In this paper,we discuss the separateness in topological molecular lattices (TML) by the molecular stratums given in [1] and [2],deal with the relationship between the compactness and separateness.
The concept of α-CT2 separation L-fuzzy subsets in L-fuzzy topological spaces is presented by taking the stratiform structure of L-fuzzy subsets as the point of departure,and its basic characterizations and some topo...The concept of α-CT2 separation L-fuzzy subsets in L-fuzzy topological spaces is presented by taking the stratiform structure of L-fuzzy subsets as the point of departure,and its basic characterizations and some topological properties are discussed,and the relation between it and other separateness is exposed,and the action is studied of α-CT2 separateness in N-compact spaces and N-paracompact spaces.展开更多
This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow con...This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow control technique utilizing a tubercle and vortex generator(VG)close to the leading edge was analyzed numerically for a NACA0015 airfoil.In this study,the Shear Stress Transport(SST)turbulence model was employed in the numerical modelling.Numerical modelling was completed using the ANSYS-Fluent 18.2 solver.Analyses were conducted to investigate the flow pattern and understand the underlying LSB control phenomena that enabled the new passive flow control method to provide this significant performance benefit.The findings indicated that the new concept of passive flow control technique suppressed the formation of an LSB at the suction surface of the NACA0015 airfoil,resulting in a higher lift coefficient and improved aerodynamic performance.Improvements in LSB dynamics and aerodynamic performance through the passive flow control method lead to increased energy output and enhanced stability.展开更多
In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar perce...In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar percentage of Na_(2)Ni_(2)Ti_(6)O_(16)(NNTO)within Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)(NMTO),with x values of 10,20,30,40,and 50.Both XPS(X-ray Photoelectron Spectroscopy)and EDX(Energy Dispersive X-ray Spectroscopy)analyses unequivocally validated the formation of the NNMTO-x solid solutions.It was observed that when x is below 40,the NNMTO-x solid solution retains the structural characteristics of the original NMTO.However,beyond this threshold,significant alterations in crystal morphology were noted,accompanied by a noticeable decline in photocatalytic activity.Notably,the absorption edge of NNMTO-x(x<40)exhibited a shift towards the visible-light spectrum,thereby substantially broadening the absorption range.The findings highlight that NNMTO-30 possesses the most pronounced photocatalytic activity for the reduction of CO_(2).Specifically,after a 6 h irradiation period,the production rates of CO and CH_(4)were recorded at 42.38 and 1.47μmol/g,respectively.This investigation provides pivotal insights that are instrumental in the advancement of highly efficient and stable photocatalysts tailored for CO_(2)reduction processes.展开更多
The existence of absorption and reflection of light underwater leads to problems such as color distortion and blue-green bias in underwater images.In this study,a depthwise separable convolution-based generative adver...The existence of absorption and reflection of light underwater leads to problems such as color distortion and blue-green bias in underwater images.In this study,a depthwise separable convolution-based generative adversarial network(GAN)algorithm was proposed.Taking GAN as the basic framework,it combined a depthwise separable convolution module,attention mechanism,and reconstructed convolution module to realize the enhancement of underwater degraded images.Multi-scale features were captured by the depthwise separable convolution module,and the attention mechanism was utilized to enhance attention to important features.The reconstructed convolution module further extracts and fuses local and global features.Experimental results showed that the algorithm performs well in improving the color bias and blurring of underwater images,with PSNR reaching 27.835,SSIM reaching 0.883,UIQM reaching 3.205,and UCIQE reaching 0.713.The enhanced image outperforms the comparison algorithm in both subjective and objective metrics.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
As an important strategic rare-earth resource,bastnaesite has long been a global research focus.The carbochlorination process,as an efficient and low-cost extraction method,can be applied to treat bastnaesite,achievin...As an important strategic rare-earth resource,bastnaesite has long been a global research focus.The carbochlorination process,as an efficient and low-cost extraction method,can be applied to treat bastnaesite,achieving ideal rare-earth extraction results in just one-step reaction.By using inexpensive chlorine gas as the chlorinating agent,it avoids lengthy procedural steps and the generation of acid-base waste liquids.Based on this,we propose a novel carbochlorination process for bastnaesite involving a fluorine-fixing agent.Thermodynamic data for the carbochlorination process of bastnaesite were calculated using the group contribution method.Thermodynamic feasibility was verified through Gibbs free energy.The effects of different chlorination times,fluorine-fixing agent dosages,chlorine flow rates,and chlorination temperatures on the carbochlorination process of bastnaesite were investigated.Experimental studies showed that under optimal chlorination conditions,a temperature of 800℃,a duration of 60 min,a fluorine-fixing agent dosage of 10%,and a chlorine flow rate of 10 L·min^(−1),the chlorination rates of rare-earth elements,Ca,Ba,and Fe in bastnaesite reached 96%,99%,98%,and 99%,respectively.The reaction mechanism was explored and analyzed based on characterization results such as mineral phase composition,micromorphology and thermogravimetry of water-washed residues under different chlorination conditions.Additionally,kinetic experiments were conducted at varying reaction temperatures and chlorine flow rates,revealing that the carbon-chlorination process is primarily controlled by chemical reactions.展开更多
With the legislative development,the organic and inorganic composition separation has become the primary requirement for sewer sediment disposal,however the relevant technology has been rarely reported and the driving...With the legislative development,the organic and inorganic composition separation has become the primary requirement for sewer sediment disposal,however the relevant technology has been rarely reported and the driving mechanism was still unclear.In this study,direct disintegration of biopolymers and indirect broken of connection point were investigated on the hydrolysis and component separation.Three typical sewer sediment treatment approaches,i.e.,alkaline,thermal and cation exchange treatments were proposed,which represented the hydrolysis-driving forces of chemical hydrolysis,physical hydrolysis and innovative cation bridging break-age.The results showed that the organic and inorganic separation rates of sewer sediment driven by alkaline,thermal and cation exchange treatments reached 21.26%,23.80%,and 19.56%-48.0%,respectively,compared to 4.43%in control.The secondary structure of proteins was disrupted,transitioning from𝛼α-helix to𝛽β-turn and random coil.Meanwhile,much biopolymers were released from solid to the liquid phase.From thermody-namic perspective,sewer sediment deposition was controlled by short-range interfacial interactions described by extended Derjaguin-Landau-Verwey-Overbeek theory.Additionally,the separation of organic and inorganic components was positively correlated with the thermodynamic parameters(Corr=0.87),highlighted the robust-ness of various driving forces.And the flocculation energy barriers were 2.40(alkaline),1.60 times(thermal),and 4.02–4.97 times(cation exchange)compared to control group.The findings revealed the contrition differ-ence of direct disintegration of gelatinous biopolymers and indirect breakage of composition connection sites in sediment composition separation,filling the critical gaps in understanding the specific mechanisms of sediment biopolymer disintegration and intermolecular connection breakage.展开更多
Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)is a carbon-neutral strategy to address global energy use and its impact on climate.Metal oxide and metal chalcogenide catalysts are the most investigated cata...Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)is a carbon-neutral strategy to address global energy use and its impact on climate.Metal oxide and metal chalcogenide catalysts are the most investigated catalysts for photocatalytic CO_(2)RR.Unfortunately,low CO_(2)adsorption ability and limited active sites of metal oxide and metal chalcogenide catalysts for CO_(2)RR make them less competitive compared to their industrial counterparts.Inspired by applications of porphyrin-based metal-organic framework(MOF)catalysts for hydrogen evolution and photodynamic therapy,the investigations of these porphyrin-based MOFs,including pristine and composite porphyrin-based MOFs in photocatalytic CO_(2)RR,have attracted significant attention in the last five years due to their excellent CO_(2)adsorption capacities,high porosity,high stability,exceptional optoelectronic properties,and multi-functionality.However,due to the difference in photocatalytic CO_(2)RR,several critical issues need to be addressed to achieve the rational design of advanced porphyrin-based MOF photocatalysts to improve activity,selectivity,and stability for CO_(2)RR.Here,we review recent developments in the field of porphyrin-based MOF CO_(2)RR photocatalysts,along with critical issues,challenges,and perspectives concerning porphyrin-based MOF catalysts for photocatalytic CO_(2)RR.展开更多
Lithium(Li)dendrites,resulting from poor ion desolvation and transport behavior at the anode/electrolyte interface during electrodeposition,severely impede the practicality of Li metal anodes.Inspired by the transmemb...Lithium(Li)dendrites,resulting from poor ion desolvation and transport behavior at the anode/electrolyte interface during electrodeposition,severely impede the practicality of Li metal anodes.Inspired by the transmembrane cascade transport mechanism of biological ion pumps,we design a biomimetic dual-cascade separator(BDS)based on gradient pore core–shell Gd_(2)O_(3)@ZIF-7 nanoparticles to stabilize Li metal anodes.The mesoporous Gd_(2)O_(3)core,via Lewis acidic surface,weakens Li^(+) -solvent interactions,thereby reconstructing the solvation structure and achieving pre-desolvation.The microporous ZIF-7 shell then promotes final desolvation through strong confinement effect and N-rich site coordination,while its nanochannels homogenize Li^(+) transport.This synergistic meso/microporous gradient creates a unique dual-cascade effect for ion desolvation and transport.Consequently,BDS achieves a low desolvation energy barrier,a high Li^(+) transference number(0.71),and dendrite-free Li deposition.The average Coulombic efficiency rises from 72.7%to 98.4%,the cycling performance of the Li||Li symmetrical cell improves by 3.2 times,and the capacity retention of LiFePO_4(LFP)||Li full cell increases from 38.3%to73.4%after 500 cycles.This work offers a novel separator design concept,deepens Li deposition understanding,and guides separators from passive protection to active regulation.展开更多
The dependence of interface structure and mechanical properties on the modulation layer thickness of VN/TiN−Ni nano-multilayered films deposited on Si substrates using a reactive magnetron sputtering technique was sys...The dependence of interface structure and mechanical properties on the modulation layer thickness of VN/TiN−Ni nano-multilayered films deposited on Si substrates using a reactive magnetron sputtering technique was systematically investigated. The films were characterized using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and nanoindentation. The results show that the TiN−Ni layer grows epitaxially on the VN layer, forming a coherent interface between the two sublayers. When the deposition time ratio of the two sublayers (TTiN−Ni꞉TVN) is 10꞉12, the films exhibit remarkable mechanical properties, with hardness, elastic modulus, and fracture toughness values of 25.9 GPa, 317 GPa, and 1.88 MPa·m^(1/2), respectively. Meanwhile, fracture toughness is improved by approximately 50% compared to the VN monolithic film. This enhancement is attributed to the coherent interface between the sublayers and the phase separation in the TiN−Ni layer.展开更多
Taking the view that pro-environmental behaviors can have spillover effects,this study examines how household waste separation(an environmental behavior with a high degree of difficulty)impacts consumers’water saving...Taking the view that pro-environmental behaviors can have spillover effects,this study examines how household waste separation(an environmental behavior with a high degree of difficulty)impacts consumers’water saving efforts(an environmental behavior with a low degree of difficulty).We assess the mediating effects of self-efficacy and ego depletion in this relationship and the moderating effect of the need for self-determination in the mediated relationships.The results show separating household waste significantly enhances consumers’water-saving efforts.Both self-efficacy and ego depletion partially mediate the relationship between household waste separation and efforts to reduce water consumption.Specifically,if consumers engage in pro environmental behaviors based on their internal,rather than external sense of moral identity,their sense of self-efficacy increases after separating household,which motivates them to engage in subsequent water-saving behaviors.In addition,consumers’sense of ego depletion declines when they engage in household waste separation,which increases subsequent water-saving behavior.Compared to low-level self-determination needs,high-level self-determination needs weaken the positive impact of household waste separation on consumers’perceived self-efficacy,but strengthens the negative impact of household waste separation on consumers’perceived ego depletion and promotes subsequent water-saving behavior.These findings suggest policymakers should pay attention to the spillover effects pro-environmental behaviors and use household waste separation policies to promote other pro-environmental behaviors such as reducing water consumption.展开更多
This study examines the dynamic response of two adjacent 9-and 20-story benchmark steel buildings subjected to six near-fault earthquake records.Two-dimensional numerical models were employed to account for the comple...This study examines the dynamic response of two adjacent 9-and 20-story benchmark steel buildings subjected to six near-fault earthquake records.Two-dimensional numerical models were employed to account for the complexities of structure-soil-structure interaction(SSSI).The research focuses on the separation gap between the buildings and the effects of pounding while considering Fixed Base(FB)and SSSI models,evaluated according to UBC 94 and ASCE 7-16 seismic codes.Key findings reveal that pounding occurs with the UBC 94 separation gap when earthquake frequency aligns with system frequency,leading to increased column stresses in the 9-story building.In contrast,the ASCE 7-16 standard effectively prevents pounding in both the FB and SSSI models.Additionally,drifts and displacements of lower floors in SSSI models exceed the allowable limits of ASCE 7-16,underscoring the impact of soil-structure interaction on seismic response.展开更多
Coal serves not only as a crucial energy resource but also as a significant reservoir of critical metal elements,including Lithium(Li),Gallium(Ga),Germanium(Ge),and rare earth elements(REE).This paper provides a syste...Coal serves not only as a crucial energy resource but also as a significant reservoir of critical metal elements,including Lithium(Li),Gallium(Ga),Germanium(Ge),and rare earth elements(REE).This paper provides a systematic review of the enrichment characteristics,occurrence modes,and comprehensive utilization potential of these critical metals in coal.Globally,the distribution of these metal resources exhibits significant regional heterogeneity.While the concentration in most coals falls below industrial cut-off grades,anomalous enrichment in specific coal basins results in Li,Ga,Ge,and REE concentrations far exceeding global averages,highlighting their considerable potential as unconventional metal deposits.The occurrence modes of these metals are diverse:Li is primarily hosted in mineral phases;Ga exists in inorganic,organic,and complex forms;Ge shows a strong association with organic matter;and REE are mainly present in adsorbed/isomorphic forms within clay minerals,while also displaying organic affinity.Direct extraction of metals from raw coal is often cost-prohibitive;effective recovery is therefore more feasible when integrated with coal processing.Metals are further enriched in solid wastes such as coal gangue,fly ash,and bottom ash,from which recovery is more economically and technically viable.Current comprehensive utilization primarily employs integrated mineral processing-hydrometallurgy approaches.Future research should focus on elucidating the precise occurrence forms of metals in coal and solid wastes,optimizing pre-treatment methods,and selecting effective activators and leachants.Advancing the synergistic extraction and green recovery of multiple associated resources from coal and its by-products is essential for achieving high-value,comprehensive utilization of coal-based resources.展开更多
The efficient flotation separation of rare earth elements(REEs)from gangue minerals is crucial in mineral processing.This study synthesized a quaternary ammonium salt ionic liquid collector,tetrabutylammonium salicylh...The efficient flotation separation of rare earth elements(REEs)from gangue minerals is crucial in mineral processing.This study synthesized a quaternary ammonium salt ionic liquid collector,tetrabutylammonium salicylhydroxamate(T-S),and investigated its performance in separating bastnaesite and fluorite.T-S was synthesized from salicylhydroxamic acid(SHA)and tetrabutylammonium chloride(TBAC),and its molecular structure was characterized using Fourier transform infrared(FTIR)spectroscopy.Microflotation tests indicate that T-S outperforms SHA and TBAC in both collecting ability and selectivity for bastnaesite.Adsorption,zeta potential,and infrared spectroscopy measurements reveal that T-S exhibits stronger adsorption on bastnaesite compared to SHA and TBAC.X-ray photoelectron spectroscopy(XPS)and molecular dynamics simulations(MDS)results confirm that chemical adsorption occurs between Ce on the bastnaesite surface and the-C(=O)NHOH groups of T-S.Moreover,the interaction between T-S and the bastnaesite surface is stronger than that with the fluorite surface.This work provides valuable insights for designing ionic liquid collectors for the flotation separation of bastnaesite and fluorite.展开更多
Bayan Obo rare earth mine is the largest light rare earth resource worldwide,primarily extracts rare earth elements(REEs)from mixed RE concentrates with bastnaesite and monazite.Nevertheless,the adoption of the concen...Bayan Obo rare earth mine is the largest light rare earth resource worldwide,primarily extracts rare earth elements(REEs)from mixed RE concentrates with bastnaesite and monazite.Nevertheless,the adoption of the concentrated sulfuric acid roasting metallurgical process has resulted in damage to the environment.Therefore,this paper adopted the method of selective mineral phase transformation(MPT)followed by enhanced micro-flotation.By determining the optimal MPT co nditions,the flotation recovery of bastnaesite-roasted products by the collector(phthalic acid,PA)is improved,and the enhanced separation of bastnaesite with monazite is realized.The results show that with the increase of roasting temperature and time,the bastnaesite decomposition product is CeOF and monazite does not change significantly.Subsequent micro-flotation exhibits a gradual decline in the PA consumption of bastnaesiteroasted products,while the flotation recovery of monazite-roasted products remains poor.The artificial mixed ore experiments result in a CeOF foam product with a content of 94.14%and a recovery of 85.80%,and a monazite tank product with a content of 73.53%and a recovery of 87.87%.Compared with the preroasting ore,the surface and interior of bastnaesite-roasted products develop numerous cracks and porosities,and no obvious structural damage is observed in monazite-roasted particles.As the roasting temperature increases,the mineral particles undergo recrystallization or closure,reducing the specific surface area of bastnaesite-roasted products and enhancing hydrophobicity,leading to diminished PA consumption.Fourier transform infrared and other flotation-relation tests show that PA is chemisorbed on the surface of CeOF.The MPT conditions are optimized in this study,which provides a reference for further advancing the efficient separation of bastnaesite and monazite.展开更多
Lithium-sulfur batteries(LSBs)represent a next-generation energy storage technology,but widespread applications are restricted by the shuttle of lithium polysulfides(LiPSs).The rational design of separators has been d...Lithium-sulfur batteries(LSBs)represent a next-generation energy storage technology,but widespread applications are restricted by the shuttle of lithium polysulfides(LiPSs).The rational design of separators has been demonstrated to be one of the most efficient and cost-effective strategies to curb the shuttle effect,and tremendous research progress has been achieved.The efficiency of a separator depends on its interaction with LiPSs,which is governed by the surface energy and binding strength.Despite several review works that have been reported to advance the separators,most of them primarily focus on active material innovation and construction.The most crucial issues of surface binding energy have not been systematically reviewed,limiting the precise design of efficient separators.In this review,fundamentals related to surface energy and binding interactions with LiPSs are comprehensively analyzed and discussed.With surface binding and energy main lines,the advancements in separator engineering strategies are elaborately summarized and discussed.Moreover,techniques for evaluating affinity to LiPSs are thoroughly analyzed to avoid any ambiguities in measurement.Based on the research context,valuable research directions are suggested to construct efficient separators.This work provides guidelines to regulate the surface binding and energy of separators for high-performance LSBs.展开更多
Developing advanced polymeric materials with enhanced mechanical properties and functionalities has been a long-standing goal in materials science.Recently,supramolecular polymeric materials (SPMs) have drawn increase...Developing advanced polymeric materials with enhanced mechanical properties and functionalities has been a long-standing goal in materials science.Recently,supramolecular polymeric materials (SPMs) have drawn increased attention due to their unique properties and potential applications in self-healing,shape memory,sensors,and flexible electronics.Here,we develop an ionic cluster-optimized microphase separation strategy to enhance the toughening and energy dissipation capabilities of polydisulfide-based supramolecular polymers.The mechanical properties,including Young’s modulus and toughness,are significantly improved by integrating the quadruple H-bonding 2-ureido-4-pyrimidone (UPy) induced microphase separation with iron(Ⅲ)-to-carboxylate ionic clusters.By combining established chemical approaches with adjustable polymer phase ratios,it is revealed that the synergistic effect of these factors expands the interchain spacing,facilitates the formation of microphase domains,and enhances the tolerance of polythioctic acid-based polymers to external mechanical and thermal stimuli,meeting the practical requirements for industrial plastic applications.Moreover,the UPy-functionalized polymers incorporating iron carboxylate clusters exhibit good one-way shape memory behavior with practical applicability at a relatively low recovery temperature.Our work demonstrates a novel strategy for constructing industrially viable shape memory dynamic SPMs and paves the way for future innovations in developing SPMs.展开更多
In this study,a polymer acceptor named BT-Cl with a“bridging”structure,which contained a benzodithiophene unit analogous to that of donor D18,and cyano(CN)groups and heterocyclic structures similar to those in accep...In this study,a polymer acceptor named BT-Cl with a“bridging”structure,which contained a benzodithiophene unit analogous to that of donor D18,and cyano(CN)groups and heterocyclic structures similar to those in acceptor N3,was synthesized.The“bridging”structure ensured good compatibility of BT-Cl with both D18 and N3,and effectively helped to reduce the large phase separation size of D18/N3 binary blend film when added as a third component.Meanwhile,the addition of BT-Cl to the D18/N3 blend can improve the crystallinity and enhance the light absorption efficiency to some extent.The“bridging”structure also resulted higher lowest unoccupied molecular orbital(LUMO)energy level of BT-Cl than that of N3,which effectively improve the open-circuit voltage(VOC)of the ternary device and consequently the power conversion efficiency(PCE).This work showed that the polymer with“bridging”structure as the third component was an effective strategy to decrease the large phase separation size.展开更多
Microporous polyimides(PIM-PIs)have emerged as promising high-performance membranes for gas separation.However,achieving an optimal balance between permeability and selectivity remains a major challenge.In this study,...Microporous polyimides(PIM-PIs)have emerged as promising high-performance membranes for gas separation.However,achieving an optimal balance between permeability and selectivity remains a major challenge.In this study,we designed and synthesized a series of PIM-PIs by combining rigid dianhydrides 9-bis(trifluoromethyl)-2,3,6,7-xanthenetetracarboxylic dianhydride(6FCDA)and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)with contorted diamines,including 9,9-bis(4-aminophenyl)fluorene(FDA),9,9′-spirobifluorene-2,2′-diamine(SBFDA),and 3,3,3′,3′-tetramethyl-1,1′-spirobiindane-5,5′-diamine-6,6′-diol(TSDA),to systematically elucidate the relationship between hierarchical microstructure and gas transport behavior.Comprehensive characterization revealed that the 6FCDA-based polymers exhibited a higher microporosity(V_(micro)/V_(total)up to 54.7%)and fractional free volume compared to their 6FDA counterparts.Gas permeation measurements showed that the 6FCDA/SBFDA membrane delivered a CO_(2)permeability of 386 Barrer and CO_(2)/CH_(4)selectivity of 30.2,exceeding the 2008 Robeson upper bound.Structure-property correlation analyses indicated that diffusion selectivity predominantly governed gas separation performance,with rigid,spirocyclic architectures suppressing chain packing to generate sub-5Åmicropores,as further validated by molecular simulations.The optimized 6FCDA/FDA membrane achieved a BET surface area of 423 m^(2)·g^(−1),while maintaining excellent mechanical strength and high thermal stability.This work establishes an effective monomer design strategy to overcome the permeability-selectivity trade-off through backbone rigidification,thereby advancing PIM-PIs for practical applications in natural gas purification and carbon capture.展开更多
文摘In this paper,we discuss the separateness in topological molecular lattices (TML) by the molecular stratums given in [1] and [2],deal with the relationship between the compactness and separateness.
文摘The concept of α-CT2 separation L-fuzzy subsets in L-fuzzy topological spaces is presented by taking the stratiform structure of L-fuzzy subsets as the point of departure,and its basic characterizations and some topological properties are discussed,and the relation between it and other separateness is exposed,and the action is studied of α-CT2 separateness in N-compact spaces and N-paracompact spaces.
基金the Scientific Research Projects Unit of Erciyes University under contract no:FDS-2022-11532 and FOA-2025-14773.
文摘This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow control technique utilizing a tubercle and vortex generator(VG)close to the leading edge was analyzed numerically for a NACA0015 airfoil.In this study,the Shear Stress Transport(SST)turbulence model was employed in the numerical modelling.Numerical modelling was completed using the ANSYS-Fluent 18.2 solver.Analyses were conducted to investigate the flow pattern and understand the underlying LSB control phenomena that enabled the new passive flow control method to provide this significant performance benefit.The findings indicated that the new concept of passive flow control technique suppressed the formation of an LSB at the suction surface of the NACA0015 airfoil,resulting in a higher lift coefficient and improved aerodynamic performance.Improvements in LSB dynamics and aerodynamic performance through the passive flow control method lead to increased energy output and enhanced stability.
基金Supported by the Doctoral Research Start-up Project of Yuncheng University(YQ-2023067)Project of Shanxi Natural Science Foundation(202303021211189)+1 种基金Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Provinces(20220036)Shanxi ProvinceIntelligent Optoelectronic Sensing Application Technology Innovation Center and Shanxi Province Optoelectronic Information Science and TechnologyLaboratory,Yuncheng University.
文摘In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar percentage of Na_(2)Ni_(2)Ti_(6)O_(16)(NNTO)within Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)(NMTO),with x values of 10,20,30,40,and 50.Both XPS(X-ray Photoelectron Spectroscopy)and EDX(Energy Dispersive X-ray Spectroscopy)analyses unequivocally validated the formation of the NNMTO-x solid solutions.It was observed that when x is below 40,the NNMTO-x solid solution retains the structural characteristics of the original NMTO.However,beyond this threshold,significant alterations in crystal morphology were noted,accompanied by a noticeable decline in photocatalytic activity.Notably,the absorption edge of NNMTO-x(x<40)exhibited a shift towards the visible-light spectrum,thereby substantially broadening the absorption range.The findings highlight that NNMTO-30 possesses the most pronounced photocatalytic activity for the reduction of CO_(2).Specifically,after a 6 h irradiation period,the production rates of CO and CH_(4)were recorded at 42.38 and 1.47μmol/g,respectively.This investigation provides pivotal insights that are instrumental in the advancement of highly efficient and stable photocatalysts tailored for CO_(2)reduction processes.
文摘The existence of absorption and reflection of light underwater leads to problems such as color distortion and blue-green bias in underwater images.In this study,a depthwise separable convolution-based generative adversarial network(GAN)algorithm was proposed.Taking GAN as the basic framework,it combined a depthwise separable convolution module,attention mechanism,and reconstructed convolution module to realize the enhancement of underwater degraded images.Multi-scale features were captured by the depthwise separable convolution module,and the attention mechanism was utilized to enhance attention to important features.The reconstructed convolution module further extracts and fuses local and global features.Experimental results showed that the algorithm performs well in improving the color bias and blurring of underwater images,with PSNR reaching 27.835,SSIM reaching 0.883,UIQM reaching 3.205,and UCIQE reaching 0.713.The enhanced image outperforms the comparison algorithm in both subjective and objective metrics.
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supported by the National Natural Science Foundation of China(ZX20230386)the 2023 Special Project for High-Industrial Base Reconstruction Quality Development of the Manufacturing Industry(2023ZY01019-11)the sixth batch of top talent support funds(QNBJ-2022-04).
文摘As an important strategic rare-earth resource,bastnaesite has long been a global research focus.The carbochlorination process,as an efficient and low-cost extraction method,can be applied to treat bastnaesite,achieving ideal rare-earth extraction results in just one-step reaction.By using inexpensive chlorine gas as the chlorinating agent,it avoids lengthy procedural steps and the generation of acid-base waste liquids.Based on this,we propose a novel carbochlorination process for bastnaesite involving a fluorine-fixing agent.Thermodynamic data for the carbochlorination process of bastnaesite were calculated using the group contribution method.Thermodynamic feasibility was verified through Gibbs free energy.The effects of different chlorination times,fluorine-fixing agent dosages,chlorine flow rates,and chlorination temperatures on the carbochlorination process of bastnaesite were investigated.Experimental studies showed that under optimal chlorination conditions,a temperature of 800℃,a duration of 60 min,a fluorine-fixing agent dosage of 10%,and a chlorine flow rate of 10 L·min^(−1),the chlorination rates of rare-earth elements,Ca,Ba,and Fe in bastnaesite reached 96%,99%,98%,and 99%,respectively.The reaction mechanism was explored and analyzed based on characterization results such as mineral phase composition,micromorphology and thermogravimetry of water-washed residues under different chlorination conditions.Additionally,kinetic experiments were conducted at varying reaction temperatures and chlorine flow rates,revealing that the carbon-chlorination process is primarily controlled by chemical reactions.
基金supported by Shaanxi Key Research and Development Program(No.2024SF-YBXM-546)the National Natural Science Foundation of China(No.52470161)the State Key Laboratory of Pollution Control and Resource Reuse Foundation(No.PCRRF21007).
文摘With the legislative development,the organic and inorganic composition separation has become the primary requirement for sewer sediment disposal,however the relevant technology has been rarely reported and the driving mechanism was still unclear.In this study,direct disintegration of biopolymers and indirect broken of connection point were investigated on the hydrolysis and component separation.Three typical sewer sediment treatment approaches,i.e.,alkaline,thermal and cation exchange treatments were proposed,which represented the hydrolysis-driving forces of chemical hydrolysis,physical hydrolysis and innovative cation bridging break-age.The results showed that the organic and inorganic separation rates of sewer sediment driven by alkaline,thermal and cation exchange treatments reached 21.26%,23.80%,and 19.56%-48.0%,respectively,compared to 4.43%in control.The secondary structure of proteins was disrupted,transitioning from𝛼α-helix to𝛽β-turn and random coil.Meanwhile,much biopolymers were released from solid to the liquid phase.From thermody-namic perspective,sewer sediment deposition was controlled by short-range interfacial interactions described by extended Derjaguin-Landau-Verwey-Overbeek theory.Additionally,the separation of organic and inorganic components was positively correlated with the thermodynamic parameters(Corr=0.87),highlighted the robust-ness of various driving forces.And the flocculation energy barriers were 2.40(alkaline),1.60 times(thermal),and 4.02–4.97 times(cation exchange)compared to control group.The findings revealed the contrition differ-ence of direct disintegration of gelatinous biopolymers and indirect breakage of composition connection sites in sediment composition separation,filling the critical gaps in understanding the specific mechanisms of sediment biopolymer disintegration and intermolecular connection breakage.
基金financially supported by the National Natural Science Foundation of China(No.22305009)the Science and Technology Development Fund,Macao SAR(File no.FDCT-0125/2022/A and FDCT-0006/2023/RIB1)Hong Kong Research Grant Council(RGC)General Research Fund(GRF)City U 11305419,11306920,CityU 11308721,CityU 11316522,and SIRG7020022。
文摘Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)is a carbon-neutral strategy to address global energy use and its impact on climate.Metal oxide and metal chalcogenide catalysts are the most investigated catalysts for photocatalytic CO_(2)RR.Unfortunately,low CO_(2)adsorption ability and limited active sites of metal oxide and metal chalcogenide catalysts for CO_(2)RR make them less competitive compared to their industrial counterparts.Inspired by applications of porphyrin-based metal-organic framework(MOF)catalysts for hydrogen evolution and photodynamic therapy,the investigations of these porphyrin-based MOFs,including pristine and composite porphyrin-based MOFs in photocatalytic CO_(2)RR,have attracted significant attention in the last five years due to their excellent CO_(2)adsorption capacities,high porosity,high stability,exceptional optoelectronic properties,and multi-functionality.However,due to the difference in photocatalytic CO_(2)RR,several critical issues need to be addressed to achieve the rational design of advanced porphyrin-based MOF photocatalysts to improve activity,selectivity,and stability for CO_(2)RR.Here,we review recent developments in the field of porphyrin-based MOF CO_(2)RR photocatalysts,along with critical issues,challenges,and perspectives concerning porphyrin-based MOF catalysts for photocatalytic CO_(2)RR.
基金the financial support from the National Natural Science Foundation of China(22408182)the Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT24024)the Natural Science Foundation of Inner Mongolia Autonomous Region(2023QN02007 and 2025QN02009)。
文摘Lithium(Li)dendrites,resulting from poor ion desolvation and transport behavior at the anode/electrolyte interface during electrodeposition,severely impede the practicality of Li metal anodes.Inspired by the transmembrane cascade transport mechanism of biological ion pumps,we design a biomimetic dual-cascade separator(BDS)based on gradient pore core–shell Gd_(2)O_(3)@ZIF-7 nanoparticles to stabilize Li metal anodes.The mesoporous Gd_(2)O_(3)core,via Lewis acidic surface,weakens Li^(+) -solvent interactions,thereby reconstructing the solvation structure and achieving pre-desolvation.The microporous ZIF-7 shell then promotes final desolvation through strong confinement effect and N-rich site coordination,while its nanochannels homogenize Li^(+) transport.This synergistic meso/microporous gradient creates a unique dual-cascade effect for ion desolvation and transport.Consequently,BDS achieves a low desolvation energy barrier,a high Li^(+) transference number(0.71),and dendrite-free Li deposition.The average Coulombic efficiency rises from 72.7%to 98.4%,the cycling performance of the Li||Li symmetrical cell improves by 3.2 times,and the capacity retention of LiFePO_4(LFP)||Li full cell increases from 38.3%to73.4%after 500 cycles.This work offers a novel separator design concept,deepens Li deposition understanding,and guides separators from passive protection to active regulation.
基金financially supported by the National Natural Science Foundation of China(No.51971148)the Key Project Foundation of Hanjiang Normal University,China(No.XJ2024A09)+1 种基金the Excellent Young and Middle-aged Science and Technology Innovation Team Project in Higher Education Institutions of Hubei Province,China(No.T2020024)the Shanghai Engineering Research Center of High-Performance Medical Device Materials,China(No.20DZ2255500)。
文摘The dependence of interface structure and mechanical properties on the modulation layer thickness of VN/TiN−Ni nano-multilayered films deposited on Si substrates using a reactive magnetron sputtering technique was systematically investigated. The films were characterized using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and nanoindentation. The results show that the TiN−Ni layer grows epitaxially on the VN layer, forming a coherent interface between the two sublayers. When the deposition time ratio of the two sublayers (TTiN−Ni꞉TVN) is 10꞉12, the films exhibit remarkable mechanical properties, with hardness, elastic modulus, and fracture toughness values of 25.9 GPa, 317 GPa, and 1.88 MPa·m^(1/2), respectively. Meanwhile, fracture toughness is improved by approximately 50% compared to the VN monolithic film. This enhancement is attributed to the coherent interface between the sublayers and the phase separation in the TiN−Ni layer.
基金supported by the National Social Science Fund of China[Grant No.25BGL131].
文摘Taking the view that pro-environmental behaviors can have spillover effects,this study examines how household waste separation(an environmental behavior with a high degree of difficulty)impacts consumers’water saving efforts(an environmental behavior with a low degree of difficulty).We assess the mediating effects of self-efficacy and ego depletion in this relationship and the moderating effect of the need for self-determination in the mediated relationships.The results show separating household waste significantly enhances consumers’water-saving efforts.Both self-efficacy and ego depletion partially mediate the relationship between household waste separation and efforts to reduce water consumption.Specifically,if consumers engage in pro environmental behaviors based on their internal,rather than external sense of moral identity,their sense of self-efficacy increases after separating household,which motivates them to engage in subsequent water-saving behaviors.In addition,consumers’sense of ego depletion declines when they engage in household waste separation,which increases subsequent water-saving behavior.Compared to low-level self-determination needs,high-level self-determination needs weaken the positive impact of household waste separation on consumers’perceived self-efficacy,but strengthens the negative impact of household waste separation on consumers’perceived ego depletion and promotes subsequent water-saving behavior.These findings suggest policymakers should pay attention to the spillover effects pro-environmental behaviors and use household waste separation policies to promote other pro-environmental behaviors such as reducing water consumption.
文摘This study examines the dynamic response of two adjacent 9-and 20-story benchmark steel buildings subjected to six near-fault earthquake records.Two-dimensional numerical models were employed to account for the complexities of structure-soil-structure interaction(SSSI).The research focuses on the separation gap between the buildings and the effects of pounding while considering Fixed Base(FB)and SSSI models,evaluated according to UBC 94 and ASCE 7-16 seismic codes.Key findings reveal that pounding occurs with the UBC 94 separation gap when earthquake frequency aligns with system frequency,leading to increased column stresses in the 9-story building.In contrast,the ASCE 7-16 standard effectively prevents pounding in both the FB and SSSI models.Additionally,drifts and displacements of lower floors in SSSI models exceed the allowable limits of ASCE 7-16,underscoring the impact of soil-structure interaction on seismic response.
基金supported by the Key Support Project of Regional Innovation and Development Joint Fund of the National Natural Science Foundation of China(No.U24A2095).
文摘Coal serves not only as a crucial energy resource but also as a significant reservoir of critical metal elements,including Lithium(Li),Gallium(Ga),Germanium(Ge),and rare earth elements(REE).This paper provides a systematic review of the enrichment characteristics,occurrence modes,and comprehensive utilization potential of these critical metals in coal.Globally,the distribution of these metal resources exhibits significant regional heterogeneity.While the concentration in most coals falls below industrial cut-off grades,anomalous enrichment in specific coal basins results in Li,Ga,Ge,and REE concentrations far exceeding global averages,highlighting their considerable potential as unconventional metal deposits.The occurrence modes of these metals are diverse:Li is primarily hosted in mineral phases;Ga exists in inorganic,organic,and complex forms;Ge shows a strong association with organic matter;and REE are mainly present in adsorbed/isomorphic forms within clay minerals,while also displaying organic affinity.Direct extraction of metals from raw coal is often cost-prohibitive;effective recovery is therefore more feasible when integrated with coal processing.Metals are further enriched in solid wastes such as coal gangue,fly ash,and bottom ash,from which recovery is more economically and technically viable.Current comprehensive utilization primarily employs integrated mineral processing-hydrometallurgy approaches.Future research should focus on elucidating the precise occurrence forms of metals in coal and solid wastes,optimizing pre-treatment methods,and selecting effective activators and leachants.Advancing the synergistic extraction and green recovery of multiple associated resources from coal and its by-products is essential for achieving high-value,comprehensive utilization of coal-based resources.
基金Project supported by the National Key Research and Development Program of China(2022YFC2905800)National Natural Science Foundation of China(52374276,52274269)+2 种基金Yunnan Fundamental Re search Projects(202401AS070051)the Natural Science Foundation of Hubei Province of China(2024AFD123)Young Elite Scientists Sponsorship Program by CAST(YESS20200276)。
文摘The efficient flotation separation of rare earth elements(REEs)from gangue minerals is crucial in mineral processing.This study synthesized a quaternary ammonium salt ionic liquid collector,tetrabutylammonium salicylhydroxamate(T-S),and investigated its performance in separating bastnaesite and fluorite.T-S was synthesized from salicylhydroxamic acid(SHA)and tetrabutylammonium chloride(TBAC),and its molecular structure was characterized using Fourier transform infrared(FTIR)spectroscopy.Microflotation tests indicate that T-S outperforms SHA and TBAC in both collecting ability and selectivity for bastnaesite.Adsorption,zeta potential,and infrared spectroscopy measurements reveal that T-S exhibits stronger adsorption on bastnaesite compared to SHA and TBAC.X-ray photoelectron spectroscopy(XPS)and molecular dynamics simulations(MDS)results confirm that chemical adsorption occurs between Ce on the bastnaesite surface and the-C(=O)NHOH groups of T-S.Moreover,the interaction between T-S and the bastnaesite surface is stronger than that with the fluorite surface.This work provides valuable insights for designing ionic liquid collectors for the flotation separation of bastnaesite and fluorite.
基金Project supported by the National Key R&D Program of China(2022YFC2905800)the National Natural Science Foundation of China(52174242)the National Youth Talent Support Program(QNBJ-2023-03)。
文摘Bayan Obo rare earth mine is the largest light rare earth resource worldwide,primarily extracts rare earth elements(REEs)from mixed RE concentrates with bastnaesite and monazite.Nevertheless,the adoption of the concentrated sulfuric acid roasting metallurgical process has resulted in damage to the environment.Therefore,this paper adopted the method of selective mineral phase transformation(MPT)followed by enhanced micro-flotation.By determining the optimal MPT co nditions,the flotation recovery of bastnaesite-roasted products by the collector(phthalic acid,PA)is improved,and the enhanced separation of bastnaesite with monazite is realized.The results show that with the increase of roasting temperature and time,the bastnaesite decomposition product is CeOF and monazite does not change significantly.Subsequent micro-flotation exhibits a gradual decline in the PA consumption of bastnaesiteroasted products,while the flotation recovery of monazite-roasted products remains poor.The artificial mixed ore experiments result in a CeOF foam product with a content of 94.14%and a recovery of 85.80%,and a monazite tank product with a content of 73.53%and a recovery of 87.87%.Compared with the preroasting ore,the surface and interior of bastnaesite-roasted products develop numerous cracks and porosities,and no obvious structural damage is observed in monazite-roasted particles.As the roasting temperature increases,the mineral particles undergo recrystallization or closure,reducing the specific surface area of bastnaesite-roasted products and enhancing hydrophobicity,leading to diminished PA consumption.Fourier transform infrared and other flotation-relation tests show that PA is chemisorbed on the surface of CeOF.The MPT conditions are optimized in this study,which provides a reference for further advancing the efficient separation of bastnaesite and monazite.
基金supported by the National Natural Science Foundation of China (52172228)the Natural Science Foundation of Fujian Province (2024J01475 and 2023J05127)
文摘Lithium-sulfur batteries(LSBs)represent a next-generation energy storage technology,but widespread applications are restricted by the shuttle of lithium polysulfides(LiPSs).The rational design of separators has been demonstrated to be one of the most efficient and cost-effective strategies to curb the shuttle effect,and tremendous research progress has been achieved.The efficiency of a separator depends on its interaction with LiPSs,which is governed by the surface energy and binding strength.Despite several review works that have been reported to advance the separators,most of them primarily focus on active material innovation and construction.The most crucial issues of surface binding energy have not been systematically reviewed,limiting the precise design of efficient separators.In this review,fundamentals related to surface energy and binding interactions with LiPSs are comprehensively analyzed and discussed.With surface binding and energy main lines,the advancements in separator engineering strategies are elaborately summarized and discussed.Moreover,techniques for evaluating affinity to LiPSs are thoroughly analyzed to avoid any ambiguities in measurement.Based on the research context,valuable research directions are suggested to construct efficient separators.This work provides guidelines to regulate the surface binding and energy of separators for high-performance LSBs.
基金supported by the National Natural Science Foundation of China(No.22375063)Science and Technology Commission of Shanghai Municipality(No.23JC1401700)the Fundamental Research Funds for the Central Universities.
文摘Developing advanced polymeric materials with enhanced mechanical properties and functionalities has been a long-standing goal in materials science.Recently,supramolecular polymeric materials (SPMs) have drawn increased attention due to their unique properties and potential applications in self-healing,shape memory,sensors,and flexible electronics.Here,we develop an ionic cluster-optimized microphase separation strategy to enhance the toughening and energy dissipation capabilities of polydisulfide-based supramolecular polymers.The mechanical properties,including Young’s modulus and toughness,are significantly improved by integrating the quadruple H-bonding 2-ureido-4-pyrimidone (UPy) induced microphase separation with iron(Ⅲ)-to-carboxylate ionic clusters.By combining established chemical approaches with adjustable polymer phase ratios,it is revealed that the synergistic effect of these factors expands the interchain spacing,facilitates the formation of microphase domains,and enhances the tolerance of polythioctic acid-based polymers to external mechanical and thermal stimuli,meeting the practical requirements for industrial plastic applications.Moreover,the UPy-functionalized polymers incorporating iron carboxylate clusters exhibit good one-way shape memory behavior with practical applicability at a relatively low recovery temperature.Our work demonstrates a novel strategy for constructing industrially viable shape memory dynamic SPMs and paves the way for future innovations in developing SPMs.
基金financially supported by the National Natural Science Foundation of China(No.52203024)the Natural Science Foundation of Shandong Province(No.ZR2022QE135)+3 种基金the Youth Innovation Team Project of Shandong Provincial University(No.2023KJ330)the Major Scientific Research Project for the Construction of State Key Lab(No.2025ZDGZ02)the Doctoral Research Foundation of SWUST(No.22zx7129)the Natural Science Foundation of Sichuan Province of China(No.2024NSFSC2006).
文摘In this study,a polymer acceptor named BT-Cl with a“bridging”structure,which contained a benzodithiophene unit analogous to that of donor D18,and cyano(CN)groups and heterocyclic structures similar to those in acceptor N3,was synthesized.The“bridging”structure ensured good compatibility of BT-Cl with both D18 and N3,and effectively helped to reduce the large phase separation size of D18/N3 binary blend film when added as a third component.Meanwhile,the addition of BT-Cl to the D18/N3 blend can improve the crystallinity and enhance the light absorption efficiency to some extent.The“bridging”structure also resulted higher lowest unoccupied molecular orbital(LUMO)energy level of BT-Cl than that of N3,which effectively improve the open-circuit voltage(VOC)of the ternary device and consequently the power conversion efficiency(PCE).This work showed that the polymer with“bridging”structure as the third component was an effective strategy to decrease the large phase separation size.
基金financially supported by the Sinopec Seed Program Project(No.223281)State Key Laboratory of Advanced Papermaking and Paper-based Materials(No.2024ZD06)+3 种基金Guangdong Basic and Applied Basic Research Foundation(Nos.2022A1515110543 and 2023A1515110170)the Natural Science Foundation of Guangdong Province(No.2024B1515040023)Guangjuyingcai program of Guangzhou(No.2024D03J0002)111 Project(No.B18023).
文摘Microporous polyimides(PIM-PIs)have emerged as promising high-performance membranes for gas separation.However,achieving an optimal balance between permeability and selectivity remains a major challenge.In this study,we designed and synthesized a series of PIM-PIs by combining rigid dianhydrides 9-bis(trifluoromethyl)-2,3,6,7-xanthenetetracarboxylic dianhydride(6FCDA)and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)with contorted diamines,including 9,9-bis(4-aminophenyl)fluorene(FDA),9,9′-spirobifluorene-2,2′-diamine(SBFDA),and 3,3,3′,3′-tetramethyl-1,1′-spirobiindane-5,5′-diamine-6,6′-diol(TSDA),to systematically elucidate the relationship between hierarchical microstructure and gas transport behavior.Comprehensive characterization revealed that the 6FCDA-based polymers exhibited a higher microporosity(V_(micro)/V_(total)up to 54.7%)and fractional free volume compared to their 6FDA counterparts.Gas permeation measurements showed that the 6FCDA/SBFDA membrane delivered a CO_(2)permeability of 386 Barrer and CO_(2)/CH_(4)selectivity of 30.2,exceeding the 2008 Robeson upper bound.Structure-property correlation analyses indicated that diffusion selectivity predominantly governed gas separation performance,with rigid,spirocyclic architectures suppressing chain packing to generate sub-5Åmicropores,as further validated by molecular simulations.The optimized 6FCDA/FDA membrane achieved a BET surface area of 423 m^(2)·g^(−1),while maintaining excellent mechanical strength and high thermal stability.This work establishes an effective monomer design strategy to overcome the permeability-selectivity trade-off through backbone rigidification,thereby advancing PIM-PIs for practical applications in natural gas purification and carbon capture.
