The sulfonated poly(α-methyl styrene-b-isobutylene-b-α-methyl styrene)copolymers(S-ASIBS)with the average molar percentage of sulfonic acid(-SO_(3)H)groups(SP)ranging from 3.6 mol%to 14.3 mol%could be synthesized by...The sulfonated poly(α-methyl styrene-b-isobutylene-b-α-methyl styrene)copolymers(S-ASIBS)with the average molar percentage of sulfonic acid(-SO_(3)H)groups(SP)ranging from 3.6 mol%to 14.3 mol%could be synthesized by sulfonation of ASIBS with acetyl sulfate.The hydrophilic ionic channels were generated for proton exchange membranes(PEMs)by ion aggregation of-SO_(3)H groups and microphase separation between hydrophobic polyisobutylene and hydrophilic sulfonated poly(α-methyl styrene)segments in S-ASIBS.The proton transport ability was improved while oxidative stability was decreased by increasing SP in S-ASIBS.The appropriate SP of about 12.7 mol%in S-ASIBS provides the available PEMs with high proton transport ability,low methanol permeability and good oxidative stability.The absence of active tertiary hydrogen atoms along S-ASIBS copolymer chains avoids their attack by peroxy radicals.The residual rates of weight(RW)and proton conductivity(Rσ)of S-ASIBS-12.7 membrane after oxidation treatment for 916 h were 84.3%and 88.1%respectively,near to those of commercial Nafion 117(RW=87.9%,Rσ=90.3%).The membrane electrode assembly(MEA)could be prepared by using various S-ASIBS as PEMs for direct methanol fuel cell.The single cell with S-ASIBS-12.7 MEA behaves high performance of open circuit voltage(OCV)of 548 mV and peak power density(Pmax)of 36.1 mW·cm^(-2),which is similar to those of Nafion 117(OCV=506 mV,P_(max)=35.6 mW·cm^(-2)).To the best of our knowledge,this is the first example of advanced S-ASIBS membrane with high proton conductivity,excellent fuel barrier property and remarkable oxidative stability for promising PEMs.展开更多
Sulfonated poly（ether ketone）s containing 3,5-dimethyl phthalazinone moieties （SPPEK-DMs） with different degrees of sulfonation （DS） were synthesized via direct polycondensation from 4-（3,5-dimethyl-4-hydroxyph...Sulfonated poly（ether ketone）s containing 3,5-dimethyl phthalazinone moieties （SPPEK-DMs） with different degrees of sulfonation （DS） were synthesized via direct polycondensation from 4-（3,5-dimethyl-4-hydroxyphenyl）-2,3- phthalazinone, 4,4＇-difluorobenzophenone and 3,3＇-disulfonate-4,4＇-difluorobenzophenone. The chemical structure of SPPEK-DMs was characterized by FTIR and 1H-NMR. Thermal stability of SPPEK-DMs was characterized by the thermogravimetric analysis. The membranes prepared from SPPEK-DMs exhibited ion exchange capacities （IEC） ranging from 0.93 mmol.g-1 to 1.86 mmol.g-1. Water uptake, swelling, oxidative stability and methanol permeability of SPPEK- DMs membranes were investigated. SPPEK-DMs membranes exhibited high oxidative stability. The methanol permeability values of SPPEK-DMs membranes were in the range 5.15× 10^-8-6.61×10^-7 cm^2.s-1, which was much lower than those of Nafion117. The proton conductivity of SPPEK-DM40 membranes was 1.1 ×10^-2 S.cm^-1 at 70℃.展开更多
A sulfonated poly（ether ether ketone） （SPEEK） membrane with fairly high degree of sulfonation （DS） swells excessively and even dissolves at high temperature. To solve these problems, sulfonated phenolphthalein p...A sulfonated poly（ether ether ketone） （SPEEK） membrane with fairly high degree of sulfonation （DS） swells excessively and even dissolves at high temperature. To solve these problems, sulfonated phenolphthalein poly（ether sulfone） （SPES-C, DS= 53.7%） is blended with the SPEEK matrix （DS= 55.1%, 61.7%） to prepare SPEEKJSPES-C blend membrane. The decrease in swelling degree and methanol permeability of the membrane is dose-dependent. Pure SPEEK （DS = 61.7%） membrane dissolves completely in water at 70℃, whereas the swelling degree of the SPEEK （DS = 61.7%）/SPES-C （40%, by mass） membrane is 29.7% at 80℃. From room temperature to 80℃, the methanol permeability of all SPEEK （DS = 55.1%）/SPES-C blend membranes is about one order of magnitude lower than that of Nafion 115. At higher temperature, the addition of SPES-C polymer increases the dimensional stability and greater proton conductivity can be achieved. The SPEEK （DS = 55.1%）/SPES-C （40%, by mass） membrane can withstand temperatures up to 150℃. The proton conductivity of SPEEK （DS = 55.1%）/SPES-C （30%, by mass） membrane approaches 0.16 S·cm^-1, matching that of Nafion 115 at 140℃ and 100% RH, while pure SPEEK （DS = 55.1%） membrane dissolves at 90℃. The SPEEK/SPES-C blend membranes are promising for use in direct methanol fuel cells because of their good dimensional stability, high proton conductivity, and low methanol permeability.展开更多
A sulfonated poly（ether ether ketone） （SPEEK） membrane with a fairly high degree of sulfonation （DS） can swell excessively and even dissolve at high temperature. To solve these problems, insolvable functionalize...A sulfonated poly（ether ether ketone） （SPEEK） membrane with a fairly high degree of sulfonation （DS） can swell excessively and even dissolve at high temperature. To solve these problems, insolvable functionalized silica powder with sulfonic acid groups （SiOx-S） was added into the SPEEK matrix （DS = 55.1%） to prepare SPEEK/ SiOx-S composite membranes. The decrease in both the swelling degree and the methanol permeability of the membranes was a dose-dependent result of addition of the SiOx-S powder. Pure SPEEK membrane swelled 52.6% at 80℃, whereas the SPEEK/SiOx-S （15%, by mass） membrane swelled only 27.3% at the same temperature. From room temperature to 80℃, all SPEEK/SPEEK/SiOx-S composite membranes had methanol permeability of about one order of magnitude lower than that ofNafion115. Compared with pure SPEEK membranes, the addition of the SiOx-S powder not only leads to higher proton conductivity, but also increases the dimensional stability at higher temperatures, and greater proton conductivity can be achieved at higher temperature. The SPEEK/SiO4-S （20%, by mass） membrane could withstand temperature up to 145℃, at which in 100% relative humidity （RH） its proton conductivity exceeded slightly that of Nafion 1 15 membrane and reached 0.17 S·cm^-1, while pure SPEEK membrane dissolved at 90℃. The SPEEK/SiOx-S composite membranes are promising for use in direct methanol fuel cells because of their good dimensional stability, high proton conductivity, and low methanol permeability.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
2-Acryloxyacetophenone （AAP） was prepared and subjected to suspension polymerization with methyl methacrylate （MMA） using azobisisobutyronitrile （AIBN） as free radical initiator. The differently sulfonated AAP-M...2-Acryloxyacetophenone （AAP） was prepared and subjected to suspension polymerization with methyl methacrylate （MMA） using azobisisobutyronitrile （AIBN） as free radical initiator. The differently sulfonated AAP-MMA cross-linked copolymer cationic exchange resins were prepared by sulfonation with concentrated sulphuric acid at 70 ~C. Several characteristics of the prepared resins were evaluated, i.e. FTIR, the ion-exchange capacity （IEC）, thermo gravimetric analysis （TGA）, particle size distribution and microscopic morphology. The resin characteristics were altered with degree of sulfonation, providing that differently sulfonated resins could be prepared. The behavior of atenolol （ATL） loading and in vitro release in the USP stimulated gastric and intestinal fluids of the obtained resins were evaluated. The drug loaded in the resin increased with increasing degree of sulfonation and hence the drug binding site in resin employed. The drug release was lower from the resins with higher content of sulfonic group due to the increase in the diffusive path depth. The drug release was a little lower in stimulated gastric fluid （SGF） than in stimulated intestinal fluids （SIF）. The basic groups, ionized to a little greater extent in SGF and preferred binding with the resin rather than releasing. Hence, the differently sulfonated resins could be utilized as novel carriers for drug delivery.展开更多
The BST oilfield in the northwestern Taklamakan Desert is a fractured carbonate reservoir,but issues of water breakthrough are becoming increasingly severe with the development of water flooding.Unfortunately,the high...The BST oilfield in the northwestern Taklamakan Desert is a fractured carbonate reservoir,but issues of water breakthrough are becoming increasingly severe with the development of water flooding.Unfortunately,the high-temperature and high-salt conditions(130°C,71695 mg/L)of the BST oilfield pose challenges for the development of plugging agents.In this study,the effects of 2-acrylamido-2-methylpropane sulfonic acid(AMPS)content on AM/AMPS copolymers and gels were studied through viscosity measurements,nuclear magnetic resonance(NMR),and cryo-scanning electron microscope(Cryo-SEM).Moreover,the AMPS stabilization mechanism of the polymers and gels was explained.Heatresistant and salt-tolerant gel systems were developed,and their gelation properties,thermal stability,injection capacity,and plugging ability were evaluated.Experimental results showed inconsistencies between the effects of AMPS content on the polymers and gels.For the polymers,the thermal stability increased with increased AMPS content in the polymer.However,excessive AMPS content resulted in poor gelation and low strength.The developed gel systems with S30 polymer(AMPS content is approximately 26%)exhibited excellent thermal stability,controllable gelation time,good injection capacity,and plugging ability.The field application results indicated that most production wells had a positive response,with reduced water-cut and increased daily oil production.展开更多
Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks...Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks (semi-IPNs) are successfully prepared by interpenetrating SPEEK into the in-situ synthesized crosslinking networks. The polymeric networks are formed by the covalent bonds between bromobenzyl groups of bro mo methylated poly (phenylene oxide) and amine groups of diamine linkers as well as the ionic bonds between amine species and sulfonated groups. Two linkers without and with sulfonated groups are applied to fabricate the semi-IPNs. The core properties of the membranes, like phase separation, water uptake, proton conductivity and methanol permeability, are systematically studied and compared. The DMFCs assembled by using the semi-IPN membranes display better performance than Nafion 117 in high concentration methanol solutions. The present work provides a facile way to prepare PEMs with enhanced DMFC performance.展开更多
N,N＇-Bis（3-hydroxyphenyl）-1,8,4,5-naphthalenetetracarboxylic bisimide was prepared from the reaction of 1,8,4,5-naphthalenetetrcarboxylic acid dianhydride and 2-aminophenol in N, N-dimethylformamide. Polymerization...N,N＇-Bis（3-hydroxyphenyl）-1,8,4,5-naphthalenetetracarboxylic bisimide was prepared from the reaction of 1,8,4,5-naphthalenetetrcarboxylic acid dianhydride and 2-aminophenol in N, N-dimethylformamide. Polymerization of this bisimide with 4,4＇-difluorodiphenylsulfone and disodium 3,3＇-disulfonate4,4＇-difluorodiphenylsulfone gave ion-exchange sulfonated poly（ether sulfone）. The structure of the title compound was characterized with H-NMR and its polymer was characterized with FT-IR.展开更多
The rising prevalence of drug-resistant Gram-positive pathogens,particularly methicillin-resistant Staphy-lococcus aureus(MRSA)and vancomycin-resistant Enterococci(VRE),poses a substantial clinical challenge.Biofilm-a...The rising prevalence of drug-resistant Gram-positive pathogens,particularly methicillin-resistant Staphy-lococcus aureus(MRSA)and vancomycin-resistant Enterococci(VRE),poses a substantial clinical challenge.Biofilm-associated infections exacerbate this problem due to their inherent antibiotic resistance and complex structure.Current antibiotic treatments struggle to penetrate biofilms and eradicate persister cells,leading to prolonged antibiotic use and increased resistance.Host defense peptides(HDPs)have shown promise,but their clinical application is limited by factors such as enzymatic degradation and difficulty in largescale preparation.Synthetic HDP mimics,such as poly(2-oxazoline),have emerged as effective alter-natives.Herein,we found that the poly(2-oxazoline),Gly-POX_(20),demonstrated rapid and potent activity against clinically isolated multidrug-resistant Gram-positive strains.Gly-POX_(20) showed greater stability under physiological conditions compared to natural peptides,including resistance to protease degradation.Importantly,Gly-POX_(20) inhibited biofilm formation and eradicated mature biofilm and demonstrated superior in vivo therapeutic efficacy to vancomycin in a MRSA biofilm-associated mouse keratitis model,suggesting its potential as a novel antimicrobial agent against drug-resistant Gram-positive bacteria,especially biofilm-associated infections.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 mild and efficient photochemical multi-component tandem reaction of quinoxalin-2(1H)-ones, alkenes and sulfinic acids is reported. This tandem reaction could be conveniently carried out at room temperature by employ...A mild and efficient photochemical multi-component tandem reaction of quinoxalin-2(1H)-ones, alkenes and sulfinic acids is reported. This tandem reaction could be conveniently carried out at room temperature by employing 4Cz IPN as the metal-free photocatalyst and dioxygen(air) as the environmentally benign oxidant. A number of sulfonated quinoxalin-2(1H)-ones were obtained in satisfactory yields with favorable functional group tolerance. Radical trapping experiment and fluorescence quenching experiments were performed to elucidate this visible-light mediated radical reaction process.展开更多
目的:探究多聚胞嘧啶结合蛋白2[poly(C)-binding protein 2,PCBP2]如何通过调节铁死亡参与大别班达病毒(Dabie Banda virus,DBV)感染后的致病过程及其作用机制。方法:以人单核细胞系THP-1为模型,采用qRT-PCR和Western blot技术检测DBV...目的:探究多聚胞嘧啶结合蛋白2[poly(C)-binding protein 2,PCBP2]如何通过调节铁死亡参与大别班达病毒(Dabie Banda virus,DBV)感染后的致病过程及其作用机制。方法:以人单核细胞系THP-1为模型,采用qRT-PCR和Western blot技术检测DBV感染的THP-1细胞中PCBP2的mRNA及蛋白表达水平。通过透射电镜观察病毒感染下的线粒体结构变化,在THP-1细胞中构建了慢病毒介导的PCBP2过表达和敲低稳转细胞系。FerroOrange荧光探针检测Fe^(2+)水平,2,7-二氯荧光素二乙酸酯(2,7-dichlorofluorescein diacetate,DCFH-DA)探针测定活性氧(reactive oxygen species,ROS)水平,Western blot检测铁死亡相关溶质载体家族7成员11(solute carrier family 7 member 11,SLC7A11)和谷胱甘肽过氧化物酶4(glutathione peroxidase 4,GPX4)蛋白表达,以评估PCBP2调控对铁死亡的影响。使用铁死亡诱导剂(RSL3、erastin)和抑制剂(Fer-1、Lip-1)处理细胞,qRT-PCR和免疫荧光检测病毒复制水平变化,探索PCBP2是否可以通过调控铁死亡影响DBV复制。结果:在DBV感染的细胞模型中,PCBP2的mRNA和蛋白表达水平显著下调,DBV感染诱导典型铁死亡特征(线粒体嵴减少、肿胀)。通过qRT-PCR和Western blot验证,PCBP2敲低和过表达的THP-1细胞系构建成功,PCBP2敲低下调了铁死亡相关基因SLC7A11和GPX4的表达,导致ROS和Fe^(2+)水平升高;相反,PCBP2过表达使得SLC7A11和GPX4的表达水平升高,ROS和Fe^(2+)的水平降低。半数组织培养感染剂量与蛋白水平的检测进一步证实:铁死亡诱导剂可部分抵消PCBP2过表达促病毒复制的效应,铁死亡抑制剂可部分逆转PCBP2敲低抑制病毒复制的效应。结论:研究发现PCBP2可以通过维持SLC7A11/GPX4系统功能抑制铁死亡,从而限制DBV复制。这不仅阐明了PCBP2在DBV感染中的调控作用,为发热伴血小板减少综合征(severe fever with thrombocytope-nia syndrome,SFTS)的发病机制提供了新见解,同时靶向PCBP2-铁死亡通路可能成为SFTS治疗的潜在策略,为抗病毒药物的研发提供新思路。展开更多
New siloxane and sulfone containing poly（benzimidazole/sulfone/siloxane/amide） （PBSSA） has been prepared for the formation of hybrid membranes （PBSSA/PS-S/SiNPs） with sulfonated polystyrene （PS-S） and 0.1 wt%-...New siloxane and sulfone containing poly（benzimidazole/sulfone/siloxane/amide） （PBSSA） has been prepared for the formation of hybrid membranes （PBSSA/PS-S/SiNPs） with sulfonated polystyrene （PS-S） and 0.1 wt%-2 wt% silica nanoparticles （SiNPs）. Field emission scanning electron micrographs showed good dispersion of filler, formation of dense nanoporous honeycomb like structure and uniform ionic pathway in these hybrids. The porous membrane structure was responsible for the fine water retention capability and higher proton conductivity of the new hybrids. Increasing the amount of nanoparticles from 0.1 wt% to 2 wt% increased the tensile stress of acid doped PBSSA/PS-S/SiNPs nanocomposites from 65.7 MPa to 68.5 MPa. A relationship between nanofiller loading and thermal stability of the membranes was also experientially studied, as the glass transition temperature of phosphoric acid doped PBSSAJPS-S/SiNPs nanocomposites increased from 207℃ to 215 ℃. The membranes also had higher ion exchange capacity （IEC） around 2.01 mmol/g to 3.01 mmol/g. The novel membranes with high IEC value achieved high proton conductivity of 1.10-2.34 S/cm in a wide range of humidity values at 80 ~C which was higher than that of perfluorinated Nafion 117 membrane （1.1 × 10^-1 S/cm） at 80 ~C （94% RH）. A H2/O2 fuel cell using the PBSSA/PS-S/SiNP 2 （IEC 3.01 retool/g） showed better performance than that of Nation 117 at 40 ℃ and 30% RH.展开更多
A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through ...A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through a facile solution casting approach. The simple, but effective monomer sulfonation was performed for SFMC to create compact and rigid hydrophobic backbone structures, while conventional random sulfonation was carried-out for SPEEK. Hydrophilic-hydrophobic-hydrophilic structure of SFMC enhances the compatibility with SPEEK and GO and allows for an unprecedented approach to alter me- chanical strength and proton conductivity of ternary hybrid membrane, as verified from universal test machine （UTM） curves and alternating current （AC） impedance plots. The impact of GO integration on the morphology and roughness of hybrid membrane was scrutinized using field emission scanning electron microscope （FE-SEM） and atomic force microscope （AFM）. Ternary hybrid showed uniform intercalation of GO nanosheets throughout the entire surface of membrane with an increased surface roughness of 8.91 nm. The constructed ternary hybrid membrane revealed excellent water absorption, ion exchange capacity and gas barrier properties, while retaining reasonable dimensional stability. The well-optimized ternary hybrid membrane containing 5 wt% GO revealed a maximum proton conductivity of 111.9 mS/cm, which is higher by a factor of two-fold with respect to that of bare SFMC membrane. The maximum PEMFC power density of 528.07mW/cm2 was yielded by ternary hybrid membrane at a load current density of 1321.1 mA/cm2 when operating the cell at 70 ℃ under 100% relative humidity （RH）. In comparison, a maximum power density of only 182.06 mW/cm2 was exhibited by the bare SFMC membrane at a load current density of 455.56 mA/cm2 under same operating conditions.展开更多
Poly(ethylene 2,5-furandicarboxylate)(PEF),a bioplastic synthesized via the polymerization of 2,5-furandicarboxylic acid(FDCA)with ethylene glycol,can be served as a substitute to petroleum-based polyethylene terephth...Poly(ethylene 2,5-furandicarboxylate)(PEF),a bioplastic synthesized via the polymerization of 2,5-furandicarboxylic acid(FDCA)with ethylene glycol,can be served as a substitute to petroleum-based polyethylene terephthalate(PET)due to its enhanced material properties.However,the fabrication of PEF with stable and desirable properties is still a challenge,largely due to the impurities in FDCA.In this study,a highly efficient purification strategy for FDCA was proposed,utilizing a dioxane/H_(2)O binary solvent system for effective crystallization.Furthermore,PEFs were synthesized from FDCA with varying impurity and the effects of these impurities were systematically characterized.The results revealed that impurities in FDCA could result in PEFs with relatively poor thermal properties.This study provides crucial insights for the impact of impurities on PEF properties and FDCA purification.展开更多
Compatibilization is crucial for the blending of immiscible polymers to develop high-performance composites;however,traditional compatibilization by copolymers(pre-made or in-situ generation)suffers from weak interfac...Compatibilization is crucial for the blending of immiscible polymers to develop high-performance composites;however,traditional compatibilization by copolymers(pre-made or in-situ generation)suffers from weak interface anchoring,and inorganic particles have gained extensive attention recently owing to their large interfacial desorption energy,while their low affinity to bulk components is a drawback.In this study,an interfacial atom transfer radical polymerization(ATRP)technique was employed to grow polystyrene(PS)and poly(2-hydroxyethyl methacrylate)(PHEMA)simultaneously on different hemispheres of Br-functionalized SiO_(2) nanoparticles to stabilize a Pickering emulsion,whereby a brush-type Janus nanoparticle(SiO_(2)@JNP)was developed.The polymer brushes were well-characterized,and the Janus feature was validated by transmission electron microscope(TEM)observation of the sole hemisphere grafting of SiO_(2)-PS as a control sample.SiO_(2)@JNP was demonstrated to be an efficient compatibilizer for a PS/poly(methyl methacrylate)(PMMA)immiscible blend,and the droplet-matrix morphology was significantly refined.The mechanical strength and toughness of the blend were synchronously enhanced at a low content SiO_(2)@JNP optimized~0.9 wt%,with the tensile strength,elongation at break and impact strength increased by 17.7%,26.6%and 19.6%,respectively.This enhancement may be attributed to the entanglements between the grafted polymer brushes and individual components that improve the particle-bulk phase affinity and enforce interfacial adhesion.展开更多
The electron transfer reaction between triplet anthraquinone-2-sulfonate with poly-guanylic acid (5) (poly[G]) in acetonitrile-H2O has been investigated by 248 nm laser flash photolysis. The transient absorption spect...The electron transfer reaction between triplet anthraquinone-2-sulfonate with poly-guanylic acid (5) (poly[G]) in acetonitrile-H2O has been investigated by 248 nm laser flash photolysis. The transient absorption spectra of radical cation of poly[G] and radical anion of anthraqunione-2-sulfonate (AQS) arising from electron transfer reaction has been observed simultaneously for the first time. The formation processes of radical cation of poly[G] and radical anion of anthraquinone-2-sulfonate as well as the decay processes of triplet anthraquinone-2-sulfonate have also been observed, the apparent rate constants for the formation and decay of transient species have been determined. The free energy changes in the process of the electron transfer was also calculated.展开更多
The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while th...The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while the TGA results revealed that the terpolymer was of high thermal stability.展开更多
Photocatalytic technology has been proven to be a simple and effective method for degrading recalcitrant organic pollutants.In this study,a series of Z-scheme heterojunction nanocomposites composed of CeO_(2)and terep...Photocatalytic technology has been proven to be a simple and effective method for degrading recalcitrant organic pollutants.In this study,a series of Z-scheme heterojunction nanocomposites composed of CeO_(2)and terephthalic acid-modified WO_(3) was prepared and further used as photocatalysts for perfluorobutane sulfonate(PFBS)degradation.In this design,terephthalic acid was used as an electron recombination center and heterojunction mediator,which effectively enhances the migration ability of electron-hole pairs and the physicochemical stability of the catalyst.In addition,in situ synthesis of CeO_(2)onto the WO_(3) surface by the coordinate bond between terephthalic acid and Ce ions can avoid CeO_(2)agglomeration.As a result,the CeO_(2)@WO_(3) photocatalyst exhibits excellent PFBS degradation ability(94%for CeO_(2)@WO_(3) vs.19%for CeO_(2)).After the fifth cyclic degradation experiment,the CeO_(2)@WO_(3) photocatalyst still maintains stable degradation efficiency.Furthermore,the reaction mechanism of the PFBS in CeO_(2)@WO_(3) photocatalytic process was analyzed by free radical trapping experiment and liquid chromatography tandem mass spectrometry(LC-MS)technique.This study provides new insights for constructing Z-scheme heterojunction and demonstrates that CeO_(2)@WO_(3) photocatalysts possess a promising prospect for degrading PFBS pollutants.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 21774006)
文摘The sulfonated poly(α-methyl styrene-b-isobutylene-b-α-methyl styrene)copolymers(S-ASIBS)with the average molar percentage of sulfonic acid(-SO_(3)H)groups(SP)ranging from 3.6 mol%to 14.3 mol%could be synthesized by sulfonation of ASIBS with acetyl sulfate.The hydrophilic ionic channels were generated for proton exchange membranes(PEMs)by ion aggregation of-SO_(3)H groups and microphase separation between hydrophobic polyisobutylene and hydrophilic sulfonated poly(α-methyl styrene)segments in S-ASIBS.The proton transport ability was improved while oxidative stability was decreased by increasing SP in S-ASIBS.The appropriate SP of about 12.7 mol%in S-ASIBS provides the available PEMs with high proton transport ability,low methanol permeability and good oxidative stability.The absence of active tertiary hydrogen atoms along S-ASIBS copolymer chains avoids their attack by peroxy radicals.The residual rates of weight(RW)and proton conductivity(Rσ)of S-ASIBS-12.7 membrane after oxidation treatment for 916 h were 84.3%and 88.1%respectively,near to those of commercial Nafion 117(RW=87.9%,Rσ=90.3%).The membrane electrode assembly(MEA)could be prepared by using various S-ASIBS as PEMs for direct methanol fuel cell.The single cell with S-ASIBS-12.7 MEA behaves high performance of open circuit voltage(OCV)of 548 mV and peak power density(Pmax)of 36.1 mW·cm^(-2),which is similar to those of Nafion 117(OCV=506 mV,P_(max)=35.6 mW·cm^(-2)).To the best of our knowledge,this is the first example of advanced S-ASIBS membrane with high proton conductivity,excellent fuel barrier property and remarkable oxidative stability for promising PEMs.
基金supported by the Natural Science Foundation of Liaoning Province of China(No.20041076)
文摘Sulfonated poly（ether ketone）s containing 3,5-dimethyl phthalazinone moieties （SPPEK-DMs） with different degrees of sulfonation （DS） were synthesized via direct polycondensation from 4-（3,5-dimethyl-4-hydroxyphenyl）-2,3- phthalazinone, 4,4＇-difluorobenzophenone and 3,3＇-disulfonate-4,4＇-difluorobenzophenone. The chemical structure of SPPEK-DMs was characterized by FTIR and 1H-NMR. Thermal stability of SPPEK-DMs was characterized by the thermogravimetric analysis. The membranes prepared from SPPEK-DMs exhibited ion exchange capacities （IEC） ranging from 0.93 mmol.g-1 to 1.86 mmol.g-1. Water uptake, swelling, oxidative stability and methanol permeability of SPPEK- DMs membranes were investigated. SPPEK-DMs membranes exhibited high oxidative stability. The methanol permeability values of SPPEK-DMs membranes were in the range 5.15× 10^-8-6.61×10^-7 cm^2.s-1, which was much lower than those of Nafion117. The proton conductivity of SPPEK-DM40 membranes was 1.1 ×10^-2 S.cm^-1 at 70℃.
基金Supported by the State Key Development Program for Basic Research of China （2008CB617502）, the National Natural Science Foundation of China （20606025）, and Program for Changjiang Scholars and Innovative Research Team in University of China （IRT0641）.
文摘A sulfonated poly（ether ether ketone） （SPEEK） membrane with fairly high degree of sulfonation （DS） swells excessively and even dissolves at high temperature. To solve these problems, sulfonated phenolphthalein poly（ether sulfone） （SPES-C, DS= 53.7%） is blended with the SPEEK matrix （DS= 55.1%, 61.7%） to prepare SPEEKJSPES-C blend membrane. The decrease in swelling degree and methanol permeability of the membrane is dose-dependent. Pure SPEEK （DS = 61.7%） membrane dissolves completely in water at 70℃, whereas the swelling degree of the SPEEK （DS = 61.7%）/SPES-C （40%, by mass） membrane is 29.7% at 80℃. From room temperature to 80℃, the methanol permeability of all SPEEK （DS = 55.1%）/SPES-C blend membranes is about one order of magnitude lower than that of Nafion 115. At higher temperature, the addition of SPES-C polymer increases the dimensional stability and greater proton conductivity can be achieved. The SPEEK （DS = 55.1%）/SPES-C （40%, by mass） membrane can withstand temperatures up to 150℃. The proton conductivity of SPEEK （DS = 55.1%）/SPES-C （30%, by mass） membrane approaches 0.16 S·cm^-1, matching that of Nafion 115 at 140℃ and 100% RH, while pure SPEEK （DS = 55.1%） membrane dissolves at 90℃. The SPEEK/SPES-C blend membranes are promising for use in direct methanol fuel cells because of their good dimensional stability, high proton conductivity, and low methanol permeability.
基金Supported by the State Key Development Program for Basic Research of China （2008CB617502）, the National Natural Science Foundation of China （20606025）, and Program for Changjiang Scholars and Innovative Research Team in University of China （IRT0641）.
文摘A sulfonated poly（ether ether ketone） （SPEEK） membrane with a fairly high degree of sulfonation （DS） can swell excessively and even dissolve at high temperature. To solve these problems, insolvable functionalized silica powder with sulfonic acid groups （SiOx-S） was added into the SPEEK matrix （DS = 55.1%） to prepare SPEEK/ SiOx-S composite membranes. The decrease in both the swelling degree and the methanol permeability of the membranes was a dose-dependent result of addition of the SiOx-S powder. Pure SPEEK membrane swelled 52.6% at 80℃, whereas the SPEEK/SiOx-S （15%, by mass） membrane swelled only 27.3% at the same temperature. From room temperature to 80℃, all SPEEK/SPEEK/SiOx-S composite membranes had methanol permeability of about one order of magnitude lower than that ofNafion115. Compared with pure SPEEK membranes, the addition of the SiOx-S powder not only leads to higher proton conductivity, but also increases the dimensional stability at higher temperatures, and greater proton conductivity can be achieved at higher temperature. The SPEEK/SiO4-S （20%, by mass） membrane could withstand temperature up to 145℃, at which in 100% relative humidity （RH） its proton conductivity exceeded slightly that of Nafion 1 15 membrane and reached 0.17 S·cm^-1, while pure SPEEK membrane dissolved at 90℃. The SPEEK/SiOx-S composite membranes are promising for use in direct methanol fuel cells because of their good dimensional stability, high proton conductivity, and low methanol permeability.
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The University Grants Commission,New Delhi for its funding of this workIndian Institute of Science,Bangalore for its instrumental support+2 种基金Department of Physics,Sri Venkateswara University,Tirupathi,for its assistance in the SEM studyUGC,New Delhi for its support under SAPDST,New Delhi for its support under FIST
文摘2-Acryloxyacetophenone （AAP） was prepared and subjected to suspension polymerization with methyl methacrylate （MMA） using azobisisobutyronitrile （AIBN） as free radical initiator. The differently sulfonated AAP-MMA cross-linked copolymer cationic exchange resins were prepared by sulfonation with concentrated sulphuric acid at 70 ~C. Several characteristics of the prepared resins were evaluated, i.e. FTIR, the ion-exchange capacity （IEC）, thermo gravimetric analysis （TGA）, particle size distribution and microscopic morphology. The resin characteristics were altered with degree of sulfonation, providing that differently sulfonated resins could be prepared. The behavior of atenolol （ATL） loading and in vitro release in the USP stimulated gastric and intestinal fluids of the obtained resins were evaluated. The drug loaded in the resin increased with increasing degree of sulfonation and hence the drug binding site in resin employed. The drug release was lower from the resins with higher content of sulfonic group due to the increase in the diffusive path depth. The drug release was a little lower in stimulated gastric fluid （SGF） than in stimulated intestinal fluids （SIF）. The basic groups, ionized to a little greater extent in SGF and preferred binding with the resin rather than releasing. Hence, the differently sulfonated resins could be utilized as novel carriers for drug delivery.
基金Financial support from the Major Scientific and Technological Project of CNPC under grant number ZD2019-183-007Sinopec Northwest Company of China for the financial support(34400007-17-ZC06070095)
文摘The BST oilfield in the northwestern Taklamakan Desert is a fractured carbonate reservoir,but issues of water breakthrough are becoming increasingly severe with the development of water flooding.Unfortunately,the high-temperature and high-salt conditions(130°C,71695 mg/L)of the BST oilfield pose challenges for the development of plugging agents.In this study,the effects of 2-acrylamido-2-methylpropane sulfonic acid(AMPS)content on AM/AMPS copolymers and gels were studied through viscosity measurements,nuclear magnetic resonance(NMR),and cryo-scanning electron microscope(Cryo-SEM).Moreover,the AMPS stabilization mechanism of the polymers and gels was explained.Heatresistant and salt-tolerant gel systems were developed,and their gelation properties,thermal stability,injection capacity,and plugging ability were evaluated.Experimental results showed inconsistencies between the effects of AMPS content on the polymers and gels.For the polymers,the thermal stability increased with increased AMPS content in the polymer.However,excessive AMPS content resulted in poor gelation and low strength.The developed gel systems with S30 polymer(AMPS content is approximately 26%)exhibited excellent thermal stability,controllable gelation time,good injection capacity,and plugging ability.The field application results indicated that most production wells had a positive response,with reduced water-cut and increased daily oil production.
基金support of the National Natural Science Foundation of China(Nos. 21603197, 21703212,21233006 and 21473164)Natural Science Foundation of Hubei Province of China(No.2016CFB181)+1 种基金Fundamental Research Funds for the Central University, China University of Geosciences (Wuhan)(No. CUGL180403)China University of Geosciences (Wuhan) for the program of Center for Advanced Energy Research and Technologies
文摘Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks (semi-IPNs) are successfully prepared by interpenetrating SPEEK into the in-situ synthesized crosslinking networks. The polymeric networks are formed by the covalent bonds between bromobenzyl groups of bro mo methylated poly (phenylene oxide) and amine groups of diamine linkers as well as the ionic bonds between amine species and sulfonated groups. Two linkers without and with sulfonated groups are applied to fabricate the semi-IPNs. The core properties of the membranes, like phase separation, water uptake, proton conductivity and methanol permeability, are systematically studied and compared. The DMFCs assembled by using the semi-IPN membranes display better performance than Nafion 117 in high concentration methanol solutions. The present work provides a facile way to prepare PEMs with enhanced DMFC performance.
基金This project is supported by the National Natural Science Foundation of China(No.20104001).
文摘N,N＇-Bis（3-hydroxyphenyl）-1,8,4,5-naphthalenetetracarboxylic bisimide was prepared from the reaction of 1,8,4,5-naphthalenetetrcarboxylic acid dianhydride and 2-aminophenol in N, N-dimethylformamide. Polymerization of this bisimide with 4,4＇-difluorodiphenylsulfone and disodium 3,3＇-disulfonate4,4＇-difluorodiphenylsulfone gave ion-exchange sulfonated poly（ether sulfone）. The structure of the title compound was characterized with H-NMR and its polymer was characterized with FT-IR.
基金financially supported by the National Key Research and Development Program of China(no.2022YFC2303100)National Natural Science Foundation of China(nos.T2325010,22305082,52203162,and 22075078)+1 种基金Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism(Shanghai Municipal Education Commission),the Fundamental Research Funds for the Central Universities(nos.JKVD1241029 and JKD01241701)Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry(Changchun Institute of Applied Chemistry,Chinese Academy of Sciences),the Open Project of Engineering Research Center of Dairy Quality and Safety Control Technology(Ministry of Education,no.R202201).
文摘The rising prevalence of drug-resistant Gram-positive pathogens,particularly methicillin-resistant Staphy-lococcus aureus(MRSA)and vancomycin-resistant Enterococci(VRE),poses a substantial clinical challenge.Biofilm-associated infections exacerbate this problem due to their inherent antibiotic resistance and complex structure.Current antibiotic treatments struggle to penetrate biofilms and eradicate persister cells,leading to prolonged antibiotic use and increased resistance.Host defense peptides(HDPs)have shown promise,but their clinical application is limited by factors such as enzymatic degradation and difficulty in largescale preparation.Synthetic HDP mimics,such as poly(2-oxazoline),have emerged as effective alter-natives.Herein,we found that the poly(2-oxazoline),Gly-POX_(20),demonstrated rapid and potent activity against clinically isolated multidrug-resistant Gram-positive strains.Gly-POX_(20) showed greater stability under physiological conditions compared to natural peptides,including resistance to protease degradation.Importantly,Gly-POX_(20) inhibited biofilm formation and eradicated mature biofilm and demonstrated superior in vivo therapeutic efficacy to vancomycin in a MRSA biofilm-associated mouse keratitis model,suggesting its potential as a novel antimicrobial agent against drug-resistant Gram-positive bacteria,especially biofilm-associated infections.
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 Youth Innovation and Technology Project of high School in Shandong Province (No. 2019KJC021)Natural Science Foundation of Qinghai Province of China (No. 2020-ZJ-915)。
文摘A mild and efficient photochemical multi-component tandem reaction of quinoxalin-2(1H)-ones, alkenes and sulfinic acids is reported. This tandem reaction could be conveniently carried out at room temperature by employing 4Cz IPN as the metal-free photocatalyst and dioxygen(air) as the environmentally benign oxidant. A number of sulfonated quinoxalin-2(1H)-ones were obtained in satisfactory yields with favorable functional group tolerance. Radical trapping experiment and fluorescence quenching experiments were performed to elucidate this visible-light mediated radical reaction process.
文摘目的:探究多聚胞嘧啶结合蛋白2[poly(C)-binding protein 2,PCBP2]如何通过调节铁死亡参与大别班达病毒(Dabie Banda virus,DBV)感染后的致病过程及其作用机制。方法:以人单核细胞系THP-1为模型,采用qRT-PCR和Western blot技术检测DBV感染的THP-1细胞中PCBP2的mRNA及蛋白表达水平。通过透射电镜观察病毒感染下的线粒体结构变化,在THP-1细胞中构建了慢病毒介导的PCBP2过表达和敲低稳转细胞系。FerroOrange荧光探针检测Fe^(2+)水平,2,7-二氯荧光素二乙酸酯(2,7-dichlorofluorescein diacetate,DCFH-DA)探针测定活性氧(reactive oxygen species,ROS)水平,Western blot检测铁死亡相关溶质载体家族7成员11(solute carrier family 7 member 11,SLC7A11)和谷胱甘肽过氧化物酶4(glutathione peroxidase 4,GPX4)蛋白表达,以评估PCBP2调控对铁死亡的影响。使用铁死亡诱导剂(RSL3、erastin)和抑制剂(Fer-1、Lip-1)处理细胞,qRT-PCR和免疫荧光检测病毒复制水平变化,探索PCBP2是否可以通过调控铁死亡影响DBV复制。结果:在DBV感染的细胞模型中,PCBP2的mRNA和蛋白表达水平显著下调,DBV感染诱导典型铁死亡特征(线粒体嵴减少、肿胀)。通过qRT-PCR和Western blot验证,PCBP2敲低和过表达的THP-1细胞系构建成功,PCBP2敲低下调了铁死亡相关基因SLC7A11和GPX4的表达,导致ROS和Fe^(2+)水平升高;相反,PCBP2过表达使得SLC7A11和GPX4的表达水平升高,ROS和Fe^(2+)的水平降低。半数组织培养感染剂量与蛋白水平的检测进一步证实:铁死亡诱导剂可部分抵消PCBP2过表达促病毒复制的效应,铁死亡抑制剂可部分逆转PCBP2敲低抑制病毒复制的效应。结论:研究发现PCBP2可以通过维持SLC7A11/GPX4系统功能抑制铁死亡,从而限制DBV复制。这不仅阐明了PCBP2在DBV感染中的调控作用,为发热伴血小板减少综合征(severe fever with thrombocytope-nia syndrome,SFTS)的发病机制提供了新见解,同时靶向PCBP2-铁死亡通路可能成为SFTS治疗的潜在策略,为抗病毒药物的研发提供新思路。
文摘New siloxane and sulfone containing poly（benzimidazole/sulfone/siloxane/amide） （PBSSA） has been prepared for the formation of hybrid membranes （PBSSA/PS-S/SiNPs） with sulfonated polystyrene （PS-S） and 0.1 wt%-2 wt% silica nanoparticles （SiNPs）. Field emission scanning electron micrographs showed good dispersion of filler, formation of dense nanoporous honeycomb like structure and uniform ionic pathway in these hybrids. The porous membrane structure was responsible for the fine water retention capability and higher proton conductivity of the new hybrids. Increasing the amount of nanoparticles from 0.1 wt% to 2 wt% increased the tensile stress of acid doped PBSSA/PS-S/SiNPs nanocomposites from 65.7 MPa to 68.5 MPa. A relationship between nanofiller loading and thermal stability of the membranes was also experientially studied, as the glass transition temperature of phosphoric acid doped PBSSAJPS-S/SiNPs nanocomposites increased from 207℃ to 215 ℃. The membranes also had higher ion exchange capacity （IEC） around 2.01 mmol/g to 3.01 mmol/g. The novel membranes with high IEC value achieved high proton conductivity of 1.10-2.34 S/cm in a wide range of humidity values at 80 ~C which was higher than that of perfluorinated Nafion 117 membrane （1.1 × 10^-1 S/cm） at 80 ~C （94% RH）. A H2/O2 fuel cell using the PBSSA/PS-S/SiNP 2 （IEC 3.01 retool/g） showed better performance than that of Nation 117 at 40 ℃ and 30% RH.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea(No.20164030201070)supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and future Planning(NRF-2017R1A2B4005230)
文摘A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through a facile solution casting approach. The simple, but effective monomer sulfonation was performed for SFMC to create compact and rigid hydrophobic backbone structures, while conventional random sulfonation was carried-out for SPEEK. Hydrophilic-hydrophobic-hydrophilic structure of SFMC enhances the compatibility with SPEEK and GO and allows for an unprecedented approach to alter me- chanical strength and proton conductivity of ternary hybrid membrane, as verified from universal test machine （UTM） curves and alternating current （AC） impedance plots. The impact of GO integration on the morphology and roughness of hybrid membrane was scrutinized using field emission scanning electron microscope （FE-SEM） and atomic force microscope （AFM）. Ternary hybrid showed uniform intercalation of GO nanosheets throughout the entire surface of membrane with an increased surface roughness of 8.91 nm. The constructed ternary hybrid membrane revealed excellent water absorption, ion exchange capacity and gas barrier properties, while retaining reasonable dimensional stability. The well-optimized ternary hybrid membrane containing 5 wt% GO revealed a maximum proton conductivity of 111.9 mS/cm, which is higher by a factor of two-fold with respect to that of bare SFMC membrane. The maximum PEMFC power density of 528.07mW/cm2 was yielded by ternary hybrid membrane at a load current density of 1321.1 mA/cm2 when operating the cell at 70 ℃ under 100% relative humidity （RH）. In comparison, a maximum power density of only 182.06 mW/cm2 was exhibited by the bare SFMC membrane at a load current density of 455.56 mA/cm2 under same operating conditions.
基金supported by the National Natural Science Foundation of China(22378338,U22A20421)the Project for Science and Technology Plan of Fujian Province of China(2024H4007)。
文摘Poly(ethylene 2,5-furandicarboxylate)(PEF),a bioplastic synthesized via the polymerization of 2,5-furandicarboxylic acid(FDCA)with ethylene glycol,can be served as a substitute to petroleum-based polyethylene terephthalate(PET)due to its enhanced material properties.However,the fabrication of PEF with stable and desirable properties is still a challenge,largely due to the impurities in FDCA.In this study,a highly efficient purification strategy for FDCA was proposed,utilizing a dioxane/H_(2)O binary solvent system for effective crystallization.Furthermore,PEFs were synthesized from FDCA with varying impurity and the effects of these impurities were systematically characterized.The results revealed that impurities in FDCA could result in PEFs with relatively poor thermal properties.This study provides crucial insights for the impact of impurities on PEF properties and FDCA purification.
基金financially supported by the National Natural Science Foundation of China(Nos.22172028,21903015,and 22403017)Natural Science Foundation of Fujian Province of China(No.2022J05041)。
文摘Compatibilization is crucial for the blending of immiscible polymers to develop high-performance composites;however,traditional compatibilization by copolymers(pre-made or in-situ generation)suffers from weak interface anchoring,and inorganic particles have gained extensive attention recently owing to their large interfacial desorption energy,while their low affinity to bulk components is a drawback.In this study,an interfacial atom transfer radical polymerization(ATRP)technique was employed to grow polystyrene(PS)and poly(2-hydroxyethyl methacrylate)(PHEMA)simultaneously on different hemispheres of Br-functionalized SiO_(2) nanoparticles to stabilize a Pickering emulsion,whereby a brush-type Janus nanoparticle(SiO_(2)@JNP)was developed.The polymer brushes were well-characterized,and the Janus feature was validated by transmission electron microscope(TEM)observation of the sole hemisphere grafting of SiO_(2)-PS as a control sample.SiO_(2)@JNP was demonstrated to be an efficient compatibilizer for a PS/poly(methyl methacrylate)(PMMA)immiscible blend,and the droplet-matrix morphology was significantly refined.The mechanical strength and toughness of the blend were synchronously enhanced at a low content SiO_(2)@JNP optimized~0.9 wt%,with the tensile strength,elongation at break and impact strength increased by 17.7%,26.6%and 19.6%,respectively.This enhancement may be attributed to the entanglements between the grafted polymer brushes and individual components that improve the particle-bulk phase affinity and enforce interfacial adhesion.
文摘The electron transfer reaction between triplet anthraquinone-2-sulfonate with poly-guanylic acid (5) (poly[G]) in acetonitrile-H2O has been investigated by 248 nm laser flash photolysis. The transient absorption spectra of radical cation of poly[G] and radical anion of anthraqunione-2-sulfonate (AQS) arising from electron transfer reaction has been observed simultaneously for the first time. The formation processes of radical cation of poly[G] and radical anion of anthraquinone-2-sulfonate as well as the decay processes of triplet anthraquinone-2-sulfonate have also been observed, the apparent rate constants for the formation and decay of transient species have been determined. The free energy changes in the process of the electron transfer was also calculated.
文摘The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while the TGA results revealed that the terpolymer was of high thermal stability.
基金Project supported by the National Natural Science Foundation of China(52300206)the Natural Science Foundation of Jiangsu Province(BK20230705)+2 种基金Industry-University Research Cooperation Project of Jiangsu Province,China(BY20221227)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJB610014)the Talent-Recruiting Program of Nanjing Institute of Technology(YKJ202124)。
文摘Photocatalytic technology has been proven to be a simple and effective method for degrading recalcitrant organic pollutants.In this study,a series of Z-scheme heterojunction nanocomposites composed of CeO_(2)and terephthalic acid-modified WO_(3) was prepared and further used as photocatalysts for perfluorobutane sulfonate(PFBS)degradation.In this design,terephthalic acid was used as an electron recombination center and heterojunction mediator,which effectively enhances the migration ability of electron-hole pairs and the physicochemical stability of the catalyst.In addition,in situ synthesis of CeO_(2)onto the WO_(3) surface by the coordinate bond between terephthalic acid and Ce ions can avoid CeO_(2)agglomeration.As a result,the CeO_(2)@WO_(3) photocatalyst exhibits excellent PFBS degradation ability(94%for CeO_(2)@WO_(3) vs.19%for CeO_(2)).After the fifth cyclic degradation experiment,the CeO_(2)@WO_(3) photocatalyst still maintains stable degradation efficiency.Furthermore,the reaction mechanism of the PFBS in CeO_(2)@WO_(3) photocatalytic process was analyzed by free radical trapping experiment and liquid chromatography tandem mass spectrometry(LC-MS)technique.This study provides new insights for constructing Z-scheme heterojunction and demonstrates that CeO_(2)@WO_(3) photocatalysts possess a promising prospect for degrading PFBS pollutants.
