Sulfonated Poly Ether Ether Ketone Research Articles

Using Layer-by-layer Assembled Clay Composite Junctions to Enhance the Water Dissociation in Bipolar Membranes.

Bipolar membranes (BPMs) with a layer-by-layer (LbL) assembled montmorillonite (K30 MMT) clay-polyelectrolyte (PE) composite junction coated onto a sulfonated poly(ether ether ketone (SPEEK)) electrospun support are prepared, characterized and their water dissociation performance is analyzed. In particular, the focus is on the effect of the presence of the K30 MMT clay as a catalyst for water dissociation, the bilayer number (three, six, and nine), and the PE strength (poly(ethylenimine) (PEI) as a weak PE and poly(diallyl dimethylammonium chloride) (PDADMAC) as a strong PE) on the BPM performance. The BPMs are prepared by electrospinning and hot pressing SPEEK and the Fumion FAA-3 polymer. Adding the composite multilayers in the BPM junction decreases the membrane area resistance in reverse bias from 560 to 21 Ohms cm2 for the best-performing modified BPM. The bilayer number has limited influence on the overall membrane resistance, while the PDADMAC BPMs outperform the PEI BPMs due to the higher and more stable PE and clay adsorptions. Electrochemical impedance spectroscopy shows that the depletion layer thickness decreases exponentially with the number of bilayers as the water dissociation reaction becomes less dependent on the junction electric field. Furthermore, the higher Donnan exclusion at the modified junctions improves the BPM permselectivity 3-fold compared to the BPM containing no catalyst. Altogether, these improvements lead to 6.7 times less energy being used in BPM electrodialysis for the production of acid and base when a BPM with composite LBL junction is used compared to a BPM without catalyst. Thus, adding MMT clay composite LbL catalyst to BPM junctions is a promising method to improve the efficiency and reduce the energy consumption of electrochemical processes that rely on BPMs.

“Janus” PEEK implant with sandwich Mg-containing coating for infected tissue repair

Having good antibacterial properties and promoting soft and hard tissue repair are the keys to successful implantation of intraosseous transcutaneous. Polyether ether ketone (PEEK) is a class of FDA-approved polymer implants. However, the surface of PEEK is bioinert, which is easy to cause postoperative infection and poor tissue integration. In this study, polypyrrole (Ppy) was polymerized on sulfonated PEEK, Mg3(PO4)2 nanosheets were grown in situ on one side, and polycaprolactone (PCL) was then spun on the surface to form a Janus-like surface on PEEK. The Ppy/Mg3(PO4)2/PCL composite coating could inhibit bacterial adhesion, and the excellent photothermal properties of Ppy/Mg3(PO4)2/PCL and Ppy coatings further promote the removal of bacteria due to the accumulated heat. After the infection was eliminated, the Janus-like surface of modified PEEK switched macrophages to anti-proinflammatory response and promoted both soft and hard tissue repair. The Ppy modified sulfonated PEEK could promote collagen secretion in the soft tissue, while the PCL films on Ppy/Mg3(PO4)2/PCL was densified by temperature response under near-infrared light treatment to close the exposed interface of Mg3(PO4)2 nanosheets that was more conducive to bone repair. In summary, PEEK with Janus-like surface consisting of Ppy/Mg3(PO4)2/PCL and Ppy has multiple biological functions of sequential antibacterial and soft and hard tissue repair, and is a promising candidate material for intraosseous transcutaneous implants.

Thorium Recovery with Crown Ether–Polymer Composite Membranes

Thorium is a weak radioactive element, but the control of its concentration in natural aqueous systems is of great interest for health, because it is a toxic heavy metal. The present paper presents the recovery of thorium from diluted synthetic aqueous systems by nanofiltration. The membranes used for the nanofiltration of systems containing thorium species are composites containing 4′-Aminobenzo-15-crown-5 ether (ABCE) and sulfonated poly–etherether–ketone (sPEEK). The composite membranes (ABCE–sPEEK) were characterized by scanning electron microscopy (SEM), energy-dispersive X–Ray spectroscopy (EDAX), thermal analysis (TG and DSC), and from the perspective of thorium removal performance. To determine the process performance, the variables were the following: the nature of the composite membrane, the concentration of thorium in the aqueous systems, the rotation speed of the stirrer, and the pressure and the pH of the thorium aqueous system. When using pure water, a permeate flux value of 12 L·m−2 h−1 was obtained for the sPEEK membrane, and a permeate flux value of up to 15 L·m−2 h−1 was obtained for the ABCE–sPEEK composite membrane. The use of mechanical stirring, with a propeller stirrer, lead to an increase in the permeate flux value of pure water by about 20% for each of the studied membranes. Depending on the concentration of thorium and the pH of the feed solution, retentions between 84.9% and 98.4% were obtained. An important observation was the retention jump at pH 2 for the ABCE–sPEEK composite membrane. In the paper, a thorium ion retention mechanism is proposed for the sPEEK membrane and the ABCE–sPEEK composite membrane.

Recent Progresses and Challenges to Determine Properties of Sulfonated Polyether Ether Ketone Based Electrolytes for Direct Methanol Fuel Cell Applications

AbstractThis review focuses on fillers, modifications, and methods used in the preparation and development of sulfonated poly(ether ether ketone) (sPEEK) membranes, specifically for direct methanol fuel cell (DMFC) applications as proton exchange membranes in recent years. The primary objective is to evaluate recent advancements by emphasizing key characteristics such as water uptake and swelling capacity, ionic conductivity, methanol permeability, and single cell polarization tests. Additionally, the review aims to provide insights for future researchers by discussing the preparation processes of electrolytes. It presents basic characterizations of membrane electrolytes, including evaluations of the sulfonation degree and ion exchange capacities of sPEEK. High performance of membrane electrolytes is essential for commercialization and to compete with established membranes like Nafion®, which has a perfluorosulfonic acid structure. Therefore, the review also covers detailed characterization methods for assessing long‐term stability when available in the related studies. Numerical results and indicators are categorized and tabulated for easy interpretation and comparative analysis.

Correlation of proton conductivity and free volume in sulfonated polyether ether ketone electrolytes: A positron annihilation lifetime spectroscopy study

Proton-conducting polymers play a pivotal role in clean energy technologies and various industrial applications, with a significant emphasis on enhancing energy efficiency and minimizing environmental impact. Sulfonated polyether ether ketone (SPEEK), which is renowned for its proton conductivity, has emerged as a key material in electrochemical processes, notably in proton exchange membrane (PEM) fuel cells. This study investigated the proton conductivity and dielectric behavior of SPEEK electrolytes at varying degree of sulfonation (DS) of 65% and 80%, correlating these properties with free volume profiles determined by positron annihilation lifetime spectroscopy (PALS). The SPEEK-65 and SPEEK-80 electrolytes were prepared via a controlled sulfonation process and characterized by FTIR, TGA, and SEM analyses. Proton conductivity and dielectric measurements were conducted at temperatures ranging from 300 to 370 K and frequencies ranging from 20 Hz to 1 MHz. The results revealed that SPEEK-80 exhibited a maximum proton conductivity of 3.4 × 10−2 S/m at 300 K and 1 MHz, which was significantly greater than the 4.38 × 10−3 S/m observed for SPEEK-65 under the same conditions. PALS analysis demonstrated a notable increase in free volume with increasing DS, with SPEEK-80 showing a higher o-Ps lifetime and intensity, indicating larger free volume sizes and fractions. These findings underscore the critical interplay between DS, free volume, and proton conductivity, offering insights into optimizing SPEEK-based electrolytes for advanced electrochemical applications.

Enhancing the electromagnetic shielding and mechanical properties of CF/PEEK composites via low-concentration fluff and Ni-Co alloy plating

Carbon Fiber Reinforced Composites (CFRC) are increasingly used in aircraft to minimize weight and maximize structural designability. However, CFRCs have limitations in electrical conductivity and Electromagnetic Interference (EMI) resistance. This study introduces a process to overcome these drawbacks by chemically plating Carbon Fiber (CF) fabrics with a thin layer of Nickel-Cobalt (Ni-Co) alloy, thereby improving electrical conductivity. Subsequently, Sulfonated Polyether Ether Ketone (SPEEK) was applied to the Nickel-Cobalt coated Carbon Fibers (NiCo@CF). The resulting fuzzy surface effectively enhanced the interfacial interactions within the PEEK matrix. The results showed that the tensile strength, tensile modulus, flexural strength, and flexural modulus of the composite panels treated with 0.1 wt.% SPEEK sizing significantly increased by 32.3 %, 26.0 %, 167.9 %, and 20.7 %, respectively, compared to NiCO@CF/PEEK composite panels treated with no SPEEK sizing agent. Additionally, the introduction of SPEEK fostered a shift in the primary fracture mechanism from fiber pull-out or debonding to fiber fracture. Remarkably, compared to CF/PEEK composites, the electromagnetic shielding efficiency of NiCo@CF/PEEK was increased by 88.98 %, reaching 46.15 dB. Long-term testing of the S-NiCO@CF/PEEK composites in a humid and hot environment confirmed consistent electromagnetic and mechanical properties, alongside good fatigue and aging resistance. These advances make the S-NiCO@CF/PEEK composites promising for broader applications in the aircraft and aerospace fields.

Stepwise Crystallization and Mass Transport Limitations in Annealed SPEEK Thin Films

Pt-supported SPEEK (sulfonated poly ether ether ketone) thin films, mimicking the ionomer-electrode interface in polymer electrolyte fuel cells (PEFCs), were synthesized with thicknesses from 12 to 105 nm. Their glass transition temperature (Tg) was analyzed via in-situ thermal ellipsometry, revealing a thickness-dependent Tg decrease, indicative of confinement effects. Particularly, a 30 nm film, typical of practical ionomer films, exhibited surface crystallization preceding that at the buried interface, a phenomenon linked to higher mobility at the free surface, as con-firmed by grazing incidence wide-angle X-ray scattering (GI-WAXS) at both sub-critical (0.09º) and supercritical (0.14º) angles. This study elucidates the dynamic interplay between the high-mobility free surface and the interaction-intensive buried interface in confined SPEEK thin films. It was observed that below 30 nm thickness, interfacial interactions become the primary factor influencing transition temperature. Additionally, spatially heterogeneous crystallization, more pronounced in the out-of-plane direction, correlates with reduced proton conduction.

Surface modification of h‐BN and electric field control of its orientation in sulfonated polyetheretherketone

AbstractSince thermally conductive fillers easily aggregate when introduced into polymer matrix, it is essential to apply a modifier to enhance the dispersion of the filler. In current study, the surface of boron nitride (h‐BN) is firstly modified by employing a double modification process and then added into sulfonated polyetheretherketone (SPEEK) to form the composite materials. Four different kinds of samples of double‐modified h‐BN were obtained. Ultimately, the XXX@h‐BN/SPEEK (XXX denoted as modifier, i.e. PDA, VTMS, TEOS, and APS) flexible film with the horizontally oriented XXX@h‐BN was produced by heating the mixture under an external electric field. The test results indicate that the thermally conductive filler PDA@h‐BN (PDA: polydopamine), which was prepared by modifying OH@h‐BN with PDA, loaded into SPEEK, and electrically oriented, shows the best overall performances. With a high tensile strength of 43.24 MPa and good flexibility, PDA@h‐BN/SPEEK flexible film exhibits an in‐plane thermal conductivity of 2.3 Wm−1 K−1 at a filling ratio of 10 wt%. The sample may be bent at a steep angle without breaking down and can recover to original shape bearing its high degree of flexibility.

Utilization of Water-Insoluble Carbon Nitride-Phosphotungstic Acid Hybrids in Composite Proton Exchange Membranes.

Phosphotungstic acid (HPW) can retain water in proton exchange membranes to increase proton conductivity; however, its water-soluble nature limits further application. In this work, we combined HPW and graphitic carbon nitride (g-C3N4) via sintering to prepare water-insoluble hybrids (HWN), where HPW was chemically linked to g-C3N4 to fix HPW. Then, HWN fillers were added to a sulfonated polyether ether ketone (SPEEK) matrix to prepare composite membranes. The conductivity of the composite membrane with 10 wt% HWN is up to 0.066 S cm-1 at room temperature, which is 53% higher than that of the SPEEK control membrane (0.043 S cm-1). The composite membrane also showed stable proton conductivity after being immersed in water for 2000 h. Therefore, our study demonstrates that preparing water-insoluble nanofillers containing HPW components through sintering is a promising approach.

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.

The ability of SPEEK to promote the proliferation and osteogenic differentiation of BMSCs on PEEK surfaces

To investigate the ability of sulfonated polyetheretherketone (SPEEK) to promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and compare the effects of different degrees of sulfonation (DS), SPEEK was made with two different DS. The L-SPEEK group had a lower DS, while the H-SPEEK group had a higher DS. The physicochemical properties of both species were evaluated by scanning electron microscopy (SEM), capitilize Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Then, proliferation and osteogenic differentiation between the two groups and with pure polyetheretherketone (PEEK) were compared after surface inoculation of bone marrow mesenchymal stem cells (BMSCs). Scanning electron microscopy (SEM) revealed that the surface of the PEEK substrates could be smooth or coarse, and the degree of roughness increased with increasing sulfonation. FTIR spectroscopy showed that both the L-SPEEK and H-SPEEK samples contained sulfonic acid. TGA and XRD revealed that the components in the two groups were the same, but the intensities were different. After BMSC inoculation, a CCK8 assay revealed that the cells proliferated more on the H-SPEEK surface and little on the L-SPEEK surface compared with the PEEK surface. Then, osteogenic differentiation was verified by immunofluorescence staining for OCN and Runx2, which indicated that H-SPEEK had the greatest effect on improving differentiation. The results of alizarin red staining (ARS) and alkaline phosphatase staining (APS) also revealed this trend. Sulfonation can change the microsurface of PEEK, which can improve both BMSC proliferation and osteogenic differentiation.

Black Phosphorus and E7-Functionalized Sulfonated Polyetheretherketone with Effective Osteogenicity and Antibacterial Activity

Given its excellent biological properties and the matching of its elastic modulus with that of human bone tissue, medical polyetheretherketone (PEEK) is considered a desirable candidate for bone-implant materials. However, its poor osseointegrative and antibacterial properties greatly limit its clinical application. To address these concerns, a functional PEEK implant is needed. Herein, a novel photo-responsive multifunctional PEEK-based implant material (sPEEK/BP/E7) with both effective osteogenesis and good disinfection properties was constructed via the self-assembly of black phosphorus (BP) nanosheets, mussel-inspired polydopamine (PDA), and bioactive short peptide E7 on sulfonated PEEK (sPEEK). The versatile micro-/nano-structured PEEK surface provides superior hydrophilicity, a favorable osteogenic microenvironment, and excellent photothermal effects under near-infrared (NIR) irradiation. The in vitro results showed that sPEEK/BP/E7 displays enhanced cytocompatibility and osteogenicity in terms of cell adhesion, proliferation, alkaline phosphatase (ALP) activity, matrix mineralization, and osteogenesis-related gene expression, superior to those of the sPEEK and sPEEK/BP samples. In addition to osteogenesis, the multifunctional coating exhibited strong antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Furthermore, it was confirmed in a rat femoral infection model that sPEEK/BP/E7 effectively resisted infection caused by S. aureus under NIR light irradiation and promoted osseointegration in vivo. Thus, this work presents a facile strategy to realize improvement of the “functional integration” of new polymer bone-implant materials and provide new ideas for their clinical application.

Enhancing the charge transfer in triboelectric nanogenerator based on sulfonated poly ether ether ketone/carbon nanotubes proton exchange composite membrane

This study introduces an innovative type of triboelectric nanogenerator (TENG) that utilizes proton exchange membranes to significantly enhance the transfer of electric charge in a triboelectric layer. To achieve this, composite membranes were fabricated by applying a blade coating technique to a mixture of carbon nanotubes (CNTs) and sulfonated poly ether ether ketone (SPEEK), serving as the critical triboelectric layer in the TENG device. These composite membranes exhibit an exceptional ability to attract water molecules through hydrogen bonding. Thanks to the high electro-positivity of these water molecules, they actively participate in the triboelectrification process, resulting in a substantial increase in charge transfer efficiency within the TENG device. As a result, when compared to the conventional dry-based SP (SPEEK)-TENG, the wet-based SP-TENG demonstrates an astonishing surge in output current, exceeding an 860-fold increase. Furthermore, a SPC (SPEEK/CNTs)-0.5-TENG cell device shows remarkable performance by generating a peak current of 0.91 mA and a power density of 0.39 W/m2. Impressively, four SPC-0.5-TENG cells can rapidly charge a 470 µF capacitor to 2.1 V within 28 seconds, making them a viable power source for a variety of portable electronic devices. This material displays substantial promise for applications in self-powered technologies, ultimately contributing to a reduced dependence on external power sources.

Enhancement of Co(II) removal via coupling of electrosorption and electrodeposition using asymmetric electrode from wastewater

The growing demand for nuclear energy and the promotion of nuclear technology applications will generate large quantities of cobalt-containing wastewater. The efficient removal of cobalt from radioactive wastewater is of great significance for the resource regeneration and environmental protection. However, conventional removal methods are constrained by the poor removal efficiency and slow removal kinetics. Herein, the sulfonated polyether ether ketone coated activated carbon fibers (anode)/activated carbon fibers (cathode) asymmetric electrodes was proposed to boost the Co(II) electrosorption performance. The experimental results showed that compared to traditional symmetric electrodes, the theoretical maximum electrosorption capacity (116.19 mg·g−1) had an exceptional enhancement of 69 %. The voltage and initial pH of the solution had an undeniable impact on the efficiency of cobalt electrosorption. Furthermore, more than 75 % of Co(II) was rapidly immobilized within 3 h. The kinetic fitting indicated that the electrosorption process was more appropriately described by pseudo-second-order kinetic model. The Co(II) removal efficiency was up to 80 % under the conditions of coexistence with Na+, Mn2+, Ni2+, Zn2+, Sr2+, and Cs+. More importantly, it combines two synthetic mechanisms of electrosorption and electrodeposition to realize the purification of cobalt-containing wastewater. Overall, considering the fast and highly-efficient cobalt removal performance and innate economy, the asymmetric electrosorption for cobalt removal provides new insights into the treatment of cobalt-containing wastewater.

Venice’s macroalgae-derived active material for aqueous, organic, and solid-state supercapacitors

In this study, self-doped porous activated biochar derived from Venice lagoon’s Sargassum brown macroalgae (ABS) has been successfully prepared through thermochemical carbonization (pyrolysis) followed by CO2 physical activation and used as electrodes for supercapacitor (SC) applications. The ABS exhibits a remarkable specific surface area of 821 m2g–1 and heteroatoms (N, O, and S) doping, both key features to attain high-performance carbon-based SC electrodes. The electrochemical performances of ABS-based SCs were assessed in three different electrolytes. Two are aqueous (i.e., 1 M H2SO4 and 8 M NaNO3), while the third one is the prototypical organic, namely 1 M TEABF4 in acetonitrile. In these three electrolytes, the ABS-based electrodes exhibited specific capacitance values (Cg) of 109.5, 79.0, and 64.3Fg–1, respectively, at a current density of 0.1 Ag–1. The capacitive performance resulted in SC energy densities of 3.45 Wh kg−1 at 22.5 W kg−1, 6.3 Wh kg−1 at 36.1 W kg−1, and 12.4 Wh kg−1 at 57.4 W kg−1 and maximum power densities of 147, 222, and 378 kW kg−1 in the acidic, quasi-neutral aqueous electrolyte and organic electrolyte, respectively. The ABS electrodes were used to realize a flexible solid-state SC based on the sulfonated polyether ether ketone (SPEEK):functionalized niobium disulfide flakes (f-NbS2) composite membrane. The flexible solid-state SC displayed a remarkable 97% Cg retention even under various mechanical stresses, including bending up to 1000 times and folding angles up to 180°, while keeping a Coulombic efficiency above 98%. This study reveals ABS as a promising sustainable source of active materials for SCs. The remarkable performance of ABS-based SCs can be attributed to their multi-scale porosity, heteroatom doping, and enhanced surface wettability, providing abundant active sites for charge accumulation, and efficient electrolyte diffusion, thus highlighting its potential as a sustainable solution for energy storage applications.

Bioactivity, hemocompatibility, and inflammatory response of calcium incorporated sulfonated polyether ether ketone on mouse-derived bone marrow cells.

Natural and synthetic polymeric materials, particularly soft and hard tissue replacements, are paramount in medicine. We prepared calcium-incorporated sulfonated polyether-ether ketone (SPEEK) polymer membranes for bone applications. The bioactivity was higher after 21 days of immersion in simulated body fluid (SBF) due to calcium concentration in the membrane. We present a new biomaterial healing system composed of calcium and sulfonated polyether ether ketone (Ca-SPEEK) that can function as a successful biomaterial without causing inflammation when tested on bone marrow cells. The Ca-SPEEK exhibited 13 ± 0.5% clot with low fibrin mesh formation compared to 21 ± 0.5% in SPEEK. In addition, the Ca-SPEEK showed higher protein adsorption than SPEEK membranes. As an inflammatory response, IL-1 and TNF-α in the case of Ca-SPEEK were lower than those for SPEEK. We found an early regulation of IL-10 in the case of Ca-SPEEK at 6 h, which may be attributed to the down-regulation of the inflammatory markers IL-1 and TNF-α. These results evidence the innovative bioactivity of Ca-SPEEK with low inflammatory response, opening venues for bone applications.

Enhancing the thermal and mechanical properties of sulfonated peek fiber composites with reduced smoke density and toxicity

AbstractPolyether ether ketone (PEEK) sulfonation process is a reasonably easy but time‐consuming to manufacture composites. This study focuses on altering PEEK powder in a sulfuric acid solution via a sulfonation process to develop sulfonated PEEK (SPEEK) resin for the fiber‐reinforced thermoplastic composite manufacturing and characterization steps. In this study, about 5 wt% PEEK powder was sulfonated in 98% sulfuric acid solution for 12 h at 65°C. The water bath technique was used for the precipitation process to obtain the SPEEK polymer. After proper washing and drying, the SPEEK matrix (resin) was obtained by dissolving it in dimethylformamide in a ratio of 1:2. This resin solution was then used to manufacture thermoplastic Kevlar and glass fiber‐reinforced composites employing wet layup process and cured at an elevated temperature under pressure. These SPEEK composites passed the flame retardancy UL94 test with a V0 rating. The average water contact angle of the glass fiber‐ and Kevlar‐SPEEK composites is 93.67° and 102.24°, respectively. The average tensile strength values of these composites were found 222.22 and 284.35 MPa, correspondingly. The smoke density and toxicity tests of the glass fiber‐SPEEK composite confirmed lower smoke generation with the modifications. These SPEEK‐fiber composites can be considered for various industrial applications, including aviation, energy, drone, defense, and automotive.

L-arginine loading porous PEEK promotes percutaneous tissue repair through macrophage orchestration

Infection and poor tissue repair are the key causes of percutaneous implantation failure. However, there is a lack of effective strategies to cope with due to its high requirements of sterilization, soft tissue healing, and osseointegration. In this work, l-arginine (L-Arg) was loaded onto a sulfonated polyetheretherketone (PEEK) surface to solve this issue. Under the infection condition, nitric oxide (NO) and reactive oxygen species (ROS) are produced through catalyzing L-Arg by inducible nitric oxide synthase (iNOS) and thus play a role in bacteria sterilization. Under the tissue repair condition, L-Arg is catalyzed to ornithine by Arginase-1 (Arg-1), which promotes the proliferation and collagen secretion of L929 and rBMSCs. Notably, L-Arg loading samples could polarize macrophages to M1 and M2 in infection and tissue repair conditions, respectively. The results in vivo show that the L-Arg loading samples could enhance infected soft tissue sealing and bone regeneration. In summary, L-Arg loading sulfonated PEEK could polarize macrophage through metabolic reprogramming, providing multi-functions of antibacterial abilities, soft tissue repair, and bone regeneration, which gives a new idea to design percutaneous implantation materials.

Unraveling the potential of N-butyl imidazolium tetrafluoroborate-modified sulfonated polyether ether ketone polymer composite for ciprofloxacin removal

This study focused on characterization and assessing the adsorption capabilities of sulfonated polyether ether ketone (SPEEK) and ionic liquid incorporated SPEEK (SPEEK-BIM) composite adsorbents for removing ciprofloxacin (CIP) from water. Fourier-transform infrared (FTIR) analysis verified successful sulfonation and interaction between the polymer and ionic liquid. Scanning electron microscopy (SEM) revealed structural changes, indicating increased surface roughness and the formation of pores after sulfonation. Thermogravimetric analysis (TGA) showed thermal stability and multiple degradation steps. Adsorption experiments demonstrated SPEEK and SPEEK-BIM's effectiveness, with maximum removal efficiencies of 75.8 % and 92.9 % respectively, at a solid/liquid ratio of 0.6 g/L. Equilibrium was reached within 300 min for SPEEK and 180 min for SPEEK-BIM, with pH 7–9 yielding optimal adsorption due to CIP's zwitterionic form. Calculated maximum adsorption capacities were found as 303.03 mg g−1 and 500.0 mg g−1 for SPEEK and SPEEK-BIM, respectively. Langmuir isotherm modeling indicated monolayer coverage, while pseudo second-order kinetics described chemisorption with active sites involvement. Thermodynamic analysis suggested spontaneous, endothermic adsorption favored at higher temperatures. Desorption studies demonstrated reusability, especially in basic conditions. Water medium affected adsorption, with reduced efficiency in drinking and tap water compared to distilled water. Comparisons with literature data highlighted competitive adsorption capacities. In conclusion, SPEEK and SPEEK-BIM composite adsorbents hold promise for CIP removal, with potential applications in water treatment and environmental remediation.

Highly sulfonated poly ether ether ketone chelated with Cu2+ as a proton exchange membrane at sub-zero temperatures

Improving the proton conductivity (σ) of proton exchange membranes at low temperatures is very important for expanding their application areas. Here, sulfonated poly ether ether ketone (SPEEK) membranes were prepared with different sulfonation degrees, and its maximum ion exchange capacity is 3.15 mmol/g for 10 h at 60 °C. Highly sulfonated SPEEK membrane exhibits ultra-high water uptake and excellent proton conductivity of 0.074 S/cm at −25 °C due to its abundant −SO3H. Nevertheless, its high swelling ratio and low mechanical strength are not conducive to the practical application of the membrane. Luckily, by employing the chelation of Cu2+ with −SO3− on the SPEEK chain, Cu2+-coordinated SPEEK membranes were prepared, and they not only retain high −SO3H content but also possess robust mechanical properties and good dimensional stability compared to pristine SPEEK membrane. Meanwhile, the σ of the SPEEK-Cu membrane reaches 0.054 S/cm at −25 °C, and its fuel cell maximum power (Wmax) reaches 0.42 W/cm2 at −10 °C, demonstrating superior low-temperature performance in comparison to other reported materials. Particularly, water states in the prepared membranes are quantified by low-temperature differential scanning calorimetry. Because much more water bound to the plentiful −SO3H and Cu2+ inside the membrane endows it with anti-freezing performance, the decay of the σ and the Wmax for the SPEEK-Cu membrane is retarded at sub-zero temperatures. It is envisioned that composite membranes comprising metal ions such as Cu2+-SPEEK have a high potential for sub-zero fuel cell applications.