Sulfonated Poly Ether Ether Ketone Research Articles

Effect of Filler Content on Transport Properties of Sulfonated Polyether Ether Ketone (SPEEK) Composite Proton Exchange Membranes

Proton exchange membrane for direct methanol fuel cell was developed by the incorporation of silicotungstic acid supported on silica (SiO2-SiWA) into SPEEK polymer. The properties of composite membranes with various silica/SiWA ratios were investigated and compared in this study. It was found that high silica to SiWA weight ratio (2:1) resulted in porous membrane with high proton conductivity and moderate methanol permeability. Reduction in the aforementioned ratio to 1:1 resulted in a more compact structure with better thermal stability, however, leaching of SiWA from the membrane occurred due to insufficient support. SPEEK membrane incorporated with 10 wt% SiO2 and 5 wt% SiWA showed the highest selectivity of 6.44 × 104 S.s/cm3 and performed better than that of the pure SPEEK membrane. These results suggested that these membranes have potential to be considered for DMFCs applications.

Preparation of the Multicomponent High Temperature Proton Exchange Membranes with Layer by Layer Self-assembly Technique

Layer by layer (LBL) self-assembly technique has been proved to be a feasible method that enables to accomplish the preparation of functional membranes with multilayered structure. In this research, the polymer of sulfonated polyetheretherketone (SPEEK) and thioglycolic acid capping of cadmium telluride (CdTe) nanocrystals as polyanion, the polymer of polyurethane (PU) as polycation have been used to prepare membrane electrolytes. These multilayered membranes showed good thermal stability and exhibited low liquid methanol permeability, which provided a possibility for the prepared membranes as proton exchange membranes (PEMs) to apply in direct methanol fuel cells (DMFCs). We have also demonstrated that the multicomponent (SPEEK/PU/CdTe/PU)100 membranes favored to combine more phosphoric acid (PA) molecules and possessed a higher proton conductivity comparing to the bicomponent (SPEEK/PU)210 membranes. So PA doped (SPEEK/PU/CdTe/PU)100 membrane presented a maximum proton conductivity up to 8.6×10-2 S/cm at 160 °C under anhydrous conditions. However, PA doped (SPEEK/PU)210 membranes underwent a drop on proton conductivity while the temperature exceeded 120 °C.

Searching for effective compatibilizing agents for the preparation of poly(ether ether ketone)/graphene nanocomposites with enhanced properties

The homogeneous dispersion of graphene into poly(ether ether ketone) (PEEK) remains a challenging task mostly due to the resistance of PEEK to most common organic solvents. The present investigation describes a careful selection of compatibilizing agents that allows effectively dispersing graphene into PEEK. Polyetherimide (PEI), polysulfone, (PSU), poly(1,4-phenylene ether-ether-sulfone) (PEES) and sulfonated PEEK (SPEEK) are considered as potential compatibilizers and the mechanical, thermal and electrical properties of PEEK/graphene nanocomposites with different filler contents are evaluated. Significant electrical conductivity values are obtained for the nanocomposite with SPEEK (σ > 0.01 S·cm−1 at 4 wt% filler content) and the one incorporating PEI exhibited a percolation threshold below 2 wt%. Finally, the nanocomposites including SPEEK, PEI and PEES show a clear enhancement of the mechanical properties with increasing graphene content. Hence, nanocomposites incorporating PEI and SPEEK as compatibilizers displayed optimized electrical and mechanical properties, in addition to a thermal stability up to 550 °C.

Preliminary Study On The Development Of Sulfonated Graphene Oxide Membranes As Potential Novel Electrolytes For PEM Fuel Cells

In this work, preliminary results about the use of a graphene oxide-based membrane as a possible alternative electrolyte for proton exchange membrane fuel cells (PEMFCs) are reported. Currently, one of the key components of a PEMFC is the ionomer electrolyte, typically the perfluorosulfonic acid membrane known as Nafion, due to its high proton conductivity in standard operating conditions (temperature range: 60-80 °C and relative humidity of 60-100 %), good mechanical properties and its effectiveness as gases separator. However, Nafion limits fuel cell maximum operating temperature, reduces its conductivity upon dehydration and suffers shrinkage and swelling if water content changes significantly [1]. An interesting alternative aiming to enhance FCs efficiency and to overcome drawbacks related to Nafion employment could be represented by graphene oxide (GO). GO is obtained by chemical functionalization and exfoliation of graphite and is attracting attention of the scientific community due to its easy dispersion in water, electronically insulating properties and gas barrier properties. Moreover, GO self-standing membranes have been found impermeable to many gases, whilst allowing permeation of water and minimizing fuel crossover [2]. Some works have reported the use of GO in composite membranes with known proton conductors such as Nafion, S-PEEK (sulfonated poly ether ether ketone), PBI (polybenzimidazole) and PVA (polyvinyl alcohol) [3]. Our research group has developed and characterized a pure GO membrane as a self-standing electrolytic membrane. In a typical experiment, a GO aqueous solution was prepared, then it was vacuum filtered and the cake was dried at 40 °C for 6 hours. A uniform self-assembled membrane was obtained and morphologically characterized by SEM, TGA, XRD and FT-IR analysis. A homogeneous surface and the presence of functional groups, i.e. hydroxyl, epoxy oxygen and carboxyl groups, which should be able in ensuring proper proton conductivity [4], have been achieved. A thickness of around 2 μm was measured. Since thickness is strongly related to initial GO solution concentration, other experiments are going to be done in order to increase it. After proper activation in a sulfuric acid solution, proton conductivity of the prepared membranes was determined by using impedance spectroscopy in the frequency range 1 MHz-1 Hz with an AC amplitude of 500 mV. Preliminary measurements were performed at 25 °C and variable relative humidities (RHs), ranging from anhydrous conditions to 100 %. RH was controlled by using sealed-off glass cell specifically designed to be immersed in a thermostatic bath with saturated aqueous solutions of different salts. A value of 8 mS/cm was found at 25 °C and anhydrous conditions. This is a very promising result since at the same operating conditions Nafion 212 has shown a conductivity of almost one magnitude lower. Conductivity increased upon increasing RH but such effect was less sharp than the one observed for Nafion and needs further tests and detailed investigation. Measurements at different temperatures, as well as in-situ electrical tests, are in progress and will be shown during the conference.

Osteogenesis and Antibacterial Activity of Graphene Oxide and Dexamethasone Coatings on Porous Polyetheretherketone via Polydopamine-Assisted Chemistry

Endowing implants with antibacterial ability and osteogenic ability plays important roles in preventing post-operative bacterial contamination and facilitating integration between implants and osseous tissue, consequently reducing implant failure rates. In this study, we develop a facile and versatile strategy with dopamine as an auxiliary for construction of dexamethasone (Dex)/liposome porous coatings. In detail, the surfaces of sulfonated polyetheretherketone (SP) plates are coated with polydopamine firstly and then modified with graphene oxide (GO) and dexamethasone (Dex)-loaded liposome, which is verified by contact angle, X-ray photoelectron spectroscopy (XPS), attenuated total reflection infrared (ATR), and Raman spectra. The results of our study suggest that the GO and Dex are successfully coated on the samples’ surfaces. In vitro cell attachment, growth, differentiation, and apatite deposition tests all illustrate that the substrate coated with GO and Dex can significantly accelerate the proliferation and osteogenic differentiation of MC3T3 cells compared with the pristine sulfonated polyetheretherketone (PEEK). Additionally, it exhibits acceptable antibacterial activity against E. coli and S. aureus in vitro. Altogether, our results demonstrate that the modified GO- and Dex-loaded substrates are endowed with impressive biocompatibility and certain antibacterial qualities, making it possible for future application as a perspective implant material.

Quality of broccoli (Brassica oleracea L. var. italica) in modified atmosphere packaging made by gas barrier-gas promoter blending materials

This work aimed to prepare a blend of sulfonated poly ether ether ketone (SPEEK) into polyvinylidene fluoride (PVDF) to develop a modified film suitable as a modified atmosphere package (MAP) for broccoli. The miscibility between SPEEK and PVDF was determined by homogeneous micro-morphology and single glass transition temperature (Tg). Results revealed that the blended material had good antifouling ability, moderate porosities and appropriate gas selectivity. Films prepared by the blended material were used as equilibrium MAP to maintain quality of broccoli samples during storage. With ∼ 300 g of broccoli in ∼ 2.1 L of internal volume, films prepared with 50% (w/w) SPEEK and 50% (w/w) PVDF maintained an internal atmosphere of 8.2% CO2 and 2.0% O2 in MAP. In this atmosphere, acceptable sensory score of the broccoli was maintained for 25 d, compared with only ∼ 15 d for control samples. The MAP also reduced loss of green color and maintained texture and chemical composition of broccoli. The results of this study reveal that the prepared gas promoter-gas barrier blending packaging has promise for preservation of harvested fresh vegetables.

Dual Ag/ZnO-Decorated Micro-/Nanoporous Sulfonated Polyetheretherketone with Superior Antibacterial Capability and Biocompatibility via Layer-by-Layer Self-Assembly Strategy.

Polyetheretherketone is attractive for dental and orthopedic applications due to its mechanical attributes close to that of human bone; however, the lack of antibacterial capability and bioactivity of polyetheretherketone has substantially impeded its clinical applications. Here, a dual therapy implant coating is developed on the 3D micro-/nanoporous sulfonated polyetheretherketone via layer-by-layer self-assembly of Ag ions and Zn ions. Material characterization studies have indicated that nanoparticles consisting of elemental Ag and ZnO are uniformly incorporated on the porous sulfonated polyetheretherketone surface. The antibacterial assays demonstrate that Ag-decorated sulfonated polyetheretherketone and Ag/ZnO-codecorated sulfonated polyetheretherketone effectively inhibit the reproduction of Gram-negative and Gram-positive bacteria. Owing to the coordination of micro-/nanoscale topological cues and Zn induction, the Ag/ZnO-codecorated sulfonated polyetheretherketone substrates are found to enhance biocompatibility (cell viability, spreading, and proliferation), and hasten osteodifferentiation and -maturation (alkaline phosphate activity (ALP) production, and osteogenesis-related genetic expression), compared with the Ag-decorated sulfonated polyetheretherketone and the ZnO-decorated sulfonated polyetheretherketone counterparts. The dual therapy Ag/ZnO-codecorated sulfonated polyetheretherketone has an appealing bacteriostatic performance and osteogenic differentiation potential, showing great potential for dental and orthopedic implants.

Hybrid electrolyte SiW9MoV2/rGO/SPEEK for solid supercapacitors with enhanced conductive performance

To improve the proton conductive performance of heteropoly acids, a novel proton-conducting hybrid electrolyte SiW9MoV2/rGO/SPEEK was prepared by a simple and effective method based on sulfonated polyether ether ketone (SPEEK), H6SiW9MoV2O40 (SiW9MoV2) and reduced graphene oxide (rGO) in this work. This hybrid material was characterized by IR, TEM and XRD. Electrochemical impedance spectroscopy shows the obtained SiW9MoV2/rGO/SPEEK electrolyte exhibits an appreciable proton conductivity of 1.07 × 10−2 S cm−1 at 16 °C and 70% relative humidity, which increases with higher temperature, and the activation energy for proton conduction of this hybrid film is 17.82 kJ mol−1. The proton conduction is speculated to be the mixing of Grotthuss mechanism and Vehicle mechanism that accelerate the proton mobility in the hybrid electrolyte. This work lays a foundation in the field of HPAs-based separator films for proton exchange membrane devices and solid supercapacitors.

Graphene-Oxide-Decorated Microporous Polyetheretherketone with Superior Antibacterial Capability and In Vitro Osteogenesis for Orthopedic Implant.

Due to its similar elastic modulus of human bones, polyetheretherketone (PEEK) has been considered as an excellent cytocompatible material. However, the bioinertness, poor osteoconduction, and weak antibacterial activity of PEEK limit its wide applications in clinics. In this study, a facile strategy is developed to prepare graphene oxide (GO) modified sulfonated polyetheretherketone (SPEEK) (GO-SPEEK) through a simple dip-coating method. After detailed characterization, it is found that the GO closely deposits on the surface of PEEK, which is attributed to the π-π stacking interaction between PEEK and GO. Antibacterial tests reveal that the GO-SPEEK exhibits excellent suppression toward Escherichia coli. In vitro cell attachment, growth, differentiation, alkaline phosphatase activity, quantitative real-time polymerase chain reaction analyses, and calcium mineral deposition all illustrate that the GO-SPEEK substrate can significantly accelerate the proliferation and osteogenic differentiation of osteoblast-like MG-63 cells compared with those on PEEK and SPEEK groups. These results suggest that the GO-SPEEK has an improved antibacterial activity and cytocompatibility in vitro, showing that the developed GO-SPEEK has a great potential as the bioactive implant material in bone tissue engineering.

High performance proton-conducting composite based on vanadium-substituted Dawson-type heteropoly acid for proton exchange membranes

Proton exchange membranes (PEMs) are the key parts in proton exchange membrane fuel cells (PEMFCs). In this work, a proton-conducting composite membrane rGO-P2W16V2@SPEEK was synthesized from vanadium-substituted Dawson-type heteropoly acid (H8P2W16V2O62•20H2O, abbreviated as P2W16V2), sulfonated polyether ether ketone (SPEEK) and reduced graphene oxide (rGO). Characterizations proved the integrity of the Dawson-structure heteropoly acids (HPAs) in composites and the uniform inorganic-organic hybrid distribution. The membrane shows excellent proton conductivity of 7.90 × 10−2 S cm−1 at 50 °C and the proton conduction was proved to comply with the Grotthuss mechanism. Up to now, this is the first time that a Dawson-type HPA was reported for the application of PEMs and this work extended the application of polyoxometalate-based materials in the field of fuel cells.

Steady State Analysis of Water Transport through Sulfonated Polyether Ether Ketone (SPEEK) Membrane for Fuel Cell Application

Steady State Analysis of Water Transport through Sulfonated Polyether Ether Ketone (SPEEK) Membrane for Fuel Cell Application

Cross-linking of Imidazole-grafted Sulfonated Poly(ether ether ketone) as Proton Exchange Membranes for Direct Methanol Fuel Cells†

Cross-linking of Imidazole-grafted Sulfonated Poly(ether ether ketone) as Proton Exchange Membranes for Direct Methanol Fuel Cells†

The development of Speek/Pva/Teos blend membrane for proton exchange membrane fuel cells

Sulfonated poly ether ether ketone (SPEEK) has high potential for proton exchange membrane fuel cell (PEMFC) application and has been widely considered as most promising alternative to commercial membranes. In this study a novel ternary composite membrane consisting of SPEEK/poly (vinyl alcohol) (PVA) and tetraethyl ortosilicate (TEOS) were prepared by blending and casting method. The obtained samples were characterized by FT-IR, dynamic mechanical analysis (DMA), electrochemical impedance spectroscopy (EIS), oxidative and hydrolytic stability, water uptake capacity, swelling property and ion exchange capacity tests. According to these characterization test results, the addition of PVA in the membrane structure increased the mechanical strength and in addition TEOS is easily incorporated into the membrane structure because of the presence of modifiable groups in PVA. The addition of TEOS to blend membranes prevented water loss at high temperatures and TEOS addition indirectly increased the proton conductivity of the membranes. The highest performance of 600 mA/cm2 was obtained SP90/PV10/TE coded membrane at 0.6 V cell potential and fuel cell operate at 1 atm and 80 °C. At the same conditions Nafion 117 gave 400 mA/cm2. This study shows that blend membrane seems to be a promising alternative membrane for PEMFC application.

L-Arginine modified multi-walled carbon nanotube/sulfonated poly(ether ether ketone) nanocomposite films for biomedical applications

Favorable implant-tissue interactions are crucial to achieve successful osseointegration of the implants. Poly(ether ether ketone) (PEEK) is an interesting alternative to titanium in orthopedics because of its low cost, high biocompatibility and comparable mechanical properties with cancellous bone. Despite these advantages; however, the untreated surface of PEEK fails to osseointegrate due to its bioinert and hydrophobic behavior. This paper deals with the surface modification of PEEK with a novel method. For this, PEEK was first treated with concentrated sulfuric acid to prepare sulfonated PEEK (SPEEK) films using a solvent casting method. Then, 1 and 2 wt% multi-walled carbon nanotube was incorporated into SPEEK to form nanocomposite films. The samples were characterized with Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy. After successful preparation of the nanocomposite films, l-arginine was covalently conjugated on the nanocomposite films to further improve their surface properties. Subsequently, the samples were characterized using X-ray Photoemission Spectroscopy (XPS), water contact angle measurements and Atomic Force Microscopy (AFM) and Dynamic Mechanical Thermal Analysis (DMTA). Finally, cell culture studies were carried out by using Alamar Blue assay to evaluate the biocompatibility of the films. The results obtained indicate the successful preparation of l-arginine-conjugated MWCNT/SPEEK nanocomposite films. The modified surface shows potential to improve implants' mechanical and biological performances.

A sandwiched bipolar membrane for all vanadium redox flow battery with high coulombic efficiency

Due to the good balance between the low vanadium permeability and high proton conductivity, AIEM (amphoteric ion exchange membrane) has attracted vast consideration for all vanadium redox flow battery (VRB) application. Similar to the AIEM, BPMs (bipolar membranes) also have both anion and cation exchange groups in the anion-selective layer and cation-selective layer. In this paper, a series of BPMs based on PTFE (polytetrafluoroethylene) reinforced QAPSF (quaternized polysulfone) and SPEEK (sulfonated poly ether ether ketone) are prepared and investigated for the VRB application. As expected, all the membranes have presented typical sandwiched structure with an obvious intermediate layer observed by SEM. Owing to the “Donnan exclusion effect” of anion groups in QAPSF, all the BPMs have shown very low VO2+ permeability. Particularly, the battery with Q/P/S-3:2 membrane has shown average coulombic efficiency of 98.9% at current density of 40–80 mA cm−2. Considering the simple adjustment and abundant choice of cation or anion resins, BPMs membranes should be a promising candidate for VRB application after further investigation.

Preliminary Study of the Use of Sulphonated Polyether Ether Ketone (SPEEK) as Proton Exchange Membrane for Microbial Fuel Cell (MFC)

Sulfonated polyether ether ketone (SPEEK) was utilized as a proton exchange membrane (PEM) in Microbial Fuel Cell (MFC). The SPEEK performance in producing electricity had been observed in MFC using wastewater and glucose as substrates. The MFC with catering and tofu wastewater produced maximum power density about 0.31 mW/m2 and 0.03 mW/m2, respectively, lower that of MFC with tapioca average power density of 39.4 W/m2 over 48 h. The power density boosted because of the presence of Saccharomyces cerevisiae as inoculum. The study using of S. cerevisiae and Acetobacter acetii, separately, were also conducted in with glucose as substrate. The MFC produced an average power densities were 7.3 and 6.4 mW/m2 for S. cerevisiae and A. acetii, respectively. The results of this study indicated that SPEEK membrane has the potential usage in MFCs and can substitute the commercial membrane, Nafion.Article History: Received: Juni 14th 2017; Received: Sept 25th 2017; Accepted: December 16th 2017; Available onlineHow to Cite This Article: Putra, H.E., Permana, D and Djaenudin, D. (2018) Preliminary Study of the Use of Sulfonated Polyether Ether Ketone (SPEEK) as Proton Exchange Membrane for Microbial Fuel Cell (MFC). International Journal of Renewable Energy Development, 7(1), 7-12.https://doi.org/10.14710/ijred.7.1.7-12

Harvesting of microalgae Coelastrella sp. FI69 using pore former induced TiO2 incorporated PES mixed matrix membranes

AbstractBACKGROUNDExtracellular polymeric substances and microalgae stimulate membrane fouling during harvesting. The objective of the study was to compare the effect of pore formers on TiO2 embedded polyethersulfone mixed matrix membranes (MMMs) to harvest Coelastrella sp. FI69. The study experimented with hydrophilic additive (polyethylene glycol), polyelectrolyte additive (polyethylenimine), inorganic additive (zinc chloride) and charged polymer (sulfonated polyetherether ketone (SPEEK)) as pore formers.RESULTSIt was found that SPEEK/TiO2 combination enhanced the hydrophilic property of the PES membrane surface. Also, contact angle value (55.22°) was decreased by 1.38 times that of a neat PES (76.63°) membrane. Morphology studies indicated that the TiO2 particles dispersed well in the PES membrane matrix along with pore formers. The existence of super hydrophilic TiO2 supported the restriction of microalgae cell attachment on the membrane surface. The filtration of alginic acid sodium solution analysis showed that PES/SPEEK/TiO2 and PES/PEG/TiO2 membranes support higher flux with minimal fouling percentage. Microalgae filtration studies indicated that synergistic effect of both SPEEK and TiO2 on PES membrane exhibited higher water recovery percentage of 96% and equilibrium flux of 66 L m‐2 h‐1.CONCLUSIONFouling propensity is significantly reduced in modified membranes. Future research on scale‐up of membranes for further microalgae dewatering applications is recommended. © 2017 Society of Chemical Industry

Increasing the proton conductivity of sulfonated polyether ether ketone by incorporating graphene oxide: Morphology effect on proton dynamics

We synthesized graphene oxide–sulfonated polyether ether ketone (GO–SPEEK) composite membrane and compare its proton conductivity with that of Nafion® 117 and SPEEK membranes. From experimental measurements, we found that GO–SPEEK has better proton conductivity (σGO–SPEEK = 3.8 × 10−2 S cm−1) when compared to Nafion® 117 (σNafion = 2.4 × 10−2 S cm−1) and SPEEK (σSPEEK = 2.9 × 10−3 S cm−1). From density functional theory (DFT-) based total energy calculations, we found that GO–SPEEK has the shortest proton diffusion distance among the three membranes, yielding the highest tunneling probability. Hence, GO–SPEEK exhibits the highest conductivity. The short proton diffusion distance in GO–SPEEK, as compared to Nafion® 117 and SPEEK, can be attributed to the presence of oxygenated functional groups of GO in the polymer matrix. This also explains why GO–SPEEK requires the lowest hydration level to reach its maximum conductivity. Moreover, we have successfully shown that the proton conductivity σ is related to the tunneling probability T, i.e., σ = σ′ exp(−1/T). We conclude that the proton diffusion distance and hydration level are the two most significant factors that determine the membrane’s good conductivity. The distance between ionic sites of the membrane should be small to obtain good conductivity. With this short distance, lower hydration level is required. Thus, a membrane with short separation between the ionic sites can have enhanced conductivity, even at low hydration conditions.

Synthesis and characterization of sulfonated poly ether ether ketone (SPEEK)/ CNTs composite proton exchange membrane for application in fuel cells

Sulfonated poly ether ether ketone (SPEEK) membrane was synthesized and evaluated for its application in proton exchange membrane. Multi-walled carbon nanotubes (MWCNTs) and SPEEK composite membrane was also prepared using solution casting method and evaluated for proton exchange membrane fuel cell (PEMFC) application. The FT-IR and UV- visible spectra confirmed the successful sulfonation of PEEK. Results showed an increase in ion exchange capacity (IEC) value from 1.426mmol/g to 1.502mmol/g for SPEEK and SPEEK/0.7%CNTs composite. The degree of sulfonation (DS %) was determined by back titration method and the value was found to be 46% and 49 % for SPEEK and SPEEK/0.7%CNTs composite respectively. The conductivity of the SPEEK membrane was found to be 9.93 mS/cm and for composite membrane (SPEEK/0.7%CNTs) the value of conductivity exceeded approximately two times and found to be 22.44 mS/cm. The ratio of water uptake and swelling was observed to decrease proving the good quality of the membrane.

CNT/SPEEK Nano‐Composite Membranes: Toward Improved Properties

This study describes the preparation, characterization and performance of carboxylated carbon nanotubes (c‐CNT) incorporated sulfonated poly ether ether ketone (SPEEK) membrane for nanofiltration application. Carboxylation was done to purify and to graft functional groups onto CNT walls. Composite membranes were synthesized by dispersing different weight fraction (0.1, 0.2 and 0.5%) of carboxylated Carbon nanotubes as filler in SPEEK matrix using N‐N' Dimethylacetamide as a solvent. Surface morphology, thermal and mechanical strength of the resulting membranes has been characterized through respective techniques. SEM and AFM images demonstrate the dispersed c‐CNT in polymer matrix. Prepared nanohybrid membranes were examined for water flux measurements and salt rejection experiments. Addition of c‐CNT in SPEEK not only enhanced the flux and salt rejection performance but also improved the thermo‐mechanical properties of the hybrid membranes as compared to SPEEK membrane.