Ether Ketone Research Articles

Plasma/Ozone Induced PolyNaSS Graft-Polymerization onto PEEK Biomaterial for Bio-integrated Orthopedic Implants

Owing to its superior bulk mechanical properties, poly (ether ether ketone) (PEEK) has gained popularity over the past 15 years as a metal substitute in biomedical implants. Low surface energy is a fundamental issue with PEEK implants. This low surface energy caused by a moderately hydrophobic surface may be able to inhibit cellular adherence and result in the development of an inflammatory response, which may result in cell necrosis and apoptosis. In this work, plasma and ozone treatments have been utilized to surface activate PEEK and graft ionic bioactive polymer polyNaSS (poly (sodium styrene sulfonate)) successfully on the surface to promote cellular attachment and biomineralization. The main goal of our research has been to find a stable green process for surface modification of PEEK by plasma/ozone approaches to increase PolyNaSS grafting efficiency and biomineralization. To further the field of bioactive orthopedic and dental implant technology, this research attempts to address a significant constraint of PEEK implants while preserving their favorable mechanical properties.

High-performance SPEEK membrane with polydopamine-bridged PTFE nanoparticles for vanadium redox flow batteries

With the growing demand of energy storage techniques in carbon-neutral environments, vanadium redox flow batteries (VRFBs) have emerged as outstanding systems for long-duration energy storage. Developing high-performance ion exchange membrane is essential for broad deployment of RFBs. In this work, a SPEEK/PTFE membrane is designed by incorporating polytetrafluoroethylene (PTFE) nanoparticles into sulfonated poly (ether ether ketone) (SPEEK) membrane by bio-inspired polydopamine (PDA) bridge. PDA combines SPEEK membrane and hydrophobic PTFE nanoparticle tightly by its abundant functional groups. The ion selectivity of optimal SPEEK/PTFE-0.5 % membrane is 8.9 times greater than that of Nafion 115. Remarkably, VRFB with optimal SPEEK/PTFE-0.5 % membrane exhibits excellent battery performances including impressive columbic efficiency (CE, 99.5 %) and energy efficiency (EE, 86.3 %) at 100 mA cm−2 surpassing Nafion 115 (CE, 95.8 %; EE, 83.4 %). Besides, VRFB employing SPEEK/PTFE-0.5 % membrane demonstrates excellent cycling stability, with higher capacity retention (71.4 % after 300 cycles) compared to Nafion 115, indicating its capability of extended operation. This work illustrates that the design of PDA bridge in composite membrane is a useful approach for developing high-performance membranes in RFBs.

Optimized Sulfonated Poly(Ether Ether Ketone) Membranes for In-House Produced Small-Sized Vanadium Redox Flow Battery Set-Up.

The ionic exchange membranes represent a core component of redox flow batteries. Their features strongly affect the performance, durability, cost, and efficiency of these energy systems. Herein, the operating conditions of a lab-scale single-cell vanadium flow battery (VRFB) were optimized in terms of membrane physicochemical features and electrolyte composition, as a way to translate such conditions into a large-scale five-cell VRFB stack system. The effects of the sulfonation degree (SD) and the presence of a filler on the performances of sulfonated poly(ether ether ketone) (SPEEK) ion-selective membranes were investigated, using the commercial perfluorosulfonic-acid Nafion 115 membrane as a reference. Furthermore, the effect of a chloride-based electrolyte was evaluated by comparing it to the commonly used standard sulfuric acid electrolyte. Among the investigated membranes, the readily available SPEEK50-0 (SD = 50%; filler = 0%) resulted in it being permeable and selective to vanadium. Improved coulombic efficiency (93.4%) compared to that of Nafion 115 (88.9%) was achieved when SPEEK50-0, in combination with an optimized chloride-based electrolyte, was employed in a single-cell VRFB at a current density of 20 mA·cm-2. The optimized conditions were successfully applied for the construction of a five-cell VRFB stack system, exhibiting a satisfactory coulombic efficiency of 94.5%.

Characterizing thrombus adhesion strength on common cardiovascular device materials.

Thrombus formation in blood-contacting medical devices is a major concern in the medical device industry, limiting the clinical efficacy of these devices. Further, a locally formed clot within the device has the potential to detach from the surface, posing a risk of embolization. Clot embolization from blood-contacting cardiovascular devices can result in serious complications like acute ischemic stroke and myocardial infarction. Therefore, clot embolization associated with device-induced thrombosis can be life-threatening and requires an enhanced fundamental understanding of embolization characteristics to come up with advanced intervention strategies. Therefore, this work aims to investigate the adhesive characteristics of blood clots on common biocompatible materials used in various cardiovascular devices. This study focuses on characterizing the adhesion strength of blood clots on materials such as polytetrafluoroethylene (PTFE), polyurethane (PU), polyether ether ketone (PEEK), nitinol, and titanium, frequently used in medical devices. In addition, the effect of incubation time on clot adhesion is explored. Results from this work demonstrated strongest clot adhesion to titanium with 3h of incubation resulting in 1.06 ± 0.20kPa detachment stresses. The clot adhesion strength on titanium was 51.5% higher than PEEK, 35.9% higher than PTFE, 63.1% higher than PU, and 35.4% higher than nitinol. Further, adhesion strength increases with incubation time for all materials. The percentage increase in detachment stress over incubation time (ranging from 30min to 3h) for polymers ranged from at least 108.75% (PEEK), 140.74% (PU), to 151.61% (PTFE). Whereas, for metallic surfaces, the percentage rise ranged from 70.21% (nitinol) to 89.28% (titanium). Confocal fluorescence imaging of clot remnants on the material surfaces revealed a well-bounded platelet-fibrin network at the residual region, representing a comparatively higher adhesive region than the non-residual zone of the surface.

Few-shot reliability evaluation of tribopairs degradation based on active learning supported generative adversarial network

The high reliability of seawater hydraulic components depends on the tribological properties of key tribopairs. It is impractical to conduct a high number of lifetime tests in a short amount of time due to the limitation of the cost and test time constraints in practical engineering applications, which has a significantly impact on the accuracy of reliability evaluation. To solve this, the Generative Adversarial Network (GAN) is provided as a few-shot learning (FSL) technique for expanding the tribopairs degradation data set, which has the potential to generate high-quality samples. Considering the uncertainty and diversity, an active learning approach is proposed to selecting the most effective generated samples. Finally, reliability is finally evaluated based on Wiener process model via using actual data combine with generated data selected from GAN model. Simulations and friction characteristics experiment of polyether ether ketone (PEEK)/17-4PH stainless steel are applied to validate the proposed method, the results show that the proposed method could generate and choose samples that are highly similar to the real samples, the accuracy of reliability evaluation is effectively improved.

Breaking the trade-off between proton conductivity and mechanical stability through liquid-crystal-modified aramid fibers in sulfonated polyether ether ketone membranes

In the quest for sustainable and high-performance hydrogen fuel cells, proton exchange membranes (PEMs) stand as a pivotal research focus. To overcome the significant challenge posed by the traditional trade-offs between proton conductivity and mechanical stability, this work introduces liquid-crystal-modified aramid fibers (DBAF) with highly ordered molecular arrangements and abundant sulfonic acid groups on the side chains as proton-hopping sites into a sulfonated poly (ether ether ketone) (SPEEK) matrix. The inclusion of components not only improves the proton conductivity of the membrane, but also boosts its mechanical strength. The results of our study demonstrate that the externally attached sulfonic acid groups create extra channels for the transport of protons. Additionally, the organized and consistently stable hydrogen-bond network enables the Grotthuss transport mechanism within the SPEEK membrane. The 1 wt% DBAF-SPEEK composite membrane exhibits a maximum proton conductivity of 0.23 S cm−1 at 80 °C, representing a 64% increase over the baseline SPEEK membrane's 0.14 S cm−1. Simultaneously, the tensile strength at normal room temperature is 39.7 MPa, exhibiting an improvement of 86% compared to the initial value of 21.3 MPa. Additionally, the swelling ratio is lowered by 18.69%. Compared with the baseline membrane, the DBAF-enhanced SPEEK composite membrane exhibits superior mechanical stability and proton conductivity within a moderate temperature range (30–80 °C). Consequently, this work offers valuable insights for the development of novel proton-conductive materials.

Performance of high sulfonated poly(ether ether ketone) improved with microcrystalline cellulose and 2,3-dialdehyde cellulose for proton exchange membranes

Sulfonated poly (ether ether ketone) (SPEEK) has received substantial attention for its potential to improve the electrochemical behavior and thermomechanical capabilities of direct methanol fuel cells. This study examines how the integration by solution casting of microcrystalline cellulose (MCC) and 2,3-dialdehyde cellulose (DAC) onto highly sulfonated PEEK (with a sulfonation degree of 80%) affects its physicochemical properties and morphological structures. The mechanical attributes and proton conductivity of the polymer matrix are impacted by MCC and DAC inclusion into SPEEK membrane. The maximum proton conductivity was seen in the SPEEK/MCC membranes at 70 °C (up to 0.1 S cm−1). The proton conductivity in methanol vapor was increased by SPEEK/DAC membranes at high temperatures as opposed to pristine SPEEK and SPEEK/MCC membranes.

A Stable Polymer-Blended Anion-Exchange Membrane for Enhanced Performance in Redox Flow Batteries

Redox flow batteries (RFBs) operate with a membrane, responsible for the separation of cationic active species and allowing the passage of counter-ions, to preserve electroneutrality on each side of RFBs. Commercial cation-exchange membranes (CEMs), such as Nafion®, possess excellent ionic conductivity and chemical stability. However, they face challenges in blocking cationic active species common in RFBs, leading to significant capacity loss over time. Anion-exchange membranes (AEMs) efficiently block active species with the assistance of the Donnan effect. Nevertheless, commercial AEMs lack acid stability and conductivity compared to their cationic counterparts.Polytetrafluoroethylene (PTFE)-reinforced quaternary ammonium cardo poly(ether)ketone (QPEK-C)-based membranes with Al2O3 additives (PQPAM), a heterogeneous AEM developed in our lab1, possess excellent ionic conductivity with low permeability of active species and good mechanical properties. PQPAM has demonstrated better acid stability than commercial AEMs. However, its acidic and oxidative stability require improvement, as evidenced by degradation after 250 hours of in-situ harsh RFB cycling due to the heterogeneous nature of PQPAM and the exposure of the susceptible QPEK-C-rich side to the electrolytes2. To address this issue, we propose a strategy to enhance the chemical stability of QPEK-C-based membranes by inhibiting the exposure of QPEK-C to oxidation agents through blending with a hydrophobic engineering thermoplastic like polybenzimidazole (PBI)3,4. Furthermore, PBI's known ability to protonate in acidic media will reinforce ionic conductivity and the separation of active species, thus improving the Donnan effect, in addition to enhancing chemical and mechanical stability.Elemental analyses and microscopy images confirm a homogeneous blending of PBI and QPEK-C, promising stability improvement. The results of ex-situ tests on ionic conductivity, cation permeability, and chemical stability align with the mentioned hypotheses, showcasing that blend of PBI/QPEK-C outperforms pure PBI and QPEK-C AEMs. Additionally, the mechanical properties of the PBI/QPEK-C blended AEMs are improved compared to pure QPEK-C AEMs and PBI/QPEK-C blended AEMs outperform pure PBI and QPEK-C AEMs in in-situ cycling tests with our patented titanium-cerium RFBs5. Moreover, this work will explore other strategies to improve the blended AEM properties, such as utilizing inorganic fillers or PTFE reinforcement.

Role of Glass Fiber in the Flow-Induced Crystallization of Poly(ether ether ketone)

Role of Glass Fiber in the Flow-Induced Crystallization of Poly(ether ether ketone)

Can mechanical heart valves perform similarly to tissue valves? An in vitro study

Current surgical aortic valve (AV) replacement options include bioprosthetic and mechanical heart valves (MHVs), each with inherent limitations. Bioprosthetic valves offer superior hemodynamics but suffer from durability issues, typically initiating deterioration within 7–8 years. MHVs, while durable, necessitate lifelong anticoagulation therapy, presenting risks such as severe bleeding and thromboembolic events. The need for anticoagulants is caused by non-physiological flow through the hinge area during the closed phase and large spikes of regional backflow velocity (RBV) during the closing phase that produces high shear events. This study introduces the iValve, a novel MHV designed to combine the hemodynamic benefits of bioprosthetic valves with the durability of MHVs without requiring anticoagulation. The iValve features eye-like leaflets, a saddle-shaped housing, and an optimized hinge design to enhance blood flow and minimize thrombotic risk. Fabricated using 6061-T6 aluminum and polyether ether ketone (PEEK), twelve iValve iterations were evaluated for their opening and closing dynamics. The reported top-performing prototypes demonstrated competitive performance against industry standards. The proposed iValve prototype exhibited a mean RBV of −4.34 m/s with no spikes in RBV, performing similarly to bioprosthetic valves and significantly outperforming existing MHVs. The iValve’s optimized design showed a 7–10% reduction in closing time and a substantial decrease in RBV spikes, potentially reducing the need for anticoagulation therapy. This study highlights the iValve’s potential to revolutionize prosthetic heart valve technology by offering a durable, hemodynamically superior solution that mitigates the drawbacks of current MHVs.

Engineering the Crystalline Architecture for Enhanced Properties in Fast-Rate Processing of Poly(ether ether ketone) (PEEK) Nanocomposites.

Rapid cooling in fast-rate manufacturing processes such as additive manufacturing and stamp forming limits the development of crystallinity in semicrystalline polymer nanocomposites and, therefore, potential improvements in the mechanical performance. While the nucleation, chain mobility, and crystallization time from rapid cooling are known competing mechanisms in crystallization, herein we elucidate that the crystalline morphology and architecture also play a key role in tuning the mechanical performance. We explore how modifying the spherulite morphology via a cellulose nanocrystal (CNC) and graphene nanoplatelet (GNP) hybrid system in their pristine form can improve or preserve the mechanical properties of poly(ether ether ketone) (PEEK) nanocomposites under two extreme cooling rates (fast -460 °C/min and slow -0.7 °C/min). A scalable manufacturing methodology using water as the medium to disperse the powder system was developed, employing a CNC as a dispersing agent and stabilizer for PEEK and GNP. Despite the expected limited mechanical reinforcement due to thermal degradation, CNCs significantly impacted PEEK's crystalline architecture and mechanical performance, suggesting that surface interactions via lattice matching with PEEK's (200) crystallographic plane play a critical role in engineering the microstructure. In fast cooling, the CNC and CNC:GNP systems reduced the crystallinity, respectively, yet led to minimizing the reduction in the tensile strength and maintaining the tensile modulus at the Neat level in slow cooling. With slow cooling, crystallinity remained relatively unchanged; however, the addition of CNC:GNP improved the strength and modulus by ∼10% and ∼16%, respectively. These findings demonstrate that a hybrid nanomaterial system can tailor PEEK's crystalline microstructure, thus presenting a promising approach for enhancing the mechanical properties of PEEK nanocomposites in fast-rate processes.

Additive manufacturing and mechanical performance of short fiber reinforced PEEK (polyether ether ketone) thermoplastic composites in a vacuum environment

Short fiber reinforced thermoplastic composites (SFRTC) have gained popularity in the material extrusion (MEX) method, which is an additive manufacturing (AM) technology, allowing for the simpler and more cost-effective production of polymer composites. However, parts produced using MEX 3D printing technology often exhibit poor mechanical properties and surface quality compared to products manufactured using injection molding, which is one of the main disadvantages of this method. Various methods are used to overcome these challenges, such as production in a vacuum environment, heat-based processes, ultrasonic vibrations, and others. The objective of this study was to achieve parts with lower porosity and improved mechanical properties when printed in a vacuum environment compared to an atmospheric environment. Additionally, an investigation into the optimization of printing parameters was conducted to determine the parameters that yield the highest mechanical properties. For this purpose, SFRTC parts were printed at different vacuum levels (0.5, 10, 100 mbar), and they were subjected to flexural tests to determine their mechanical properties. The results showed that the flexural stress and elastic modulus of the samples produced in a 0.5 mbar vacuum environment increased by 79.75% and 39.41%, respectively, compared to samples produced in an atmospheric environment. Furthermore, the cross-sectional images of the samples were examined using an optical microscope, revealing the lowest porosity in the samples printed in 0.5 mbar vacuum environment.

Dual synergies of functionalized hydrophilic MOFs based poly (aryl ether ketone sulfone) ultrafiltration membranes: Electrostatic action and pore size screening

In this paper, amino monomer (4Am-PH) and the sulfonated poly (arylene ether ketone sulfone) involving amino groups (Am-SPAEKS) were successfully prepared by diazotization reaction and direct polycondensation, respectively. The polyethyleneimine-modified UiO-66-NH2 (P-MOFs) were prepared as fillers. Composite membranes were fabricated by incorporating different contents of P-MOFs into Am-SPAEKS polymer matrix using non-solvent-induced phase separation. The morphology, chemical structure and properties of the polymers, fillers and composite membranes were proved by FT-IR, 1H NMR, FE-SEM, XPS and etc. The final experimental results showed that the introduction of hydrophilic fillers, P-MOFs, substantially improved the hydrophilicity, water flux and antifouling capabilities of the membranes. The water contact angle decreased from 78.5° to 56.4°. The flux of water from a pure membrane was 333.68 L/m2 h. When the content of P-MOFs was 0.1 %, the water flux could attain to 830.23 L/m2 h, the retention rate of bovine serum albumin (BSA) solution could attain to 98.6 % and the flux recovery rate (FRR) values of the composite membrane remained high (86.1 %) for BSA solution. In addition, after three cycles, the pure water flux of the composite membrane could still attain 595.49 L/m2 h. The results demonstrated that P-MOFs have significant potential for utilization in the preparation of composite ultrafiltration membranes and provided an effective idea for the modification and design of other hydrophilic MOFs applied in the study area of ultrafiltration membranes.

Comparative study of random and block SPEEK copolymers for high-temperature proton exchange membrane electrolysis

Traditionally, High-temperature proton Exchange Membrane Electrolysis (HT-PEME) has relied on costly and exceptionally hydrogen-permeable PFSA ionomers like Nafion®, Flemion®, and Aciplex®. Sulfonated Poly (ether ether ketone) (SPEEK) membranes have been developed as potential substitutes for the highly hydrogen permeable Nafion® membranes. The ion exchange capacity (IEC) of SPEEK membranes has been varied, ranging from 0.5 to 2.2 meq/g, to enhance their performance. Furthermore, the incorporation of ion-conducting units into these polymers is explored using both random and block copolymerization approaches. At 75 °C, SPEEK membranes exhibit significantly lower hydrogen diffusivity (35–50 barriers) compared to Nafion® and Flemion® membranes (∼202 barriers). Among SPEEK yttria-stabilized zirconia membranes (YSZM), those produced through random copolymerization exhibit marginally greater proton-to-hydrogen selectivity than YSZM derived from block SPEEK copolymers with a similar ion exchange capacity (IEC). This could be ascribed to the improved hydrogen-blocking capability resulting from an underdeveloped hydrophilic component. Among the SPEEK membranes tested, the random SPEEK membrane with an IEC of approximately 1.9 meq/g demonstrates superior performance (6.8 A/cm2) compared to a similarly thick (∼45 μm) Flemion® membrane (4.4 A/cm2) at 2.2 V. However, during an accelerated stress test involving 410 successive fluctuating flow densities of 2.8 and 0.04 A/cm2 imitating the alternating period's cycles of a water electrolyzer, the random SPEEK membrane exhibits a higher degradation rate (860 μV/h) compared to Flemion® and Nafion® (505 μV/h).

Developing PEEK composites with exceptional thermal conductivity and electromagnetic shielding properties by constructing a dense dual-continuous filler network

Polyether ether ketone (PEEK) has regular and rigid molecular chain and is insoluble in most organic solvents. Therefore, it is challenging to use PEEK matrix composites for thermal conductivity (TC) and electromagnetic interference (EMI) shielding applications. Herein, PEEK composites with hybrid fillers were fabricated by solution blending and non-solvent-induced phase separation (NIPS) methods based on a chemical conversion reaction between soluble precursor PEEK-dithiolane and PEEK. Synergistic interaction between hybrid fillers (graphene nanosheets and multiwalled carbon nanotubes) improves the thermal and electrical conductivity of the composites. The effect of the hot-pressing pressure on the conductive/thermal network densification was investigated. The composites performed optimally at a hot pressure of 200 MPa and a filler content of 20.08 vol%. The maximum in-plane and out-of-plane TC reached 10.46 W·m–1·K–1 and 4.8 W·m–1·K–1, respectively, which were 4619 % and 2414 % higher than the corresponding TC of PEEK. Simultaneously, the optimised composite demonstrated significantly improved electrical conductivity (3517 S/m) and EMI shielding effectiveness (66.1 dB). These excellent characteristics are attributed to the solution blending–NIPS method, which improves the dispersion of hybrid fillers in the matrix and forms an internal and external dual-continuous thermal conductive network. The dual-continuous network creates effective channels for phonon and electron transport and enhances EM wave loss. This work provides inspiration for the preparation of PEEK composites as advanced EMI protection and thermal management materials.

Simulating the Morphological Changes of Facial Deformities after Using 3D-printed Polyether Ether Ketone Facial Implants.

Patient-specific implants (PSIs) have been presented as an effective solution for diseases that require reconstruction. PSIs are designed to precisely fit anatomical defects or deformities in terms of shape and size. In addition to the possibility of predicting the results of surgery regarding soft tissue changes. A research sample consisting of 10 patients with facial deformities underwent maxillofacial reconstructive surgery between 2020 and 2021 in the Tishreen University Hospital, Syria. All patients underwent computed tomography scans; then, the design of the required facial implant was carried out, and the three-dimensional soft tissues were reconstructed using the ExoCad 3.0 program based on the computed tomography. The final form of the facial implant was printed from polyether ether ketone, and then surgical work was performed. The patients were followed up after 6 months. Then, a comparison was made between the virtual design and the real result. The absolute difference between the expected soft tissue changes result and the actual result did not exceed three-tenths for all patients, and only two of 10 patients had measurements higher than 20%. This technique can be relied upon with the placement of implants to predict the outcome of the surgical procedure in terms of morphological changes in the facial soft tissues covering PSI polyether ether ketone. Therefore, it is possible to make a virtual design based on the cosmetic requirements of the patient.

Obtaining excellent mechanical properties with additively manufactured short fiber reinforced polyether-ether-ketone thermoplastics through simultaneous vacuum and infrared heating

Additive manufacturing of short fiber reinforced thermoplastic composite with high-performance engineering thermoplastics is important in various industrial sectors because of their ability to manufacture complex and lightweight products. Although extensive studies in the literature are aimed at enhancing the mechanical performance of additively manufactured short fiber reinforced thermoplastics through methods like refining printing parameters, enhancing fiber fractions, and optimizing printing parameters, their mechanical performance remains limited. In this study, the individual effects of vacuum-assisted printing and infrared pre-heater-assisted printing and their combined effects were investigated to substantially increase the mechanical properties, interlaminar performance, and crystallinity ratios. The polyether ether ketone (PEEK) samples were printed with vacuum-assisted, infrared-assisted, and a combination of vacuum and infrared-assisted environments were subjected to three-point bending tests to evaluate their mechanical properties. Synergistic vacuum and infrared-assisted printing significantly enhanced the mechanical properties as the flexural strength increased by 54.58 % compared to printing under vacuum alone. Moreover, the flexural strength and elasticity modulus of samples printed with vacuum-infrared-assisted manufacturing increased by 324.48 % and 239.77 %, respectively, when compared to printing under atmospheric pressure without additional heating. Thermal and structural characterizations of the printed parts revealed that this significant improvement was attributed to reduced porosity ratios and increased crystallinity.

Preparation of sulfonated poly(arylene ether ketone sulfone) PEMs with enhanced proton conductivity by introducing ionic liquid impregnated MOFs

In this research, sulfonated poly(arylene ether ketone sulfone) containing -COOH groups (C-SPAEKS) was chosen as the substrate, and ionic liquid functionalized MOFs (UiO-66-AS@ILs) were selected as fillers to prepare C-S-U-AS@ILs hybrid membranes (The term “C-S-U-AS@ILs” signifies C-SPAEKS with an incorporated ionic liquid functionalized UiO-66-AS@ILs). The UiO-66-AS@ILs and C-S-U-AS@ILs hybrid membranes were characterized by 1H NMR, FT-IR, PXRD and SEM. The prepared membranes exhibited suitable water uptake and swelling ratios, and the C-S-U-AS@ILs-5 % hybrid membrane possessed superior proton conductivity (0.197 S cm−1 at 90 °C) was much higher than C-SPAEKS (0.156 S cm−1 at 90 °C) and Nafion 117 (0.110 S cm−1 at 90 °C). Moreover, the C-S-U-AS@ILs-5 % hybrid membranes’ power density up to 474.24 mW cm−2, significantly higher than that of C-SPAEKS (220.88 mW cm−2) under the same conditions. These results reflect that the hybrid membranes exhibited superior properties and fit the standards of proton exchange membranes.

Increasing the toughness while reducing the viscosity of carbon nano-tube/polyether imide/polyether ether ketone nanocomposites

Polyether ether ketone (PEEK) has good mechanical properties. However, its high viscosity when molten limits its use because it is hard to process. PEEK nanocomposites containing both carbon nanotubes (CNTs) and polyether imide (PEI) were prepared by a direct wet powder blending method using a vertical injection molding machine. The addition of an optimum amount of PEI lowered the viscosity of the molten PEEK by approximately 50% while producing an increase in the toughness of the nanocomposites, whose strain to failure increased by 129%, and fracture energy increased by 97%. The uniformly dispersed CNT/PEI powder reduced the processing difficulty of PEEK nanocomposites without affecting the thermal resistance. This improvement of the strength and viscosity of PEEK facilitate its use in the preparation of thermoplastic composites.

MnO2-modified PEEK membrane for efficient oil-water separation and solar-assisted seawater desalination

Economic and efficient routes to achieve clean freshwater from oil-water mixtures and seawater have gained special attention to reduce the current water crisis, but still a challenge unsolved. Herein, poly (ether ether ketone) (PEEK) membrane, modified with MnO2 layer, has been prepared by facile hydrothermal method to address this issue aforementioned. Given the existence of PEEK and underwater superoleophobicity/underoil superhydrophilicity of MnO2, the composite membrane exhibits strong mechanic properties (tensile stress: 110.2 MPa) and high separation efficiencies (99.9 %) for different oil–water mixtures under gravity. Additionally, our membrane could also effectively separate immiscible oil mixtures according to the dipole–dipole interaction. Furthermore, firm chemical stability against dichloromethane, N, N-Dimethylformamide, 1 M NaOH, 1 M HCl, and 1 M NaCl has been achieved. Most importantly, our membrane displays durable evaporation efficiency (2.63 kg m-2h−1), high energy efficiency (85.9 %), and super salt tolerance under 1 sun irradiation, for solar-assisted seawater desalination.