Oil spills have been a persistent environmental challenge globally,resulting in severe long-term impacts.Thus,developing materials for efficient oil-water separation is crucial.Metal-organic frameworks(MOFs),as a rapi...Oil spills have been a persistent environmental challenge globally,resulting in severe long-term impacts.Thus,developing materials for efficient oil-water separation is crucial.Metal-organic frameworks(MOFs),as a rapidly emerging class of porous materials,have gained tremendous attention due to their ultra-high surface area.In this study,four fluorinated MOFs with UiO-66 topology were synthesized and characterized.Their hydrophobicity was tailored by varying the types and quantities of the fluorine-containing functional groups(-F or-CF_(3))on the ligands.Among them,2CF_(3)-UiO-66 showed the highest hydrophobicity,with a water contact angle(WCA)of 145.9°,making it promising for adsorbing organic pollutants and as a hydrophobic coating material.2CF_(3)-UiO-66 powder efficiently reduced the concentration of 3,5-dichlorophenol(a model halogenated water pollutant)from 300 ppm to 23.4 ppm within 2 hours.Furthermore,2CF_(3)-UiO-66 was in situ coated on cotton(CT)and sponge(SP)to form composite materials,2CF_(3)-UiO-66@CT and 2CF_(3)-UiO-66@SP.2CF_(3)-UiO-66@CT is superhydrophobic(WCA=164.7°),flexible,and fire retardant.It efficiently separated water and nine organic solvents via filtration,meeting commercial standards of<0.01%water content in the filtered organic solvents.2CF_(3)-UiO-66@CT remains structurally intact after 20 filtration recycles,suggesting its durability.These advantages make the 2CF_(3)-UiO-66@CT an ideal candidate for oil-water separation via filtration.Alternatively,2CF_(3)-UiO-66@SP,with a porous sponge backbone,is suitable for oil-water separation by adsorbing the organic phase efficiently(60-140 g g^(−1)adsorption capacity on nine organic solvents),and the adsorbed oil can be easily pumped out.Overall,we believe the fluorinated MOFs reported in this work have great potential for adsorption and superhydrophobic coating applications.展开更多
Ferroelastic materials,as a significant category of primary ferroic materials,have paved the way for the development of shape memory,superelasticity,tunable electronics,MEMS and actuators.The ferroic phase transition ...Ferroelastic materials,as a significant category of primary ferroic materials,have paved the way for the development of shape memory,superelasticity,tunable electronics,MEMS and actuators.The ferroic phase transition rules summarized by Aizu provide a theoretical guideline for material design.However,ferroelectrics and ferroelastics are to some extent intertwined with each other.Decoupling these properties is essential for optimizing material performance and developing better theoretical models.By modifying[(CH_(3))_(4)N][FeCl_(4)],a typical molecular ferroelectric that is not ferroelastic,we synthesized(Me_(2)EtNCH_(3)CH_(2)Cl)FeCl_(4)(DMCE-FeCl_(4)),an organic-inorganic hybrid compound that introduces ferroelasticity while maintaining ferroelectricity.DFT calculations reveal that the shape of the organic cations contributes to ferroelasticity,while their dipole moments contribute to ferroelectricity.This work advances the understanding of ferroic properties and their independent control,with implications for reconfigurable memory devices and intelligent actuators.展开更多
Metal-organic frameworks(MOFs),as multifunctional materials,have shown excellent potential.However,the powder form of MOFs has always influenced their practical application.In this study,ZIF-67 was in situ grown on wo...Metal-organic frameworks(MOFs),as multifunctional materials,have shown excellent potential.However,the powder form of MOFs has always influenced their practical application.In this study,ZIF-67 was in situ grown on wood to obtain self-supported ZIF-67/wood.It was then carbonized at different temperatures to prepare three-dimensional(3D)porous carbon skeleton/magnetic composites(Co/C@WC).The carbon skeleton of the carbonized wood forms a 3D conductive network structure,while Co/C core-shell type magnetic nanoparticles are firmly and uniformly embedded in the carbon skeleton,enhancing the electrical conductivity and magnetism.After carbonization at 1000℃,the Co/C@WC composite delivered an excellent conductivity of 3247 S m^(-1) and an average EMI SET of about 43.2 dB at 8.2-12.4 GHz.Co/C@WC composites also exhibited sound insulation,temperature resistance and good mechanical performance,which endow the composites with the potential to be applied as multifunctional shielding materials for use in extreme conditions.展开更多
Pillared layer metal-organic frameworks(PL-MOFs),belonging to one representative of porous materials,have witnessed major advances in the past few years.They can be classified into subsets-3D pillared layers,2D pillar...Pillared layer metal-organic frameworks(PL-MOFs),belonging to one representative of porous materials,have witnessed major advances in the past few years.They can be classified into subsets-3D pillared layers,2D pillared bilayers,and interpenetrated and interdigitated layers.By choosing the molecular structures and chemical properties of the modular organic ligands used in PL-MOFs,high porosity and large internal surface areas can be achieved,while the shape,size,and surface of the channels can be modified to enhance their physical properties.The structural flexibility and response to different vips and external physical stimuli render PL-MOFs good candidates for investigating solid state structural transformations and reactions.In this review,we explore how modular ligand design leads to various PL-MOFs.The importance of PL-MOFs will be highlighted by their special functions including magnetism,sorption,separation,sensing,catalysis etc.We will also introduce recent findings on PL-MOFs in dynamic structural transformations,step-by-step assembly,and preparation of hybridized MOFs and nano-films.展开更多
基金supported by National Natural Science Foundation of China(22361031)the Natural Science Foundation of Inner Mongolia Autonomous Region of China(2022QN02015)Research Program of Science and technology at Universities of Inner Mongolia Autonomous Region(NJZY22334).
文摘Oil spills have been a persistent environmental challenge globally,resulting in severe long-term impacts.Thus,developing materials for efficient oil-water separation is crucial.Metal-organic frameworks(MOFs),as a rapidly emerging class of porous materials,have gained tremendous attention due to their ultra-high surface area.In this study,four fluorinated MOFs with UiO-66 topology were synthesized and characterized.Their hydrophobicity was tailored by varying the types and quantities of the fluorine-containing functional groups(-F or-CF_(3))on the ligands.Among them,2CF_(3)-UiO-66 showed the highest hydrophobicity,with a water contact angle(WCA)of 145.9°,making it promising for adsorbing organic pollutants and as a hydrophobic coating material.2CF_(3)-UiO-66 powder efficiently reduced the concentration of 3,5-dichlorophenol(a model halogenated water pollutant)from 300 ppm to 23.4 ppm within 2 hours.Furthermore,2CF_(3)-UiO-66 was in situ coated on cotton(CT)and sponge(SP)to form composite materials,2CF_(3)-UiO-66@CT and 2CF_(3)-UiO-66@SP.2CF_(3)-UiO-66@CT is superhydrophobic(WCA=164.7°),flexible,and fire retardant.It efficiently separated water and nine organic solvents via filtration,meeting commercial standards of<0.01%water content in the filtered organic solvents.2CF_(3)-UiO-66@CT remains structurally intact after 20 filtration recycles,suggesting its durability.These advantages make the 2CF_(3)-UiO-66@CT an ideal candidate for oil-water separation via filtration.Alternatively,2CF_(3)-UiO-66@SP,with a porous sponge backbone,is suitable for oil-water separation by adsorbing the organic phase efficiently(60-140 g g^(−1)adsorption capacity on nine organic solvents),and the adsorbed oil can be easily pumped out.Overall,we believe the fluorinated MOFs reported in this work have great potential for adsorption and superhydrophobic coating applications.
基金supported by the National Key R&D Program of China(Grant No.2021YFA1200700)the National Natural Science Foundation of China(Grant No.21925502)the Fundamental Research Funds for the Central Universities,China.
文摘Ferroelastic materials,as a significant category of primary ferroic materials,have paved the way for the development of shape memory,superelasticity,tunable electronics,MEMS and actuators.The ferroic phase transition rules summarized by Aizu provide a theoretical guideline for material design.However,ferroelectrics and ferroelastics are to some extent intertwined with each other.Decoupling these properties is essential for optimizing material performance and developing better theoretical models.By modifying[(CH_(3))_(4)N][FeCl_(4)],a typical molecular ferroelectric that is not ferroelastic,we synthesized(Me_(2)EtNCH_(3)CH_(2)Cl)FeCl_(4)(DMCE-FeCl_(4)),an organic-inorganic hybrid compound that introduces ferroelasticity while maintaining ferroelectricity.DFT calculations reveal that the shape of the organic cations contributes to ferroelasticity,while their dipole moments contribute to ferroelectricity.This work advances the understanding of ferroic properties and their independent control,with implications for reconfigurable memory devices and intelligent actuators.
基金supported by the National Natural Science Foundation of China(51903123)the Natural Science Foundation of Jiangsu Province(BK20190760)the National Key Research and Development Program of China(2017YFA0204600).
文摘Metal-organic frameworks(MOFs),as multifunctional materials,have shown excellent potential.However,the powder form of MOFs has always influenced their practical application.In this study,ZIF-67 was in situ grown on wood to obtain self-supported ZIF-67/wood.It was then carbonized at different temperatures to prepare three-dimensional(3D)porous carbon skeleton/magnetic composites(Co/C@WC).The carbon skeleton of the carbonized wood forms a 3D conductive network structure,while Co/C core-shell type magnetic nanoparticles are firmly and uniformly embedded in the carbon skeleton,enhancing the electrical conductivity and magnetism.After carbonization at 1000℃,the Co/C@WC composite delivered an excellent conductivity of 3247 S m^(-1) and an average EMI SET of about 43.2 dB at 8.2-12.4 GHz.Co/C@WC composites also exhibited sound insulation,temperature resistance and good mechanical performance,which endow the composites with the potential to be applied as multifunctional shielding materials for use in extreme conditions.
基金supported by the NSFC for distinguished young scholars(no.21525101)NSFC(no.91422302,21371037)+2 种基金NSFGX(no.2014GXNSFFA118003)BAGUI scholar program(2014A001)the Project of Talents Highland of Guangxi Province.MK thanks the CNRS-France.
文摘Pillared layer metal-organic frameworks(PL-MOFs),belonging to one representative of porous materials,have witnessed major advances in the past few years.They can be classified into subsets-3D pillared layers,2D pillared bilayers,and interpenetrated and interdigitated layers.By choosing the molecular structures and chemical properties of the modular organic ligands used in PL-MOFs,high porosity and large internal surface areas can be achieved,while the shape,size,and surface of the channels can be modified to enhance their physical properties.The structural flexibility and response to different vips and external physical stimuli render PL-MOFs good candidates for investigating solid state structural transformations and reactions.In this review,we explore how modular ligand design leads to various PL-MOFs.The importance of PL-MOFs will be highlighted by their special functions including magnetism,sorption,separation,sensing,catalysis etc.We will also introduce recent findings on PL-MOFs in dynamic structural transformations,step-by-step assembly,and preparation of hybridized MOFs and nano-films.
