gravity field enables the assembling of carbon quantum dots (CQDs) with short-range periodicity on carbon sphere (CS) with long-range periodicity. The concentration gradient of CQDs on the surface of CS (CQDs/CS-x) can be finely controlled by the tuned gradient field strength , finally achieving the controllable regulation of defective density and electron transfer capability in carbon-conjugated CQDs. The resultant CQDs/CS-4 composite exhibits a high power conversion efficiency up to 8.42% with a low E pp value of 0.11 V, as probed by triiodide reduction. Taken together, density functional theory calculations and experimental results reveal that the edge/defective sites derived from CQDs modulate the charge density of local sites for enhanced capability of the adsorption for I 2 molecule, and meanwhile the long-range π-π conjugated configuration of CS sites promotes the fast electron transfer in the carbon-conjugated CQDs. The design concept in this work presents a simple & facile technology for integration of the micro/nano-structured carbon materials with different scales to achieve the delicate regulation. Also, this provides fundamental guidance towards the assembly of ultrafine structure especially small-sized/ultrathin materials at atomic scales.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Xiuyu Nie,Mingzhang Xiong,Jing Zeng,Chenggang Li,Yue Chen,Zushun Xu,Wen Fan
Nanoscale structuring of gallium-based liquid metals has emerged as a promising approach for generating unique properties and functionalities in advanced materials and devices. However, their exceptionally high surface tension presents significant challenges for achieving surface nanostructuring using conventional fabrication techniques. Here, a hypergravity nanoimprinting method is introduced, which harnesses horizontal centrifugation to generate hypergravity fields that drive liquid gallium into nanoscale cavities on an elastic polymer stamp surface at subzero temperatures, where it solidifies and preserves imprinted features down to 100 nm lateral resolution. This surpasses previous limits of gallium patterning, enabling phenomena such as iridescent structural colors with a wide range of hues and high saturation. Numerical simulations reveal the intricate fluid dynamic behaviors and interfacial interactions during the imprinting process, providing valuable insights for process optimization and control. By synergistically combining advanced soft lithography techniques with the reversible solid-liquid phase transition properties of liquid metals, hypergravity nanoimprinting offers a practical nanofabrication approach, facilitating the development of next-generation nanoscale gallium devices with finely structured nanofeatures across diverse application domains, such as nanoelectronics and photonic metamaterials.
研究领域:
材料科学
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纳米技术
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
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2016
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IF 2.687
Shuang Guo,Bai-Ling Qiu,Chen-Qi Zhu,Ya-Ya Gao Yang,Di Wu,Qi-Hui Liang,Nan-Yin Han
Gravitational field-flow fractionation (GrFFF) is a useful technique for separation and characterization for micrometer-sized particles. Elution behavior of micrometer-sized particles in GrFFF was researched in this study. Particles in GrFFF channel are subject to hydrodynamic lift forces (HLF), fluid inertial forces and gravity, which drive them to different velocities by carrier flow, resulting in a size-based separation. Effects of ionic strength, flow rate and viscosity as well as methanol were investigated using polystyrene latex beads as model particles. This study is devoted to experimental verification of the effect of every factor and their comprehensive function. All experiments were performed to show isolated influence of every variable factor. The orthogonal design test was used to evaluate various factors comprehensively. Results suggested that retention ratio of particles increases with increasing flow rate or the viscosity of carrier liquid by adjusting external forces acting on particles. In addition, retention ratio increases as ionic strength decreases because of decreased electrostatic repulsion between particles and channel accumulation wall. As far as methanol, there is no general trend due to the change of both density and viscosity. On the basis of orthogonal design test it was found that viscosity of carrier liquid plays a significant role in determining resolution of micrometer-sized particles in GrFFF.
研究领域:
分析化学
·
胶体科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2015
·
IF 6.723
Chao Jiang,Caijun Luo,Xiaolin Liu,Lei Shao,Youqing Dong,Yingwei Zhang,Feng Shi
The layer-by-layer (LbL) assembled multilayer has been widely used as good barrier film or capsule due to the advantages of its flexible tailoring of film permeability and compactness. Although many specific systems have been proposed for film design, developing a versatile strategy to control film compactness remains a challenge. We introduced the simple mechanical energy of a high gravity field to the LbL assembly process to tailor the multilayer permeability through adjusting film compactness. By taking poly(diallyldimethylammonium chloride) (PDDA) and poly{1–4[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfonamido]-1,2-ethanediyl sodium salt} (PAzo) as a model system, we investigated the LbL assembly process under a high gravity field. The results showed that the high gravity field introduced effectively accelerated the multilayer deposition process by 20-fold compared with conventional dipping assembly; the adsorption rate was positively dependent on the rotating speed of the high gravity equipment and the concentration of the building block solutions. More interestingly, the film compactness of the PDDA/PAzo multilayer prepared under the high gravity field increased remarkably with the growing rotational speed of the high gravity equipment, as demonstrated through comparisons of surface morphology, cyclic voltammetry curves, and photoisomerization kinetics of PDDA/PAzo multilayers fabricated through the conventional dipping method and through LbL assembly under a high gravity field, respectively. In this way, we have introduced a simple and versatile external form of mechanical energy into the LbL assembling process to improve film compactness, which should be useful for further applications in controlled ion permeability, anticorrosion, and drug loading.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2014
·
IF 2.063
Yibo Zhao,Moses Arowo,Wei Wu,Haikui Zou,Jianfeng Chen,Guangwen Chu
Polyaniline/graphene (PANI/GN) nanocomposites were synthesized by in situ high gravity chemical oxidative polymerization in a rotating packed bed (RPB). The effects of graphene dosage, ammonium persulfate/aniline mole ratio, aniline concentration and reactor type on their morphology and electrochemical performances were discussed in detail. Results indicated that this process can synthesize PANI/GN nanocomposites easily under relatively extensive conditions. Particularly, it was demonstrated that it is appropriate for higher aniline concentration condition, which is favorable for large scale production. Furthermore, RPB produced PANI/GN nanocomposites of more uniform morphology and thinner coating than those synthesized in a stirred tank reactor (STR). These advantages resulted in nanocomposites of higher specific capacitance of up to 403 F/g as compared to 255 F/g for those of STR at 0.5 A/g. This process is not only simple and efficient, but also has a good prospect for industrial application.
研究领域:
材料科学
·
纳米科技
·
电化学
·
能源存储
·
化学工程
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Zhiliang Zhang,Hui Xue,Wei Liu,Weiling Zhao,Zhaoyang Chen,Qiao Chen,Dongting Wang,Jianbing Ji
Microchannel reactors have garnered significant attention in various chemical processes due to their ability to achieve rapid mixing. However, there remains ample opportunity for the development of microchannel reactors with simple structures and high throughput. In this work, we propose a novel microannular rotating bed (MARB) that integrates the high-gravity field and microscale effect to enhance the micromixing efficiency. The Villermaux–Dushman reaction system is employed to investigate the influence of the operating parameters on the mixing performance. The micromixing time of the MARB ranges from 10–4 to 10–3 s for low-viscosity Newtonian fluids and from 10–4 to 10–2 s for shear-thinning non-Newtonian fluids. In a lab-scale setup, the MARB demonstrates a throughput of 6 L/min, markedly surpassing the capabilities of the existing microchannel reactors. Furthermore, the evaluation of energy dissipation rate underscores the MARB’s remarkable energetic efficiency in intensifying mixing processes. The MARB, with its simple design, high throughput capacity, and efficiency, presents a promising alternative for the intensification of mixing across diverse chemical applications.
研究领域:
化学工程
·
过程强化
·
反应器设计
✓ 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）