NEXIONIC® SPEEK is a non-fluorinated proton exchange membrane material based on sulfonated polyether ether ketone, Sulfonated Polyether Ether Ketone. By introducing sulfonic acid groups onto the aromatic PEEK backbone, it forms a continuous hydrophilic ion transport network, combining ion conductivity, mechanical strength, dimensional stability, and non-PFAS material attributes. Standard thicknesses include 25 μm, 50 μm, and 75 μm, covering low-resistance conduction, general assembly, and enhanced separator application requirements.
NEXIONIC® SPEEK is developed for research-grade electrochemical systems and is suitable for experimental platforms requiring proton conduction, ion separation, reaction partitioning, and material tunability.
NEXIONIC® SPEEK is a non-fluorinated proton exchange membrane based on sulfonated polyether ether ketone. SPEEK introduces –SO₃H sulfonic acid groups through sulfonation modification of the PEEK backbone, giving the originally hydrophobic aromatic polymer backbone hydrophilic ion-exchange sites. In the hydrated state, the sulfonic acid groups can form continuous or semi-continuous hydrophilic transport domains, allowing protons to migrate among these ionic sites and enabling ion exchange and proton conduction.
Compared with traditional perfluorosulfonic acid membranes such as PFSA / Nafion®, SPEEK belongs to a non-fluorinated aromatic polymer material system. It does not rely on perfluorinated main-chain or side-chain structures, making it more suitable for non-PFAS membrane material research, green electrochemical material development, low-cost proton exchange membrane validation, and polymer separator structure regulation studies. At the same time, the aromatic PEEK backbone provides good rigidity, heat resistance, and mechanical support, helping the membrane maintain its shape during cutting, clamping, assembly, and long-term testing.
NEXIONIC® SPEEK is regularly supplied in three thicknesses: 25 μm, 50 μm, and 75 μm. 25 μm is more suitable for systems focused on low ohmic resistance, short ion transport paths, and rapid performance screening; 50 μm provides a balance among conductivity, mechanical strength, and assembly stability; 75 μm is more suitable for research scenarios requiring stronger membrane support, resistance to assembly deformation, separation stability, and long-term operating reliability.
This membrane can be used as a separator for flow batteries, electrochemical reactors, proton-conductive layers, and water-treatment ion separation membranes, as well as functional membranes for chemical sensors, electrodialysis, electrocatalytic reaction partitioning, and evaluation of new non-fluorinated ion exchange materials. For research projects exploring non-PFAS membrane materials, low-cost proton exchange membranes, or high-strength polymer separators, SPEEK is a representative candidate material.
The performance of SPEEK comes from the synergistic effect between the aromatic polymer backbone and sulfonic-acid hydrophilic regions.
PEEK itself is an aromatic engineering polymer with high mechanical strength and good heat resistance. After the PEEK backbone is sulfonated, strongly hydrophilic sulfonic acid groups are introduced onto the polymer segments. After absorbing water, these sulfonic acid groups form hydrated structures with water molecules, creating hydrophilic phase regions inside the membrane for proton migration.
In electrochemical testing, the two sides of the membrane usually differ in ion concentration, potential, or reactant composition. The SPEEK membrane can isolate the reaction environments on both sides while allowing protons or specific ions to participate in transport, thereby enabling charge balance, reaction partitioning, and ion exchange.
Membrane performance is related to the degree of sulfonation, membrane thickness, hydration state, test temperature, electrolyte environment, assembly pressure, and other factors. Therefore, selecting the appropriate thickness and pretreatment method for different systems is very important.
Different thicknesses correspond to different conduction resistance, mechanical support, assembly tolerance, and separation stability, and can be selected according to the experimental device and test objectives.
The 25 μm membrane is thinner and has a shorter ion transport path, making it generally more suitable for systems focused on low ohmic resistance, high conduction efficiency, rapid material screening, and small-area electrochemical testing. Recommended for small-area flow cells, electrochemical reactors, proton conduction evaluation, preliminary membrane material screening, and resistance-sensitive experiments.
50 μm provides a balance among conductivity, mechanical strength, cutting convenience, and assembly stability, making it suitable as a general-purpose thickness for most research tests. Recommended for flow battery separators, electrochemical reactor separators, water-treatment ion separation, and routine ion-exchange testing.
The 75 μm membrane provides stronger support and is less prone to deformation during assembly, making it suitable for larger-area fixtures, higher clamping pressure, long-term cycling tests, and systems requiring higher anode/cathode separation stability. Recommended for larger-area flow batteries, electrochemical reactors, and long-term durability evaluation.
From material system, conduction performance, mechanical stability, thickness options, and experimental adaptability, it improves the usability of the membrane material in research testing.
With an ionic conductivity of 14.5 mS/cm, it is suitable for proton conduction, ion exchange, electrochemical separators, and material screening studies.
It offers good dimensional retention during wet-state use, helping improve assembly sealing, reaction-zone separation, and test repeatability.
The aromatic PEEK backbone provides strong structural support, facilitating cutting, clamping, installation, and longer-duration testing.
Standard thicknesses include 25 / 50 / 75 μm, with customization available for thickness, size, degree of sulfonation, and other parameters.
As a non-fluorinated aromatic polymer membrane material, it is suitable for PFAS alternatives, green membrane materials, and low-cost proton exchange membrane research.
It can be used for flow batteries, electrochemical reactors, water treatment, sensors, electrodialysis, and validation of new ion-exchange materials.
It can be compared with Nafion®, PFSA membranes, hydrocarbon proton membranes, and other ion-exchange membranes for performance and mechanism studies.
It can be cut or customized according to fixture size, active area, sealing structure, and testing requirements, facilitating integration into experimental platforms.
Standard specifications are suitable for research testing and small-scale validation, and can also be customized according to device size, test conditions, and conduction requirements.
| Item | Technical Specification | Description |
|---|---|---|
| Product Name | NEXIONIC® SPEEK Sulfonated Polyether Ether Ketone Membrane | Research-grade non-fluorinated ion exchange membrane / proton exchange membrane material |
| Material | Sulfonated PEEK | Sulfonated polyether ether ketone; non-fluorinated aromatic polymer membrane material |
| Appearance | Colorless and transparent | Easy to observe, cut, position, and assemble |
| Standard Thickness | 25 / 50 / 75 μm | 25 μm emphasizes low resistance, 50 μm provides general balance, and 75 μm emphasizes enhanced stability |
| Custom Thickness | 15–200 μm | Customizable according to experimental device, membrane area, clamping pressure, and target resistance |
| Degree of Sulfonation | 60% | Affects conductivity, water uptake, ion-exchange capacity, and dimensional stability |
| Ionic Conductivity | 14.5 mS/cm | Suitable for proton conduction, ion exchange, and electrochemical separator testing |
| Tensile Strength | 24–28 MPa | Meets routine research assembly, cutting, clamping, and operation requirements |
| Elongation at Break | 28–32% | Provides certain flexibility for membrane installation and sealing compression |
| Material Attribute | Non-PFAS / Non-fluorinated system | Suitable for green electrochemical materials, PFAS alternatives, and low-cost membrane material research |
| Applicable Directions | Flow batteries, electrochemical reactors, water treatment, sensors, etc. | Suitable for experimental systems requiring ion separation, proton conduction, reaction partitioning, or ion exchange |
SPEEK is more suitable for non-fluorinated membrane material research, cost-sensitive validation, and development of tunable polymer membrane systems.
| Comparison Item | NEXIONIC® SPEEK | Nafion® / PFSA Membrane |
|---|---|---|
| Material System | Non-fluorinated aromatic polymer system | Perfluorosulfonic acid polymer system |
| PFAS Attribute | Non-PFAS route | Involves a PFAS material system |
| Cost Attribute | More suitable for cost-sensitive research validation and scalable material exploration | Commercially mature, but usually higher in cost |
| Mechanical Stability | The aromatic PEEK backbone provides good rigidity and mechanical support | Good flexibility, but dimensional stability depends on usage conditions |
| Performance Tuning | Can be tuned through degree of sulfonation, membrane thickness, post-treatment, and structural design | Commercial specifications are relatively fixed, with limited customization space |
| Thickness Selection | Standard 25 / 50 / 75 μm specifications, with 15–200 μm customization supported | Usually selected according to fixed commercial models and thicknesses |
| Applicable Research Directions | Flow batteries, electrochemical reactors, water treatment, sensors, and non-fluorinated membrane material research | Widely used in mature systems such as PEM fuel cells and PEM water electrolysis |
| Recommended Use Logic | Suitable for material development, alternative route validation, cost optimization, and research comparison | Suitable for mature standard systems and high-performance benchmark comparison |
When selecting a SPEEK membrane, membrane thickness, active area, assembly pressure, electrolyte environment, target resistance, and test duration should be considered comprehensively.
Membrane thickness affects both ion transport resistance and mechanical support. A thinner membrane is generally more favorable for reducing transport distance and ohmic resistance; a thicker membrane is generally more favorable for improving mechanical stability, assembly tolerance, and anode/cathode separation. Therefore, selection should not be based only on thickness, but should be made according to the specific experimental purpose.
Suitable for various research scenarios requiring proton conduction, ion separation, reaction partitioning, or ion-selective transport.
Used for separating positive and negative electrolytes and enabling ion transport, helping improve Coulombic efficiency, energy efficiency, and long-term stability during cycling. Suitable for vanadium flow batteries, organic flow batteries, and new redox system research.
Suitable for devices such as electrolysis, electrocatalytic synthesis, and redox reactions, enabling separation of anode and cathode reaction zones, charge balance, and ion conduction. Can be used in H-cells, flow cells, and customized reactors.
Can be used in electrodialysis, ion migration, salinity-gradient separation, acid-base separation, and water-treatment membrane material research, and is suitable for validating the application potential of non-fluorinated membrane materials in water treatment.
Can serve as a proton-conductive sensitive material or functional membrane layer for humidity response, ion response, electrochemical detection, and functional polymer membrane layer research.
Can be used as a candidate PFAS-alternative membrane material for structural and performance comparison with Nafion®, PFSA membranes, and other hydrocarbon membrane materials.
Can be used to test membrane conductivity, water uptake, swelling ratio, mechanical strength, resistance, durability, and other indicators.
Suitable for experiments involving ion migration, transmembrane transport, electric-field-driven separation, and electrochemical water treatment.
Different thicknesses or custom membrane sizes can be selected according to fixture active area, sealing structure, flow-field layout, and test pressure.
SPEEK membranes are hydrophilic polymer membrane materials. During use and storage, attention should be paid to humidity, temperature, mechanical stress, and pretreatment methods.
SPEEK membranes contain hydrophilic sulfonic acid groups and may absorb or lose moisture as ambient humidity changes. Slight curling, edge warping, or surface wrinkling is usually caused by changes in internal polymer stress, and does not indicate material failure. Before use, DI water wetting or short soaking can restore the membrane to a flexible and flat state.
SPEEK membranes contain hydrophilic sulfonic acid groups and are sensitive to ambient humidity. When the membrane absorbs or loses moisture, internal polymer stress changes, which may cause slight curling, edge warping, or surface wrinkling. This is a common moisture-related change and does not indicate material failure.
The membrane can be wetted with DI water spray or soaked briefly in DI water. After sufficient wetting, the membrane usually returns to a flexible and flat state. During assembly, avoid forced stretching when the membrane is completely dry.
25 μm is more suitable for low resistance, small-area testing, rapid screening, and conductivity evaluation; 50 μm is more suitable for most general electrochemical tests; 75 μm is more suitable for larger-area fixtures, higher assembly pressure, long-cycle operation, and higher separation stability requirements.
75 μm is more suitable for testing systems requiring enhanced mechanical support, higher assembly pressure, larger membrane area, or long-term cycling stability, such as larger-area flow batteries, electrochemical reactor separators, long-cycle ion separation tests, and experimental platforms requiring higher assembly tolerance.
Customization of thickness, size, degree of sulfonation, and other parameters is supported. It can be matched to the needs of flow batteries, electrochemical reactors, water-treatment devices, sensor structures, or other research fixtures.
SPEEK is a non-fluorinated aromatic polymer membrane that emphasizes non-PFAS chemistry, cost friendliness, mechanical support, and structural tunability; Nafion® is a perfluorosulfonic acid membrane with mature applications and is often used as a high-performance benchmark material in PEM systems, but its material cost is usually higher.
It depends on the specific experimental system. In general, wetting with DI water or pretreatment according to the experimental protocol is recommended before use. For specific electrolyte, acidic/alkaline environments, or ionic form requirements, appropriate equilibration should be performed according to the experimental conditions.
Sealed and light-protected storage is recommended. Avoid long-term exposure to high temperature, high humidity, strong light, dust, or volatile chemical environments. Use clean tweezers or gloves when handling to avoid surface contamination.
According to the experimental system, electrolyte, operating temperature, membrane area, assembly pressure, sealing structure, and target ion conduction requirements, you can choose standard 25 μm, 50 μm, or 75 μm specifications, or customize thicknesses from 15–200 μm. For low-resistance testing, 25 μm is recommended; for general research testing, 50 μm is recommended; for large-area, long-term, or high-stability requirements, 75 μm is recommended.
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NEXIONIC® Sulfonated Polyether Ether Ketone (SPEEK, DS 60%) Membrane – Specifications & Prices
| Model | Thickness (μm) | 5×5 cm | 10×10 cm | 20×20 cm | 20×30 cm |
|---|---|---|---|---|---|
| SPEEK-2560a | 25 | $11 | $36 | $121 | $171 |
| SPEEK-5060a | 50 | $11 | $36 | $121 | $171 |
| SPEEK-7560a | 75 | $11 | $36 | $121 | $171 |
Partial references citing our materials (from Google Scholar)
Carbon Dioxide Reduction
1. ACS Nano Strain Relaxation in Metal Alloy Catalysts Steers the Product Selectivity of Electrocatalytic CO2 Reduction
The bipolar membrane (Fumasep FBM) in this paper was purchased from SCI Materials Hub, which was used in rechargeable Zn-CO2 battery tests. The authors reported a strain relaxation strategy to determine lattice strains in bimetal MNi alloys (M = Pd, Ag, and Au) and realized an outstanding CO2-to-CO Faradaic efficiency of 96.6% with outstanding activity and durability toward a Zn-CO2 battery.
2. Front. Chem. Boosting Electrochemical Carbon Dioxide Reduction on Atomically Dispersed Nickel Catalyst
In this paper, Vulcan XC-72R was purchased from SCI Materials Hub. Vulcan XC 72R carbon is the most common catalyst support used in the anode and cathode electrodes of Polymer Electrolyte Membrane Fuel Cells (PEMFC), Direct Methanol Fuel Cells (DMFC), Alkaline Fuel Cells (AFC), Microbial Fuel Cells (MFC), Phosphoric Acid Fuel Cells (PAFC), and many more!
3. Adv. Mater. Partially Nitrided Ni Nanoclusters Achieve Energy-Efficient Electrocatalytic CO2 Reduction to CO at Ultralow Overpotential
An AEM membrane (Sustainion X37-50 Grade RT, purchased from SCI Materials Hub) was activated in 1 M KOH for 24 h, washed with ultra-purity water prior to use.
4. Adv. Funct. Mater. Nanoconfined Molecular Catalysts in Integrated Gas Diffusion Electrodes for High-Current-Density CO2 Electroreduction
In this paper (Supporting Information), an anion exchanged membrane (Fumasep FAB-PK-130 obtained from SCI Materials Hub (www.scimaterials.cn)) was used to separate the catholyte and anolyte chambers.
SCI Materials Hub: we also recommend our Fumasep FAB-PK-75 for the use in a flow cell.
5. Appl. Catal. B Efficient utilization of nickel single atoms for CO2 electroreduction by constructing 3D interconnected nitrogen-doped carbon tube network
In this paper, the Nafion 117 membrane was obtained from SCI Materials Hub.
In this paper, Proton exchange membrane (Nafion 117), Nafion D520, and Toray 060 carbon paper were purchased from SCI Materials Hub.
7. National Science Review Confinement of ionomer for electrocatalytic CO2 reduction reaction via efficient mass transfer pathways
An anion exchange membrane (PiperION-A15-HCO3) was obtained from SCI Materials Hub.
8. Catalysis Communications Facilitating CO2 electroreduction to C2H4 through facile regulating {100} & {111} grain boundary of Cu2O
Carbon paper (TGPH060), membrane solution (Nafion D520), and ionic membrane (Nafion N117) were obtained from Wuhu Eryi Material Technology Co., Ltd (a company under SCI Materials Hub).
Batteries
1. J. Mater. Chem. A Blocking polysulfides with a Janus Fe3C/N-CNF@RGO electrode via physiochemical confinement and catalytic conversion for high-performance lithium–sulfur batteries
Graphene oxide (GO) in this paper was obtained from SCI Materials Hub. The authors introduced a Janus Fe3C/N-CNF@RGO electrode consisting of 1D Fe3C decorated N-doped carbon nanofibers (Fe3C/N-CNFs) side and 2D reduced graphene oxide (RGO) side as the free-standing carrier of Li2S6 catholyte to improve the overall electrochemical performance of Li-S batteries.
This paper used more than 10 kinds of materials from SCI Materials Hub and the authors gave detailed properity comparsion.
The commercial IEMs of Fumasep FAB-PK-130 and Nafion N117 were obtained from SCI Materials Hub.
Gas diffusion layers of GDL340 (CeTech) and SGL39BC (Sigracet) and Nafion dispersion (Nafion D520) were obtained from SCI Materials Hub.
Zn foil (100 mm thickness) and Zn powder were obtained from the SCI Materials Hub.
Commercial 20% Pt/C, 40% Pt/C and IrO2 catalysts were also obtained from SCI Materials Hub.
3. Journal of Energy Chemistry Vanadium oxide nanospheres encapsulated in N-doped carbon nanofibers with morphology and defect dual-engineering toward advanced aqueous zinc-ion batteries
In this paper, carbon cloth (W0S1011) was obtained from SCI Materials Hub. The flexible carbon cloth matrix guaranteed the stabilization of the electrode and improved the conductivity of the cathode.
4. Energy Storage Materials Defect-abundant commercializable 3D carbon papers for fabricating composite Li anode with high loading and long life
The 3D carbon paper (TGPH060 raw paper) were purchased from SCI Materials Hub.
5. Nanomaterials A Stable Rechargeable Aqueous Zn–Air Battery Enabled by Heterogeneous MoS2 Cathode Catalysts
Nafion D520 (5 wt%), and carbon paper (GDL340) were received from SCI-Materials-Hub.
Carbon cloth (W0S1011) and other electrochemical consumables required for air cathode were provided by SCI Materials Hub.
Oxygen Reduction Reaction
1. J. Chem. Eng. Superior Efficiency Hydrogen Peroxide Production in Acidic Media through Epoxy Group Adjacent to Co-O/C Active Centers on Carbon Black
In this paper, Vulcan XC 72 carbon black, ion membrane (Nafion N115, 127 μL), Nafion solution (D520, 5 wt%), and carbon paper (AvCarb GDS 2230 and Spectracarb 2050A-1050) were purchased from SCI Materials Hub.
2. Journal of Colloid and Interface Science Gaining insight into the impact of electronic property and interface electrostatic field on ORR kinetics in alloy engineering via theoretical prognostication and experimental validation
The 20 wt% Pt3M (M = Cr, Co, Cu, Pd, Sn, and Ir) were purchased from SCI Materials Hub. This work places emphasis on the kinetics of the ORR concerning Pt3M (M = Cr, Co, Cu, Pd, Sn, and Ir) catalysts, and integrates theoretical prognostication and experimental validation to illuminate the fundamental principles of alloy engineering.
Water Electrolysis
1. International Journal of Hydrogen Energy Gold as an efficient hydrogen isotope separation catalyst in proton exchange membrane water electrolysis
The cathodic catalysts of Pt/C (20 wt%, 2–3 nm) and Au/C (20 wt%, 4–5 nm) were purchased from SCI Materials Hub.
2. Small Science Silver Compositing Boosts Water Electrolysis Activity and Durability of RuO2 in a Proton-Exchange-Membrane Water Electrolyzer
Two fiber felts (0.35 mm thickness, SCI Materials Hub) were used as the porous transport layers at both the cathode and the anode.
3. Advanced Functional Materials Hierarchical Crystalline/Amorphous Heterostructure MoNi/NiMoOx for Electrochemical Hydrogen Evolution with Industry-Level Activity and Stability
Anion-exchange membrane (FAA-3-PK-130) was obtained from SCI Materials Hub website.
Fuel Cells
1. Polymer Sub-two-micron ultrathin proton exchange membrane with reinforced mechanical strength
Gas diffusion electrode (60% Pt/C, Carbon paper) was purchased from SCI Materials Hub.
Characterization
1. Chemical Engineering Journal Electrochemical reconstitution of Prussian blue analogue for coupling furfural electro-oxidation with photo-assisted hydrogen evolution reaction
An Au nanoparticle film was deposited on the total reflecting plane of a single reflection ATR crystal (SCI Materials Hub, Wuhu, China) via sputter coater.
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