Numerous studies have indicated that nano calcium carbonate(NCC)has the potential to enhance the mechanics,durability,and functionality of cementitious composites,thus developing high performance,durable,multifunction...Numerous studies have indicated that nano calcium carbonate(NCC)has the potential to enhance the mechanics,durability,and functionality of cementitious composites,thus developing high performance,durable,multifunctional,and low carbon cementitious composites.This paper reviews the recent progress in NCC modified cementitious composites and provides a comprehensiveness overview of the impact of NCC on the performances of cementitious composites,which includes the fabrication(materials,preparation methods,and curing methods),structures(hydration products and microstructures),and properties(hydration,workability,mechanical properties,durability,and functionality).Moreover,the mechanisms and the challenges as well as future directions of NCC modified cementitious composites are also explored and prospected.展开更多
Advancements in nanostructures and nanomaterials have significantly impacted both academic research and industry.Notable nanomaterials include carbon materials,polymeric nanoparticles,dendrimers,metal and metal oxide ...Advancements in nanostructures and nanomaterials have significantly impacted both academic research and industry.Notable nanomaterials include carbon materials,polymeric nanoparticles,dendrimers,metal and metal oxide nanoparticles,liposomes,zeolites,Metal-Organic Frameworks(MOFs),MXenes,molecular cages,and covalent organic frameworks(COFs).Their unique structures and properties make them suitable for diverse applications.Nano-structuration,which generates various nano-architectures with unique characteristics,influences the physical,chemical,and electrical properties of nanomaterials.This process is essential for achieving desired properties and maximizing application potential.Carbon materials,MOFs,and other nanomaterials have been classified based on their architectural dimensionality and the effects of nano-structuration on their applications.However,comprehensive studies on the synthesis and fabrication of COF nanostructures with desired architectures and dimensionalities are lacking.This review discusses the library of available nanostructures based on dimensionality,factors influencing nano-structuration,and the potential applications of nanomaterials like carbon materials,MOFs,and organic cage molecules.Additionally,it attempts to classify COFs based on architectural variation,specific synthetic strategies,and other factors influencing nano-structuration and applications.The aim is to develop novel synthetic methods for COF architectures across all dimensions,utilizing their morphological diversity for targeted applications based on their structure-property relationship,and to explore new methodologies for interconverting COF architectures through covalent and supramolecular self-assembly.展开更多
Magnesium-sulfur batteries(MSBs)are promising due to Mg’s lower propensity to form dendrites,its natural abundance,and high volumetric energy densities for large-scale energy storage.Nonetheless,Mg2+ions have poor di...Magnesium-sulfur batteries(MSBs)are promising due to Mg’s lower propensity to form dendrites,its natural abundance,and high volumetric energy densities for large-scale energy storage.Nonetheless,Mg2+ions have poor diffusion kinetics and the magnesium polysulfide(MgPS)shuttle effect present significant challenges for MSBs.Herein,a Mg-S pouch cell is designed using rich N-doped porous carbon(ZIF8-NC)and a Cu current collector.This architecture provides numerous benefits:i)ZIF8-NC offers a conductive skeleton that significantly enhances electron and Mg2+ion conduction,ii)zeolite imidazolate frameworks(ZIF-8)derived N rich sites demonstrate superior MgPS anchoring capability,iii)the Cu collector not only accelerates conversion of anchored MgPS to MgS,but also participates in the electrode reaction and iv)the material is easy to synthesize on a large scale,facilitating its potential for practical applications.Mg-S/ZIF8-NC coin cells maintain∼310 mAh·g-1after 1000 cycles even at 1C.Furthermore,Mg-S/ZIF8-NC pouch cells achieve high cathodic energy densities of∼120 Wh·kg-1and∼330 mAh·g-1after 300 cycles at 1C,outperforming the state-of-the-art results in the literature.Soft X-ray absorption spectroscopy(sXAS)revealed that the initial catalytic reaction of Cu follows Cu0↔Cu2S,and later Cu2S↔CuxS.Theoretical calculations and experimental results reveal that pyridine nitrogen acts as catalytic site for polysulfide adsorption.Therefore,this work not only provides a facile method to prepare high-performance Mg-S pouch cells,but also proposes mechanisms whereby N active sites and Cu catalytic reactions promote all aspects of performance.展开更多
This study innovatively prepared a high-performance Fe18Co18Cr18Ni36Al9Y0.5Hf0.5high-entropy alloy coating via laser cladding.The coating features a stable face-centered cubic(FCC)solid solution p...This study innovatively prepared a high-performance Fe18Co18Cr18Ni36Al9Y0.5Hf0.5high-entropy alloy coating via laser cladding.The coating features a stable face-centered cubic(FCC)solid solution phase and a unique nanoscale(AlNi2)@(YNi3+Cr2O3+Hf)core-shell structure.The study also proposed a triple oxide barrier design using Cr,Y,and Al,enhancing oxide stability and compactness.The oxide layer forms Cr2O3outer shell and Al2O3+Y2O3bonding layer,effectively blocking oxygen and reducing oxidation rate.This structure promotes Hf distribution and rare earth element activity.The high-entropy alloy with this nano core-shell structure,featuring a Cr2O3outer shell,an Al2O3and Y2O3triple oxide barrier bonding layer and uniformly dispersed rare earth elements,effectively prevents further contact between oxygen and metal,and reduces the oxidation rate.展开更多
超疏水高疏油表面(superhydrophobic and oleophobic surface,SHOS)在海洋工程、能源输送与精密制造等领域应用前景广阔,但其发展始终受制于表面性能与机械耐久性难以兼顾等问题。本文针对SHOS材料普遍存在的“疏水不疏油”与“双疏不...超疏水高疏油表面(superhydrophobic and oleophobic surface,SHOS)在海洋工程、能源输送与精密制造等领域应用前景广阔,但其发展始终受制于表面性能与机械耐久性难以兼顾等问题。本文针对SHOS材料普遍存在的“疏水不疏油”与“双疏不长效”两大核心问题,系统剖析了纳米二氧化硅(Nano-SiO2)基SHOS的构建策略与性能强化机制。研究结果表明,氟化Nano-SiO2实现双疏性能的关键在于“低表面能”与“微纳粗糙结构”的协同效应:氟碳基团通过电子云屏蔽效应从化学本质上削弱液-固界面相互作用,而多级粗糙结构则通过截留空气形成气垫层,从物理结构上阻隔液滴渗透,二者共同赋予表面优异的疏液特性。在改性策略方面,氟化接枝改性虽可获得较高初始疏液性能,但受限于工艺复杂性与均匀性问题;含氟聚合物混合改性则在维持功能性的同时,更有利于提升涂层的机械韧性与结构稳定性。据此,最优氟化方案应遵循“应用场景驱动”原则进行选择。为进一步提升SHOS在复杂工况下的服役寿命,构建“低成本随机基底+关键区域规则强化”的跨尺度复合结构(如微米/纳米多级复合体系)以及引入自修复机制(如微胶囊修复与拓扑结构再生结合)是增强其耐磨性与化学稳定性的有效路径。最后,后续研究应聚焦于推动材料体系绿色化与结构功能智能化的深度融合,为高性能、长寿命SHOS的可持续研发与工程应用提供理论指导。展开更多
The magnetohydrodynamics of bubbly nanofluid flow in a horizontal pipe was studied.The drag-reduction effect of the behavior of a magnetohydrodynamic nanofluid in bubbly flow was experimentally verified by generating ...The magnetohydrodynamics of bubbly nanofluid flow in a horizontal pipe was studied.The drag-reduction effect of the behavior of a magnetohydrodynamic nanofluid in bubbly flow was experimentally verified by generating bubbles in the flow.The study examined the effects of the magnetic field on bubble formation by observing bubble characteristics,including shape,size,and trajectory.The experimental analysis adopted an optical system using a high-speed video camera.A MATLAB code was developed to track bubble formation in bubbly flow.The magnetic field affects the continuous nanofluid phase and,in turn,influences the gas phase and bubble features,such as bubble growth,shape,size,trajectory,and formation velocity.The results showed that under a magnetic field up to 4000 gauss and a nanofluid superficial velocity of 17.78 cm/s,the magnetic force had the greatest effect due to the increased electrical conductivity of the nanofluid.Also,in a magnetic field,bubble formation is delayed,leading to increased collisions and bubble merging.The magnetic field makes the bubble turbulent and unstable,especially after it separates from the nozzle tip,as evidenced by changes in its shape and trajectory.The shape factor of bubbles decreases as the magnetic field intensity increases.This effect is confirmed by the elongation of bubbles within the nanofluid flow.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.52368031,52163034)the China Postdoctoral Science Foundation(No.2022M713497)+2 种基金Jiangxi Provincial Natural Science Foundation(No.20252BAC250115)Jiangxi Provincial Department of Transportation Science and Technology Project(No.2022H0017)Key Project of Hunan Provincial Department of Education(No.25A0510)。
摘要Numerous studies have indicated that nano calcium carbonate(NCC)has the potential to enhance the mechanics,durability,and functionality of cementitious composites,thus developing high performance,durable,multifunctional,and low carbon cementitious composites.This paper reviews the recent progress in NCC modified cementitious composites and provides a comprehensiveness overview of the impact of NCC on the performances of cementitious composites,which includes the fabrication(materials,preparation methods,and curing methods),structures(hydration products and microstructures),and properties(hydration,workability,mechanical properties,durability,and functionality).Moreover,the mechanisms and the challenges as well as future directions of NCC modified cementitious composites are also explored and prospected.
基金the funding from the SERB SUPRA[SPR/2021/000020]for funding.
摘要Advancements in nanostructures and nanomaterials have significantly impacted both academic research and industry.Notable nanomaterials include carbon materials,polymeric nanoparticles,dendrimers,metal and metal oxide nanoparticles,liposomes,zeolites,Metal-Organic Frameworks(MOFs),MXenes,molecular cages,and covalent organic frameworks(COFs).Their unique structures and properties make them suitable for diverse applications.Nano-structuration,which generates various nano-architectures with unique characteristics,influences the physical,chemical,and electrical properties of nanomaterials.This process is essential for achieving desired properties and maximizing application potential.Carbon materials,MOFs,and other nanomaterials have been classified based on their architectural dimensionality and the effects of nano-structuration on their applications.However,comprehensive studies on the synthesis and fabrication of COF nanostructures with desired architectures and dimensionalities are lacking.This review discusses the library of available nanostructures based on dimensionality,factors influencing nano-structuration,and the potential applications of nanomaterials like carbon materials,MOFs,and organic cage molecules.Additionally,it attempts to classify COFs based on architectural variation,specific synthetic strategies,and other factors influencing nano-structuration and applications.The aim is to develop novel synthetic methods for COF architectures across all dimensions,utilizing their morphological diversity for targeted applications based on their structure-property relationship,and to explore new methodologies for interconverting COF architectures through covalent and supramolecular self-assembly.
基金supported by the National Key R&D Program of China(2022YFB3803700)National Natural Science Foundation of China(52201266,52171186)+1 种基金Startup Fund for Young Faculty at SJTU(SFYF at SJTU)Collaborative Fund for Forward-looking Innovation in Marine Equipment of China State Shipbuilding Corporation Limited-Shanghai Jiao Tong University(ZCJDQZ202305A01).
摘要Magnesium-sulfur batteries(MSBs)are promising due to Mg’s lower propensity to form dendrites,its natural abundance,and high volumetric energy densities for large-scale energy storage.Nonetheless,Mg2+ions have poor diffusion kinetics and the magnesium polysulfide(MgPS)shuttle effect present significant challenges for MSBs.Herein,a Mg-S pouch cell is designed using rich N-doped porous carbon(ZIF8-NC)and a Cu current collector.This architecture provides numerous benefits:i)ZIF8-NC offers a conductive skeleton that significantly enhances electron and Mg2+ion conduction,ii)zeolite imidazolate frameworks(ZIF-8)derived N rich sites demonstrate superior MgPS anchoring capability,iii)the Cu collector not only accelerates conversion of anchored MgPS to MgS,but also participates in the electrode reaction and iv)the material is easy to synthesize on a large scale,facilitating its potential for practical applications.Mg-S/ZIF8-NC coin cells maintain∼310 mAh·g-1after 1000 cycles even at 1C.Furthermore,Mg-S/ZIF8-NC pouch cells achieve high cathodic energy densities of∼120 Wh·kg-1and∼330 mAh·g-1after 300 cycles at 1C,outperforming the state-of-the-art results in the literature.Soft X-ray absorption spectroscopy(sXAS)revealed that the initial catalytic reaction of Cu follows Cu0↔Cu2S,and later Cu2S↔CuxS.Theoretical calculations and experimental results reveal that pyridine nitrogen acts as catalytic site for polysulfide adsorption.Therefore,this work not only provides a facile method to prepare high-performance Mg-S pouch cells,but also proposes mechanisms whereby N active sites and Cu catalytic reactions promote all aspects of performance.
基金Project supported by National Natural Science Foundation of China(52274340,52004190)。
摘要This study innovatively prepared a high-performance Fe18Co18Cr18Ni36Al9Y0.5Hf0.5high-entropy alloy coating via laser cladding.The coating features a stable face-centered cubic(FCC)solid solution phase and a unique nanoscale(AlNi2)@(YNi3+Cr2O3+Hf)core-shell structure.The study also proposed a triple oxide barrier design using Cr,Y,and Al,enhancing oxide stability and compactness.The oxide layer forms Cr2O3outer shell and Al2O3+Y2O3bonding layer,effectively blocking oxygen and reducing oxidation rate.This structure promotes Hf distribution and rare earth element activity.The high-entropy alloy with this nano core-shell structure,featuring a Cr2O3outer shell,an Al2O3and Y2O3triple oxide barrier bonding layer and uniformly dispersed rare earth elements,effectively prevents further contact between oxygen and metal,and reduces the oxidation rate.
摘要超疏水高疏油表面(superhydrophobic and oleophobic surface,SHOS)在海洋工程、能源输送与精密制造等领域应用前景广阔,但其发展始终受制于表面性能与机械耐久性难以兼顾等问题。本文针对SHOS材料普遍存在的“疏水不疏油”与“双疏不长效”两大核心问题,系统剖析了纳米二氧化硅(Nano-SiO2)基SHOS的构建策略与性能强化机制。研究结果表明,氟化Nano-SiO2实现双疏性能的关键在于“低表面能”与“微纳粗糙结构”的协同效应:氟碳基团通过电子云屏蔽效应从化学本质上削弱液-固界面相互作用,而多级粗糙结构则通过截留空气形成气垫层,从物理结构上阻隔液滴渗透,二者共同赋予表面优异的疏液特性。在改性策略方面,氟化接枝改性虽可获得较高初始疏液性能,但受限于工艺复杂性与均匀性问题;含氟聚合物混合改性则在维持功能性的同时,更有利于提升涂层的机械韧性与结构稳定性。据此,最优氟化方案应遵循“应用场景驱动”原则进行选择。为进一步提升SHOS在复杂工况下的服役寿命,构建“低成本随机基底+关键区域规则强化”的跨尺度复合结构(如微米/纳米多级复合体系)以及引入自修复机制(如微胶囊修复与拓扑结构再生结合)是增强其耐磨性与化学稳定性的有效路径。最后,后续研究应聚焦于推动材料体系绿色化与结构功能智能化的深度融合,为高性能、长寿命SHOS的可持续研发与工程应用提供理论指导。
摘要The magnetohydrodynamics of bubbly nanofluid flow in a horizontal pipe was studied.The drag-reduction effect of the behavior of a magnetohydrodynamic nanofluid in bubbly flow was experimentally verified by generating bubbles in the flow.The study examined the effects of the magnetic field on bubble formation by observing bubble characteristics,including shape,size,and trajectory.The experimental analysis adopted an optical system using a high-speed video camera.A MATLAB code was developed to track bubble formation in bubbly flow.The magnetic field affects the continuous nanofluid phase and,in turn,influences the gas phase and bubble features,such as bubble growth,shape,size,trajectory,and formation velocity.The results showed that under a magnetic field up to 4000 gauss and a nanofluid superficial velocity of 17.78 cm/s,the magnetic force had the greatest effect due to the increased electrical conductivity of the nanofluid.Also,in a magnetic field,bubble formation is delayed,leading to increased collisions and bubble merging.The magnetic field makes the bubble turbulent and unstable,especially after it separates from the nozzle tip,as evidenced by changes in its shape and trajectory.The shape factor of bubbles decreases as the magnetic field intensity increases.This effect is confirmed by the elongation of bubbles within the nanofluid flow.