Metal-organic framework(MOF)has been widely used as filler of mixed-matrix membranes(MMMs)because of their tunable pore sizes,large surface areas,and rich functional groups.However,a relatively high diffusion barrier ...Metal-organic framework(MOF)has been widely used as filler of mixed-matrix membranes(MMMs)because of their tunable pore sizes,large surface areas,and rich functional groups.However,a relatively high diffusion barrier in the framework of bulk MOF fillers inevitably reduces gas permeability.Introduction of hierarchically porous structure represents an effective method for reducing vip diffusion resistance with no compromise in gas selectivity.In this study,hierarchical ZIF-8(H-ZIF-8)was prepared using carboxylated polystyrene(PS-COOH)nanospheres as a hard template.Owing to the introduction of carboxyl groups,electrostatic interaction between PS nanospheres and Zn^(2+)ions is enhanced,facilitating uniform embedment of PS nanospheres in bulk ZIF-8 filler.After dissolution of PS-COOH nanospheres with dimethylformamide solvents,H-ZIF-8 with tunable textural properties is readily obtained.Gas permeation results indicate that compared with bulk ZIF-8 filler,fast diffusion pathways for vip molecules are established in H-ZIF-8 filler,resulting in a CO_(2)/N_(2)separation factor(SF)of 48.77 with CO_(2)permeability of 645.76 Barrer in terms of H-ZIF-8 MMMs with 6 wt%loading,which well exceeds the 2008 Robenson upper bound for CO_(2)/N_(2)gas pair,thus showing promising prospects for high-efficiency CO_(2)capture from flue gas.展开更多
The abuse of antibiotics has brought great harm to the human living environment and health,so it is extremely significant to develop an efficient and simple method to detect trace antibiotic residues in various wastew...The abuse of antibiotics has brought great harm to the human living environment and health,so it is extremely significant to develop an efficient and simple method to detect trace antibiotic residues in various wastewaters.Herein,a new two-dimensional(2D)Cd-based metal−organic framework(Cd-MOF,namely LCU-111)and its mixed matrix membranes(MMMs)is sifted as luminescence sensors for efficient monitoring antibiotic nitrofurazone(NFZ)in various aqueous systems and applied as visible fingerprint identifying.The LCU-111 has good selectivity,sensibility,reproducibility and anti-interference for luminescent quenching NFZ with low detection limits(LODs)of 0.4567,0.3649 and 0.8071 ppm in aqueous solution,HEPES biological buffer,and real urban Tuhai River water,respectively.Interestingly,the luminescent test papers and MMMs allow the NFZ sensing easier and more rapid by naked eyes,only with a low LOD of 0.8117 ppm for MMMs sensor.Notably,by combining multiple experiments with density functional theory(DFT)calculations,the photo-induced electron transfer(PET)quenching mechanism is further elucidated.More importantly,potential practical applications of LCU-111 for latent fingerprint visualization provide lifelike evidences for effective identification of individuals,which can be applied in criminal investigation.展开更多
Membrane separation is a high-efficiency,energy-saving,and environment-friendly separation technology.Covalent organic framework(COF)-based mixed-matrix membranes(MMMs)have broad application prospects in gas separatio...Membrane separation is a high-efficiency,energy-saving,and environment-friendly separation technology.Covalent organic framework(COF)-based mixed-matrix membranes(MMMs)have broad application prospects in gas separation and are expected to provide new solutions for coal-bed methane purification.Herein,a high-throughput screening method is used to calculate and evaluate COF-based MMMs for CH_(4)/N_(2) separation.General design rules are proposed from thermodynamic and kinetic points of view using the computation-ready,experimental COFs.From our database containing 471,671 generated COFs,5 COF membrane materials were screened with excellent membrane selectivities,which were then used as the filler of MMMs for separation performance evaluation.Among them,BAR-NAP-Benzene_CF_(3) combined with polydimethylsiloxane and styrene-b-butadiene-b-styrene show high CH_(4) permeability of 4.43×10^(-13) mol·m·s^(-1)·Pa^(-1)·m^(-2) and high CH_(4)/N_(2) selectivity of 9.54,respectively.The obtained results may provide reasonable information for the design of COF-based membranes for the efficient separation of CH_(4)/N_(2).展开更多
For the application of carbon capture by membrane process,it is crucial to develop a highly permeable CO_(2)-selective membrane.In this work,we reported an ultra-thin polyether-block-amide(Pebax)mixedmatrix membranes(...For the application of carbon capture by membrane process,it is crucial to develop a highly permeable CO_(2)-selective membrane.In this work,we reported an ultra-thin polyether-block-amide(Pebax)mixedmatrix membranes(MMMs)incorporated by graphene oxide(GO),in which the interlayer channels were regulated to optimize the CO_(2)/N_(2) separation performance.Various membrane preparation conditions were systematically investigated on the influence of the membrane structure and separation performance,including the lateral size of GO nanosheets,GO loading,thermal reduction temperature,and time.The results demonstrated that the precisely regulated interlayer channel of GO nanosheets can rapidly provide CO_(2)-selective transport channels due to the synergetic effects of size sieving and preferential adsorption.The GO/Pebax ultra-thin MMMs exhibited CO_(2)/N_(2) selectivity of 72 and CO_(2) permeance of 400 GPU(1 GPU=106 cm^(3)(STP)·cm^(2)·s^(-1)·cmHg^(-1)),providing a promising candidate for CO_(2) capture.展开更多
This research investigates the permeability of CO2 and N2 as well as selectivity of CO2 over N2 of polysulfone (PSF) mixed matrix membranes filled with zeolite 4Å particles. The membranes were prepared by sol...This research investigates the permeability of CO2 and N2 as well as selectivity of CO2 over N2 of polysulfone (PSF) mixed matrix membranes filled with zeolite 4Å particles. The membranes were prepared by solution-casting method and utilized to determine the permeation rates of N2 and CO2. It was characterized by FTIR and the gas separation performance was analysed by Design of Expert (DOE) method. FTIR result revealed the intensity of peak for sulfone S=O vibration at 1322 cm-1;it was related to O=S=O bound of polysulfone in the sample. The single concentration variable has low outcome, however the mixture concentration interaction was effectively to lead better selectivity of CO2 over N2. In terms of interaction between mixture concentrations, interaction between PSF and N-Methyl-2-pyrrolidone (NMP) has considerable effect on the permeability of CO2 with the highest F value of 0.46 membrane. NMP exhibited a high degree of polarity and hydrogen bonding which led to effect of selective skin and permeation rate. The model regression equations were developed as the potential use for screening the permeability of CO2 and N2 based on the deviation effect of polymer concentration.展开更多
Here,we demonstrate the assembly of a new stable lanthanide-based metal-organic framework(MOF),Eu(HDPB)(phen)(1)(HDPB=(1,1’:3’,1’’-terphenyl)-3,3’’,5,5’’-tetracarboxylic acid,phen=1,10-phenanthroline),with a t...Here,we demonstrate the assembly of a new stable lanthanide-based metal-organic framework(MOF),Eu(HDPB)(phen)(1)(HDPB=(1,1’:3’,1’’-terphenyl)-3,3’’,5,5’’-tetracarboxylic acid,phen=1,10-phenanthroline),with a three-dimensional framework under solvothermal conditions.1 showed strong red fluorescence emission at room temperature and could be used as a selective and sensitive chemical sensor for pH and folic acid(FA)detection.Moreover,1 could also be applied as a fluorescent material for the visible identification of fingerprints.Then,using 1 as a filler,two mixed-matrix membranes(MMMs),1@poly(ε-caprolactone)(PCL)and 1@poly(vinylidene difluoride)(PVDF),have been fabricated.Notably,owing to the hydrophobic protection provided by the polymer matrix of the MOF particles,these two MMMs also exhibited fluorescence emission comparable to that of 1 and could be used for FA sensing with good selectivity and remarkable recyclability.More importantly,this is the first time that Eu-MOF-based MMMs have been employed in FA detection.The fabrication of MOF-based MMMs not only provides a facile method for sensing biomarkers,but it also enhances the recyclability of sensors.展开更多
Raw water temperature can fluctuate significantly throughout the year,with peaks above 30℃in summer and below 15℃in winter.Traditional desalination systems(e.g.,reverse osmosis,RO)face challenges under these varying...Raw water temperature can fluctuate significantly throughout the year,with peaks above 30℃in summer and below 15℃in winter.Traditional desalination systems(e.g.,reverse osmosis,RO)face challenges under these varying temperature conditions.Specifically,while the RO system performs well under high temperatures,its efficiency decreases sharply at lower temperatures.Membrane capacitive deionization(MCDI)is considered as an emergent and promising technology for brackish water desalination.While plenty of studies have been devoted to investigating the impacts of raw water properties(e.g.,salinity,coexisting ions,and natural organic matter)on MCDI performance,the role of water temperatures during the desalination remains under-explored.In this study,we first tested and determined the optimized MCDI operation parameters,such as the cell voltage and feedwater flow rate.Key findings showed that MCDI’s salt removal efficiency remains unaffected by feedwater temperature fluctuations.However,as feedwater temperature increases from 15℃to 40℃,the specific energy consumption for desalination slightly rises by 16.3%,and current efficiency drops by 14.1%.Compared to RO systems,the resilience of MCDI to temperature fluctuations makes it a preferable choice for brackish water treatment in areas with a large temperature difference.展开更多
Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied p...Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied performance mainly due to the sluggish oxygen reduction reaction(ORR)kinetics even on state-of-the-art Pt catalyst.Octahedral PtNi nanoparticles(oct-PtNi NPs)with excellent ORR activity in a half-cell have been widely studied,while their performance in membrane electrode assembly(MEA)has much less reported.Herein,we investigated the MEA performance using the carbon supported oct-PtNi NPs(oct-PtNi/C)as the cathode catalyst.Under the mild acid washing condition,the surface Ni atoms of oct-PtNi/C were largely removed,and the performance of the MEA using the acid-leaching oct-PtNi/C(PNC-A)as the cathode catalyst was greatly improved.The maximum power density of the MEA reached 1.0 W·cm^(-2) with the cath-ode Pt loading of 0.2 mg·cm^(-2),which is 15%higher than that using Pt/C as the catalyst.After 30k cycles in the accelerated degradation test(ADT),the MEA using PNC-A as the catalyst showed a performance retention of 82%,higher than that of Pt/C(74%).The results reported here verify the possibility of using PNC-A as an advanced cathode catalyst in PEMFCs,thus enhancing the performance of PEMFCs while lowering the amount of expensive Pt.展开更多
Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,per...Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,performance advan-tages,research progress,ion conduction mechanism and existing issues of ISMs,primarily classifying them according to the matrix structure.A detailed analysis of performance enhancement methods,key performance indicators of ISMs and performance influencing factors is also presented.The article contributes to further optimizing the design and application of ion-solvation membranes,providing theoretical support for the development of fields such as hydrogen production through electrolysis of water and electrochemical energy in the future.展开更多
Urine consists of approximately 95%water,3.5%organic matter,and 1.5%inorganic salts.Membrane distillation(MD)offers a potential approach for urine resource utilization.To some extent,it reduces the loss of nitrogen an...Urine consists of approximately 95%water,3.5%organic matter,and 1.5%inorganic salts.Membrane distillation(MD)offers a potential approach for urine resource utilization.To some extent,it reduces the loss of nitrogen and phosphorus resources.However,MD is also accompanied by problems such as high membrane cost,membrane fouling and membrane wetting.In light of these issues,this study employs polytetrafluoroethylene(PTFE)as the separation layer and polypropylene(PP)as the support layer to make a distillation membrane.The feasibility and efficiency of the PTFE-PP membrane in intercepting and recovering nitrogen and phosphorus from source-separated urine were investigated.Results obtained through 14 days of continuous operation demonstrated that the recovery rates of nitrogen and phosphorus were 95%and 99%,respectively.The dissolved organic carbon recovery rate was 95%,and urea as well as the macromolecular organic matter in dissolved organic matter were significantly intercepted.The phosphorus content in the permeate was 0.022 mg/L,which met theⅡclass standard of China’s surface water and the basic water use standard of the United States Environmental Protection Agency.This finding reduces the pressure on sewage treatment plants.PTFE-PP distillation membrane has important potential in recovering nitrogen and phosphorus from urine and alleviating global water shortage.展开更多
Materials from natural sources have been studied to replace the conventional synthetic or animal-derived products as a safer alternative to be used in the healthcare field.In dentistry,guided bone regeneration(GBR)rel...Materials from natural sources have been studied to replace the conventional synthetic or animal-derived products as a safer alternative to be used in the healthcare field.In dentistry,guided bone regeneration(GBR)relies on barrier membranes,predominantly from animals or synthetic materials,to improve osteogenesis by avoiding undesired soft tissue cells from defect sites.In this study,membranes were prepared from zein,a corn-derived protein,using a simple extraction and casting method,followed by optional formaldehyde cross-linking to evaluate their behavior for application in GBR.The membranes were characterised by FTIR,DSC,TGA,tensile strength analysis,and in vitro biological assays.Cross-linked membranes exhibited improved mechanical strength(~5 MPa)and slower degradation(~43%mass loss over 30 days),while non-cross-linked membranes disintegrated more rapidly.Cytotoxicity assays using GM07492 fibroblasts confirmed biocompatibility,and cell migration studies demonstrated effective barrier function.These results indicated that zein membranes,particularly in their cross-linked form,combine biodegradability,mechanical integrity,and cellular safety,suggesting significant potential as sustainable GBR materials.This work introduces,for the first time,zein membranes prepared from corn crude extract for GBR in dentistry,paving the way for eco-friendly alternatives to animal-derived products.展开更多
Diabetic wounds present challenges in clinical management due to persistent inflammation caused by excessive exudate infiltration.Inspired by the gradient wettability of cactus thorn,this study has devised a biomimeti...Diabetic wounds present challenges in clinical management due to persistent inflammation caused by excessive exudate infiltration.Inspired by the gradient wettability of cactus thorn,this study has devised a biomimetic Janus nanofiber membrane as a water diode,which endows with gradient wettability and gradient pore size,offering sustainable unidirectional self-drainage and antibacterial properties for enhanced diabetic wound healing.The Janus membrane is fabricated by depositing a hydrophilic polyacrylonitrile/chlorin e6 layer with smaller pore sizes onto a hydrophobic poly(ε-caprolactone)with larger pore sizes,thereby generating a vertical gradient in both wettability and pore structure.The incorporation of chlorin e6 in the upper layer enables the utilization of external light energy to generate heat for evaporation and produce reactive oxygen species,achieving a high sterilization efficiency of 99%.Meanwhile,the gradient structure of the Janus membrane facilitates continuous antigravity exudate drainage at a rate of 0.95 g cm^(−2) h^(−1).This dual functionality of effective exudate drainage and sterilization significantly reduces inflammatory factors,allows the polarization of macrophages toward the M2 proliferative phenotype,enhances angiogenesis,and accelerates wound healing.Therefore,this study provides a groundbreaking bioinspired strategy for the development of advanced wound dressings tailored for diabetic wound regeneration.展开更多
Membrane distillation(MD)is an advanced membrane separation process that employs hydrophobic microporous membranes to sepa rate non-volatile solutes from the feed solution,driven by vapor pressure gradients generated ...Membrane distillation(MD)is an advanced membrane separation process that employs hydrophobic microporous membranes to sepa rate non-volatile solutes from the feed solution,driven by vapor pressure gradients generated through thermal difference.This technology offers strong desalination capabilities and efficiently harnesses low-grade thermal energy sources,including geothermal and waste heat,making it a cost-effective solution for freshwater scarcity.Nevertheless,hydrophobic membranes are prone to contamination by surfactants,inorganic salts,and other substances in feed solutions.To address this,low-surface-energy composite nano-inorganic materials composed of carbon nanotubes and silica were modified and synthesized via organosilicon chemistry.A superhydrophobic surface exhibiting a water contact angle of157.96°was successfully fabricated using above nano-materials on poly(vinylidene fluoride)(PVDF)membrane surface with micro-nano structures via a one-step spray-coating method.Compared to unmodified PVDF membra ne,the superhydrophobic membrane demonstrated superior resistance to common scaling agents such as CaCl_(2),Mg(OH)_(2),CaCO_(3),and CaSO_(4),while maintaining stable permeate flux(13.4 kg·m^(-2)·h^(-1))during MD tests.Additionally,the modified membra ne exhibited enhanced wetting resistance when treating feed solutions containing sodium dodecyl sulfate(SDS),significantly extending the operational lifespan of the membrane.Due to its outstanding performance,this superhydrophobic membrane is expected to promote the practical application of MD technology in the treatment of complex wa stewater and efficient seawater desalination.展开更多
Nanofiltration(NF) technology,with its capacity for nanoscale filtration and controllable selectivity,holds significant promise in diverse applications.However,the current upper bound of permeance and selectivity of N...Nanofiltration(NF) technology,with its capacity for nanoscale filtration and controllable selectivity,holds significant promise in diverse applications.However,the current upper bound of permeance and selectivity of NF membranes is intrinsically constrained by the morphology and structure of the polyamide(PA) selective layer.This issue arises because NF membranes typically exhibit relatively smooth nodular structures,which theoretically impede efficient water transport.In this study,we enhanced the formation of nanobubbles by synergistically regulating with surfactant and low temperatures,resulting in the fabrication of PA NF membranes with a crumpled morphology.We observed that lower temperatures promote enhanced gas solubility in the aqueous phase,facilitating increased nanobubble formation through the foaming effect of surfactant sodium dodecylbenzene sulfonate(SDBS).Consequently,this resulted in the creation of PA NF membranes with more crumpled structures and superior performance,with pure water permeance reaching 36.25 ± 0.42 L m^(-2)h^(-1)bar^(-1),representing an improvement of 14.47 L m^(-2)h^(-1)bar^(-1)compared to the control group.Additionally,it maintains a high Na_(2)SO_(4) rejection rate of97.00 % ± 0.58 %.The PA NF membranes produced by eliminating nanobubbles and free interfaces exhibited a smooth structure,whereas introducing nanobubbles(through Na HCO_(3) addition,N_(2) pressurization,and ultrasonication) resulted in the formation of crumpled membranes.This emphasized that the large amount of nanobubbles generated by SDBS and low temperature in the interfacial process played a critical role in shaping crumpled PA NF membranes and enhancing membrane performance.This approach has the potential to provide valuable insights into customizing the structural design of TFC PA NF membranes,contributing to further advancements in this field.展开更多
Abstract:Graphene-Based separation membranes hold promise for water treatment.However,their practical deployment in high-salinity brines remains challenging due to structural instability.Herein,a defect-free Na^(+)-Cu...Abstract:Graphene-Based separation membranes hold promise for water treatment.However,their practical deployment in high-salinity brines remains challenging due to structural instability.Herein,a defect-free Na^(+)-Cu^(2+)/GO-PEI nanocomposite membrane was fabricated via a pH-controlled cross-linking polymerization strategy.Polyethyleneimine(PEI)serves as a critical interfacial stabilizer,enhancing the connection between the Na^(+)-GO and Cu^(2+)-GO layers through amide bond formation with GO nanosheets while facilitating Cu^(2+)chelation.The Na^(+)/GO layer modifies the pore structure of the polyether sulfone(PES)substrate,synergistically optimizing the membrane’s microstructure.Performances evaluation revealed that the as-prepared membrane achieved exceptional separation efficiency(>98%)for tributyl phosphate,sulfonated kerosene,and bis(2-ethylhexyl)phosphate in high-salinity brine,accompanied by a high flux of 160~224 L·m^(-2)·h^(-1).Notably,it exhibited robust chemical stability in corrosive environment and maintained mechanical durability after 500 folding cycles coupled with consistent separation performances over 10 recycles.This study presents a novel multi-component modification approach for constructing high-performance GObased membrane,promising practical applications in organic pollutant removal from high salt solution.展开更多
Bacterial outer membrane vesicles(OMVs)are spherical nanostructures that originate from Gram-negative bacteria.They are gaining attention as powerful tools in cancer diagnostics and therapy due to their unique biologi...Bacterial outer membrane vesicles(OMVs)are spherical nanostructures that originate from Gram-negative bacteria.They are gaining attention as powerful tools in cancer diagnostics and therapy due to their unique biological properties.These vesicles,which range from 50 to 250 nm in size,carry molecular components from their parent bacteria,allowing them to play important roles in bacterial defense and microbial ecosystems.Their lipid bilayer structure facilitates targeted drug delivery,while their natural immunogenic properties hold promise for cancer immunotherapy by helping overcome immune evasion in the tumor microenvironment.Moreover,OMVs have potential as biomarkers in liquid biopsies,particularly for cancers associated with bacteria,such as gastric and colorectal cancers.Their ability to interact with the intratumoral microbiota further indicates their relevance in tumor pathogenesis.This review aims to provide a comprehensive overview of the fundamental biology of OMVs and their emerging applications in cancer therapy.展开更多
The demand for sensors capable of operating in extreme environment of the fields,such as aerospace vehicles,aeroengines and fire protection,is rapidly increasing.However,developing flexible ceramic fibrous pressure se...The demand for sensors capable of operating in extreme environment of the fields,such as aerospace vehicles,aeroengines and fire protection,is rapidly increasing.However,developing flexible ceramic fibrous pressure sensors that combine high temperature stability with robust mechanical properties remains a significant challenge.Herein,through precise multi-scale process control,high-strength(2.1 MPa)TiC-SiC flexible fibrous membrane is successfully fabricated.The membrane exhibits exceptional thermal resistance(2000℃)and long–term thermal stability(1800℃ for 5 h)in the inert atmosphere.Meanwhile,the TiC-SiC fibrous membrane shows excellent oxidation resistance and still achieves strength of 1.8 MPa after being oxidized at 1200℃ for 1 h in air.Remarkably,TiC-SiC fibrous membrane withstands a load of approximately 1400 times its own weight and the ablation of butane flame(~1300℃)for at least 1 h without breaking.Notably,after heat treatment at 1800℃ for 5 h in an argon atmosphere,the TiC-SiC fibrous membrane even sustains pressure–sensing performance for up to 300 cycles.The membrane exhibits stable resistivity up to 900℃ and shows sensing stability under butane flame.The results of this work provide an effective and feasible solution to fill the research gap of flexible fibrous sensors for extreme environments.展开更多
Alkaline water electrolysis(AWE)represents a promising approach for green hydrogen production,yet the development of high-performance separators with gas impermeability,high ion conductivity,and stability under alkali...Alkaline water electrolysis(AWE)represents a promising approach for green hydrogen production,yet the development of high-performance separators with gas impermeability,high ion conductivity,and stability under alkaline operating conditions has proven challenging.To address this challenge,we develop a pre-concentration regulated phase separation strategy for scalable fabrication of asymmetric hierarchical porous membranes(AHPMs)for AWE.The resulting AHPMs demonstrate a hierarchical structure composed of an ultrathin dense skin layer and highly interconnected porous support.Benefitting from the structural advantages,the AHPMs exhibit outstanding characteristics,including a high bubble point pressure up to 12.4 bar,extremely low area resistance of 0.03Ωcm^(2) in 30 wt%KOH at 80℃,and excellent hydrophilicity and long-term alkaline stability.When applied in AWE with commercial catalysts,the AHPMs achieved an impressive current density of 1.9 A cm^(-2) at 2.0 V in 30 wt%KOH and the anodic hydrogen contents(AHCs)below 0.5 vol.%at a low current density of 0.1 A cm^(-2),differential pressure of 2 bar,and temperature of 80℃.Moreover,AHPMs demonstrate exceptional stability over 2,400 h of continuous operation and maintain superior performance in a 1 Nm^(3) h^(-1) industrialscale electrolyzer stack.This work advances the development of efficient separators for highperformance AWE systems,contributing to the advancement of hydrogen technologies in sustainable energy applications.展开更多
We successfully incorporated phenyl groups into a small-molecule quaternary ammonium cross-linker and synthesized cross-linked polybenzimidazole membranes via a one-step cross-linking process.Compared with conventiona...We successfully incorporated phenyl groups into a small-molecule quaternary ammonium cross-linker and synthesized cross-linked polybenzimidazole membranes via a one-step cross-linking process.Compared with conventional quaternary ammonium-crosslinked benzimidazole membranes,the introduction of phenyl groups significantly increases the free volume within the membrane.After phosphoric acid doping,the benzimidazole membrane with larger free volume retains more phosphoric acid compared to conventional quaternary ammonium-crosslinked membranes,forming an extensive hydrogen-bonding network that effectively enhances its anhydrous proton conductivity.The anhydrous proton conductivity reaches 91 mS·cm^(-1)at 160℃,substantially higher than that of conventional quaternary ammonium-crosslinked membranes with the same mass fraction.Benefiting from the improved conductivity,the membrane electrode assembly exhibits reduced ohmic polarization,achieving a peak power density of 792 mW·cm^(-2)at 160℃.展开更多
This study explores the nonlinear resonance of a rotating solar sail membrane exposed to time-varying solar thermal and solar radiation pressure.The sail membrane is modeled using a cantilever membrane,applying the vo...This study explores the nonlinear resonance of a rotating solar sail membrane exposed to time-varying solar thermal and solar radiation pressure.The sail membrane is modeled using a cantilever membrane,applying the von Kármán theory for membrane large deflection.The membrane’s nonlinear equation is derived by employing the Lagrange equation while accounting for excitations from solar thermal and radiation pressure.The equation is solved via the Rayleigh-Ritz method.The bifurcation diagram of membrane motion is applied to reveal membrane resonance responses under different solar sail rotating frequencies.The displacement time history,phase portrait,Poincarémap,frequency spectrum,and the largest Lyapunov exponent are used to study nonlinear vibrations that occur near resonance regions.The results indicate that time-varying thermal loading excites membrane motions with multiple natural frequencies by the parametric resonance mechanics,leading to the onset of membrane chaotic motion.The membrane’s primary resonance is stimulated in harmonic oscillation by the time-varying radiation pressure.The divergence instability caused by thermal excitation is also illustrated by comparing the membrane’s vibration amplitude with and without thermal excitation.The membrane’s nonlinear vibration characteristics vary significantly with solar illumination angles,the membrane’s thermal expansion coefficients,and structural damping.展开更多
基金Fund for Creative Research Groups of the National Natural Science Foundation of China(22021005)National Natural Science Foundation of China(22478056,22078039),Liaoning Binhai Laboratory(LBLG-2024-07)+2 种基金State Key Laboratory of Catalysis(2024SKL-A-003),National Key Research and Development Program of China(2023YFB3810700)Science and Technology Innovation Fund of Dalian(2023JJ12GX024)Fundamental Research Funds for the Central Universities(DUT22-LAB602)for the financial support.
文摘Metal-organic framework(MOF)has been widely used as filler of mixed-matrix membranes(MMMs)because of their tunable pore sizes,large surface areas,and rich functional groups.However,a relatively high diffusion barrier in the framework of bulk MOF fillers inevitably reduces gas permeability.Introduction of hierarchically porous structure represents an effective method for reducing vip diffusion resistance with no compromise in gas selectivity.In this study,hierarchical ZIF-8(H-ZIF-8)was prepared using carboxylated polystyrene(PS-COOH)nanospheres as a hard template.Owing to the introduction of carboxyl groups,electrostatic interaction between PS nanospheres and Zn^(2+)ions is enhanced,facilitating uniform embedment of PS nanospheres in bulk ZIF-8 filler.After dissolution of PS-COOH nanospheres with dimethylformamide solvents,H-ZIF-8 with tunable textural properties is readily obtained.Gas permeation results indicate that compared with bulk ZIF-8 filler,fast diffusion pathways for vip molecules are established in H-ZIF-8 filler,resulting in a CO_(2)/N_(2)separation factor(SF)of 48.77 with CO_(2)permeability of 645.76 Barrer in terms of H-ZIF-8 MMMs with 6 wt%loading,which well exceeds the 2008 Robenson upper bound for CO_(2)/N_(2)gas pair,thus showing promising prospects for high-efficiency CO_(2)capture from flue gas.
基金supported by the National Natural Science Foundation of China(Nos.21771095 and 22061019)the Natural Science Foundation of Shandong Province(Nos.ZR2021MB114 and ZR2021MB073)the Youth Innovation Team of Shandong Colleges and Universities(No.2019KJC027).
文摘The abuse of antibiotics has brought great harm to the human living environment and health,so it is extremely significant to develop an efficient and simple method to detect trace antibiotic residues in various wastewaters.Herein,a new two-dimensional(2D)Cd-based metal−organic framework(Cd-MOF,namely LCU-111)and its mixed matrix membranes(MMMs)is sifted as luminescence sensors for efficient monitoring antibiotic nitrofurazone(NFZ)in various aqueous systems and applied as visible fingerprint identifying.The LCU-111 has good selectivity,sensibility,reproducibility and anti-interference for luminescent quenching NFZ with low detection limits(LODs)of 0.4567,0.3649 and 0.8071 ppm in aqueous solution,HEPES biological buffer,and real urban Tuhai River water,respectively.Interestingly,the luminescent test papers and MMMs allow the NFZ sensing easier and more rapid by naked eyes,only with a low LOD of 0.8117 ppm for MMMs sensor.Notably,by combining multiple experiments with density functional theory(DFT)calculations,the photo-induced electron transfer(PET)quenching mechanism is further elucidated.More importantly,potential practical applications of LCU-111 for latent fingerprint visualization provide lifelike evidences for effective identification of individuals,which can be applied in criminal investigation.
基金financially supported by the National Key Research & Development Program of China (2021YFB3802200)the National Natural Science Foundation of China (Nos. 22078004 and 21978005)
文摘Membrane separation is a high-efficiency,energy-saving,and environment-friendly separation technology.Covalent organic framework(COF)-based mixed-matrix membranes(MMMs)have broad application prospects in gas separation and are expected to provide new solutions for coal-bed methane purification.Herein,a high-throughput screening method is used to calculate and evaluate COF-based MMMs for CH_(4)/N_(2) separation.General design rules are proposed from thermodynamic and kinetic points of view using the computation-ready,experimental COFs.From our database containing 471,671 generated COFs,5 COF membrane materials were screened with excellent membrane selectivities,which were then used as the filler of MMMs for separation performance evaluation.Among them,BAR-NAP-Benzene_CF_(3) combined with polydimethylsiloxane and styrene-b-butadiene-b-styrene show high CH_(4) permeability of 4.43×10^(-13) mol·m·s^(-1)·Pa^(-1)·m^(-2) and high CH_(4)/N_(2) selectivity of 9.54,respectively.The obtained results may provide reasonable information for the design of COF-based membranes for the efficient separation of CH_(4)/N_(2).
基金financially supported by The Natural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJB530007,22KJA530001)National Natural Science Foundation of China(22208151)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20220002)the State Key Laboratory of MaterialsOriented Chemical Engineering(SKL-MCE-22B07).
文摘For the application of carbon capture by membrane process,it is crucial to develop a highly permeable CO_(2)-selective membrane.In this work,we reported an ultra-thin polyether-block-amide(Pebax)mixedmatrix membranes(MMMs)incorporated by graphene oxide(GO),in which the interlayer channels were regulated to optimize the CO_(2)/N_(2) separation performance.Various membrane preparation conditions were systematically investigated on the influence of the membrane structure and separation performance,including the lateral size of GO nanosheets,GO loading,thermal reduction temperature,and time.The results demonstrated that the precisely regulated interlayer channel of GO nanosheets can rapidly provide CO_(2)-selective transport channels due to the synergetic effects of size sieving and preferential adsorption.The GO/Pebax ultra-thin MMMs exhibited CO_(2)/N_(2) selectivity of 72 and CO_(2) permeance of 400 GPU(1 GPU=106 cm^(3)(STP)·cm^(2)·s^(-1)·cmHg^(-1)),providing a promising candidate for CO_(2) capture.
文摘This research investigates the permeability of CO2 and N2 as well as selectivity of CO2 over N2 of polysulfone (PSF) mixed matrix membranes filled with zeolite 4Å particles. The membranes were prepared by solution-casting method and utilized to determine the permeation rates of N2 and CO2. It was characterized by FTIR and the gas separation performance was analysed by Design of Expert (DOE) method. FTIR result revealed the intensity of peak for sulfone S=O vibration at 1322 cm-1;it was related to O=S=O bound of polysulfone in the sample. The single concentration variable has low outcome, however the mixture concentration interaction was effectively to lead better selectivity of CO2 over N2. In terms of interaction between mixture concentrations, interaction between PSF and N-Methyl-2-pyrrolidone (NMP) has considerable effect on the permeability of CO2 with the highest F value of 0.46 membrane. NMP exhibited a high degree of polarity and hydrogen bonding which led to effect of selective skin and permeation rate. The model regression equations were developed as the potential use for screening the permeability of CO2 and N2 based on the deviation effect of polymer concentration.
基金the National Science Foundation of China(No.52075218,51775232).
文摘Here,we demonstrate the assembly of a new stable lanthanide-based metal-organic framework(MOF),Eu(HDPB)(phen)(1)(HDPB=(1,1’:3’,1’’-terphenyl)-3,3’’,5,5’’-tetracarboxylic acid,phen=1,10-phenanthroline),with a three-dimensional framework under solvothermal conditions.1 showed strong red fluorescence emission at room temperature and could be used as a selective and sensitive chemical sensor for pH and folic acid(FA)detection.Moreover,1 could also be applied as a fluorescent material for the visible identification of fingerprints.Then,using 1 as a filler,two mixed-matrix membranes(MMMs),1@poly(ε-caprolactone)(PCL)and 1@poly(vinylidene difluoride)(PVDF),have been fabricated.Notably,owing to the hydrophobic protection provided by the polymer matrix of the MOF particles,these two MMMs also exhibited fluorescence emission comparable to that of 1 and could be used for FA sensing with good selectivity and remarkable recyclability.More importantly,this is the first time that Eu-MOF-based MMMs have been employed in FA detection.The fabrication of MOF-based MMMs not only provides a facile method for sensing biomarkers,but it also enhances the recyclability of sensors.
基金supported by the National Natural Science Foundation of China(Nos.52370090,52300016)China Postdoctoral Science Foundation(Nos.2023M733379,2024M753122).
文摘Raw water temperature can fluctuate significantly throughout the year,with peaks above 30℃in summer and below 15℃in winter.Traditional desalination systems(e.g.,reverse osmosis,RO)face challenges under these varying temperature conditions.Specifically,while the RO system performs well under high temperatures,its efficiency decreases sharply at lower temperatures.Membrane capacitive deionization(MCDI)is considered as an emergent and promising technology for brackish water desalination.While plenty of studies have been devoted to investigating the impacts of raw water properties(e.g.,salinity,coexisting ions,and natural organic matter)on MCDI performance,the role of water temperatures during the desalination remains under-explored.In this study,we first tested and determined the optimized MCDI operation parameters,such as the cell voltage and feedwater flow rate.Key findings showed that MCDI’s salt removal efficiency remains unaffected by feedwater temperature fluctuations.However,as feedwater temperature increases from 15℃to 40℃,the specific energy consumption for desalination slightly rises by 16.3%,and current efficiency drops by 14.1%.Compared to RO systems,the resilience of MCDI to temperature fluctuations makes it a preferable choice for brackish water treatment in areas with a large temperature difference.
基金supported by grants from the Natural Science Foundation of China(22362031 and 21805121)the Science and Technology Project of Yunnan Province(2019FD137)。
文摘Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied performance mainly due to the sluggish oxygen reduction reaction(ORR)kinetics even on state-of-the-art Pt catalyst.Octahedral PtNi nanoparticles(oct-PtNi NPs)with excellent ORR activity in a half-cell have been widely studied,while their performance in membrane electrode assembly(MEA)has much less reported.Herein,we investigated the MEA performance using the carbon supported oct-PtNi NPs(oct-PtNi/C)as the cathode catalyst.Under the mild acid washing condition,the surface Ni atoms of oct-PtNi/C were largely removed,and the performance of the MEA using the acid-leaching oct-PtNi/C(PNC-A)as the cathode catalyst was greatly improved.The maximum power density of the MEA reached 1.0 W·cm^(-2) with the cath-ode Pt loading of 0.2 mg·cm^(-2),which is 15%higher than that using Pt/C as the catalyst.After 30k cycles in the accelerated degradation test(ADT),the MEA using PNC-A as the catalyst showed a performance retention of 82%,higher than that of Pt/C(74%).The results reported here verify the possibility of using PNC-A as an advanced cathode catalyst in PEMFCs,thus enhancing the performance of PEMFCs while lowering the amount of expensive Pt.
基金supported by the National Key Research and Development Program of China (2022YFE0138900)the “Scientific and Technical Innovation Action Plan” Basic Research Field of Shanghai Science and Technology Committee (19JC1410500)。
文摘Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,performance advan-tages,research progress,ion conduction mechanism and existing issues of ISMs,primarily classifying them according to the matrix structure.A detailed analysis of performance enhancement methods,key performance indicators of ISMs and performance influencing factors is also presented.The article contributes to further optimizing the design and application of ion-solvation membranes,providing theoretical support for the development of fields such as hydrogen production through electrolysis of water and electrochemical energy in the future.
基金supported by the Joint Research Program for Ecological Conservation and High Quality Development of the Yellow River Basin(No.2022-YRUC-01-0203).
文摘Urine consists of approximately 95%water,3.5%organic matter,and 1.5%inorganic salts.Membrane distillation(MD)offers a potential approach for urine resource utilization.To some extent,it reduces the loss of nitrogen and phosphorus resources.However,MD is also accompanied by problems such as high membrane cost,membrane fouling and membrane wetting.In light of these issues,this study employs polytetrafluoroethylene(PTFE)as the separation layer and polypropylene(PP)as the support layer to make a distillation membrane.The feasibility and efficiency of the PTFE-PP membrane in intercepting and recovering nitrogen and phosphorus from source-separated urine were investigated.Results obtained through 14 days of continuous operation demonstrated that the recovery rates of nitrogen and phosphorus were 95%and 99%,respectively.The dissolved organic carbon recovery rate was 95%,and urea as well as the macromolecular organic matter in dissolved organic matter were significantly intercepted.The phosphorus content in the permeate was 0.022 mg/L,which met theⅡclass standard of China’s surface water and the basic water use standard of the United States Environmental Protection Agency.This finding reduces the pressure on sewage treatment plants.PTFE-PP distillation membrane has important potential in recovering nitrogen and phosphorus from urine and alleviating global water shortage.
基金funded by São Paulo Research Foundation,FAPESP[research project funding 2019-25318-0 and 2017-18782-6]Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq,grant number 305518/2023-2.
文摘Materials from natural sources have been studied to replace the conventional synthetic or animal-derived products as a safer alternative to be used in the healthcare field.In dentistry,guided bone regeneration(GBR)relies on barrier membranes,predominantly from animals or synthetic materials,to improve osteogenesis by avoiding undesired soft tissue cells from defect sites.In this study,membranes were prepared from zein,a corn-derived protein,using a simple extraction and casting method,followed by optional formaldehyde cross-linking to evaluate their behavior for application in GBR.The membranes were characterised by FTIR,DSC,TGA,tensile strength analysis,and in vitro biological assays.Cross-linked membranes exhibited improved mechanical strength(~5 MPa)and slower degradation(~43%mass loss over 30 days),while non-cross-linked membranes disintegrated more rapidly.Cytotoxicity assays using GM07492 fibroblasts confirmed biocompatibility,and cell migration studies demonstrated effective barrier function.These results indicated that zein membranes,particularly in their cross-linked form,combine biodegradability,mechanical integrity,and cellular safety,suggesting significant potential as sustainable GBR materials.This work introduces,for the first time,zein membranes prepared from corn crude extract for GBR in dentistry,paving the way for eco-friendly alternatives to animal-derived products.
基金financially supported by the National Key Research and Development Program of China (2021YFA1201304)the National Natural Science Foundation of China (52503082)+3 种基金China Postdoctoral Science Foundation (2024M750402)Postdoctoral Fellowship Program of CPSF (GZC20230419)Shanghai Anticancer Association EYAS PROJECT (SACA-CY23C05)The Fundamental Research Funds for the Central Universities (2232023D-03, 2232024Y-01)
文摘Diabetic wounds present challenges in clinical management due to persistent inflammation caused by excessive exudate infiltration.Inspired by the gradient wettability of cactus thorn,this study has devised a biomimetic Janus nanofiber membrane as a water diode,which endows with gradient wettability and gradient pore size,offering sustainable unidirectional self-drainage and antibacterial properties for enhanced diabetic wound healing.The Janus membrane is fabricated by depositing a hydrophilic polyacrylonitrile/chlorin e6 layer with smaller pore sizes onto a hydrophobic poly(ε-caprolactone)with larger pore sizes,thereby generating a vertical gradient in both wettability and pore structure.The incorporation of chlorin e6 in the upper layer enables the utilization of external light energy to generate heat for evaporation and produce reactive oxygen species,achieving a high sterilization efficiency of 99%.Meanwhile,the gradient structure of the Janus membrane facilitates continuous antigravity exudate drainage at a rate of 0.95 g cm^(−2) h^(−1).This dual functionality of effective exudate drainage and sterilization significantly reduces inflammatory factors,allows the polarization of macrophages toward the M2 proliferative phenotype,enhances angiogenesis,and accelerates wound healing.Therefore,this study provides a groundbreaking bioinspired strategy for the development of advanced wound dressings tailored for diabetic wound regeneration.
基金financially supported by the National Natural Science Foundation of China(No.22308085)Science and Technology Plan Project of Shijiazhuang(Nos.241130547A and241791337A)Natural Science Foundation of Hebei Province(No.B2020208083)。
文摘Membrane distillation(MD)is an advanced membrane separation process that employs hydrophobic microporous membranes to sepa rate non-volatile solutes from the feed solution,driven by vapor pressure gradients generated through thermal difference.This technology offers strong desalination capabilities and efficiently harnesses low-grade thermal energy sources,including geothermal and waste heat,making it a cost-effective solution for freshwater scarcity.Nevertheless,hydrophobic membranes are prone to contamination by surfactants,inorganic salts,and other substances in feed solutions.To address this,low-surface-energy composite nano-inorganic materials composed of carbon nanotubes and silica were modified and synthesized via organosilicon chemistry.A superhydrophobic surface exhibiting a water contact angle of157.96°was successfully fabricated using above nano-materials on poly(vinylidene fluoride)(PVDF)membrane surface with micro-nano structures via a one-step spray-coating method.Compared to unmodified PVDF membra ne,the superhydrophobic membrane demonstrated superior resistance to common scaling agents such as CaCl_(2),Mg(OH)_(2),CaCO_(3),and CaSO_(4),while maintaining stable permeate flux(13.4 kg·m^(-2)·h^(-1))during MD tests.Additionally,the modified membra ne exhibited enhanced wetting resistance when treating feed solutions containing sodium dodecyl sulfate(SDS),significantly extending the operational lifespan of the membrane.Due to its outstanding performance,this superhydrophobic membrane is expected to promote the practical application of MD technology in the treatment of complex wa stewater and efficient seawater desalination.
基金the National Natural Science Foundation of China (Nos.52430001,52470091,52200108) for the financial support。
文摘Nanofiltration(NF) technology,with its capacity for nanoscale filtration and controllable selectivity,holds significant promise in diverse applications.However,the current upper bound of permeance and selectivity of NF membranes is intrinsically constrained by the morphology and structure of the polyamide(PA) selective layer.This issue arises because NF membranes typically exhibit relatively smooth nodular structures,which theoretically impede efficient water transport.In this study,we enhanced the formation of nanobubbles by synergistically regulating with surfactant and low temperatures,resulting in the fabrication of PA NF membranes with a crumpled morphology.We observed that lower temperatures promote enhanced gas solubility in the aqueous phase,facilitating increased nanobubble formation through the foaming effect of surfactant sodium dodecylbenzene sulfonate(SDBS).Consequently,this resulted in the creation of PA NF membranes with more crumpled structures and superior performance,with pure water permeance reaching 36.25 ± 0.42 L m^(-2)h^(-1)bar^(-1),representing an improvement of 14.47 L m^(-2)h^(-1)bar^(-1)compared to the control group.Additionally,it maintains a high Na_(2)SO_(4) rejection rate of97.00 % ± 0.58 %.The PA NF membranes produced by eliminating nanobubbles and free interfaces exhibited a smooth structure,whereas introducing nanobubbles(through Na HCO_(3) addition,N_(2) pressurization,and ultrasonication) resulted in the formation of crumpled membranes.This emphasized that the large amount of nanobubbles generated by SDBS and low temperature in the interfacial process played a critical role in shaping crumpled PA NF membranes and enhancing membrane performance.This approach has the potential to provide valuable insights into customizing the structural design of TFC PA NF membranes,contributing to further advancements in this field.
基金Special Research Assistant Program,China(2024000020)the Science and Technology Department of Qinghai Province,China(2024-ZJ-918)the“Kunlun Talents”Program of Qinghai(2024000075)。
文摘Abstract:Graphene-Based separation membranes hold promise for water treatment.However,their practical deployment in high-salinity brines remains challenging due to structural instability.Herein,a defect-free Na^(+)-Cu^(2+)/GO-PEI nanocomposite membrane was fabricated via a pH-controlled cross-linking polymerization strategy.Polyethyleneimine(PEI)serves as a critical interfacial stabilizer,enhancing the connection between the Na^(+)-GO and Cu^(2+)-GO layers through amide bond formation with GO nanosheets while facilitating Cu^(2+)chelation.The Na^(+)/GO layer modifies the pore structure of the polyether sulfone(PES)substrate,synergistically optimizing the membrane’s microstructure.Performances evaluation revealed that the as-prepared membrane achieved exceptional separation efficiency(>98%)for tributyl phosphate,sulfonated kerosene,and bis(2-ethylhexyl)phosphate in high-salinity brine,accompanied by a high flux of 160~224 L·m^(-2)·h^(-1).Notably,it exhibited robust chemical stability in corrosive environment and maintained mechanical durability after 500 folding cycles coupled with consistent separation performances over 10 recycles.This study presents a novel multi-component modification approach for constructing high-performance GObased membrane,promising practical applications in organic pollutant removal from high salt solution.
文摘Bacterial outer membrane vesicles(OMVs)are spherical nanostructures that originate from Gram-negative bacteria.They are gaining attention as powerful tools in cancer diagnostics and therapy due to their unique biological properties.These vesicles,which range from 50 to 250 nm in size,carry molecular components from their parent bacteria,allowing them to play important roles in bacterial defense and microbial ecosystems.Their lipid bilayer structure facilitates targeted drug delivery,while their natural immunogenic properties hold promise for cancer immunotherapy by helping overcome immune evasion in the tumor microenvironment.Moreover,OMVs have potential as biomarkers in liquid biopsies,particularly for cancers associated with bacteria,such as gastric and colorectal cancers.Their ability to interact with the intratumoral microbiota further indicates their relevance in tumor pathogenesis.This review aims to provide a comprehensive overview of the fundamental biology of OMVs and their emerging applications in cancer therapy.
基金supported by National Natural Science Foundation of China(Grant No.52272100)the Fund of Science and Technology on Advanced Ceramic Fibers and Composites Laboratory(Grant No.WDZC20215250507)the Fund of National Key Laboratory of Nuclear Reactor Technology of Nuclear Power Institute of China(KGSW-0324-0301-08)。
文摘The demand for sensors capable of operating in extreme environment of the fields,such as aerospace vehicles,aeroengines and fire protection,is rapidly increasing.However,developing flexible ceramic fibrous pressure sensors that combine high temperature stability with robust mechanical properties remains a significant challenge.Herein,through precise multi-scale process control,high-strength(2.1 MPa)TiC-SiC flexible fibrous membrane is successfully fabricated.The membrane exhibits exceptional thermal resistance(2000℃)and long–term thermal stability(1800℃ for 5 h)in the inert atmosphere.Meanwhile,the TiC-SiC fibrous membrane shows excellent oxidation resistance and still achieves strength of 1.8 MPa after being oxidized at 1200℃ for 1 h in air.Remarkably,TiC-SiC fibrous membrane withstands a load of approximately 1400 times its own weight and the ablation of butane flame(~1300℃)for at least 1 h without breaking.Notably,after heat treatment at 1800℃ for 5 h in an argon atmosphere,the TiC-SiC fibrous membrane even sustains pressure–sensing performance for up to 300 cycles.The membrane exhibits stable resistivity up to 900℃ and shows sensing stability under butane flame.The results of this work provide an effective and feasible solution to fill the research gap of flexible fibrous sensors for extreme environments.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52273059 and 52473219)the Natural Science Foundation of Tianjin(Grant Nos.22JCYBJC01030 and 23JCYBJC00650)provided by Yantai Tayho Advanced Materials Group Co.,Ltd.
文摘Alkaline water electrolysis(AWE)represents a promising approach for green hydrogen production,yet the development of high-performance separators with gas impermeability,high ion conductivity,and stability under alkaline operating conditions has proven challenging.To address this challenge,we develop a pre-concentration regulated phase separation strategy for scalable fabrication of asymmetric hierarchical porous membranes(AHPMs)for AWE.The resulting AHPMs demonstrate a hierarchical structure composed of an ultrathin dense skin layer and highly interconnected porous support.Benefitting from the structural advantages,the AHPMs exhibit outstanding characteristics,including a high bubble point pressure up to 12.4 bar,extremely low area resistance of 0.03Ωcm^(2) in 30 wt%KOH at 80℃,and excellent hydrophilicity and long-term alkaline stability.When applied in AWE with commercial catalysts,the AHPMs achieved an impressive current density of 1.9 A cm^(-2) at 2.0 V in 30 wt%KOH and the anodic hydrogen contents(AHCs)below 0.5 vol.%at a low current density of 0.1 A cm^(-2),differential pressure of 2 bar,and temperature of 80℃.Moreover,AHPMs demonstrate exceptional stability over 2,400 h of continuous operation and maintain superior performance in a 1 Nm^(3) h^(-1) industrialscale electrolyzer stack.This work advances the development of efficient separators for highperformance AWE systems,contributing to the advancement of hydrogen technologies in sustainable energy applications.
基金Funded in part by the National Key Research and Development Program of China(No.2023YFB4006302)。
文摘We successfully incorporated phenyl groups into a small-molecule quaternary ammonium cross-linker and synthesized cross-linked polybenzimidazole membranes via a one-step cross-linking process.Compared with conventional quaternary ammonium-crosslinked benzimidazole membranes,the introduction of phenyl groups significantly increases the free volume within the membrane.After phosphoric acid doping,the benzimidazole membrane with larger free volume retains more phosphoric acid compared to conventional quaternary ammonium-crosslinked membranes,forming an extensive hydrogen-bonding network that effectively enhances its anhydrous proton conductivity.The anhydrous proton conductivity reaches 91 mS·cm^(-1)at 160℃,substantially higher than that of conventional quaternary ammonium-crosslinked membranes with the same mass fraction.Benefiting from the improved conductivity,the membrane electrode assembly exhibits reduced ohmic polarization,achieving a peak power density of 792 mW·cm^(-2)at 160℃.
基金supported by the Science Fund of NPU-Duke China Seeds Program(Grant No.119003067)the CAST-BISEE Fund(Grant No.MC010175)+1 种基金the Project of National Natural Science Foundation of China(Grant No.12372233)the“111”project of China(Grant No.B17037).
文摘This study explores the nonlinear resonance of a rotating solar sail membrane exposed to time-varying solar thermal and solar radiation pressure.The sail membrane is modeled using a cantilever membrane,applying the von Kármán theory for membrane large deflection.The membrane’s nonlinear equation is derived by employing the Lagrange equation while accounting for excitations from solar thermal and radiation pressure.The equation is solved via the Rayleigh-Ritz method.The bifurcation diagram of membrane motion is applied to reveal membrane resonance responses under different solar sail rotating frequencies.The displacement time history,phase portrait,Poincarémap,frequency spectrum,and the largest Lyapunov exponent are used to study nonlinear vibrations that occur near resonance regions.The results indicate that time-varying thermal loading excites membrane motions with multiple natural frequencies by the parametric resonance mechanics,leading to the onset of membrane chaotic motion.The membrane’s primary resonance is stimulated in harmonic oscillation by the time-varying radiation pressure.The divergence instability caused by thermal excitation is also illustrated by comparing the membrane’s vibration amplitude with and without thermal excitation.The membrane’s nonlinear vibration characteristics vary significantly with solar illumination angles,the membrane’s thermal expansion coefficients,and structural damping.
