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1.
The sulphonated phenol novolac (PNBS) which was used as a curing agent of epoxy was synthesised from phenol novolac (PN) and 1, 4‐butane sultone and confirmed by FTIR and 1H NMR. The degree of sulphonation (DS) in PNBS was calculated by 1H NMR. The semi‐IPN membranes composed of sulphonated tetramethyl poly(ether ether ketone) (STMPEEK) (the value of ion exchange capacity is 2.01 meq g–1), epoxy (TMBP) and PNBS were successfully prepared. The semi‐IPN membranes showed high thermal properties which were measured by differential scanning calorimeter (DSC) and thermogravimetric analyses (TGA). With the introduction of the cross‐linked TMBP/PNBS, the mechanical properties, dimensional stability, methanol resistance and oxidative stability of the membranes were improved in comparison to the pristine STMPEEK membrane. Although the proton conductivities of the semi‐IPN membranes were lower than those of the pristine STMPEEK membrane, the higher selectivity defined as the ratio of the proton conductivity to methanol permeability was obtained from the STMPEEK/TMBP/PNBS‐14 semi‐IPN membrane. The results indicated that the semi‐IPN membranes could be promising candidates for usage as proton exchange membranes in direct methanol fuel cells (DMFCs).  相似文献   

2.
Mixed matrix membranes based on zeolite 4A‐methane sulfonic acid (MSA)‐sulfonated poly(ether ether ketone) (SPEEK) are evaluated as a potential polymer electrolyte membrane (PEM) for direct methanol fuel cells (DMFCs). Ion‐exchange capacity, sorption of water, and water–methanol mixture, proton conductivity, and methanol permeability for the mixed‐matrix membranes have been extensively investigated. The mixed‐matrix membranes are also characterized for their cross‐sectional morphology, mechanical, and thermal properties. DMFCs employing SPEEK‐MSA (20 wt.%) blend, zeolite 4A (4 wt.%)‐SPEEK‐MSA (20 wt.%) mixed matrix membranes deliver peak power densities of 130 and 159 mW cm–2, respectively; while a peak power density of only 95 mW cm–2 is obtained for the DMFC employing pristine SPEEK membrane at 70 °C. The results showed that these SPEEK based mixed matrix membranes exhibit higher DMFC performance and lower methanol permeability in comparison to Nafion‐117 membrane.  相似文献   

3.
Sulfonated poly(aryl ether ketone)s (SPAEK) copolymers were synthesized by aromatic nucleophilic polycondensation from 3,3′, 5,5′‐tetramethyl‐4, 4′–biphenol, 1,4‐bis(4‐fluorobenzoyl) benzene, and disulfonated difluorobenzophenone. The SPAEK membranes did not exhibit excessive swelling in hot water and at the same time show the proton conductivities in the range of 0.030 S/cm to 0.099 S/cm at 80°C. The methanol diffusion coefficients of the SPAEK membranes were in the range of 4.7 × 10?7 to 8.1 × 10?7cm2/s measured at 25°C. The transport properties of this series of SPAEK copolymers were compared to poly(aryl ether ether ketone)s (SPEEK), poly(aryl ether ether ketone ketone)s (SPEEKK), and Nafion® membranes. It was found that the transport properties (including proton conductivity and methanol permeability) follows the trend of SPEEKK‐60 < SPAEK‐60 < SPEEK‐60 < Nafion® 117, the order of which is also attributed to the differences in the chemical structure of the polymers and the membrane morphology. In general, this novel series of SPAEK membranes possess various advantages, such as low cost of the initial monomers, high thermal and mechanical stability, and low methanol permeability while simultaneously possessing sufficient proton conductivity, which makes them notably promising as proton exchange membrane (PEM) materials in direct methanol fuel cell (DMFC) applications. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

4.
In this study, crosslinked polymer electrolyte membranes for polymer electrolyte membrane fuel cell (PEMFC) applications are prepared using electron beam irradiation with a mixture of sulfonated poly(ether ether ketone) (SPEEK), poly(vinylidene fluoride) (PVDF), and triallyl isocyanurate (TAIC) at a dose of 300 kGy. The gel‐fraction of the irradiated SPEEK/PVDF/TAIC (95/4.5/0.5) membrane is 87% while the unirradiated membrane completely dissolves in DMAc solvent. In addition, the water uptake of the irradiated membrane is 221% at 70 °C while that of the unirradiated membrane completely dissolves in water at above 70 °C. The ion exchange capacity and proton conductivity of the crosslinked membrane are 1.57 meq g−1, and 4.0 × 10−2 S cm−1 (at 80 °C and RH 90%), respectively. Furthermore, a morphology study of the membranes is conducted using differential scanning calorimetry and X‐ray diffractometry. The cell performance study with the crosslinked membrane demonstrates that the maximum power density is 518 mW cm−2 at 1036 mA cm−2 and the maximum current density at applied voltage of 0.4 V is 1190 mA cm−2.  相似文献   

5.
Song Xue 《Polymer》2006,47(14):5044-5049
Blend membranes were obtained by solution casting from poly(vinylidene fluoride) (PVDF) and sulfonated poly(ether ether ketone) (SPEEK) in N,N-dimethylacetamide (DMAc). DSC and XRD were used to characterize the structure of the blend membranes. The effect of PVDF content on the membrane properties was investigated. The methanol permeability, water uptake and the swelling ratio of blend membranes decreased with the increase of PVDF content. Though the proton conductivity decreased upon the addition of PVDF, they were still comparable to that of Nafion® 117 membrane. Higher selectivities were also found for most blend membranes in comparison with Nafion® 117 membrane. The effect of methanol concentration on solution uptake, swelling ratio and methanol permeability of the blend membranes was also studied.  相似文献   

6.
The proton exchange membrane (PEM) is the core component of a high-performance proton exchange membrane fuel cell (PEMFC). Since the traditional PEM has the disadvantages of poor cell performance and high cost, a new kind of PEM with good proton conductivity, low cost and simple preparation should be explored. In this paper, several different binary hybrid membranes were successfully prepared through one-step encapsulation of different ionic liquids (ILs) in sulfonated poly(ether ether ketone) (SPEEK). The prepared membranes were characterized by scanning electron microscope (SEM), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), proton conductivity measurements and dynamic mechanical analysis (DMA). SEM images showed that ILs were fully doped into SPEEK. FT-IR and XPS proved that SPEEK and IL formed a new chemical bond combined with intermolecular hydrogen bonds. The TG results showed that the binary hybrid membranes could maintain stability even at 300°C. The water uptake and swelling ratio showed that the water absorption capacity of the binary composite membrane played a vital role in improving proton conductivity. The proton conductivity study showed that ILs doping also helped to improve the proton conductivity of the SPEEK membrane. When the doping amount of IL was maintained at 30 wt.%, it has the highest proton conductivity, 25 mS cm−1 at 120°C. It was proved that anhydrous hybrid membrane tetraphenyl imidazole sulfate/SPEEK ([IM2][H2PO4]/SPEEK) could be used in PEMFC at medium temperature.  相似文献   

7.
New types of metal–organic framework based hybrid materials are designed and prepared, which involving the hybridization of various content of boron phosphate (BPO4) with the precursor of HKUST-1. The structure of obtained HKUST-1/BPO4 hybrid materials (HB) is fully investigated, and then applied to construct sulfonated poly (ether ether ketone) (SPEEK) based proton exchange membranes (SPEEK/HB). Owing to effective interactions between hybrid materials and SPEEK matrix, the achieved composite membranes reflect a considerable improvement in mechanical and thermal stability, oxidative stability, methanol permeation, and proton conductivity. In particular, the tensile strength of SPEEK/HB-20 composite membrane is 41.3 MPa, which is 1.5 times higher than pristine SPEEK, and the methanol permeability reduced to one-third of SPEEK at the same time. The SPEEK/HB-10 displays the highest proton conductivity of 37.4 mS cm−1 at 80 °C, which is obviously higher than pristine SPEEK. These results reveal that the hybridization of HKUST-1 with BPO4 provide a promising candidate in the modification of proton exchange membranes (PEMs), and this strategy also possess great application potential in other types of MOFs-based hybrid materials.  相似文献   

8.
Polyether ether ketone (PEEK) with a low sulfonation degree was blended using different proportions of sodium rich Smectite clay (3 and 6 wt%) to use as an electrolyte membrane for fuel cell application. The structural functionalities, surface morphologies, and the thermal stability of the resultant composite membranes were characterized using Fourier-transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, atom force microscopy, and thermo-gravimetric analysis. FT-IR showed that no chemical reactions take place between the sulfonated polyether ether ketone (SPEEK) and the clay with different ratios. XRD diffractograms illustrated a lower degree of crystallinity of the blended SPEEK than pristine SPEEK. The elaborated composite membranes proved to have a higher thermal stability than SPEEK. Furthermore, the SPEEK/clay composite membranes with 3 and 6 wt% in clay loading had higher water uptake and lower methanol uptake than those in pristine SPEEK It was also shown that, the incorporation of sodium ions rich Smectite clay layers between the clusters in SPEEK improved the conductivity to 2 × 10−2 S/cm at 140°C (for 6 wt% in clay) without compromising the dimensional stability of the composite membranes. These results propose the composite membranes as a potential candidate for methanol fuel cells at temperatures above 120°C making SPEEK composite membrane competitive to that of Nafion membrane.  相似文献   

9.
In this work, the properties of novel ionic polymer blends of crosslinked and sulfonated poly(vinyl alcohol) (PVA) and sulfonated poly(ether ether ketone) (SPEEK) are investigated. Crosslinking and sulfonation of PVA were carried out using sulfosuccinic acid (SSA) in the presence of dispersed SPEEK to obtain semi‐interpenetrating network blends. PVA–SSA/SPEEK blend membranes of different compositions were studied for their ion‐exchange capacity, proton conductivity, water uptake, and thermal and mechanical properties. The hydrated blend membranes show good proton conductivities in the range of 10?3 to 10?2 S/cm. When compared with pure component membranes, the PVA–SSA/SPEEK blend membranes also exhibit improvement in tensile strength, tensile modulus, and delay in the onset of thermal and chemical degradation. Semi‐interpenetrating nature of the blends is established from morphology and dynamic mechanical analysis. Morphology of the membranes was studied using scanning electron microscopy after selective chemical treatment. The dynamic mechanical properties of the membranes are examined to understand the miscibility characteristics of the blends. The relative proportions of PVA and SPEEK and the degree of crosslinking of PVA–SSA are important factors in determining the optimum properties for the blend. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

10.
The ethylenediamine-modified graphite oxide (EGO)-doped sulfonated poly (arylene ether ketone) (SPEEK) composite membranes have been prepared and developed for fuel cell applications in the present work. The base-modified EGO improves the dispersion of inorganic nanosheet in the polymer matrix and enhances proton conductivity by creating continuous conduction pathways. Furthermore, the methanol barrier property also be enhanced due to the nanosheet block the methanol-transport channels. EGO-filled membranes display improved dimensional stability, proton conductivity, and ethanol permeability than those using SPEEK control and graphite oxide (GO)-filled membranes. In the direct methanol fuel cells (DMFCs), the SPEEK/EGO-1.5 membrane displays the highest current density of 395.9 mA/cm2 at 60°C, which is 1.6- and 1.4-fold higher than that of SPEEK (254.0 mA/cm2) and SPEEK/GO membrane (292.6 mA/cm2).  相似文献   

11.
Highly disulfonated poly(aryl ether ether ketone)s (SPEEK-70) copolymer was synthesized via direct polymerization to precisely control the degree of sulfonation (Ds = 1.40), which was confirmed and estimated by 1H NMR. As expected, the proton conductivity of SPEEK-70 membrane is 0.084 S/cm at 25 °C and increases to 0.167 S/cm at 80 °C, surpassing that of Nafion® 117. However, the relatively high methanol crossover and excessively swelling properties limited its usage in DMFC. Poly(amide imide) was blended with SPEEK-70 to improve the methanol resistance and mechanical properties. These blend membranes were characterized as a function of weight fraction of PAI in terms of ion exchange capacity (IEC), water uptake, water desorption, proton conductivity and methanol permeability in detail. Although the proton conductivities decreased upon the addition of PAI, higher selectivity values defined as the ratio of proton conductivity to methanol permeability were found for the blend membranes. Therefore, the SPEEK/PAI blend membranes are promising for usage in DMFC.  相似文献   

12.
Sulfonated poly(ether ether ketone) (SPEEK)/clay hybrid membranes were prepared using three types of commercially available clays, the sodium montmorillonite (IC), hydrophobic organo‐clay with long alkyl chains (OC), and organo‐clay with carboxylic acid end groups (HC). It was found that the SPEEK/HC hybrid membranes achieved the best clay dispersion, with the exfoliation of the clay nano‐platelets when the filler loading was < 10 wt%. The incorporation of the carboxylic acid groups in clay layers also improved the connectivity between the ionic clusters in the membrane, resulting in higher proton conductivity without compromising the dimensional stability of membranes. The selectivity higher than the pristine SPEEK membranes was obtained for the SPEEK/HC hybrid membranes at low filler loading (<10 wt%), with higher proton conductivity and similar methanol permeability. POLYM. COMPOS., 37:2632–2638, 2016. © 2015 Society of Plastics Engineers  相似文献   

13.
Sulfonated poly(ether ether ketone) (SPEEK) is a very promising alternative membrane material for direct methanol fuel cells. However, with a fairly high degree of sulfonation (DS), SPEEK membranes can swell excessively and even dissolve at high temperature. This restricts membranes from working above a high tolerable temperature to get high proton conductivity. To deal with this contradictory situation, insolvable zirconium tricarboxybutylphosphonate (Zr(PBTC)) powder was employed to make a composite with SPEEK polymer in an attempt to improve temperature tolerance of the membranes. SPEEK/Zr(PBTC) composite membranes were obtained by casting a homogeneous mixture of Zr(PBTC) and SPEEK in N,N-dimethylacetamide on a glass plate and then evaporating the solvent at 60°C. Many characteristics were investigated, including thermal stability, liquid uptake, methanol permeability and proton conductivity. Results showed significant improvement not only in temperature tolerance, but also in methanol resistance of the SPEEK/Zr(PBTC) composite membranes. The membranes containing 30 wt-% ∼ 40 wt-% of Zr(PBTC) had their methanol permeability around 10−7 cm2·s−1 at room temperature to 80°C, which was one order of magnitude lower than that of Nafion?115. High proton conductivity of the composite membranes, however, could also be achieved from higher temperature applied. At 100% relative humidity, above 90°C the conductivity of the composite membrane containing 40 wt-% of Zr(PBTC) exceeded that of the Nafion?115 membrane and even reached a high value of 0.36 S·cm−1 at 160°C. Improved applicable temperature and high conductivity of the compositemembrane indicated its promising application inDMFC operations at high temperature. __________ Translated from Acta Polymerica Sinica, 2007, (4): 337–342 [译自:高分子学报]  相似文献   

14.
Asymmetric ultrafiltration (UF) membranes were prepared by the blending of poly(ether sulfone) (PES) and sulfonated poly(ether ether ketone) (SPEEK) polymers with N,N′‐dimethylformamide solvent by the phase‐inversion method. SPEEK was selected as the hydrophilic polymer in a blend with different composition of PES and SPEEK. The solution‐cast PES/SPEEK blend membranes were homogeneous for all of the studied compositions from 100/0 to 60/40 wt % in a total of 17.5 wt % polymer and 82.5 wt % solvent. The presence of SPEEK beyond 40 wt % in the casting solution did not form membranes. The prepared membranes were characterized for their UF performances, such as pure water flux, water content, porosity, and membrane hydraulic resistance, and morphology and melting temperature. We estimated that the pure water flux of the PES/SPEEK blend membranes increased from 17.3 to 85.6 L m?2 h?1 when the concentration of SPEEK increased from 0 to 40 wt % in the casting solution. The membranes were also characterized their separation performance with proteins and metal‐ion solutions. The results indicate significant improvement in the performance characteristics of the blend membranes with the addition of SPEEK. In particular, the rejection of proteins and metal ions was marginally decreased, whereas the permeate flux was radically improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

15.
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 SPEEK/SPES-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 70ºC, whereas the swelling degree of the SPEEK (DS 61.7%)/SPES-C (40%, by mass) membrane is 29.7% at 80ºC. From room temperature to 80ºC, 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 150ºC. The proton conductivity of SPEEK (DS 55.1%)/SPES-C (30%, by mass) membrane approaches 0.16 S&#8226;cm-1, matching that of Nafion&#61650;115 at 140ºC and 100% RH, while pure SPEEK (DS 55.1%) membrane dissolves at 90ºC. 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.  相似文献   

16.
The aim of this study was to find a suitable aniline derivative to develop composite sulfonated poly(ether ether ketone) (SPEEK) membranes and detail evaluation of their physico‐ and electrochemical properties. The hypothesis was high basicity of the aniline derivatives could form good composite membranes with better physicochemical and electrochemical properties. To assess the basicity we measured the zeta potentials of the polymers and correlated them with ion‐exchange capacities, water uptakes, transport numbers, water‐diffusion coefficients, conductivities, and methanol permeabilities. The obtained values of zeta potentials at pH 7 were 6.52, ?14.66, ?25.17, and ?28 for SPEEK/polynaphthalene (PNAPH), SPEEK/polyanisidine (PANIS), SPEEK/polyaniline (PANI), and SPEEK/polyxylindine (PXYL), respectively supports the hypothesis and strongly suggests polyaniline derivative's basicity‐dependent properties. Of the four derivatives (PNAPH, PANIS, PANI, and PXYL), the SPEEK/PXYL composite membrane had the lowest methanol permeability of 1 × 10?4 cm2/s and highest proton conductivity of 161 mS/cm. These values are far better than the neat SPEEK and SPEEK/PANI composite. The suitability of SPEEK/PXYL can be explained by the high basicity of the PXYL composite membrane, which leads to the formation of effective Debye spheres, meaning that the ionic complex can interact with surrounding hydronium ions and form hydrophilic channels resulting in high proton conductivity and low methanol permeability. These results suggest that SPEEK/PXYL is a highly suitable membrane for methanol fuel cells or other electrochemical applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43978.  相似文献   

17.
In this study, a method is developed to fabricate sulfonated poly (ether ether ketone)/phosphotungstic acid‐polyaniline (SPEEK/HPW‐PANI) membranes by in situ polymerization of aniline for the purpose of decreasing the weight loss of HPW in the membranes. The synthesis involves the production of a SPEEK/HPW hybrid membrane followed by different layer of PANI coatings on the membrane surface, and subsequent treatment using drying in vacuum procedures. The scanning electronic microscopy images showed that HPW had good compatibility with SPEEK polymers and energy dispersive X‐ray spectroscopy revealed the successfully doping with HPW and polymerization of PANI. The surface of SPEEK/HPW‐PANI becomes more compact than that of SPEEK/HPW and pure SPEEK, which may lead to reduce the water uptake and swelling property. The proton conductivity was found for the SPEEK/HPW‐PANI‐5 composite membrane (91.53 mS/cm at 80°C) higher than that of pure SPEEK membrane (68.72 mS/cm at 80°C). Better thermal stability was determined in both SPEEK/HPW and SPEEK/HPW‐PANI membranes than pristine SPEEK membrane. Therefore, PANI is a good potential coating for organic–inorganic hybrid e.g. SPEEK/HPW membrane materials to improve their hydrothermal stable properties and SPEEK/HPW PANI is a material that shows promise as a proton exchange membranes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41033.  相似文献   

18.
Sulfonated poly(ether ether ketone) (SPEEK) is currently considered to be one of the most potential candidates of commercial perfluorinated sulfonic acid proton exchange membranes. To balance the proton conductivity and mechanical properties of SPEEK, nano TiO2 coated carbon nanotubes (TiO2@CNTs) were prepared using a benzyl alcohol-assisted sol-gel method and then used as a new nanofiller to modify SPEEK to prepare SPEEK/TiO2@CNTs composite membranes. The thick insulated TiO2 coating layer can effectively avoid the risk of electronic short-circuiting formed by CNTs, while the hydrophilicity of TiO2 can also reduce the polar difference between CNTs and SPEEK matrix, thus promoting the homogeneous dispersion of CNTs in the composites. As a result, the composite membranes demonstrated simultaneously improved strength and proton conductivity. Incorporating 5 wt% of TiO2@CNTs exhibited 31% growth in mechanical strength when compared with pure SPEEK. Moreover, the maximum conductivity was 0.104 S cm−1 (80°C) for the composite membrane with 5 wt% of TiO2@CNTs, which was nearly twice as high as that of SPEEK membrane (0.052 S cm−1).  相似文献   

19.
Poly(arylene ether benzonitrile) (PAEBN) was synthesized with 2,6‐dichlorobenzonitrile and biphenol. PAEBNs with various molecular weights (MWs), 1,640,000 and 185,000 g/mol, were synthesized by control of the stoichiometry of the monomers and were blended with sulfonated poly(ether ether ketone) (SPEEK). The effects of MW on the water uptake, swelling, methanol permeability, and proton conductivity of the SPEEK/PAEBN blend membranes were investigated. The molecular mobility of the SPEEK/PAEBN blends was also examined in this study. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

20.
采用流延法制备了聚醚砜(PES)含量不同的PES/磺化聚醚醚酮(SPEEK)共混膜。PES与SPEEK具有良好的相容性。所制备PES/SPEEK共混膜的含水率、溶胀度和甲醇透过系数均随PES含量的增加而降低。虽然共混膜的质子传导性能有所降低.但阻醇性能和溶胀性能提高,这说明PES/SPEEK共混膜是一种很好的直接甲醇燃料电池用固体高分子电解质膜材料。  相似文献   

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