As a prevailing cathode material of lithium-ion batteries(LIBs),LiCoO_(2)(LCO)still encounters the tricky problems of structural collapse,whose morphological engineering and cation doping are crucial for surmounting t...As a prevailing cathode material of lithium-ion batteries(LIBs),LiCoO_(2)(LCO)still encounters the tricky problems of structural collapse,whose morphological engineering and cation doping are crucial for surmounting the mechanical strains and alleviating phase degradation upon cycling.Hereinafter,we propose a strategy using a zeolitic imidazolate framework(ZIF)as the self-sacrificing template to directionally prepare a series of LiNi_(0.1)Co_(0.9)O_(2)(LNCO)with tailorable electrochemical properties.The rational selection of sintering temperature imparts the superiority of the resultant products in lithium storage,during which the sample prepared at 700℃(LNCO-700)outperforms its counterparts in cyclability(156.8 mA h g^(-1)at 1 C for 200 cycles in half cells,1 C=275 mA g^(-1))and rate capability due to the expedited ion/electron transport and the strengthen mechanical robustness.The feasibility of proper Ni doping is also divulged by half/full cell tests and theoretical study,during which LNCO-700(167 mA h g^(-1)at 1 C for 100 cycles in full cells)surpasses LCO-700 in battery performance due to the mitigated phase deterioration,stabilized layered structu re,ameliorated electro nic co nductivity,a nd exalted lithium sto rage activity.This work systematically unveils tailorable electrochemical behaviors of LNCO to better direct their practical application.展开更多
Metal-organic frameworks(MOFs)have been intensely studied for the past few decades as an enormous family of highly tunable porous materials with promisingly applicable functionalities in adsorption,separation,catalysi...Metal-organic frameworks(MOFs)have been intensely studied for the past few decades as an enormous family of highly tunable porous materials with promisingly applicable functionalities in adsorption,separation,catalysis,sensing,electrochemistry,and a great number of emerging purposes.As a classic MOF,zeolitic imidazolate framework-8(ZIF-8)is conventionally one of the very few MOF members that has been commercialized with considerable production.展开更多
Zeolitic imidazolate frameworks(ZIFs)as smart drug delivery systems with microenvironment-triggered release have attracted much attention for tumor therapy.However,the exploration of ZIFs in biomedicine still encounte...Zeolitic imidazolate frameworks(ZIFs)as smart drug delivery systems with microenvironment-triggered release have attracted much attention for tumor therapy.However,the exploration of ZIFs in biomedicine still encounters many issues,such as inconvenient surface modification,fast drug release during blood circulation,undesired damage to major organs,and severe in vivo toxicity.To address the above issues,we developed an Mn-ZIF-90 nanosystem functionalized with an originally designed active-targeting and pH-responsive magnetic resonance imaging(MRI)Y1 receptor ligand[Asn28,Pro30,Trp32]-NPY(25-36)for imaging-guided tumor therapy.After Y1 receptor ligand modification,the Mn-ZIF-90 nanosystem exhibited high drug loading,better blood circulation stability,and dual breast cancer cell membrane and mitochondria targetability,further favoring specific microenvironment-triggered tumor therapy.Meanwhile,this nanosystem showed promising T1-weighted magnetic resonance imaging contrast in vivo in the tumor sites.Especially,this nanosystem with fast clean-up had almost no obvious toxicity and no damage occurred to the major organs in mice.Therefore,this nanosystem shows potential for use in imaging-guided tumor therapy.展开更多
Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-co...Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-cost commercial production technique.Here,we report an uncon ventional method suitable for environmentally friendly and low-cost mass-production of ZIFs.In this method,taking the synthesis of ZIF-8 as an example,ZnO was used instead of Zn(NO_(3))_(2) in traditional solvent synthesis methods and CO_(2) was introduced to dissolve ZnO in aqueous solution of 2-methylimidazole(HMeim)and form water soluble salt([ZnMeim]^(+)[MeimCOO]^(-))at room temperature.Then,by removing CO_(2) through heating or vacuuming,Meim-ions are produced and instantaneously assemble with[ZnMeim]^(+)s to generate ZIF-8 without any by product.Due to the absence of strong acid anions(such as NO^(-)_(3) and Cl^(-) et al.)in solution,the washing of filter cake required in the conventional approaches could be omitted and the filtrate containing only water and HMeim could be reused completely.This method is really green as no waste gas or liquid generates because CO_(2) and water could be recycled perfectly.It overcomes almost all bottlenecks occurred in commercial production of ZIF-8 when using traditional methods.A pilot plant was established for mass-production of ZIF-8 and hundreds kilograms of ZIF-8 was produced,which indicates that the new method is not only environmentally friendly but also low cost and commercial accessibility.It is expected that the new method would open an avenue for commercial applications of ZIFs.展开更多
A novel ZIF-8-CMC hybrid material was fabricated from the hybridization of ZIF-8 and carboxymethylcellulose(CMC) by impregnation method for n-hexane/3-methylpentane separation.The surface properties of ZIF-8 were tail...A novel ZIF-8-CMC hybrid material was fabricated from the hybridization of ZIF-8 and carboxymethylcellulose(CMC) by impregnation method for n-hexane/3-methylpentane separation.The surface properties of ZIF-8 were tailored by introducing CMC into ZIF-8 nanoparticles.In this work,adsorption separation of n-hexane(nHEX) and 3-methylpentane(3 MP) on ZIF-8-CMC were investigated by batch vapor-phase adsorption and liquid-phase breakthrough adsorption.The adsorption selectivity of nHEX/3 MP reversed from preferable adsorption of nHEX to preferable adsorption of 3 MP upon the increasing of CMC containing in the hybrid materials.As the temperature increases,the adsorption amounts of nHEX and 3 MP decrease.With the increasing of CMC contents,the nHEX uptake decreased,the uptake capacity of 3 MP increased gradually.For liquid-phase breakthrough adsorption,the dynamic adsorption capacity of nHEX also decreased with the increasing of temperature.展开更多
Urothermal method was firstly used to synthesize zeolitic tetrazolate-imidazolate frameworks. By using 2-imidazolidone hemihydrate(e-urea) as solvent, a new compound, namely ZTIF-17 with GIS topology, has been obtaine...Urothermal method was firstly used to synthesize zeolitic tetrazolate-imidazolate frameworks. By using 2-imidazolidone hemihydrate(e-urea) as solvent, a new compound, namely ZTIF-17 with GIS topology, has been obtained by mixing 5,6-dimethylbenzimidazole and 5-ethylthiotrazole ligands, and characterized by powder and single-crystal X-ray diffraction, and thermogravimetric(TG) analyses. In addition, ZTIF-17 exhibited strong photoluminescence at room temperature. The result suggests that urothermal method is powerful to construct new kind of porous materials.展开更多
Recently, the development of high-performance bifunctional oxygen catalysts integrated with flexible conductive scaffolds f or rechargeable metal-air batteries has attracted considerable interest, driving by fastgrowi...Recently, the development of high-performance bifunctional oxygen catalysts integrated with flexible conductive scaffolds f or rechargeable metal-air batteries has attracted considerable interest, driving by fastgrowing wearable electronics. Herein, we report a flexible bifunctional oxygen catalyst thin film consisting of Co–N–C bifunctional catalysts embedding in carbon nanotube(CNT) networks. The catalyst is readily prepared by pyrolysis of cobalt-based zeolitic imidazolate frameworks(ZIF-67) that are in-situ synthesized in CNT networks. Such catalyst film demonstrates very high catalytic activities for oxygen reduction(onset potential: 0.91 V, and half-wave potential: 0.87 V vs. RHE) and oxygen evolution(10 m Acm^-2 at 1.58 V) reactions, high methanol tolerance property, and long-term stability(97% current retention). Moreover, our integrated catalyst film shows very good structure flexibility and robustness. Based on the obtained film air electrodes, flexible Zn–air batteries demonstrate low charging and discharging overpotentials(0.82 V at 1 m A cm^-1) and excellent structure stability in the bending tests. These results indicate that presently reported catalyst films are potential air electrodes for flexible metal–air batteries.展开更多
Layered assembled membranes of 2D leaf-like zeolitic imidazolate frameworks(ZIF-L)nanosheets have received great attention in the field of water treatment due to the porous structure and excellent antibacterial abilit...Layered assembled membranes of 2D leaf-like zeolitic imidazolate frameworks(ZIF-L)nanosheets have received great attention in the field of water treatment due to the porous structure and excellent antibacterial ability,but the dense accumulation on the membrane surface and the low permeate flux greatly hinder their application.Herein,we synthesized m HNTs(modified halloysite nanotubes)/ZIF-L nanocomposites on modified m HNTs by in situ growth method.Interestingly,due to the different size of m HNTs and ZIF-L,m HNTs were packed in ZIF-L nanosheets.The hollow m HNTs provided additional transport channels for water molecules,and the accumulation of the ZIF-L nanosheets was decreased after assembling m HNTs/ZIF-L nanocomposites into membrane by filtration.The prepared m HNTs/ZIF-L membrane presented high permeate flux(59.6 L·m^(-2)·h^(-1)),which is 2-4 times of the ZIF-L membranes(14.8 L·m^(-2)·h^(-1)).Moreover,m HNTs/ZIF-L membranes are intrinsically antimicrobial,which exhibit extremely high bacterial resistance.We provide a controllable strategy to improve 2D ZIF-L assembles,and develops novel membranes using 2D package structure as building units.展开更多
The feasibility of adsorption and the adsorption behavior of radon on a nanomaterial-based zeolitic imidazolate framework-8(ZIF-8) adsorbent were investigated.Grand canonical Monte Carlo simulation and four-channel lo...The feasibility of adsorption and the adsorption behavior of radon on a nanomaterial-based zeolitic imidazolate framework-8(ZIF-8) adsorbent were investigated.Grand canonical Monte Carlo simulation and four-channel low-background a/b measurement were performed to examine the adsorption kinetics of this adsorbent. Results demonstrated that ZIF-8 is a good adsorbent of radon.Therefore, this adsorbent can be used to significantly reduce the hazardous effects of radon on occupational radiation workers.展开更多
The adsorption and separation of diols from dilute aqueous solution using hydrophobic materials is very challenging due to the strong diol-water hydrogen-bonding interactions. Herein, we screened hydrophobic zeolitic ...The adsorption and separation of diols from dilute aqueous solution using hydrophobic materials is very challenging due to the strong diol-water hydrogen-bonding interactions. Herein, we screened hydrophobic zeolitic imidazolate frameworks(ZIFs) with chabazite(CHA) topology for separation of 2,3-butanediol(2,3-BDO) and 1,3-propanediol(1,3-PDO), which had junctional and hydrophobic traps matching the two end methyl groups of the 2,3-BDO molecule. Based on CHA-ZIFs with the same small-sized ligand 2-methylimidazole(mIm) and different large-sized ligand benzimidazole derivatives(RbIm),CHA-ZIFs with larger surface areas were obtained by the addition of excess small-sized ligand mIm in the synthesis process. We showed that all of the hydrophobic CHA-ZIFs preferentially adsorbed 2,3-BDO over 1,3-PDO by static batch adsorption and dynamic column adsorption experiments. But ZIF-301 and ZIF-300 with halogen groups exhibited better adsorptive separation performance for 2,3-BDO/1,3-PDO than ZIF-302 with methyl groups. For a typical ZIF-301, its adsorption capacity for 2,3-BDO was 116.4 mg·g^(-1)and selectivity for 2,3-BDO/1,3-PDO was 3.8 in dynamic column adsorption of the binary-component system(2,3-BDO/1,3-PDO: 50 g·L^(-1)/50 g·L^(-1)). Computational simulations revealed that 2,3-BDO preferentially adsorbed in a trap at the junction between the cha and d6r cages of CHA-ZIFs,meaning the strong host-guest interactions. Therefore, the hydrophobic CHA-ZIFs with a junctional trap were promising candidate materials for adsorbing 2,3-BDO, which also provided a new perspective for separating diols in dilute aqueous solutions.展开更多
Zeolite imidazole frameworks(ZIFs),a class of the metal organic framework,have been extensively studied in environmental applications.However,their environmental fate and potential ecological impact on plants remain u...Zeolite imidazole frameworks(ZIFs),a class of the metal organic framework,have been extensively studied in environmental applications.However,their environmental fate and potential ecological impact on plants remain unknown.Here,we investigated the phytotoxicity,transformation,and bioaccumulation processes of two typical ZIFs(ZIF-8 and ZIF-67)in rice(Oryza sativa L.)under hydroponic conditions.ZIF-8 and ZIF-67 in the concentration of 50 mg/L decreased root and shoot dry weight maximally by 55.2%and 27.5%,53.5%and 37.5%,respectively.The scanning electron microscopy(SEM)imaging combined with X-ray diffraction(XRD)patterns revealed that ZIFs on the root surface gradually collapsed and transformed into nanosheets with increasing cultivation time.The fluorescein isothiocyanate(FITC)labeled ZIFs were applied to trace the uptake and translocation of ZIFs in rice.The results demonstrated that the transformed ZIFs were mainly distributed in the intercellular spaces of rice root,while they cannot be transported to culms and leaves.Even so,the Co and Zn contents of rice roots and shoots in the ZIFs treated groups were increased by 1145%and 1259%,145%and 259%,respectively,compared with the control groups.These findings suggested that the phytotoxicity of ZIFs are primarily attributed to the transformed ZIFs and to a less extent,the metal ions and their ligands,and they were internalized by rice root and increased the Co and Zn contents of shoots.This study reported the transformation of ZIFs and their biological effectiveness in rice,highlighting the potential environmental hazards and risks of ZIFs to crop plants.展开更多
The use of intumescent flame retardants(IFRs)is considered an environmentally friendly and cost-effective strategy to suppress potential fire hazards from synthetic polymers.However,some conventional IFRs are neither ...The use of intumescent flame retardants(IFRs)is considered an environmentally friendly and cost-effective strategy to suppress potential fire hazards from synthetic polymers.However,some conventional IFRs are neither efficient in developing a thermally stable char layer nor reducing the release of toxic byproducts during polymer combustion.In this work,we aim to discuss the effects of zeolitic imidazolate frameworks(ZIFs)on synergistically improving the flame retardancy behaviors in polypropylene(PP)composites,including thermal degradation(evolved gas analysis),free radical reactions in the gaseous phase(in-situ chemiluminescent image analysis),and carbonaceous structure in the condensed phase(micro-morphology and composition analysis).It is found that the transition metals in ZIFs can catalytically accelerate the crosslinking reaction at a lower initial temperature and decrease the amount of hydrocarbon volatiles in the gaseous phase.Once ignited,the embedded ZIFs can firstly bridge adjacent phosphorus chains in the polymer matrix to expand crosslinking degrees and then they are anchored in the developed N-doped phospho-carbonaceous networks after pyrolysis.As a result,more compact char residue structures are observed in the condensed phase for ZIF-reinforced composites.For example,by replacing 2 wt%of IFR with ZIF-67,the peak heat release rate,peak smoke production rate,and peak CO production rate are reduced by 69%,80%,and 72%,respectively,when compared to the conventional composite.These results indicate an excellent solution to resolve inherent fire hazards associated with IFRs in polymers and achieve necessary efficiency for industrial applications.It also provides a new strategy for determining flammability characteristics and combustion mechanisms of polymer composites using in-situ chemiluminescence analysis.展开更多
基金the financial support from the Special Funds for the Cultivation of Guangdong College Students’Scientific and Technological Innovation(“Climbing Program”Special Funds,pdjh2023b0145)Guangdong Provincial International Joint Research Center for Energy Storage Materials(2023A0505090009)。
文摘As a prevailing cathode material of lithium-ion batteries(LIBs),LiCoO_(2)(LCO)still encounters the tricky problems of structural collapse,whose morphological engineering and cation doping are crucial for surmounting the mechanical strains and alleviating phase degradation upon cycling.Hereinafter,we propose a strategy using a zeolitic imidazolate framework(ZIF)as the self-sacrificing template to directionally prepare a series of LiNi_(0.1)Co_(0.9)O_(2)(LNCO)with tailorable electrochemical properties.The rational selection of sintering temperature imparts the superiority of the resultant products in lithium storage,during which the sample prepared at 700℃(LNCO-700)outperforms its counterparts in cyclability(156.8 mA h g^(-1)at 1 C for 200 cycles in half cells,1 C=275 mA g^(-1))and rate capability due to the expedited ion/electron transport and the strengthen mechanical robustness.The feasibility of proper Ni doping is also divulged by half/full cell tests and theoretical study,during which LNCO-700(167 mA h g^(-1)at 1 C for 100 cycles in full cells)surpasses LCO-700 in battery performance due to the mitigated phase deterioration,stabilized layered structu re,ameliorated electro nic co nductivity,a nd exalted lithium sto rage activity.This work systematically unveils tailorable electrochemical behaviors of LNCO to better direct their practical application.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51603052 and 51573216)the Fundamental Research Funds for the Central Universities(Grant Nos.18lgpy02 and 16lgjc66).
文摘Metal-organic frameworks(MOFs)have been intensely studied for the past few decades as an enormous family of highly tunable porous materials with promisingly applicable functionalities in adsorption,separation,catalysis,sensing,electrochemistry,and a great number of emerging purposes.As a classic MOF,zeolitic imidazolate framework-8(ZIF-8)is conventionally one of the very few MOF members that has been commercialized with considerable production.
基金financially supported by Natural Science Foundation of China(No.81871411)National Key R&D Program of China(2018YFC0910601)+1 种基金Youth Innovation Promotion Association Foundation of CAS(2017340)The Science&Technology Bureau of Ningbo City(2015B11002).
文摘Zeolitic imidazolate frameworks(ZIFs)as smart drug delivery systems with microenvironment-triggered release have attracted much attention for tumor therapy.However,the exploration of ZIFs in biomedicine still encounters many issues,such as inconvenient surface modification,fast drug release during blood circulation,undesired damage to major organs,and severe in vivo toxicity.To address the above issues,we developed an Mn-ZIF-90 nanosystem functionalized with an originally designed active-targeting and pH-responsive magnetic resonance imaging(MRI)Y1 receptor ligand[Asn28,Pro30,Trp32]-NPY(25-36)for imaging-guided tumor therapy.After Y1 receptor ligand modification,the Mn-ZIF-90 nanosystem exhibited high drug loading,better blood circulation stability,and dual breast cancer cell membrane and mitochondria targetability,further favoring specific microenvironment-triggered tumor therapy.Meanwhile,this nanosystem showed promising T1-weighted magnetic resonance imaging contrast in vivo in the tumor sites.Especially,this nanosystem with fast clean-up had almost no obvious toxicity and no damage occurred to the major organs in mice.Therefore,this nanosystem shows potential for use in imaging-guided tumor therapy.
基金supports received from the National Natural Science Foundation of China (21776301,21636009)are gratefully acknowledged.
文摘Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-cost commercial production technique.Here,we report an uncon ventional method suitable for environmentally friendly and low-cost mass-production of ZIFs.In this method,taking the synthesis of ZIF-8 as an example,ZnO was used instead of Zn(NO_(3))_(2) in traditional solvent synthesis methods and CO_(2) was introduced to dissolve ZnO in aqueous solution of 2-methylimidazole(HMeim)and form water soluble salt([ZnMeim]^(+)[MeimCOO]^(-))at room temperature.Then,by removing CO_(2) through heating or vacuuming,Meim-ions are produced and instantaneously assemble with[ZnMeim]^(+)s to generate ZIF-8 without any by product.Due to the absence of strong acid anions(such as NO^(-)_(3) and Cl^(-) et al.)in solution,the washing of filter cake required in the conventional approaches could be omitted and the filtrate containing only water and HMeim could be reused completely.This method is really green as no waste gas or liquid generates because CO_(2) and water could be recycled perfectly.It overcomes almost all bottlenecks occurred in commercial production of ZIF-8 when using traditional methods.A pilot plant was established for mass-production of ZIF-8 and hundreds kilograms of ZIF-8 was produced,which indicates that the new method is not only environmentally friendly but also low cost and commercial accessibility.It is expected that the new method would open an avenue for commercial applications of ZIFs.
基金supported by the National Natural Science Foundation of China (Nos. 11775037 and 21676030)the Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology (BM212110)The Postgraduate Innovation Project of Changzhou University (KYCX19_1782)。
文摘A novel ZIF-8-CMC hybrid material was fabricated from the hybridization of ZIF-8 and carboxymethylcellulose(CMC) by impregnation method for n-hexane/3-methylpentane separation.The surface properties of ZIF-8 were tailored by introducing CMC into ZIF-8 nanoparticles.In this work,adsorption separation of n-hexane(nHEX) and 3-methylpentane(3 MP) on ZIF-8-CMC were investigated by batch vapor-phase adsorption and liquid-phase breakthrough adsorption.The adsorption selectivity of nHEX/3 MP reversed from preferable adsorption of nHEX to preferable adsorption of 3 MP upon the increasing of CMC containing in the hybrid materials.As the temperature increases,the adsorption amounts of nHEX and 3 MP decrease.With the increasing of CMC contents,the nHEX uptake decreased,the uptake capacity of 3 MP increased gradually.For liquid-phase breakthrough adsorption,the dynamic adsorption capacity of nHEX also decreased with the increasing of temperature.
基金Supported by NNSFC(No.21573236)the State Key Laboratory of Fine Chemicals(No.KF 1804)+1 种基金the Foundation of Ningde Normal University(No.2018Y04 and 2018Q105)the Natural Science Foundation of Fujian Province(No.2019J01839)
文摘Urothermal method was firstly used to synthesize zeolitic tetrazolate-imidazolate frameworks. By using 2-imidazolidone hemihydrate(e-urea) as solvent, a new compound, namely ZTIF-17 with GIS topology, has been obtained by mixing 5,6-dimethylbenzimidazole and 5-ethylthiotrazole ligands, and characterized by powder and single-crystal X-ray diffraction, and thermogravimetric(TG) analyses. In addition, ZTIF-17 exhibited strong photoluminescence at room temperature. The result suggests that urothermal method is powerful to construct new kind of porous materials.
基金financial supports from the National Natural Science Foundation of China(21773293 , 21603264)CAS Pioneer Hundred Talents Program (J. Di)+1 种基金The National Key Research and Development Program of China(2016YFA0203301)Key Research Program of Frontier Science of Chinese Academy of Sciences(QYZDB-SSW-SLH031)
文摘Recently, the development of high-performance bifunctional oxygen catalysts integrated with flexible conductive scaffolds f or rechargeable metal-air batteries has attracted considerable interest, driving by fastgrowing wearable electronics. Herein, we report a flexible bifunctional oxygen catalyst thin film consisting of Co–N–C bifunctional catalysts embedding in carbon nanotube(CNT) networks. The catalyst is readily prepared by pyrolysis of cobalt-based zeolitic imidazolate frameworks(ZIF-67) that are in-situ synthesized in CNT networks. Such catalyst film demonstrates very high catalytic activities for oxygen reduction(onset potential: 0.91 V, and half-wave potential: 0.87 V vs. RHE) and oxygen evolution(10 m Acm^-2 at 1.58 V) reactions, high methanol tolerance property, and long-term stability(97% current retention). Moreover, our integrated catalyst film shows very good structure flexibility and robustness. Based on the obtained film air electrodes, flexible Zn–air batteries demonstrate low charging and discharging overpotentials(0.82 V at 1 m A cm^-1) and excellent structure stability in the bending tests. These results indicate that presently reported catalyst films are potential air electrodes for flexible metal–air batteries.
基金supported by the Excellent Youth Foundation of Henan Scientific Committee,China(222300420018)Key Scientific Research Projects in Universities of Henan Province,China(21zx006)。
文摘Layered assembled membranes of 2D leaf-like zeolitic imidazolate frameworks(ZIF-L)nanosheets have received great attention in the field of water treatment due to the porous structure and excellent antibacterial ability,but the dense accumulation on the membrane surface and the low permeate flux greatly hinder their application.Herein,we synthesized m HNTs(modified halloysite nanotubes)/ZIF-L nanocomposites on modified m HNTs by in situ growth method.Interestingly,due to the different size of m HNTs and ZIF-L,m HNTs were packed in ZIF-L nanosheets.The hollow m HNTs provided additional transport channels for water molecules,and the accumulation of the ZIF-L nanosheets was decreased after assembling m HNTs/ZIF-L nanocomposites into membrane by filtration.The prepared m HNTs/ZIF-L membrane presented high permeate flux(59.6 L·m^(-2)·h^(-1)),which is 2-4 times of the ZIF-L membranes(14.8 L·m^(-2)·h^(-1)).Moreover,m HNTs/ZIF-L membranes are intrinsically antimicrobial,which exhibit extremely high bacterial resistance.We provide a controllable strategy to improve 2D ZIF-L assembles,and develops novel membranes using 2D package structure as building units.
基金Supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Open Project of Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection(No.KJS1246)
文摘The feasibility of adsorption and the adsorption behavior of radon on a nanomaterial-based zeolitic imidazolate framework-8(ZIF-8) adsorbent were investigated.Grand canonical Monte Carlo simulation and four-channel low-background a/b measurement were performed to examine the adsorption kinetics of this adsorbent. Results demonstrated that ZIF-8 is a good adsorbent of radon.Therefore, this adsorbent can be used to significantly reduce the hazardous effects of radon on occupational radiation workers.
基金supported by the National Natural Science Foundation of China(22278289 and 21822808)the Science Foundation for Distinguished Young Scholar of Shanxi Province(202303021223002)the Special Fund for Science and Technology Innovation Teams of Shanxi Province(202204051001009).
文摘The adsorption and separation of diols from dilute aqueous solution using hydrophobic materials is very challenging due to the strong diol-water hydrogen-bonding interactions. Herein, we screened hydrophobic zeolitic imidazolate frameworks(ZIFs) with chabazite(CHA) topology for separation of 2,3-butanediol(2,3-BDO) and 1,3-propanediol(1,3-PDO), which had junctional and hydrophobic traps matching the two end methyl groups of the 2,3-BDO molecule. Based on CHA-ZIFs with the same small-sized ligand 2-methylimidazole(mIm) and different large-sized ligand benzimidazole derivatives(RbIm),CHA-ZIFs with larger surface areas were obtained by the addition of excess small-sized ligand mIm in the synthesis process. We showed that all of the hydrophobic CHA-ZIFs preferentially adsorbed 2,3-BDO over 1,3-PDO by static batch adsorption and dynamic column adsorption experiments. But ZIF-301 and ZIF-300 with halogen groups exhibited better adsorptive separation performance for 2,3-BDO/1,3-PDO than ZIF-302 with methyl groups. For a typical ZIF-301, its adsorption capacity for 2,3-BDO was 116.4 mg·g^(-1)and selectivity for 2,3-BDO/1,3-PDO was 3.8 in dynamic column adsorption of the binary-component system(2,3-BDO/1,3-PDO: 50 g·L^(-1)/50 g·L^(-1)). Computational simulations revealed that 2,3-BDO preferentially adsorbed in a trap at the junction between the cha and d6r cages of CHA-ZIFs,meaning the strong host-guest interactions. Therefore, the hydrophobic CHA-ZIFs with a junctional trap were promising candidate materials for adsorbing 2,3-BDO, which also provided a new perspective for separating diols in dilute aqueous solutions.
基金This work was supported by the National Natural Science Foundation of China(Nos.30800705 and 31101599)the Provincial Natural Science Foundation of Zhejiang(Nos.LY15C150004 and LY18C150007)the Key Research and Devel opment Projects of Social Development of Jinhua Science and Technology Program(No.2021C22750).
文摘Zeolite imidazole frameworks(ZIFs),a class of the metal organic framework,have been extensively studied in environmental applications.However,their environmental fate and potential ecological impact on plants remain unknown.Here,we investigated the phytotoxicity,transformation,and bioaccumulation processes of two typical ZIFs(ZIF-8 and ZIF-67)in rice(Oryza sativa L.)under hydroponic conditions.ZIF-8 and ZIF-67 in the concentration of 50 mg/L decreased root and shoot dry weight maximally by 55.2%and 27.5%,53.5%and 37.5%,respectively.The scanning electron microscopy(SEM)imaging combined with X-ray diffraction(XRD)patterns revealed that ZIFs on the root surface gradually collapsed and transformed into nanosheets with increasing cultivation time.The fluorescein isothiocyanate(FITC)labeled ZIFs were applied to trace the uptake and translocation of ZIFs in rice.The results demonstrated that the transformed ZIFs were mainly distributed in the intercellular spaces of rice root,while they cannot be transported to culms and leaves.Even so,the Co and Zn contents of rice roots and shoots in the ZIFs treated groups were increased by 1145%and 1259%,145%and 259%,respectively,compared with the control groups.These findings suggested that the phytotoxicity of ZIFs are primarily attributed to the transformed ZIFs and to a less extent,the metal ions and their ligands,and they were internalized by rice root and increased the Co and Zn contents of shoots.This study reported the transformation of ZIFs and their biological effectiveness in rice,highlighting the potential environmental hazards and risks of ZIFs to crop plants.
文摘The use of intumescent flame retardants(IFRs)is considered an environmentally friendly and cost-effective strategy to suppress potential fire hazards from synthetic polymers.However,some conventional IFRs are neither efficient in developing a thermally stable char layer nor reducing the release of toxic byproducts during polymer combustion.In this work,we aim to discuss the effects of zeolitic imidazolate frameworks(ZIFs)on synergistically improving the flame retardancy behaviors in polypropylene(PP)composites,including thermal degradation(evolved gas analysis),free radical reactions in the gaseous phase(in-situ chemiluminescent image analysis),and carbonaceous structure in the condensed phase(micro-morphology and composition analysis).It is found that the transition metals in ZIFs can catalytically accelerate the crosslinking reaction at a lower initial temperature and decrease the amount of hydrocarbon volatiles in the gaseous phase.Once ignited,the embedded ZIFs can firstly bridge adjacent phosphorus chains in the polymer matrix to expand crosslinking degrees and then they are anchored in the developed N-doped phospho-carbonaceous networks after pyrolysis.As a result,more compact char residue structures are observed in the condensed phase for ZIF-reinforced composites.For example,by replacing 2 wt%of IFR with ZIF-67,the peak heat release rate,peak smoke production rate,and peak CO production rate are reduced by 69%,80%,and 72%,respectively,when compared to the conventional composite.These results indicate an excellent solution to resolve inherent fire hazards associated with IFRs in polymers and achieve necessary efficiency for industrial applications.It also provides a new strategy for determining flammability characteristics and combustion mechanisms of polymer composites using in-situ chemiluminescence analysis.
