Mesostructured Ce0.6Zr0.4O2 solid solutions were synthesized by coprecipitation combined with evaporation-induced self-assembly process. The obtained materials were characterized by X-ray diffractometer （XRD）, Raman...Mesostructured Ce0.6Zr0.4O2 solid solutions were synthesized by coprecipitation combined with evaporation-induced self-assembly process. The obtained materials were characterized by X-ray diffractometer （XRD）, Raman, transmission electron microscopy （TEM）, N2 sorption, and hydrogen temperature programmed reduction （H2-TPR）. The results showed that the solid solutions consisted of uniform nanocrystals, which piled homogeneous mesopores of about 4 nm. Furthermore, different surfactants had little influence on the mesoporous structures. All these samples exhibited high thermal stability.展开更多
Silica-based materials are usually used as delivery systems for antibacterial applications.In rare cases,bactericidal cationic surfactant templated silica composites have been reported as antimicrobial agents.However,...Silica-based materials are usually used as delivery systems for antibacterial applications.In rare cases,bactericidal cationic surfactant templated silica composites have been reported as antimicrobial agents.However,their antibacterial efficacy is limited due to limited control in content and structure.Herein,we report a“dual active templating”strategy in the design of nanostructured silica composites with intrinsic antibacterial performance.This strategy uses cationic and anionic structural directing agents as dual templates,both with active antibacterial property.The cationic-anionic dual active templating strategy further contributes to antibacterial nanocomposites with a spiky surface.With controllable release of dual active antibacterial agents,the spiky nanocomposite displays enhanced anti-microbial and anti-biofilm properties toward Staphylococcus epidermidis.These findings pave a new avenue toward the designed synthesis of novel antibacterial nanocomposites with improved performance for diverse antibacterial applications.展开更多
More and more attention has been paid to the synthesis of mesostructuredaluminophosphates for many years. A lot of valuable research results, including various syntheticapproaches and structural materials, have been o...More and more attention has been paid to the synthesis of mesostructuredaluminophosphates for many years. A lot of valuable research results, including various syntheticapproaches and structural materials, have been obtained. This paper reviews the progress in thesynthesis of mesostructured aluminophosphates over the past few years, with the hope of revealingopportunities for future work.展开更多
Mesostructured iron oxides（MIOs） were nanocasted from a plugged hexagonal templated silica（PHTS） with a Brunauer-Emmett-Teller（BET） surface area of 694 m 2 /g.Results of X-ray diffraction（XRD）,transmission ele...Mesostructured iron oxides（MIOs） were nanocasted from a plugged hexagonal templated silica（PHTS） with a Brunauer-Emmett-Teller（BET） surface area of 694 m 2 /g.Results of X-ray diffraction（XRD）,transmission electron microscopy（TEM） and N 2 adsorption-desorption suggest that the nanocasted MIOs are synthetic hematite（α-Fe2O3） with a wormhole-like mesoporous network.As（V） adsorption test shows that the selected MIO—MIO-500（calcinated at 500 °C） with a BET surface area of 82 m^ 2 /g has a maximum adsorption capacity of 5.39 mg/g for As（V）,which is 2.5 times as large as that of natural hematite adsorbent.The study suggests that MIOs could be potentially used as the adsorbent of As（V） in wastewater.展开更多
This work investigated the possibility of incorporation of nickel into several mesostructured cellular foam (MCF) silica supports prepared at various aging times (1, 2, and 3 days) by using deposition-precipitation me...This work investigated the possibility of incorporation of nickel into several mesostructured cellular foam (MCF) silica supports prepared at various aging times (1, 2, and 3 days) by using deposition-precipitation method followed by reducetion process and to look for the best support to obtain supported nickel catalyst with highest nickel loading and smallest size of nickel nanoparticles. Analyses using nitrogen adsorption-desorption, transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) showed that MCF silica prepared at aging time of 3 days was the best support as the corresponding nickel functionalized MCF catalyst had the highest nickel content (17.57 wt%) and the smallest size of nickel nanoparticles (1 - 2 nm) together with high porosity (window pore size of 90A). The result was attributed to the highest window pore size in the MCF support which allowed more nickel nanoparticles to be incorporated.展开更多
Tetraphenylethylene(TPE)and its derivatives,the typical aggregation-induced emission(AIE)luminogens,exhibit unique chirality in the condensed phase due to their propeller-shaped structure.However,precisely regulating ...Tetraphenylethylene(TPE)and its derivatives,the typical aggregation-induced emission(AIE)luminogens,exhibit unique chirality in the condensed phase due to their propeller-shaped structure.However,precisely regulating the chiral assembly of TPE and its derivatives is challenging,owing to their inherent spontaneous self-assembly behavior.Herein,we report the controllable self-assembly of the chiral mesostructured AIEgens-silica(CMAS)via a co-structure directing route,using 2-[4-(1,2,2-triphenylethenyl)phenoxy]-acetic acid(TPEA)as a structure-directing agent,binaphthol as a symmetry-breaking agent,quaternized aminosilane N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride as the co-structure directing agent,and tetraethyl orthosilicate as the inorganic source.The CMAS materials were characterized by nanotubes with lengths ranging from hundreds of nanometers to dozens of micrometers and diameters of 150–300 nm.The CMAS materials exhibited optical activities originating from J-aggregates,which possess a one-handed excess helical conformation of TPEA induced by binaphthol.Our work elucidates the underlying mechanisms of chirality transfer during self-assembly and expands the potential applications of AIEgens in chiral response.展开更多
Hematite(α-Fe_(2)O_(3))is known to undergo conversion from weak ferromagnetic to antiferromagnetic as the temperature decreases below the Morin temperature(TM=250 K)due to spin moment rotation occurring during the Mo...Hematite(α-Fe_(2)O_(3))is known to undergo conversion from weak ferromagnetic to antiferromagnetic as the temperature decreases below the Morin temperature(TM=250 K)due to spin moment rotation occurring during the Morin transition(MT).Herein,we endowed hematite with mesostructured chirality to maintain weak ferromagnetism without MT.Chiral mesostructured hematite(CMH)nanoparticles were prepared by a hydrothermal method with glutamic acid(Glu)as the symmetry-breaking agent.The triangular bipyramidal CMH nanoparticles were composed of helically cleaved nanoflakes with twisted crystal lattice.Field-cooled(FC)magnetization measurements showed that the magnetic moments of CMH were stabilized without MT within the temperature range of 10–300 K.Hysteresis loop measurements confirmed the weak ferromagnetism of CMH.The enhanced Dzyaloshinskii–Moriya interaction(DMI)was speculated to be responsible for the temperature-independent weak ferromagnetism,in which the spin configuration would be confined with canted antiferromagnetic coupling due to the mesostructured chirality of CMH.展开更多
Spin chiral anisotropy(SChA)refers to the occurrence of different spin polarization in antipodal chiral structures.Herein,we report the SChA in diamagnetic chiral mesostructured In2O3 films(CMIFs)with manifestation of...Spin chiral anisotropy(SChA)refers to the occurrence of different spin polarization in antipodal chiral structures.Herein,we report the SChA in diamagnetic chiral mesostructured In2O3 films(CMIFs)with manifestation of chirality-dependent magnetic circular dichroism(MCD)signals.CMIFs were grown on fluorine-doped tin dioxide conductive glass(FTO)substrates,which were synthesized via a hydrothermal route,with malic acid used as the symmetry-breaking agent.Two levels of chirality have been identified in CMIFs:primary nanoflakes with atomically twisted crystal lattices and secondary helical stacking of the nanoflakes.CMIFs exhibit chirality-dependent asymmetric MCD signals due to the different interactions of chirality-induced effective magnetic field and external magnetic field,which distinguish from the commonly observed external magnetic fielddependent symmetric MCD signals.These findings provide insights into spin manipulation of spin-paired diamagnets.展开更多
The electrochemistry in energy conversion and storage(ECS) not only relies on the active species in catalysts or energy-storage materials, but also involves mass/ion transport around the active species and electron tr...The electrochemistry in energy conversion and storage(ECS) not only relies on the active species in catalysts or energy-storage materials, but also involves mass/ion transport around the active species and electron transfer to the external circuit. To realize high-rate ECS process, new architectures for catalysts or energy-storage electrodes are required to ensure more efficient mass/charge transport. 3 D porous mesostructured materials constructed by nanoscale functional units can form a continuous conductive network for electron transfer and an interconnected multiscale pores for mass/ion transport while maintaining the high surface area, showing great promise in boosting the ECS process. In this review, we summarize the recent progress on the design,construction and applications of 3 D mesostructured carbon-based nanocages for ECS. The role of the hierarchical architectures to the high rate performance is discussed to highlight the merits of the mesostructured materials. The perspective on future opportunities and challenges is also outlined for deepening and extending the related studies and applications.展开更多
Analysis of the atomic structure of monoclinic BiVO4 reveals its fascinating structure-related dual response to visible light and temperature.Although there have been a few reported studies of its responses to visible...Analysis of the atomic structure of monoclinic BiVO4 reveals its fascinating structure-related dual response to visible light and temperature.Although there have been a few reported studies of its responses to visible light and temperature,an understanding of the effects of quantum size,particle shape or specific exposed facets on its dual responsive properties remains elusive;this is primarily due to the limited availability of high-quality monodisperse nanocrystals with extremely small sizes and specific_(4)exposed facets.Herein,we describe a novel assembly-fusion strategy for the synthesis of mesostructured monoclinic BiVO_(4)quantum tubes with ultranarrow diameter of 5 nm,ultrathin wall thickness down to 1 nm and exposed{020}facets,via a convenient hydrothermal method at temperatures as low as 100℃.Notably,the resulting high-quality quantum tubes possess significantly superior dual-responsive properties compared with bulk BiVO_(4)or even BiVO4 nanoellipsoids,and thus,show high promise for applications as visible-light photocatalysts and temperature indicators offering improved environmental quality and safety.This mild and facile methodology should be capable of extension to the preparation of other mesostructured inorganic quantum tubes with similar characteristics,giving a range of materials with enhanced dual-responsive properties.展开更多
The chirality-induced spin selectivity(CISS)has been found in the antiferromagnetic and paramagnetic chiral inorganic materials with unpaired electrons,while rarely reported in the spin-paired diamagnetic inorganic ma...The chirality-induced spin selectivity(CISS)has been found in the antiferromagnetic and paramagnetic chiral inorganic materials with unpaired electrons,while rarely reported in the spin-paired diamagnetic inorganic materials with spin-pairing energy.Here,we report the CISS in the spin-paired diamagnetic BiOBr endowed with three levels of chiral mesostructures.Chiral mesostructured BiOBr films(CMBFs)were fabricated through a sugar alcohol-induced hydrothermal route.The antipodal CMBFs exhibited chirality-dependent,magnetic field-independent magnetic circular dichroism(MCD)signals,which indicates the existence of spin selectivity.The spin selectivity of CMBFs was speculated to be the result of the competing effect between the externally applied magnetic field and the effective magnetic field arisen from the spin electron motions in chiral potential.The chirality-induced effective magnetic field acts on the magnetic moment of electrons,potentially overcoming the spin-pairing energy and producing opposite energy changes for spin-down and spin-up electrons.展开更多
An exquisite mesostructure model was presented to predict the effective elastic modulus of concrete,in which concrete is realized as a four-phase composite material consisting of coarse aggregates,mortar matrix,interf...An exquisite mesostructure model was presented to predict the effective elastic modulus of concrete,in which concrete is realized as a four-phase composite material consisting of coarse aggregates,mortar matrix,interfacial transition zone(ITZ),and initial defects.With the three-dimensional(3D)finite element(FE)simulation,the highly heterogeneous composite elastic behavior of concrete was modeled,and the predicted results were compared with theoretical estimations for validation.Monte Carlo(MC)simulations were performed with the proposed mesostructure model to investigate the various factors of initial defects influencing the elastic modulus of concrete,such as the shape and concentration(pore volume fraction or crack density)of microspores and microcracks.It is found that the effective elastic modulus of concrete decreases with the increase of initial defects concentration,while the distribution and shape characteristics also exert certain influences due to the stress concentration caused by irregular inclusion shape.展开更多
The interfacial structure has an important effect on the mechanical properties and safety of the energetic material.In this work,a mesostructure model reflecting the real internal structure of PBX is established throu...The interfacial structure has an important effect on the mechanical properties and safety of the energetic material.In this work,a mesostructure model reflecting the real internal structure of PBX is established through image digital modeling and vectorization processing technology.The microscopic molecular structure model of PBX is constructed by molecular dynamics,and the interface bonding energy is calculated and transferred to the mesostructure model.Numerical simulations are used to study the influence of the interface roughness on the dynamic compression and impact ignition response of PBX,and to regulate and optimize the mechanical properties and safety of the explosive to obtain the optimal design of the surface roughness of the explosive crystal.The results show that the critical hot spot density of PBX ignition under impact loading is 0.68 mm^(-2).The improvement of crystal surface roughness can improve the mechanical properties of materials,but at the same time it can improve the impact ignition sensitivity and reduce the safety of materials.The optimal friction coefficient range for the crystal surface that satisfies both the mechanical properties and safety of PBX is 0.06-0.12.This work can provide a reference basis for the formulation design and production processing of energetic materials.展开更多
Various ordered mesoporous carbons （OMCs） have been prepared by evaporation-induced trieonstituent co-assembly method. Their mesostructural stability under different carbon content, aging time and acidity were conve...Various ordered mesoporous carbons （OMCs） have been prepared by evaporation-induced trieonstituent co-assembly method. Their mesostructural stability under different carbon content, aging time and acidity were conveniently monitored by X-ray diffraction, transmission electron microscopy, and N2 sorption isotherms techniques. The results show mesostruetural stability of OMCs is enhanced as the carbon content increases from 36% to 46%, further increasing carbon content deteriorates the mesostructural stability. Increasing aging time from 0.5 h to 5.0 h make the mesostructural stability go through an optimum （2.0 h） and gradually reduce framework shrinkage of the OMCs. Highly OMCs can only be obtained in the acidity range of 0.2-1.2 mol/L HC1, when the acidity is near the isoelectrie point of silica, the resulting OMCs have the best mesostructure stability. Under the optimum condition, the carbon content of 46%, aging time of 2.0 h, and 0.2 mol/L HCl, the resulting OMCs have the best mesostrueture stability and the highest BET surface areas of 2281 m2/g.展开更多
Common structures in engineering such as slopes,roadbeds,ballasts,etc.,are closely related to granular materials.They are usually subjected to long-term cyclic loads.This study mainly focused on the mechanical behavio...Common structures in engineering such as slopes,roadbeds,ballasts,etc.,are closely related to granular materials.They are usually subjected to long-term cyclic loads.This study mainly focused on the mechanical behaviors of randomly arranged granular materials before they reach a stable state under different cyclic loads.The variation of the maximum axial strain and the influence of CSR(cyclic stress ratio)were analyzed.The energy consumed in each cycle under constant confining stress loading condition is significantly greater than that of the fixed wall loading condition.The internal deformation evolution of granular materials is studied in detail.The deformation mode of granular material under cyclic loading at different positions inside the material is different according to the strain variation.In addition,the strain,force chain structure and contact force magnitude are combined to explore their effects on local deformation of granular materials under cyclic loading.From the perspective of the deformation form,the material sample can be divided into several regions,and the ability to adjust particle positions determines the deformation mode of different regions.The changes of local strain with the cyclic loading also reflect the contribution of particle displacements to the evolution ofmicrostructure.This research will provide insights into the understanding of granular materials behaviors under cyclic loading.展开更多
We reported here the simultaneous influence of surface acidity and pore size of M-substituted hexagonal mesoporous silicas （Al- doped plugs-containing SBA-15 and M-doped MCM-41） on polymerization of THE These materi...We reported here the simultaneous influence of surface acidity and pore size of M-substituted hexagonal mesoporous silicas （Al- doped plugs-containing SBA-15 and M-doped MCM-41） on polymerization of THE These materials were directly synthesized by introduced aluminum isopropoxide into reaction mixture including surfactant and siliceous precursor. Al-doped plugs-containing SBA-15 （denotes as PAS） samples not only possess typical two-step desorption isotherms, which implied PAS materials generated plugs in their mesochannel, but also exhibit larger pore size and thicker wall than that of Al-doped MCM-41 （denotes as ACM）, which implied PAS would have a great advantage on catalytic reaction involving large molecular （e.g. polymer of THF） in industrial point＇of view. To investigate catalytic activity of PAS and ACM with moderate acidic sites the polymerization of THF in the presence of acetic anhydride was carried out. The results showed PAS exhibiting good performance on polymerization of THF. Such result could be related to the large pore size and moderate acidic sites.展开更多
The mechanically guided assembly that relies on the compressive buckling of strate- gically patterned 2D thin films represents a robust route to complex 3D mesostructures in advanced materials and even functional micr...The mechanically guided assembly that relies on the compressive buckling of strate- gically patterned 2D thin films represents a robust route to complex 3D mesostructures in advanced materials and even functional micro-devices. Based on this approach, formation of complex 3D configurations with suspended curvy features or hierarchical geometries remains a challenge. In this paper, we incorporate the prestrained shape memory polymer in the 2D precur- sor design to enable local rolling deformations after the mechanical assembly through compressive buckling. A theoretical model captures quantitatively the effect of key design parameters on local rolling deformations. The combination of precisely controlled global buckling and local rolling expands substantially the range of accessible 3D configurations. The combined experimental and theoretical studies over a dozen of examples demonstrate the utility of the proposed strategy in achieving complex reprogrammable 3D mesostructures.展开更多
A series of NiMo/FDU-12 catalysts with tunable pore diameters and mesostructures have been controllably synthesized by adjusting the synthetic hydrothermal temperature and applied for the hydrodesulfurization of diben...A series of NiMo/FDU-12 catalysts with tunable pore diameters and mesostructures have been controllably synthesized by adjusting the synthetic hydrothermal temperature and applied for the hydrodesulfurization of dibenzothiophene and its derivative.The state-of-the-art electron tomography revealed that the pore sizes of FDU-12 supports were enlarged with the increase in the hydrothermal temperature and the mesostructures were transformed from ordered cage-type pores to locally disordered channels.Meanwhile,the MoS2 morphology altered from small straight bar to semibending arc to spherical shape and finally to larger straight bar with the change of support structures.Among them,FDU-12 hydrothermally treated at 150℃possessed appropriate pore diameter and connected pore structure and was favorable for the formation of highly active MoS2 with curved morphology;thus,its corresponding catalyst exhibited the best HDS activity.Furthermore,it was indicated that the isomerization pathway could be significantly improved for HDS of 4,6-dimethyldibenzothiophene after the addition of aluminum,which was expected to be applied to the removal of the macromolecular sulfur compounds.Our study sheds lights on the relationship between support effect,active sites morphology and HDS performance,and also provides a guidance for the development of highly active HDS catalysts.展开更多
Soft robots complement the existing efforts of miniaturizing conventional,rigid robots,and have the potential to revolutionize areas such as military equipment and biomedical devices.This type of system can accomplish...Soft robots complement the existing efforts of miniaturizing conventional,rigid robots,and have the potential to revolutionize areas such as military equipment and biomedical devices.This type of system can accomplish tasks in complex and time-varying environments through geometric reconfiguration induced by diverse external stimuli,such as heat,solvent,light,electric field,magnetic field,and mechanical field.Approaches to achieve reconfigurable mesostructures are essential to the design and fabrication of soft robots.Existing studies mainly focus on four key aspects:reconfiguration mechanisms,fabrication schemes,deformation control principles,and practical applications.This review presents a detailed survey of methodologies for morphable mesostructures triggered by a wide range of stimuli,with a number of impressive examples,demonstrating high degrees of deformation complexities and varied multi-functionalities.The latest progress based on the development of new materials and unique design concepts is highlighted.An outlook on the remaining challenges and open opportunities is provided.展开更多
基金supported by 973 Project (2004CB719500)the New Century Excellent Talents in University (NCET-05-415)the Natural Science Foundation of China (20673037)
文摘Mesostructured Ce0.6Zr0.4O2 solid solutions were synthesized by coprecipitation combined with evaporation-induced self-assembly process. The obtained materials were characterized by X-ray diffractometer （XRD）, Raman, transmission electron microscopy （TEM）, N2 sorption, and hydrogen temperature programmed reduction （H2-TPR）. The results showed that the solid solutions consisted of uniform nanocrystals, which piled homogeneous mesopores of about 4 nm. Furthermore, different surfactants had little influence on the mesoporous structures. All these samples exhibited high thermal stability.
基金Open access funding provided by Shanghai Jiao Tong University
文摘Silica-based materials are usually used as delivery systems for antibacterial applications.In rare cases,bactericidal cationic surfactant templated silica composites have been reported as antimicrobial agents.However,their antibacterial efficacy is limited due to limited control in content and structure.Herein,we report a“dual active templating”strategy in the design of nanostructured silica composites with intrinsic antibacterial performance.This strategy uses cationic and anionic structural directing agents as dual templates,both with active antibacterial property.The cationic-anionic dual active templating strategy further contributes to antibacterial nanocomposites with a spiky surface.With controllable release of dual active antibacterial agents,the spiky nanocomposite displays enhanced anti-microbial and anti-biofilm properties toward Staphylococcus epidermidis.These findings pave a new avenue toward the designed synthesis of novel antibacterial nanocomposites with improved performance for diverse antibacterial applications.
文摘More and more attention has been paid to the synthesis of mesostructuredaluminophosphates for many years. A lot of valuable research results, including various syntheticapproaches and structural materials, have been obtained. This paper reviews the progress in thesynthesis of mesostructured aluminophosphates over the past few years, with the hope of revealingopportunities for future work.
基金Supported by the National Natural Science Foundation of China(No.51002080)the Research Funds of Nanjing University of Information Science and Technology(NUIST),China(No.S8108179001)+1 种基金the College Students Practice Innovative Projects of Jiangsu Province,China(No.N1885010087)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Mesostructured iron oxides（MIOs） were nanocasted from a plugged hexagonal templated silica（PHTS） with a Brunauer-Emmett-Teller（BET） surface area of 694 m 2 /g.Results of X-ray diffraction（XRD）,transmission electron microscopy（TEM） and N 2 adsorption-desorption suggest that the nanocasted MIOs are synthetic hematite（α-Fe2O3） with a wormhole-like mesoporous network.As（V） adsorption test shows that the selected MIO—MIO-500（calcinated at 500 °C） with a BET surface area of 82 m^ 2 /g has a maximum adsorption capacity of 5.39 mg/g for As（V）,which is 2.5 times as large as that of natural hematite adsorbent.The study suggests that MIOs could be potentially used as the adsorbent of As（V） in wastewater.
文摘This work investigated the possibility of incorporation of nickel into several mesostructured cellular foam (MCF) silica supports prepared at various aging times (1, 2, and 3 days) by using deposition-precipitation method followed by reducetion process and to look for the best support to obtain supported nickel catalyst with highest nickel loading and smallest size of nickel nanoparticles. Analyses using nitrogen adsorption-desorption, transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) showed that MCF silica prepared at aging time of 3 days was the best support as the corresponding nickel functionalized MCF catalyst had the highest nickel content (17.57 wt%) and the smallest size of nickel nanoparticles (1 - 2 nm) together with high porosity (window pore size of 90A). The result was attributed to the highest window pore size in the MCF support which allowed more nickel nanoparticles to be incorporated.
基金supported by the National Key R&D Program of China(No.2021YFA1200301)the Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University(No.21TQ1400219).
文摘Tetraphenylethylene(TPE)and its derivatives,the typical aggregation-induced emission(AIE)luminogens,exhibit unique chirality in the condensed phase due to their propeller-shaped structure.However,precisely regulating the chiral assembly of TPE and its derivatives is challenging,owing to their inherent spontaneous self-assembly behavior.Herein,we report the controllable self-assembly of the chiral mesostructured AIEgens-silica(CMAS)via a co-structure directing route,using 2-[4-(1,2,2-triphenylethenyl)phenoxy]-acetic acid(TPEA)as a structure-directing agent,binaphthol as a symmetry-breaking agent,quaternized aminosilane N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride as the co-structure directing agent,and tetraethyl orthosilicate as the inorganic source.The CMAS materials were characterized by nanotubes with lengths ranging from hundreds of nanometers to dozens of micrometers and diameters of 150–300 nm.The CMAS materials exhibited optical activities originating from J-aggregates,which possess a one-handed excess helical conformation of TPEA induced by binaphthol.Our work elucidates the underlying mechanisms of chirality transfer during self-assembly and expands the potential applications of AIEgens in chiral response.
基金supported by the National Natural Science Foundation of China(Nos.21931008,21873072,21922304,and 21975184)the National Key R&D Program of China(No.2021YFA1200301)+2 种基金Fundamental Research Funds for the Central Universities,Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University(No.21TQ1400219)Natural Science Fund for Colleges and Universities in Jiangsu Province(No.22KJB150041)Wuxi"Taihu Light"Science and Technology Project-Basic Research(No.K20221067).
文摘Hematite(α-Fe_(2)O_(3))is known to undergo conversion from weak ferromagnetic to antiferromagnetic as the temperature decreases below the Morin temperature(TM=250 K)due to spin moment rotation occurring during the Morin transition(MT).Herein,we endowed hematite with mesostructured chirality to maintain weak ferromagnetism without MT.Chiral mesostructured hematite(CMH)nanoparticles were prepared by a hydrothermal method with glutamic acid(Glu)as the symmetry-breaking agent.The triangular bipyramidal CMH nanoparticles were composed of helically cleaved nanoflakes with twisted crystal lattice.Field-cooled(FC)magnetization measurements showed that the magnetic moments of CMH were stabilized without MT within the temperature range of 10–300 K.Hysteresis loop measurements confirmed the weak ferromagnetism of CMH.The enhanced Dzyaloshinskii–Moriya interaction(DMI)was speculated to be responsible for the temperature-independent weak ferromagnetism,in which the spin configuration would be confined with canted antiferromagnetic coupling due to the mesostructured chirality of CMH.
基金supported by the National Key Research and Development Program of China(No.2021YFA1200301,S.A.C.)the National Natural Science Foundation of China(Nos.21931008,S.A.C.and 21975184,Y.Y.D.)Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University(No.21TQ1400219).
文摘Spin chiral anisotropy(SChA)refers to the occurrence of different spin polarization in antipodal chiral structures.Herein,we report the SChA in diamagnetic chiral mesostructured In2O3 films(CMIFs)with manifestation of chirality-dependent magnetic circular dichroism(MCD)signals.CMIFs were grown on fluorine-doped tin dioxide conductive glass(FTO)substrates,which were synthesized via a hydrothermal route,with malic acid used as the symmetry-breaking agent.Two levels of chirality have been identified in CMIFs:primary nanoflakes with atomically twisted crystal lattices and secondary helical stacking of the nanoflakes.CMIFs exhibit chirality-dependent asymmetric MCD signals due to the different interactions of chirality-induced effective magnetic field and external magnetic field,which distinguish from the commonly observed external magnetic fielddependent symmetric MCD signals.These findings provide insights into spin manipulation of spin-paired diamagnets.
基金supported by the National Key Research and Development Program of China(2017YFA0206500,2018YFA0209103)the National Natural Science Foundation of China(21832003,21773111,51571110,21573107)。
文摘The electrochemistry in energy conversion and storage(ECS) not only relies on the active species in catalysts or energy-storage materials, but also involves mass/ion transport around the active species and electron transfer to the external circuit. To realize high-rate ECS process, new architectures for catalysts or energy-storage electrodes are required to ensure more efficient mass/charge transport. 3 D porous mesostructured materials constructed by nanoscale functional units can form a continuous conductive network for electron transfer and an interconnected multiscale pores for mass/ion transport while maintaining the high surface area, showing great promise in boosting the ECS process. In this review, we summarize the recent progress on the design,construction and applications of 3 D mesostructured carbon-based nanocages for ECS. The role of the hierarchical architectures to the high rate performance is discussed to highlight the merits of the mesostructured materials. The perspective on future opportunities and challenges is also outlined for deepening and extending the related studies and applications.
基金This work was financially supported by the National Basic Research Program of China(No.2009CB939901)the National Natural Science Foundation of China(Nos.90922016 and 10979047)the Innovative Project of Chinese Academy of Sciences(No.KJCX2-YW-H2O).
文摘Analysis of the atomic structure of monoclinic BiVO4 reveals its fascinating structure-related dual response to visible light and temperature.Although there have been a few reported studies of its responses to visible light and temperature,an understanding of the effects of quantum size,particle shape or specific exposed facets on its dual responsive properties remains elusive;this is primarily due to the limited availability of high-quality monodisperse nanocrystals with extremely small sizes and specific_(4)exposed facets.Herein,we describe a novel assembly-fusion strategy for the synthesis of mesostructured monoclinic BiVO_(4)quantum tubes with ultranarrow diameter of 5 nm,ultrathin wall thickness down to 1 nm and exposed{020}facets,via a convenient hydrothermal method at temperatures as low as 100℃.Notably,the resulting high-quality quantum tubes possess significantly superior dual-responsive properties compared with bulk BiVO_(4)or even BiVO4 nanoellipsoids,and thus,show high promise for applications as visible-light photocatalysts and temperature indicators offering improved environmental quality and safety.This mild and facile methodology should be capable of extension to the preparation of other mesostructured inorganic quantum tubes with similar characteristics,giving a range of materials with enhanced dual-responsive properties.
基金supported by the National Key R&D Program of China(No.2021YFA1200300)the National Natural Science Foundation of China(Nos.21931008,21975184,21873072,and 21922304)the scientific foundation of the Shanghai Municipal Science and Technology Commission(Nos.19JC1410300).
文摘The chirality-induced spin selectivity(CISS)has been found in the antiferromagnetic and paramagnetic chiral inorganic materials with unpaired electrons,while rarely reported in the spin-paired diamagnetic inorganic materials with spin-pairing energy.Here,we report the CISS in the spin-paired diamagnetic BiOBr endowed with three levels of chiral mesostructures.Chiral mesostructured BiOBr films(CMBFs)were fabricated through a sugar alcohol-induced hydrothermal route.The antipodal CMBFs exhibited chirality-dependent,magnetic field-independent magnetic circular dichroism(MCD)signals,which indicates the existence of spin selectivity.The spin selectivity of CMBFs was speculated to be the result of the competing effect between the externally applied magnetic field and the effective magnetic field arisen from the spin electron motions in chiral potential.The chirality-induced effective magnetic field acts on the magnetic moment of electrons,potentially overcoming the spin-pairing energy and producing opposite energy changes for spin-down and spin-up electrons.
基金Founded by the National Natural Science Foundation of China(No.42002287)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(No.CUG2106335)。
文摘An exquisite mesostructure model was presented to predict the effective elastic modulus of concrete,in which concrete is realized as a four-phase composite material consisting of coarse aggregates,mortar matrix,interfacial transition zone(ITZ),and initial defects.With the three-dimensional(3D)finite element(FE)simulation,the highly heterogeneous composite elastic behavior of concrete was modeled,and the predicted results were compared with theoretical estimations for validation.Monte Carlo(MC)simulations were performed with the proposed mesostructure model to investigate the various factors of initial defects influencing the elastic modulus of concrete,such as the shape and concentration(pore volume fraction or crack density)of microspores and microcracks.It is found that the effective elastic modulus of concrete decreases with the increase of initial defects concentration,while the distribution and shape characteristics also exert certain influences due to the stress concentration caused by irregular inclusion shape.
基金National Natural Science Foundation of China(Grant No.U22B20131)General Program of National Nature Science Foundation of China(Grant No.12202060)for supporting this project。
文摘The interfacial structure has an important effect on the mechanical properties and safety of the energetic material.In this work,a mesostructure model reflecting the real internal structure of PBX is established through image digital modeling and vectorization processing technology.The microscopic molecular structure model of PBX is constructed by molecular dynamics,and the interface bonding energy is calculated and transferred to the mesostructure model.Numerical simulations are used to study the influence of the interface roughness on the dynamic compression and impact ignition response of PBX,and to regulate and optimize the mechanical properties and safety of the explosive to obtain the optimal design of the surface roughness of the explosive crystal.The results show that the critical hot spot density of PBX ignition under impact loading is 0.68 mm^(-2).The improvement of crystal surface roughness can improve the mechanical properties of materials,but at the same time it can improve the impact ignition sensitivity and reduce the safety of materials.The optimal friction coefficient range for the crystal surface that satisfies both the mechanical properties and safety of PBX is 0.06-0.12.This work can provide a reference basis for the formulation design and production processing of energetic materials.
基金This work was supported by the National Natural Science Foundation of China （No.20872135）.
文摘Various ordered mesoporous carbons （OMCs） have been prepared by evaporation-induced trieonstituent co-assembly method. Their mesostructural stability under different carbon content, aging time and acidity were conveniently monitored by X-ray diffraction, transmission electron microscopy, and N2 sorption isotherms techniques. The results show mesostruetural stability of OMCs is enhanced as the carbon content increases from 36% to 46%, further increasing carbon content deteriorates the mesostructural stability. Increasing aging time from 0.5 h to 5.0 h make the mesostructural stability go through an optimum （2.0 h） and gradually reduce framework shrinkage of the OMCs. Highly OMCs can only be obtained in the acidity range of 0.2-1.2 mol/L HC1, when the acidity is near the isoelectrie point of silica, the resulting OMCs have the best mesostructure stability. Under the optimum condition, the carbon content of 46%, aging time of 2.0 h, and 0.2 mol/L HCl, the resulting OMCs have the best mesostrueture stability and the highest BET surface areas of 2281 m2/g.
基金the National Natural Science Foundation of China(Nos.11902228,11772237)the Fundamental Research Funds for Central Universities(No.2682021CX083).
文摘Common structures in engineering such as slopes,roadbeds,ballasts,etc.,are closely related to granular materials.They are usually subjected to long-term cyclic loads.This study mainly focused on the mechanical behaviors of randomly arranged granular materials before they reach a stable state under different cyclic loads.The variation of the maximum axial strain and the influence of CSR(cyclic stress ratio)were analyzed.The energy consumed in each cycle under constant confining stress loading condition is significantly greater than that of the fixed wall loading condition.The internal deformation evolution of granular materials is studied in detail.The deformation mode of granular material under cyclic loading at different positions inside the material is different according to the strain variation.In addition,the strain,force chain structure and contact force magnitude are combined to explore their effects on local deformation of granular materials under cyclic loading.From the perspective of the deformation form,the material sample can be divided into several regions,and the ability to adjust particle positions determines the deformation mode of different regions.The changes of local strain with the cyclic loading also reflect the contribution of particle displacements to the evolution ofmicrostructure.This research will provide insights into the understanding of granular materials behaviors under cyclic loading.
基金supported by Science Foundation of China(No.20573071)Key Scientific and Technological Projects of Shanxi Province(No.20090321059)
文摘We reported here the simultaneous influence of surface acidity and pore size of M-substituted hexagonal mesoporous silicas （Al- doped plugs-containing SBA-15 and M-doped MCM-41） on polymerization of THE These materials were directly synthesized by introduced aluminum isopropoxide into reaction mixture including surfactant and siliceous precursor. Al-doped plugs-containing SBA-15 （denotes as PAS） samples not only possess typical two-step desorption isotherms, which implied PAS materials generated plugs in their mesochannel, but also exhibit larger pore size and thicker wall than that of Al-doped MCM-41 （denotes as ACM）, which implied PAS would have a great advantage on catalytic reaction involving large molecular （e.g. polymer of THF） in industrial point＇of view. To investigate catalytic activity of PAS and ACM with moderate acidic sites the polymerization of THF in the presence of acetic anhydride was carried out. The results showed PAS exhibiting good performance on polymerization of THF. Such result could be related to the large pore size and moderate acidic sites.
基金X.G. and Z.X. contributed equally to this work. Y.Z. acknowledges the support from the National Natural Science Foundation of China （Grant Nos. 11502129 and 11722217） and the Tsinghua National Laboratory for Information Science and Technology. Y.H. acknowledges the support from the NSF （Grant Nos. CMMI1400169, CMMI1534120 and CMMI1635443）. X.G. acknowledges the support from the National Natural Science Foundation of China （Grant Nos. 11702155）.
文摘The mechanically guided assembly that relies on the compressive buckling of strate- gically patterned 2D thin films represents a robust route to complex 3D mesostructures in advanced materials and even functional micro-devices. Based on this approach, formation of complex 3D configurations with suspended curvy features or hierarchical geometries remains a challenge. In this paper, we incorporate the prestrained shape memory polymer in the 2D precur- sor design to enable local rolling deformations after the mechanical assembly through compressive buckling. A theoretical model captures quantitatively the effect of key design parameters on local rolling deformations. The combination of precisely controlled global buckling and local rolling expands substantially the range of accessible 3D configurations. The combined experimental and theoretical studies over a dozen of examples demonstrate the utility of the proposed strategy in achieving complex reprogrammable 3D mesostructures.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.21776048,21576290,21106182)the Natural Science Foundation of Fujian Province(2018J06002)。
文摘A series of NiMo/FDU-12 catalysts with tunable pore diameters and mesostructures have been controllably synthesized by adjusting the synthetic hydrothermal temperature and applied for the hydrodesulfurization of dibenzothiophene and its derivative.The state-of-the-art electron tomography revealed that the pore sizes of FDU-12 supports were enlarged with the increase in the hydrothermal temperature and the mesostructures were transformed from ordered cage-type pores to locally disordered channels.Meanwhile,the MoS2 morphology altered from small straight bar to semibending arc to spherical shape and finally to larger straight bar with the change of support structures.Among them,FDU-12 hydrothermally treated at 150℃possessed appropriate pore diameter and connected pore structure and was favorable for the formation of highly active MoS2 with curved morphology;thus,its corresponding catalyst exhibited the best HDS activity.Furthermore,it was indicated that the isomerization pathway could be significantly improved for HDS of 4,6-dimethyldibenzothiophene after the addition of aluminum,which was expected to be applied to the removal of the macromolecular sulfur compounds.Our study sheds lights on the relationship between support effect,active sites morphology and HDS performance,and also provides a guidance for the development of highly active HDS catalysts.
文摘Soft robots complement the existing efforts of miniaturizing conventional,rigid robots,and have the potential to revolutionize areas such as military equipment and biomedical devices.This type of system can accomplish tasks in complex and time-varying environments through geometric reconfiguration induced by diverse external stimuli,such as heat,solvent,light,electric field,magnetic field,and mechanical field.Approaches to achieve reconfigurable mesostructures are essential to the design and fabrication of soft robots.Existing studies mainly focus on four key aspects:reconfiguration mechanisms,fabrication schemes,deformation control principles,and practical applications.This review presents a detailed survey of methodologies for morphable mesostructures triggered by a wide range of stimuli,with a number of impressive examples,demonstrating high degrees of deformation complexities and varied multi-functionalities.The latest progress based on the development of new materials and unique design concepts is highlighted.An outlook on the remaining challenges and open opportunities is provided.
