Small
·
2025
·
IF 12.1
Jian Zhang,Xinpeng Wang,Xiaomeng Guo,Wenhao Sang,Qing He,Wen Zhang
Metal–organic frameworks (MOFs) with unique pore architectures and electron-rich sites exhibit an unprecedented iodine capture property. In this contribution, the crystal-size and pore-size-dependent iodine adsorption behavior in MOFs ranging in crystal size from nanometers to micrometers with mesoporous and microporous structures is reported. Nano-sized MOFs have much higher iodine adsorption capacities and rates than Micro-sized MOFs. The pore diffusion for iodine adsorption in MOFs is the rate-controlling step and small-sized MOFs can provide larger external surface areas for iodine transport into adsorbents. Raman spectra suggest the diffusion of iodine molecules is more restricted than iodide species in micropores, and the iodine concentration gradient is more significant in microporous MOF-74 than in mesoporous PCN-222. Molecular simulation indicates iodine transports from mesopores to micropores, and aggregates in micropore cages and framework walls. The electron-rich O/N sites in MOFs attract iodine strongly and restrict iodine diffusion, while the weak interaction between iodine molecules becomes prominent at a high iodine loading amount and thus increases the iodine diffusivity in MOFs. The above result reveals a strong size dependence in iodine adsorption behaviors sensitive to MOFs' intrinsic crystal size, porosity, and guest–host interactions, and MOFs with smaller crystal sizes and mesoporous construction have better iodine capture performance.
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
CHEMISTRY OF MATERIALS
·
2024
·
IF 7.2
Yilun Ding,Yihan Ye,Dengyun Miao,Haodi Wang,Jingyao Feng,Jiaqi Qu,Yongzhi Zhao,Ziquan Chen,Peng Zhang,Runsheng Yu,Xingzhong Cao,Xiulian Pan,Xinhe Bao
Hierarchical zeolites have been demonstrated to be advantageous in catalysis and adsorption applications due to facilitated diffusion without degrading its molecule sieving function. However, the direct synthesis of hierarchical zeolites in one step is still challenging. Herein, we report a simple one-step synthesis of single-crystalline hierarchical zeolites by fractal growth induced by the strong adsorption of heteroatom metal species on the initially formed crystals. This method is feasible in the presence of a variety of metal species (M–OH), which can develop a stronger hydrogen bond with Si–OH in comparison to that among Si–OH themselves, such as Ti, Sn, Ga, Nb, and V. Furthermore, the method is versatile as substantiated with several common zeolites, including ZSM-5, TS-1, and ZSM-11. Such a hierarchical zeolite exhibits significantly enhanced activity in polyethylene pyrolysis and a remarkably prolonged lifetime in methanol conversion to hydrocarbons due to facilitated diffusion.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2021
·Vol. 67
·期 6
·e17177
·
IF 3.993
Baoyu Liu,Jiajin Huang,Zhantu Liao,Chongzhi Zhu,Qiaoli Chen,Guan Sheng,Yihan Zhu,Yi Huang,Jinxiang Dong
Zeolite belongs to one of the most important families of solid acid catalysts in chemical industries. It is, however, severely constrained by the diffusion limitation for bulky molecules, a lack of multifunctionality for sequential reactions and pore adaptability toward specific adsorbates due to its small micropore size and simple aluminosilicate framework. Introducing mesopores into a zeolite toward realizing hierarchical zeolites is a prevailing strategy but one that usually suffers from compromised crystallinity as well as insufficient interconnectivity and openness of the mesopores. Herein, a novel acid-redox co-functionalized single-crystalline zeolite with highly open and interconnected mesopores is designed and fabricated. As a proof-of-concept study, we integrate solid acid and Fe-oxy redox sites into a hierarchical MEL zeolite with well-characterized microporosity and mesoporosity. This zeolite exhibits superior activity and stability toward alkylation between mesitylene with benzyl alcohol, arising from greatly facilitated intra-crystal molecular diffusion, mitigated metal leaching and optimized adsorbate-pore wall interactions.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2019
·Vol. 10
·期 1
·12
·
IF 3.444
Xiaohui Wang,Xin Ding,Houbing Zou
The channel lengths of mesoporous materials have a crucial impact on the catalytic performances of as-loaded active components. However, it remains a challenge to precisely tune the mesochannel length in a wide range from ≤50 nm to 200 nm. In this paper, we developed a top-down strategy, that is to say, crushing hollow microspheres, for preparing mesoporous silica nanosheets (MSSs) with perpendicular mesochannels and tunable thicknesses. Owing to the heterogeneous growth of the mesoporous silica layer on the surfaces of polystyrene microspheres (hard template), it was achieved to regulate the mesochannel length continuously in the range of 20–200 nm. The obtained materials were characterized by X-ray diffraction (XRD), nitrogen sorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of channel lengths on the catalytic activity of metal nanoparticles was then investigated in the selective hydrogenation reaction of nitroarenes. It was found that a short channel not only favored dispersing metal nanoparticles uniformly and then avoiding pore blocking, but also improved the accessibility of metal nanoparticles largely during reactions.Keywords:mesoporous silica;nanosheet;channel length;molecular diffusion;hydrogenation
研究领域:
材料科学
·
催化
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Manufacturing Processes
·
2021
·
IF 5.01
Mengyuan Zhou,Xiaowei Zhou,Liang Si,Peng Chen,Maoyuan Li,Yun Zhang,Huamin Zhou
Fused Filament Fabrication (FFF) is one of the most widely used material extrusion additive manufacturing techniques . Its application is limited by the poor mechanical properties because of the weak bonding interface between strands. Although numerous experimental studies have investigated the effects of process parameters on mechanical performances, the bonding fracture mechanism and the quantitative relationship between process parameters and the bonding strength are not well understood. Here, we report a novel theoretical model considering coupled effects of the bonding interface evolution and molecular diffusion for predicting the bonding strength, which provides a comprehensive insight into the FFF bonding process. The model establishes an accurate relationship between process parameters and the bonding strength parallel/perpendicular to the deposition direction. Predictions agree well with experimental results and the average root mean square error (RMS) is ~5.52%. The fracture mechanism confirms the variation of the bonding interface and molecular diffusion assumed in the model. The bonding interface evolution and molecular diffusion are proved to play an important role in the bonding strength.
研究领域:
材料科学
·
力学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 45
·27050-27057
·
IF 3.119
Yajie Hu,Yanan Yang,Jiejing Zhang,Shengnan Jin,Hong Zheng
The removal of low concentration PPCPs from water is a challenging issue. A graphene hydrogel with 3D networks shows great potential for accelerating eddy diffusion of low concentration PPCPs. Herein, to further promote its molecular diffusion, a graphene/TiO2 nanowires (GNW) hybrid structure was implanted into graphene hydrogel. The as-prepared rGO/GNW hydrogel exhibited significantly enhanced adsorption–photocatalytic performance and excellent stability for low concentration ethenzamide, a typical pharmaceutical pollutant in water, under vacuum ultraviolet (VUV), ultraviolet (UV), visible and near-infrared light irradiation. When the initial ethenzamide concentration was 500 ppb and catalyst dosage was 10 mg/150 mL, ethenzamide was completely removed in 3 min and the corresponding photocatalytic apparent rate constant was 2.20 times that by GNW, 4.09 times that by rGO/P25 and 4.31 times that by rGO/NW under VUV irradiation, respectively, and its removal rate attained 99.0% in 120 min and the corresponding photocatalytic apparent rate constant was 2.06 times that by GNW, 3.34 times that by rGO/P25 and 17.42 times that by rGO/NW under UV irradiation, respectively. The GNW hybrid structure in the hydrogel played a vital role in overcoming the mass transfer resistance of low concentration PPCPs. The as-prepared rGO/GNW hydrogel exhibits significant potential for the removal of low concentration PPCPs from water.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Zhaohui Xu,Gaoming Li,Yinyu Zhang,Yeping Wu,Xiaolin Lu
Generally, for adhesive joints, the polar water molecules in humid environments can have a critical effect on the interfacial structures and structural evolution adjacent to the solid substrates. Regarding this, it is still a big challenge to detect and understand the interfacial hygrothermal aging process at the molecular level in real time and in situ. In this study, to trace the interfacial hygrothermal aging process of a classical epoxy formula containing diglycidyl ether of biphenyl A (DGEBA) and 2,2′-(ethylenedioxy) diethylamine (EDDA) with sapphire and fused silica in a typical hygrothermal environment (85 °C and 85% RH), sum frequency generation (SFG) vibrational spectroscopy was used to probe the molecular-level interfacial structural change over the time. The structural evolution dynamics at the buried epoxy/sapphire and epoxy/silica interfaces upon hygrothermal aging were revealed directly in situ. The interfacial delamination during hygrothermal aging was also elucidated from the molecular level. Upon hygrothermal aging, the interfacial CH signals, such as the ones from methyl, methylene, and phenyl groups, decreased significantly and the water OH signals increased substantially, indicating the water molecules had diffused into the interfaces and destroyed the original interactions between the epoxy formula and the substrates. Further analysis indicates that when the integrated signals in the CH range declined to their minimum and leveled off, the interfacial delamination happened. The tensile experiment proved the validity of these spectroscopic experimental results. Our study provides first-hand and molecular-level evidence on a direct correlation between the diffusion of the surrounding water molecules into the interface and the evolution/destruction of the interfacial structures during hygrothermal aging. More importantly, it is proved, SFG can be developed into a powerful tool to noninvasively reveal the local interfacial delamination in real time and in situ under extreme hygrothermal conditions, complemented by the mechanic test.
研究领域:
材料科学
·
表面化学
✓ 已验证
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2025
·
IF 6.7
Simin Bi,Yumo Li,Jianpeng Ao,Zhijie Liu,Meilin Weng,Minbiao Ji
Numerous chemical reactions and most life processes occur in aqueous solutions, where the physical diffusion of small molecules plays a vital role, including solvent water molecules, solute biomolecules, and ions. Conventional methods of measuring diffusion coefficients are often limited by technical complexity, large sample consumption, or significant time cost. Here, we present an optical imaging method to study molecular diffusion by combining stimulated Raman scattering (SRS) microscopy with microfluidics: a “Y”-shaped microfluidic channel forming two laminar flows with a stable concentration gradient across the interface. SRS imaging of a specific molecule allows us to obtain a high-resolution chemical profile of the diffusion region at varying inspection locations and flow rates, which enables the extraction of diffusion coefficients using the convection–diffusion model. As a proof of concept, we measured diffusion coefficients of molecules including water, protein, and multiple ions, with a sample volume of less than 1 mL and a time cost of less than 10 min. Moreover, we demonstrated a high-resolution three-dimensional (3D) reconstruction of the diffusion patterns in the microfluidic channel. The high-speed microfluidic SRS platform holds the potential for quantitative measurements of molecular diffusion, chemical reaction, and fluidic dynamics at the liquid–liquid interfaces.
研究领域:
生物化学
·
光学成像
·
微流体技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Bowen Gan,Saren Qi,Xiaoxiao Song,Zhe Yang,Chuyang Y. Tang,Xingzhong Cao,Yong Zhou,Congjie Gao
Ultrathin polyamide (PA) nanofilm based separation membranes have attracted drastically increasing attention recently. Typically, PA nanofilms with the thickness of around tens of nanometers are supported by a PSF substrate membrane which provides mechanical support. However, the low surface porosity of the PSF substrate membrane has required the transverse diffusion (parallel to the membrane plane) of water molecules in the nanofilm, which causes much longer mean diffusion paths compared to the thickness of the nanofilm. In this study, we address this problem by introducing a much looser polypiperazinamide (PPA) interlayer in between the PA nanofilm and the PSF support membrane, with the PPA nanofilm serving as a low resistance region for water molecules. A dual interfacial polymerization strategy was applied to create an asymmetrical ultrathin polyamide selective layer comprised of a high permeability loose PPA sublayer and a high selectivity dense PA top layer. Quartz crystal microbalance with dissipation (QCMD) techniques and Doppler broadening energy spectroscopy (DBES) were applied to study the asymmetry structure of the ultrathin polyamide nanofilms. Compared with the home-made traditional ultrathin polyamide (uPA) membrane, the asymmetrical ultrathin polyamide (A-uPA) membrane has 2–2.5 folds higher permeability while maintaining higher salt rejection. Our study demonstrates that the asymmetrical structure can significantly enhance the flux for ultrathin polyamide membranes. Further, the impact of the structure of the top layer and the sublayer on the membrane separation performance was explored by tuning the recipe of the PA top layer and the PPA sublayer.
研究领域:
材料科学
·
膜分离技术
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Jinmei Lei,Yuxia Gao,Xin Zhao,Yanqiu Zhu,Chenhui Zhang,Yue Ma,Kefei Zhao,Fengpei Du
A new series of ionic liquid-type imidazolium Gemini surfactants, 1,10-(Propane-1,3-diyl-2-ol)bis(3-alkyl-1H-imidazol-3-ium) chloride, were synthesized and investigated for their dilational rheology at the air/water interface using the oscillating drop method. The surface properties and splashing behavior of these ionic liquid-type imidazolium Gemini surfactants were studied at different hydrophobic chain lengths, surfactant concentrations and dilational frequencies. With increasing concentration, increasing intermolecular interaction had a positive effect on the dilational modulus, and the increasing surfactant molecular diffusion exchange had a negative effect on the dilational modulus; thus, the surface dilational modulus demonstrated a maximum value. Furthermore, the surface dilational modulus for 1,10-(Propane-1,3-diyl-2-ol) bis (3-tetradecyl-1H-imidazol-3-ium) chloride is higher than that for the other two short-chain ionic liquid-type imidazolium Gemini surfactants, which is due to an increase in the hydrophobic interaction. The results reveal that the bouncing heights of ionic liquid-type imidazolium Gemini surfactants on a paraffin liquid surface decrease with increasing alkyl chain length. The splashing behavior of ionic liquid-type imidazolium Gemini surfactants observed on liquid surfaces and the spreading behavior observed on a paraffin surface are closely related to the dilational loss modulus . These findings not only reveal the relationship between dilational rheology and splashing behavior but also provide insights for the potential application of ionic liquid-type imidazolium Gemini surfactants in more fields.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2020
·
IF 3.557
Haofei Li,Zhuojun Cai,Yilin Wang
Improving water droplet deposition on superhydrophobic surfaces is essential in many agricultural and industrial spraying processes. Adding surfactants is generally considered a simple way to enhance the wetting ability of droplets on surfaces. However, finding effective surfactants for the deposition and spread of high-speed impacting droplets on superhydrophobic surfaces remains a challenge. Here, we propose a model to predict the deposition results of impacting droplets on superhydrophobic surfaces by studying the droplets containing a series of asymmetric double-chain quaternary ammonium ionic surfactants with different chain lengths. By introducing the molecular diffusion rate, the ability of molecules to reduce surface tension, as well as the stability of aggregates into the model, the impact outcomes of surfactant droplets on the superhydrophobic surface are described and predicted. This study provides a beneficial blueprint for the selection of surfactants and the control of droplet impact behavior on superhydrophobic surfaces.
研究领域:
材料科学
·
表面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Research Express
·
2022
·Vol. 9
·期 3
·035101
·
IF 2.025
Yue Jiang,Yichen Cai,Jianping Li,Naibo Chen,Laigui Hu,Wenchong Wang,Qing-Miao Nie,Bo Yan
Oganic devices have gained much progress in the past decades, as a promising candidate for flexible/wearable electronics. However, the realization of organic microelectronic systems for wide applications is still difficult, due to the incompatibility of organic semiconductors (OSCs) with the conventional top-down lithography techniques for inorganics. To solve this challenge, bottom-up lithography-compatible methods have been developed for organic device arrays, i.e., template-directed growth or area-selective growth (ASG). Unfortunately, the physics on the dynamic process of the ASG method for molecular semiconductors is still not well understood. In order to explore this issue, the growth of particles on prepatterned surfaces under different diffusion lengths (Ld) was simulated in a microscopic point of view by using kinetic Monte Carlo method. Simulation results show that ASG of the particles is strongly related to the Ld of the particles, periodicity and size of prepatterned surfaces. It is notable that such simulated results were found to fit well with those of our experiments, which can be favorable for improving the ASG method for patterning functional molecules.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）