Quaternary ammonium densely functionalized octa-benzylmethyl-containing poly(arylene ether ketone)s(QA-OMPAEKs) with ion exchange capacities(IECs) ranging from 1.23 to 2.21 mmol g^(-1) were synthesized from:(1) Ullman...Quaternary ammonium densely functionalized octa-benzylmethyl-containing poly(arylene ether ketone)s(QA-OMPAEKs) with ion exchange capacities(IECs) ranging from 1.23 to 2.21 mmol g^(-1) were synthesized from:(1) Ullmann coupling extension of tetra-benzylmethyl-containing bisphenol A;(2) condensation polymerization with activated dihalide in the presence of K_2CO_3;(3) selective bromination using N-bromosuccinimide; and(4) quantitative quaternization using trimethylamine. Both smallangle X-ray scattering(SAXS) and transmission electron microscope(TEM) characterizations revealed distinct nano-phase separation in QA-OMPAEKs as a result of the dense quaternization. The QA-OMPAEK-20 with an IEC of 1.98 mmol g^(-1) exhibited a high SO_4^(2-) conductivity of 11.4 mS cm^(-1) and a low VO^(2+) permeability of 0.06×10^(-12) m^2 s^(-1) at room temperature,leading to a dramatically higher ion selectivity than Nafion N212. Consequently, the vanadium redox flow battery(VRFB)assembled with QA-OMPAEK-20 achieved a Coulombic efficiency of 96.9% and an energy efficiency of 84.8% at a current density of 50 mA cm^(-2), which were much higher than those of the batteries assembled with Nafion N212 and a home-made control membrane without distinct nano-phase separation. Therefore, ion segregation is demonstrated to be a strategical route for the design of high performance anion exchange membranes(AEMs) for VRFBs.展开更多
Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes...Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes(ICMs)that provide high ion selectivity,proton conductivity,and stability under rigorous condition.Herein,a‘side-chain-type’strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s(PAEKs)membrane with low area resistance(0.058Ωcm^(2)),in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable backbone.The assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium(Q-PPhEK)demonstrated an energy efficiency above 80%over 700 cycles at 160 mA/cm^(2).Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment,meanwhile,more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.展开更多
The microstructure of polymer electrolyte membranes plays a key role in ion conductivity and water transport.Herein,fluorinated poly(aryl ether)s with tetra-alkylsulfonate side chains(SFPAEs)have been successfully syn...The microstructure of polymer electrolyte membranes plays a key role in ion conductivity and water transport.Herein,fluorinated poly(aryl ether)s with tetra-alkylsulfonate side chains(SFPAEs)have been successfully synthesized from the copolymerization of a newly developed tetra-allyl-containing bisphenol(TABP)monomer,followed by the thiol-ene addition with sodium 3-mercapto-1-propanesulfonate to attach the ionic groups at the end of the flexible chains.Being the first of its kind,the densely distributed and lengthy alkylsulfonate group possesses the benefit of ease to self-assemble into hydrophilic domains during membrane preparation via solution casting.Indeed,the TEM characterizations revealed that distinct hydrophilic channels of 1-2 nm width had been formed,much larger than those of a home-made control sample where only di-alkylsulfonate side chains were attached.The SFPAE-4-45 with an IECw of 2.0 mmol g^-1 exhibited an enhanced proton conductivity of 143.7 m S cm^-1 at room temperature,which was superior to that of Nafion 212(91.0 m S cm^-1).Furthermore,the oxidative stabilities of SFPAEs were significantly higher than those of non-fluorinated analogs in literature.This study offered a new route to engineering the pendent structure of ionomers for well-defined microscopic morphologies.展开更多
Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]...Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared.展开更多
Dielectric energy storage materials that are extensively employed in capacitors and other electronic devices have attracted increasing attentions amid the rapid progress of electronic technology.However,the commercial...Dielectric energy storage materials that are extensively employed in capacitors and other electronic devices have attracted increasing attentions amid the rapid progress of electronic technology.However,the commercialized polymeric and ceramic dielectric materials characterized by low energy storage density face numerous limitations in practical applications.In this study,we report the simultaneous enhancement of dielectric properties of poly(arylene ether nitrile)(PEN)through the incorporating of sulfonated PEN(SPEN)modified barium titanate nanorods(BTNR)(SPEN@BTNR)and hot-stretching.BTNR is synthesized using a two-step hydrothermal method,aminated with KH550,and then reacted with SPEN to form the cladding-modified SPEN@BTNR.Due to the intrinsic high permittivity of barium titanate(BT)and enhanced compatibility between SPEN@BTNR and PEN stemming from the cladding of SPEN,the dielectric constant and breakdown strength of SPEN@BTNR/PEN composite are as high as 14.0 at 103 Hz and 198.1 kV/mm at the doping amount of 15 wt.%,respectively.As a result,the energy storage density of SPEN@BTNR/PEN is increased to 2.43 J/cm^(3),compared with that of 0.82 J/cm^(3)for PEN.In addition,derived from the rearrangement of SPEN@BTNR and orientation of PEN after hot-stretching,the dielectric constant and breakdown strength of SPEN@BTNR/PEN with 15 wt.%fillers are further enhanced to 17.1 and 204.8 kV/mm,respectively,resulting in an energy storage density of 3.36 J/cm^(3).The boosting of energy storage density up to 310%provides a new idea for improving the performances of dielectric energy storage materials.展开更多
Polyoxometalates(POMs)are classified as solid superacids which can exhibit notable proton conductivity,making them a promising functional inorganic filler for enhancing the proton conductivity of proton exchange membr...Polyoxometalates(POMs)are classified as solid superacids which can exhibit notable proton conductivity,making them a promising functional inorganic filler for enhancing the proton conductivity of proton exchange membranes(PEMs).In this study,a series of hybrid membranes were obtained by molecular-level hybridization of Weakley-type POM Na_(7)H_(2)LaW_(10)O_(36)(LaW_(10))clusters into sulfonated poly(aryl ether ketone sulfone)(SPAEKS).All hybrid membranes exhibited greater proton conductivity than the pristine membrane in the 30–80℃temperature range.When the doping amount of LaW 10 reached 7 wt.%,the proton conductivity of M-LaW 10^(-7)achieved 64 mS·cm^(−1)at 80℃.Lanthanide ions'high coordination number property and variable coordination environment can aid to attract more water molecules from the environment.LaW 10 and these bound water can construct denser hydrogen bonds with–SO_(3)H of SPAEKS.These intensive hydrogen bonds will facilitate the constitution of more continuous proton transport channels,and improve the proton conductivity of the hybrid membrane.This work off ers a fresh approach to using POMs containing rare-earth components in PEMs.展开更多
The thermal degradation of poly（arylene sulfide sulfone）/N-methylpyrrolidone （PASS/NMP） crystal solvate was studied by thermogravimetric analysis （TGA） and was compared with pure PASS in order to determine the w...The thermal degradation of poly（arylene sulfide sulfone）/N-methylpyrrolidone （PASS/NMP） crystal solvate was studied by thermogravimetric analysis （TGA） and was compared with pure PASS in order to determine the way in which the formation of the crystal solvate affected the thermal properties of the polymer. The activation energy of the solid state process was determined using Kissinger＇s method, which does not require knowledge of the reaction mechanism （RM）, to be 174.18 kJ/mol which was lower than that for pure PASS （E = 214 kJ/mol）. The study of master curves together with interpretation of integral methods, allows confirmation that the thermal degradation mechanism for PASS in the crystal solvate system is a decelerated Rn type, which is a solid-state process based on a phase boundary controlled reaction, in the conversion range considered. Whereas, the pure PASS follows a decelerated Dn thermodegradation mechanism in the same conversion range.展开更多
A novel sulfonated poly（arylene ether） containing triphenylmethane moieties was synthesized by the sulfonation of a designed parent polymer using chlorosulfonic acid as sulfonation agent. The sulfonation took place ...A novel sulfonated poly（arylene ether） containing triphenylmethane moieties was synthesized by the sulfonation of a designed parent polymer using chlorosulfonic acid as sulfonation agent. The sulfonation took place at the para position of the pendant phenyl rings because of the specially designed parent polymer. The position and degree of sulfonation were characterized by ^1H-NMR and elemental analysis. The sulfonated polymers are highly soluble in common organic solvents, such as dimethylsulfoxide, N,N＇-dimethylacetamide, dimethylformamide, ethylene glycol monomethyl ether, and can be readily cast into tough and smooth films from solutions. The films showed good thermal and hydrolysis stabilities. Moreover, Fenton＇s reagent test revealed that the films exhibited superior stability to oxidation. The proton conductivities of the films were comparable with Nation 117 under same conditions. The membrane electrode assembly （MEA） prepared with the asmade film （706 EW, 100 μm dry thickness） shows better cell performance than Nation 115-MEA in the whole current density range.展开更多
Critical issues of Zn anodes including undesirable dendrites formation and parasitic reactions severely limit the reversibility and cyclability of Zn anodes.To address these issues,a functional Janus separator with th...Critical issues of Zn anodes including undesirable dendrites formation and parasitic reactions severely limit the reversibility and cyclability of Zn anodes.To address these issues,a functional Janus separator with the structure of a mechanically strong sulfonated poly(arylene ether sulfone)(SPAES)dense layer composited on a porous glass fiber(GF)substrate is designed.The SPAES dense layer that faces the Zn anode containing abundant sulfonic acid groups effectively promotes the desolvation process of hydrated Zn ions,guides uniform Zn ion transfer,and blocks anions and water,contributing to dendrite-free and highly reversible Zn plating/stripping cycles,while the porous GF substrate retains high electrolyte uptake.As a result,the Zn symmetric cell with the Janus separator demonstrates an ultralong cycling lifespan of over 2000 h at the areal capacity of 1 m A h cm^(-2),which is 23-fold superior to that with a pristine glass fiber separator(<90 h).More impressively,the as-prepared Janus separator enables outstanding rate performance and excellent cycling stability of full Zn ion batteries with diverse cathode materials.For instance,when paired with the V_2O_(5)cathode,the full battery with a Janus separator attains an ultrahigh initial specific capacity of 416.3 m A h g^(-1)and capacity retention of 60%over 450 cycles at 1 A g^(-1),exceeding that with a glass fiber separator.Hence,this work provides a facile yet effective approach to mitigating the dendrites formation and ameliorating the parasitic reactions of Zn metal anodes for high-performance Zn ion batteries.展开更多
Owing to the excellent filtration performance and low energy cost,polymeric nanofibers microfiltration(MF)membranes have attracted increasing attentions.Poly(arylene sulfide sulfone)(PASS),as one of the structurally m...Owing to the excellent filtration performance and low energy cost,polymeric nanofibers microfiltration(MF)membranes have attracted increasing attentions.Poly(arylene sulfide sulfone)(PASS),as one of the structurally modified polymers based on poly-(phenylene sulfide)(PPS),has been selected as the raw material to fabricate nanofibers MF membranes via electrospun techniques.The effects of PASS solution and the electrospinning processing parameters on the structural morphology of nanofibers were investigated in detail.The average diameter of PASS nanofibers was(296±46)nm under the optimal condition:polymer concentration of 0.27 g·m L^–1 PASS/DMI,applied voltage of 20 kV,and speed of collector drum of 300 r·min^–1.And then the multi-layer PASS nanofibers MF membranes were fabricated from cold-pressing the optimized PASS nanofibers(as-prepared PASS nanofibers)membrane.The morphology,porosity,pore size,mechanical properties,and surface wettability of the multi-layer PASS nanofibers MF membranes could be tuned by the layers of as-prepared nanofibers membrane.The results demonstrated that the membrane with 6 layers(marked as PASS-6)exhibited the smallest porosity,smallest pore size,highest mechanical property,and best surface wettability.Meanwhile,the multi-layer PASS nanofibers MF membranes showed that the rejection ratio gradually increased,while the pure water flux decreased with increasing membranes thickness.The PASS-6 membrane exhibited large water flux of 747.76 L·m^–2·h^–1 and high separation efficiency of 99.9%to 0.2μm particles,making it a promising candidate for microfilter.展开更多
The direct polymerization of an unsymmetrical kink non-coplanar heterocyclic diamine (1) with various aromatic bis(trimellitimide)s (2a-e) using triphenyl phosphite and pyridine as condensing agents could generate a s...The direct polymerization of an unsymmetrical kink non-coplanar heterocyclic diamine (1) with various aromatic bis(trimellitimide)s (2a-e) using triphenyl phosphite and pyridine as condensing agents could generate a series of new aromatic poly(amide imide)s (3a-e) containing the kink non-coplanar phthalazinone heterocyclic units in the polymer main chains with inherent viscosities of 0.58-0.66 dL/g. The polymers are readily soluble in a variety of solvents such as N,N- dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidinone, pyridine and m-cresol and can be cast to form flexible and tough films. The glass transition temperatures of polymers (Tg) are in the range of 301-327°C, and the temperatures for 5% weight loss in nitrogen are in the range of 498-521 'C.展开更多
Compared with conventional π-conjugated polymers,poly（arylene ether）s（PAEs） may take advantages of excellent thermal properties,well-defined effective conjugated length and no catalyst contamination.Recently,thei...Compared with conventional π-conjugated polymers,poly（arylene ether）s（PAEs） may take advantages of excellent thermal properties,well-defined effective conjugated length and no catalyst contamination.Recently,their applications have been extended from engineering plastics to optoelectronic materials.In this review,various kinds of functional PAEs used as fluorescent polymers,host polymers and phosphorescent polymers in organic light-emitting diodes（OLEDs） are outlined,and their molecular design,synthesis and device performance are overviewed.展开更多
Functionalized poly（phthalazinone ether sulfone ketone） was synthesized by successive chloromethylation and azidation, followed by curing reaction with the propargyl end-groups of various molecular weight crosslinki...Functionalized poly（phthalazinone ether sulfone ketone） was synthesized by successive chloromethylation and azidation, followed by curing reaction with the propargyl end-groups of various molecular weight crosslinking agents in the presence of Cu（I） catalyst via the azide-alkyne click reaction. The influences of the chain length of crosslinking agents on the poly（phthalazinone ether sulfone ketone） system were studied. FTIR and DSC tests demonstrated certain crosslinking by azide-alkyne reaction with the formation of triazole ring. DSC results showed that curing temperature shifted to lower temperatures considerably in the presence of Cu（I） catalyst. TGA showed cured polymers were of much higher thermal stability, including higher thermal decomposition temperatures and higher char-yielding properties. After being cured, the polymers became insoluble in organic solvents and the gel fraction of the cured polymers exceeded 71%. Wide-angle X-ray diffraction results indicated there was a short distance order in the poly（ether sulfone） （PES） main chain except for the azido methyl poly（phthalazinone ether sulfone ketone） and 4,4＇-bis（2-propynyloxy） biphenyl （AMPPESK-BP） system.展开更多
The authors presented a novel synthetic route for the imidazolium functionalized poly（arylene ether ke- tone）s, derived from an engineering plastics polymer, a poly（arylene ether ketone） with 3,3＇,5,5＇- tetramet...The authors presented a novel synthetic route for the imidazolium functionalized poly（arylene ether ke- tone）s, derived from an engineering plastics polymer, a poly（arylene ether ketone） with 3,3＇,5,5＇- tetramethyl-4,4＇-dihydroxybiphenyl moiety（PAEK-TM）. The preparation of anion exchange membranes comprised converting benzylic methyl groups to bromomethyl groups by a radical reaction, followed by the functionalization of bromomethylated PAEK with alkyl imidazoles, i.e., methyl, butyl or vinyl imidazole. The structure of imidazolium functionalized PAEK was proved by 1H NMR spectra. A class of flexible and tough membranes was then achieved by subsequent film-forming and anion exchange processes. The water uptake and hydroxide conductivities of mem- branes are comparable or superior to those of quaternary ammonium（QA） anion exchange membranes. This work demonstrated a new route for non-QA anion exchange membrane design, avoiding the chloromethylation reagent and oreciselv controlling the degree and location of imidazolium grouos.展开更多
Poly(arylene ether diketone)s were prepared by the aromatic nucleophilic displacement reaction of 4,4'-difluorobenzil with different bisphenols in the presence of anhydrous potassium carbonate in diphenylsulfone a...Poly(arylene ether diketone)s were prepared by the aromatic nucleophilic displacement reaction of 4,4'-difluorobenzil with different bisphenols in the presence of anhydrous potassium carbonate in diphenylsulfone at elevated temperature. The polymers obtained had inherent viscosity of 0.51 similar to 0.63 dL/g, and exhibited glass transition temperature ranging from 136 similar to 217 degrees C mainly depending on the bisphenols used in the polymer synthesis. Thermogravimetry of these polymers showed excellent thermal stability, indicating that 10% weight losses of the polymers were observed in the range above 428 degrees C and 438 degrees C in air and nitrogen, respectively. The mechanical properties of these polymers were also described and the permeability of five polymers for H-2, O-2 and N-2 was determined at 30 degrees C.展开更多
This report details the properties of fluorine-containing anion exchange membranes（AEMs） synthesized by chloromethylation and quaternization of fluorinated poly（arylene ether）s（FPAEs） based on decafluorobiphenyl...This report details the properties of fluorine-containing anion exchange membranes（AEMs） synthesized by chloromethylation and quaternization of fluorinated poly（arylene ether）s（FPAEs） based on decafluorobiphenyl and bisphenol A. Meanwhile, we compared their properties with those of their non-fluorinated counterparts, Udel-based AEMs. The reactivity of the chloromethylation of fluorinated poly（arylene ether）s was lowered by the strong elec- tron-withdrawing group, per-fluorinated biphenyl residue. Therefore higher temperature, more chloromethylation reagent, and longer reaction time were needed in the chloromethylation of FPAEs. Because of the hydrophobicity of fluorine, the swelling of FPAEs was depressed. In the FPAE-based AEMs, the water uptake of FPAE-1 membrane（F-1） was just 30%. There is a strong correlation between water uptake and conductivity for both Udel- and FPAE-based AEMs. Among all the membranes, the water uptake and the conductivity of FPAE-3 membrane（F-3） could reach up to 100% and 13.47 mS/cm respectively at 30 ℃. The mechanical properties of FPAE-based AEMs at room tempera- ture were worse than those of Udel-based ones because of the weak intermolecular interaction caused by the low po- larizability of fluorine. However, their high temperature mechanical properties are better, which can be explained in terms of low swelling.展开更多
A series of multiblock sulfonated poly(arylene ether sulfone)s(SPAES)with various block lengths and predictable ion exchange capacity were synthesized from 4,4’-difluorodiphenyl sulfone,4,4’-dihydrodiphenyl sulfone ...A series of multiblock sulfonated poly(arylene ether sulfone)s(SPAES)with various block lengths and predictable ion exchange capacity were synthesized from 4,4’-difluorodiphenyl sulfone,4,4’-dihydrodiphenyl sulfone and 4,4’-biphenol by one-pot and two-pot polymerization.;H-NMR and FTIR spectra confirmed the structure that sulfonic acid groups were introduced precisely on the poly(arylene ether sulfone)s by post-sulfonation which resulted in controllable sulfonation degree.The proton exchange membranes(PEMs)-based SPAES displayed excellent dimensional,thermal,antioxidant stability,proton conductivity and mechanical properties(maximum tensile stress>35 MPa).Thermogravimetric analysis indicated the prepared SPAES began to degrade above 310℃.The effects of polymerization processes,those were,one-pot hydrophobic segment process,one-pot hydrophilic segment process and two-pot process,on the properties of polymers were investigated.The proton conductivity and microphase separation of SPAES PEMs increased in order of those prepared by one-pot hydrophobic segment process,two-pot process and one-pot hydrophilic segment process.The highest conductivities of SPAES synthesized by the above processes under 80℃ and 100%relative humidity were 213(MS4),297(MB3)and 360 mS·cm^(-1)(MQ2),respectively.展开更多
A new series of poly(arylene piperidinium)-based anion exchange membranes(AEMs)are proposed for vanadium redox flow batteries(VRFBs).The AEMs are fabricated via the Menshutkin reaction between poly(arylene piperidine)...A new series of poly(arylene piperidinium)-based anion exchange membranes(AEMs)are proposed for vanadium redox flow batteries(VRFBs).The AEMs are fabricated via the Menshutkin reaction between poly(arylene piperidine)without ether bonds in the backbone and various quaternizing agents,including iodomethane,1-bromopentane,and(5-bromopentyl)-trimethylammonium bromide.The properties of the AEMs are investigated in terms of sulfuric acid doping content,swelling,vanadium permeability,ion selectivity,area-specific resistance,mechanical properties,VRFB performance,and cyclic testing.Particularly,a method of measuring the H^(+) permeability of the AEM is developed.It demonstrates that the poly(p-terphenyl-N-methylpiperidine)-quaternary ammonium(PTP-QA)membrane with a QA cation-tethered alkyl chain exhibits high H^(+) permeability,resulting in low area resistance.Combined with its low vanadium permeance,the PTP-QA membrane achieves nearly 370 times higher ion selectivity than Nafion 115.The VRFB based on PTP-QA-based AEM displays high Coulombic efficiencies above 99% at current densities of 80-160 mA cm^(-2).The higher energy efficiency of 89.8% is achieved at 100 mA cm^(-2)(vs.73.6% for Nafion 115).Meanwhile,the PTPQA-based AEM shows good cycling stability and capacity retention,proving great potential as the ion exchange membrane for VRFB applications.展开更多
High-quality film capacitors are widely used in many fields such as new energy vehicles,electronic communications,etc.,due to their advantages in wide frequency response and low dielectric loss.The dielectric film is ...High-quality film capacitors are widely used in many fields such as new energy vehicles,electronic communications,etc.,due to their advantages in wide frequency response and low dielectric loss.The dielectric film is a crucial part of the film capacitor,and its properties have an important impact on the performance and use conditions of the film capacitor.In this work,a novel high-temperature-resistant dielectric film was prepared.Firstly,the Bi_(2)S_(3)/rGO-CN fillers were prepared by hydrothermal method combined with cyanation treatment,and then added to the poly(arylene ether nitrile)(PEN)matrix to prepare the dielectric film materials(PEN/Bi_(2)S_(3)/rGO-CN).After high temperature treatment,the fillers Bi_(2)S_(3)/rGO-CN reacted with the PEN matrix,and the composites materials transformed into a thermosetting hybrid film(PEN-Bi_(2)S_(3)/rGO)with gel content of 97.88%.The prepared hybrid dielectric films did not decompose significantly before 400℃,and showed a glass transition temperature(Tg)of up to 252.4℃,which could increase the effective use temperature of the materials.Compared with the composite films without heat treatment,they exhibit better mechanical properties,with further improvement in tensile strength and elastic modulus,and a decrease in elongation at break.The dielectric constant of the hybrid films can be up to 6.8 while the dielectric loss is only about 0.02 at 1 kHz.Moreover,the hybrid films showed excellent dielectric stability during temperature changes,and remain relatively stable before 250℃,which is suitable as a high-temperature-resistant high-dielectric material and is more advantageous for practical applications.展开更多
A series of comb-shaped poly(arylene ether sulfone)s containing pendant 2-methyl-3-alkylimidazolitun group(ImPAES-Cx,x=1,6,10)was prepared and characterized as novel anion exchange membranes.These Im-PAES-Cx membranes...A series of comb-shaped poly(arylene ether sulfone)s containing pendant 2-methyl-3-alkylimidazolitun group(ImPAES-Cx,x=1,6,10)was prepared and characterized as novel anion exchange membranes.These Im-PAES-Cx membranes were obtained by benzylic bromination and imidazolium functionalization.The characteristic nano-phase separation structure was formed in membranes with longer alkyl side chains,as confmned by small-angle X-ray scattering.The nano-phase separation structures endowed ImPAES-Cx membranes with improved ionic conductivity,dimensional stability(at least 60% decrease water uptake and swelling ratio at 60℃)and mechanical properties,together with excellent alkaline stability.Especially,ImPAES-C6 membranes possessed enhanced hydroxide conductivity and chemical stability simultaneously.These results suggest that it is a feasible strategy to introduce appropriate length of alkyl side chains into anion exchange membranes(AEMs)to improve the performance.展开更多
基金supported by the National Natural Science Foundation of China (51503038, 51873037)
文摘Quaternary ammonium densely functionalized octa-benzylmethyl-containing poly(arylene ether ketone)s(QA-OMPAEKs) with ion exchange capacities(IECs) ranging from 1.23 to 2.21 mmol g^(-1) were synthesized from:(1) Ullmann coupling extension of tetra-benzylmethyl-containing bisphenol A;(2) condensation polymerization with activated dihalide in the presence of K_2CO_3;(3) selective bromination using N-bromosuccinimide; and(4) quantitative quaternization using trimethylamine. Both smallangle X-ray scattering(SAXS) and transmission electron microscope(TEM) characterizations revealed distinct nano-phase separation in QA-OMPAEKs as a result of the dense quaternization. The QA-OMPAEK-20 with an IEC of 1.98 mmol g^(-1) exhibited a high SO_4^(2-) conductivity of 11.4 mS cm^(-1) and a low VO^(2+) permeability of 0.06×10^(-12) m^2 s^(-1) at room temperature,leading to a dramatically higher ion selectivity than Nafion N212. Consequently, the vanadium redox flow battery(VRFB)assembled with QA-OMPAEK-20 achieved a Coulombic efficiency of 96.9% and an energy efficiency of 84.8% at a current density of 50 mA cm^(-2), which were much higher than those of the batteries assembled with Nafion N212 and a home-made control membrane without distinct nano-phase separation. Therefore, ion segregation is demonstrated to be a strategical route for the design of high performance anion exchange membranes(AEMs) for VRFBs.
基金the financial support of the National Natural Science Foundation of China(Nos.22075276,U19A2016,U22B6012)CAS Strategic Leading Science&Technology Program(A)(No.XDA21070000)+2 种基金Dalian High Level Talent Innovation Support Program(No.2020RD05)the Development of Scientic and Technological Project of the Jilin Province(No.20210101126JC)International Partnership Program of Chinese Academy of Sciences(No.121421KYSB20210028)。
文摘Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes(ICMs)that provide high ion selectivity,proton conductivity,and stability under rigorous condition.Herein,a‘side-chain-type’strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s(PAEKs)membrane with low area resistance(0.058Ωcm^(2)),in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable backbone.The assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium(Q-PPhEK)demonstrated an energy efficiency above 80%over 700 cycles at 160 mA/cm^(2).Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment,meanwhile,more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51503038 and 51873037)
文摘The microstructure of polymer electrolyte membranes plays a key role in ion conductivity and water transport.Herein,fluorinated poly(aryl ether)s with tetra-alkylsulfonate side chains(SFPAEs)have been successfully synthesized from the copolymerization of a newly developed tetra-allyl-containing bisphenol(TABP)monomer,followed by the thiol-ene addition with sodium 3-mercapto-1-propanesulfonate to attach the ionic groups at the end of the flexible chains.Being the first of its kind,the densely distributed and lengthy alkylsulfonate group possesses the benefit of ease to self-assemble into hydrophilic domains during membrane preparation via solution casting.Indeed,the TEM characterizations revealed that distinct hydrophilic channels of 1-2 nm width had been formed,much larger than those of a home-made control sample where only di-alkylsulfonate side chains were attached.The SFPAE-4-45 with an IECw of 2.0 mmol g^-1 exhibited an enhanced proton conductivity of 143.7 m S cm^-1 at room temperature,which was superior to that of Nafion 212(91.0 m S cm^-1).Furthermore,the oxidative stabilities of SFPAEs were significantly higher than those of non-fluorinated analogs in literature.This study offered a new route to engineering the pendent structure of ionomers for well-defined microscopic morphologies.
基金support of this work by National Natural Science Foundation of China(22075031,51673030,51603017 and 51803011)Jilin Provincial Science&Technology Department(20220201105GX)Chang Bai Mountain Scholars Program of Jilin Province.
文摘Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared.
基金the National Natural Science Foundation of China(No.21978237)Natural Science Foundation of Shaanxi Province(Nos.2023-JC-YB-370 and 2024-JC-YBQN-0140)Shaanxi Fundamental Science Research Project for Chemistry and Biology(No.22JHQ032)are gratefully acknowledged.
文摘Dielectric energy storage materials that are extensively employed in capacitors and other electronic devices have attracted increasing attentions amid the rapid progress of electronic technology.However,the commercialized polymeric and ceramic dielectric materials characterized by low energy storage density face numerous limitations in practical applications.In this study,we report the simultaneous enhancement of dielectric properties of poly(arylene ether nitrile)(PEN)through the incorporating of sulfonated PEN(SPEN)modified barium titanate nanorods(BTNR)(SPEN@BTNR)and hot-stretching.BTNR is synthesized using a two-step hydrothermal method,aminated with KH550,and then reacted with SPEN to form the cladding-modified SPEN@BTNR.Due to the intrinsic high permittivity of barium titanate(BT)and enhanced compatibility between SPEN@BTNR and PEN stemming from the cladding of SPEN,the dielectric constant and breakdown strength of SPEN@BTNR/PEN composite are as high as 14.0 at 103 Hz and 198.1 kV/mm at the doping amount of 15 wt.%,respectively.As a result,the energy storage density of SPEN@BTNR/PEN is increased to 2.43 J/cm^(3),compared with that of 0.82 J/cm^(3)for PEN.In addition,derived from the rearrangement of SPEN@BTNR and orientation of PEN after hot-stretching,the dielectric constant and breakdown strength of SPEN@BTNR/PEN with 15 wt.%fillers are further enhanced to 17.1 and 204.8 kV/mm,respectively,resulting in an energy storage density of 3.36 J/cm^(3).The boosting of energy storage density up to 310%provides a new idea for improving the performances of dielectric energy storage materials.
基金financially supported by the National Natural Science Foundation of China(No.22271022)the Natural Science Foundation of Jilin Province(No.YDZJ202201ZYTS342)supported by the China Scholarship Council(CSC No.201802335014).
文摘Polyoxometalates(POMs)are classified as solid superacids which can exhibit notable proton conductivity,making them a promising functional inorganic filler for enhancing the proton conductivity of proton exchange membranes(PEMs).In this study,a series of hybrid membranes were obtained by molecular-level hybridization of Weakley-type POM Na_(7)H_(2)LaW_(10)O_(36)(LaW_(10))clusters into sulfonated poly(aryl ether ketone sulfone)(SPAEKS).All hybrid membranes exhibited greater proton conductivity than the pristine membrane in the 30–80℃temperature range.When the doping amount of LaW 10 reached 7 wt.%,the proton conductivity of M-LaW 10^(-7)achieved 64 mS·cm^(−1)at 80℃.Lanthanide ions'high coordination number property and variable coordination environment can aid to attract more water molecules from the environment.LaW 10 and these bound water can construct denser hydrogen bonds with–SO_(3)H of SPAEKS.These intensive hydrogen bonds will facilitate the constitution of more continuous proton transport channels,and improve the proton conductivity of the hybrid membrane.This work off ers a fresh approach to using POMs containing rare-earth components in PEMs.
基金supported by the 863 program of China(No.2007AA 03Z561)
文摘The thermal degradation of poly（arylene sulfide sulfone）/N-methylpyrrolidone （PASS/NMP） crystal solvate was studied by thermogravimetric analysis （TGA） and was compared with pure PASS in order to determine the way in which the formation of the crystal solvate affected the thermal properties of the polymer. The activation energy of the solid state process was determined using Kissinger＇s method, which does not require knowledge of the reaction mechanism （RM）, to be 174.18 kJ/mol which was lower than that for pure PASS （E = 214 kJ/mol）. The study of master curves together with interpretation of integral methods, allows confirmation that the thermal degradation mechanism for PASS in the crystal solvate system is a decelerated Rn type, which is a solid-state process based on a phase boundary controlled reaction, in the conversion range considered. Whereas, the pure PASS follows a decelerated Dn thermodegradation mechanism in the same conversion range.
基金This work was financially supported by the National Science Foundation of China (NSFC) (Key project, No. 29734120)the China High-Tech Development 863 Program (No. 2003AA302410)+1 种基金Natural Science Foundation of Guangdong Province (Excellent Team Project, No. 015007)Canton Province Sci & Tech Bureau (Key Strategic Project, No. A1100402) and Guangzhou Sci & Tech Bureau
文摘A novel sulfonated poly（arylene ether） containing triphenylmethane moieties was synthesized by the sulfonation of a designed parent polymer using chlorosulfonic acid as sulfonation agent. The sulfonation took place at the para position of the pendant phenyl rings because of the specially designed parent polymer. The position and degree of sulfonation were characterized by ^1H-NMR and elemental analysis. The sulfonated polymers are highly soluble in common organic solvents, such as dimethylsulfoxide, N,N＇-dimethylacetamide, dimethylformamide, ethylene glycol monomethyl ether, and can be readily cast into tough and smooth films from solutions. The films showed good thermal and hydrolysis stabilities. Moreover, Fenton＇s reagent test revealed that the films exhibited superior stability to oxidation. The proton conductivities of the films were comparable with Nation 117 under same conditions. The membrane electrode assembly （MEA） prepared with the asmade film （706 EW, 100 μm dry thickness） shows better cell performance than Nation 115-MEA in the whole current density range.
基金fully supported by the Research Grant Council Collaborative Research Fund of the Hong Kong Special Administrative Region,China (C5031-20G)。
文摘Critical issues of Zn anodes including undesirable dendrites formation and parasitic reactions severely limit the reversibility and cyclability of Zn anodes.To address these issues,a functional Janus separator with the structure of a mechanically strong sulfonated poly(arylene ether sulfone)(SPAES)dense layer composited on a porous glass fiber(GF)substrate is designed.The SPAES dense layer that faces the Zn anode containing abundant sulfonic acid groups effectively promotes the desolvation process of hydrated Zn ions,guides uniform Zn ion transfer,and blocks anions and water,contributing to dendrite-free and highly reversible Zn plating/stripping cycles,while the porous GF substrate retains high electrolyte uptake.As a result,the Zn symmetric cell with the Janus separator demonstrates an ultralong cycling lifespan of over 2000 h at the areal capacity of 1 m A h cm^(-2),which is 23-fold superior to that with a pristine glass fiber separator(<90 h).More impressively,the as-prepared Janus separator enables outstanding rate performance and excellent cycling stability of full Zn ion batteries with diverse cathode materials.For instance,when paired with the V_2O_(5)cathode,the full battery with a Janus separator attains an ultrahigh initial specific capacity of 416.3 m A h g^(-1)and capacity retention of 60%over 450 cycles at 1 A g^(-1),exceeding that with a glass fiber separator.Hence,this work provides a facile yet effective approach to mitigating the dendrites formation and ameliorating the parasitic reactions of Zn metal anodes for high-performance Zn ion batteries.
文摘Owing to the excellent filtration performance and low energy cost,polymeric nanofibers microfiltration(MF)membranes have attracted increasing attentions.Poly(arylene sulfide sulfone)(PASS),as one of the structurally modified polymers based on poly-(phenylene sulfide)(PPS),has been selected as the raw material to fabricate nanofibers MF membranes via electrospun techniques.The effects of PASS solution and the electrospinning processing parameters on the structural morphology of nanofibers were investigated in detail.The average diameter of PASS nanofibers was(296±46)nm under the optimal condition:polymer concentration of 0.27 g·m L^–1 PASS/DMI,applied voltage of 20 kV,and speed of collector drum of 300 r·min^–1.And then the multi-layer PASS nanofibers MF membranes were fabricated from cold-pressing the optimized PASS nanofibers(as-prepared PASS nanofibers)membrane.The morphology,porosity,pore size,mechanical properties,and surface wettability of the multi-layer PASS nanofibers MF membranes could be tuned by the layers of as-prepared nanofibers membrane.The results demonstrated that the membrane with 6 layers(marked as PASS-6)exhibited the smallest porosity,smallest pore size,highest mechanical property,and best surface wettability.Meanwhile,the multi-layer PASS nanofibers MF membranes showed that the rejection ratio gradually increased,while the pure water flux decreased with increasing membranes thickness.The PASS-6 membrane exhibited large water flux of 747.76 L·m^–2·h^–1 and high separation efficiency of 99.9%to 0.2μm particles,making it a promising candidate for microfilter.
基金This work was supported by the Key Natural Science Foundation of Fujian Province (E0320003).
文摘The direct polymerization of an unsymmetrical kink non-coplanar heterocyclic diamine (1) with various aromatic bis(trimellitimide)s (2a-e) using triphenyl phosphite and pyridine as condensing agents could generate a series of new aromatic poly(amide imide)s (3a-e) containing the kink non-coplanar phthalazinone heterocyclic units in the polymer main chains with inherent viscosities of 0.58-0.66 dL/g. The polymers are readily soluble in a variety of solvents such as N,N- dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidinone, pyridine and m-cresol and can be cast to form flexible and tough films. The glass transition temperatures of polymers (Tg) are in the range of 301-327°C, and the temperatures for 5% weight loss in nitrogen are in the range of 498-521 'C.
基金the National Natural Science Foundation of China(Nos.51573182,51203149,21204084,91333205)the 973 Project(No.2015CB655000)for financial support of this research
文摘Compared with conventional π-conjugated polymers,poly（arylene ether）s（PAEs） may take advantages of excellent thermal properties,well-defined effective conjugated length and no catalyst contamination.Recently,their applications have been extended from engineering plastics to optoelectronic materials.In this review,various kinds of functional PAEs used as fluorescent polymers,host polymers and phosphorescent polymers in organic light-emitting diodes（OLEDs） are outlined,and their molecular design,synthesis and device performance are overviewed.
基金financially supported by the National Natural Science Foundation of China(No.51273029)
文摘Functionalized poly（phthalazinone ether sulfone ketone） was synthesized by successive chloromethylation and azidation, followed by curing reaction with the propargyl end-groups of various molecular weight crosslinking agents in the presence of Cu（I） catalyst via the azide-alkyne click reaction. The influences of the chain length of crosslinking agents on the poly（phthalazinone ether sulfone ketone） system were studied. FTIR and DSC tests demonstrated certain crosslinking by azide-alkyne reaction with the formation of triazole ring. DSC results showed that curing temperature shifted to lower temperatures considerably in the presence of Cu（I） catalyst. TGA showed cured polymers were of much higher thermal stability, including higher thermal decomposition temperatures and higher char-yielding properties. After being cured, the polymers became insoluble in organic solvents and the gel fraction of the cured polymers exceeded 71%. Wide-angle X-ray diffraction results indicated there was a short distance order in the poly（ether sulfone） （PES） main chain except for the azido methyl poly（phthalazinone ether sulfone ketone） and 4,4＇-bis（2-propynyloxy） biphenyl （AMPPESK-BP） system.
基金Sui~ported by the National Natural Science Foundation of China（No.21104022） and the Special Fund for Basic Scientific Research of Central Colleges, Jilin University, China（No.450060491017）.
文摘The authors presented a novel synthetic route for the imidazolium functionalized poly（arylene ether ke- tone）s, derived from an engineering plastics polymer, a poly（arylene ether ketone） with 3,3＇,5,5＇- tetramethyl-4,4＇-dihydroxybiphenyl moiety（PAEK-TM）. The preparation of anion exchange membranes comprised converting benzylic methyl groups to bromomethyl groups by a radical reaction, followed by the functionalization of bromomethylated PAEK with alkyl imidazoles, i.e., methyl, butyl or vinyl imidazole. The structure of imidazolium functionalized PAEK was proved by 1H NMR spectra. A class of flexible and tough membranes was then achieved by subsequent film-forming and anion exchange processes. The water uptake and hydroxide conductivities of mem- branes are comparable or superior to those of quaternary ammonium（QA） anion exchange membranes. This work demonstrated a new route for non-QA anion exchange membrane design, avoiding the chloromethylation reagent and oreciselv controlling the degree and location of imidazolium grouos.
文摘Poly(arylene ether diketone)s were prepared by the aromatic nucleophilic displacement reaction of 4,4'-difluorobenzil with different bisphenols in the presence of anhydrous potassium carbonate in diphenylsulfone at elevated temperature. The polymers obtained had inherent viscosity of 0.51 similar to 0.63 dL/g, and exhibited glass transition temperature ranging from 136 similar to 217 degrees C mainly depending on the bisphenols used in the polymer synthesis. Thermogravimetry of these polymers showed excellent thermal stability, indicating that 10% weight losses of the polymers were observed in the range above 428 degrees C and 438 degrees C in air and nitrogen, respectively. The mechanical properties of these polymers were also described and the permeability of five polymers for H-2, O-2 and N-2 was determined at 30 degrees C.
基金Supported by the National Natural Science Foundation of China（Nos.51173178, 514＂73157, 21304093）.
文摘This report details the properties of fluorine-containing anion exchange membranes（AEMs） synthesized by chloromethylation and quaternization of fluorinated poly（arylene ether）s（FPAEs） based on decafluorobiphenyl and bisphenol A. Meanwhile, we compared their properties with those of their non-fluorinated counterparts, Udel-based AEMs. The reactivity of the chloromethylation of fluorinated poly（arylene ether）s was lowered by the strong elec- tron-withdrawing group, per-fluorinated biphenyl residue. Therefore higher temperature, more chloromethylation reagent, and longer reaction time were needed in the chloromethylation of FPAEs. Because of the hydrophobicity of fluorine, the swelling of FPAEs was depressed. In the FPAE-based AEMs, the water uptake of FPAE-1 membrane（F-1） was just 30%. There is a strong correlation between water uptake and conductivity for both Udel- and FPAE-based AEMs. Among all the membranes, the water uptake and the conductivity of FPAE-3 membrane（F-3） could reach up to 100% and 13.47 mS/cm respectively at 30 ℃. The mechanical properties of FPAE-based AEMs at room tempera- ture were worse than those of Udel-based ones because of the weak intermolecular interaction caused by the low po- larizability of fluorine. However, their high temperature mechanical properties are better, which can be explained in terms of low swelling.
基金financially supported by the National Natural Science Foundation of China(No.21306010)。
文摘A series of multiblock sulfonated poly(arylene ether sulfone)s(SPAES)with various block lengths and predictable ion exchange capacity were synthesized from 4,4’-difluorodiphenyl sulfone,4,4’-dihydrodiphenyl sulfone and 4,4’-biphenol by one-pot and two-pot polymerization.;H-NMR and FTIR spectra confirmed the structure that sulfonic acid groups were introduced precisely on the poly(arylene ether sulfone)s by post-sulfonation which resulted in controllable sulfonation degree.The proton exchange membranes(PEMs)-based SPAES displayed excellent dimensional,thermal,antioxidant stability,proton conductivity and mechanical properties(maximum tensile stress>35 MPa).Thermogravimetric analysis indicated the prepared SPAES began to degrade above 310℃.The effects of polymerization processes,those were,one-pot hydrophobic segment process,one-pot hydrophilic segment process and two-pot process,on the properties of polymers were investigated.The proton conductivity and microphase separation of SPAES PEMs increased in order of those prepared by one-pot hydrophobic segment process,two-pot process and one-pot hydrophilic segment process.The highest conductivities of SPAES synthesized by the above processes under 80℃ and 100%relative humidity were 213(MS4),297(MB3)and 360 mS·cm^(-1)(MQ2),respectively.
基金supported by the National Natural Science Foundation of China(51603031)the Fundamental Research Funds for the Central Universities of China(N2005026)+1 种基金Liaoning Provincial Natural Science Foundation of China(20180550871 and 2020-MS-087)the Innovation Fund Denmark(DanFlow)。
文摘A new series of poly(arylene piperidinium)-based anion exchange membranes(AEMs)are proposed for vanadium redox flow batteries(VRFBs).The AEMs are fabricated via the Menshutkin reaction between poly(arylene piperidine)without ether bonds in the backbone and various quaternizing agents,including iodomethane,1-bromopentane,and(5-bromopentyl)-trimethylammonium bromide.The properties of the AEMs are investigated in terms of sulfuric acid doping content,swelling,vanadium permeability,ion selectivity,area-specific resistance,mechanical properties,VRFB performance,and cyclic testing.Particularly,a method of measuring the H^(+) permeability of the AEM is developed.It demonstrates that the poly(p-terphenyl-N-methylpiperidine)-quaternary ammonium(PTP-QA)membrane with a QA cation-tethered alkyl chain exhibits high H^(+) permeability,resulting in low area resistance.Combined with its low vanadium permeance,the PTP-QA membrane achieves nearly 370 times higher ion selectivity than Nafion 115.The VRFB based on PTP-QA-based AEM displays high Coulombic efficiencies above 99% at current densities of 80-160 mA cm^(-2).The higher energy efficiency of 89.8% is achieved at 100 mA cm^(-2)(vs.73.6% for Nafion 115).Meanwhile,the PTPQA-based AEM shows good cycling stability and capacity retention,proving great potential as the ion exchange membrane for VRFB applications.
基金financially supported by the National Natural Science Foundation of China(Nos.52073039,51903029,21805027,51803020 and 51773028)International Science and Technology Cooperation Project(No.52011530027)+3 种基金Major Special Projects of Sichuan Province(Nos.2020YFG0270,2020ZDZX0020,2019ZDZX0027 and 2019ZDZX0016)the Fundamental Research Funds for the Central Universities(No.ZYGX2019J026)Sichuan Science and Technology Program(Nos.2019YJ0197,2019YFG0056 and 2020YFG0100)International Science and Technology Cooperation Project from Chengdu municipal government(No.2019-GH02-00037-HZ)。
文摘High-quality film capacitors are widely used in many fields such as new energy vehicles,electronic communications,etc.,due to their advantages in wide frequency response and low dielectric loss.The dielectric film is a crucial part of the film capacitor,and its properties have an important impact on the performance and use conditions of the film capacitor.In this work,a novel high-temperature-resistant dielectric film was prepared.Firstly,the Bi_(2)S_(3)/rGO-CN fillers were prepared by hydrothermal method combined with cyanation treatment,and then added to the poly(arylene ether nitrile)(PEN)matrix to prepare the dielectric film materials(PEN/Bi_(2)S_(3)/rGO-CN).After high temperature treatment,the fillers Bi_(2)S_(3)/rGO-CN reacted with the PEN matrix,and the composites materials transformed into a thermosetting hybrid film(PEN-Bi_(2)S_(3)/rGO)with gel content of 97.88%.The prepared hybrid dielectric films did not decompose significantly before 400℃,and showed a glass transition temperature(Tg)of up to 252.4℃,which could increase the effective use temperature of the materials.Compared with the composite films without heat treatment,they exhibit better mechanical properties,with further improvement in tensile strength and elastic modulus,and a decrease in elongation at break.The dielectric constant of the hybrid films can be up to 6.8 while the dielectric loss is only about 0.02 at 1 kHz.Moreover,the hybrid films showed excellent dielectric stability during temperature changes,and remain relatively stable before 250℃,which is suitable as a high-temperature-resistant high-dielectric material and is more advantageous for practical applications.
基金the National Natural Science Foundation of China(No.21474036).
文摘A series of comb-shaped poly(arylene ether sulfone)s containing pendant 2-methyl-3-alkylimidazolitun group(ImPAES-Cx,x=1,6,10)was prepared and characterized as novel anion exchange membranes.These Im-PAES-Cx membranes were obtained by benzylic bromination and imidazolium functionalization.The characteristic nano-phase separation structure was formed in membranes with longer alkyl side chains,as confmned by small-angle X-ray scattering.The nano-phase separation structures endowed ImPAES-Cx membranes with improved ionic conductivity,dimensional stability(at least 60% decrease water uptake and swelling ratio at 60℃)and mechanical properties,together with excellent alkaline stability.Especially,ImPAES-C6 membranes possessed enhanced hydroxide conductivity and chemical stability simultaneously.These results suggest that it is a feasible strategy to introduce appropriate length of alkyl side chains into anion exchange membranes(AEMs)to improve the performance.
