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Poly(ether ether ketone) (PEEK) was found to form gels in the benign solvent 1,3-diphenylacetone (DPA). Gelation of PEEK in DPA was found to form an interconnected, strut-like morphology composed of polymer axialites. To our knowledge, this is the first report of a strut-like morphology for PEEK aerogels. PEEK/DPA gels were prepared by first dissolving PEEK in DPA at 320 °C. Upon cooling to 50 °C, PEEK crystallizes and forms a gel in DPA. The PEEK/DPA phase diagram indicated that phase separation occurs by solid–liquid phase separation, implying that DPA is a good solvent for PEEK. The Flory–Huggins interaction parameter, calculated as χ12 = 0.093 for the PEEK/DPA system, confirmed that DPA is a good solvent for PEEK. PEEK aerogels were prepared by solvent exchanging DPA to water then freeze-drying. PEEK aerogels were found to have densities between 0.09 and 0.25 g/cm3, porosities between 80 and 93%, and surface areas between 200 and 225 m2/g, depending on the initial gel concentration. Using nitrogen adsorption analyses, PEEK aerogels were found to be mesoporous adsorbents, with mesopore sizes of about 8 nm, which formed between stacks of platelike crystalline lamellae. Scanning electron microscopy and X-ray scattering were utilized to elucidate the hierarchical structure of the PEEK aerogels. Morphological analysis found that the PEEK/DPA gels were composed of a highly nucleated network of PEEK axialites (i.e., aggregates of stacked crystalline lamellae). The highly connected axialite network imparted robust mechanical properties on PEEK aerogels, which were found to densify less upon freeze-drying than globular PEEK aerogel counterparts gelled from dichloroacetic acid (DCA) or 4-chlorphenol (4CP). PEEK aerogels formed from DPA were also found to have a modulus–density scaling that was far more efficient in supporting loads than the poorly connected aerogels formed from PEEK/DCA or PEEK/4CP solutions. The strut-like morphology in these new PEEK aerogels also significantly improved the modulus to a degree that is comparable to high-performance crosslinked aerogels based on polyimide and polyurea of comparable densities. [ABSTRACT FROM AUTHOR]

Black absorber with wide‐angle high absorption properties is of great significance to the in‐orbit operation of space optical system. However, up to now, black absorber used in space optical system with wide‐angle high absorption properties has rarely been reported. Herein, this work reports a multiscale structure coordinated black poly(ether ether ketone) (PEEK)‐based black absorber with lightweight, low volatilization, and wide‐angle high absorption properties through 3D printing method. The as‐prepared absorber with honeycomb structure shows a high surface absorptivity (about 96.89%), and excellent wide‐angle high absorption properties which absorptivity attenuation rate is only 1.43% at 70°, benefiting from 3D‐printed honeycomb structure and multi‐scale light trap structure on the absorber inner surface. Besides, high and low temperature cycling test shows that its wide‐angle high absorption properties have a good stability at the space extreme environment, and its collected volatile condensable material (CVCM) is as low as 0.00%. This work provides a new strategy for simple fabrication method of novel lightweight multifunctional‐structure integrated absorber for space optical system. [ABSTRACT FROM AUTHOR]

In this article, a high‐temperature resistant ionic liquid ([(Ph)4P]+[N(CF3SO3)2]−) was introduced into PEEK to improve its processing performance. The effect of the IL on the rheology, crystalline, thermal, and mechanical properties of PEEK was analyzed. The rheological results show that the viscosity of PEEK decreases after adding IL, and the complex viscosity of PEEK decreases to 490 Pa s after adding 5 wt% IL, which is 15% lower than that of neat PEEK. Besides, it was found that adding a small amount of IL improved the crystallization ability of PEEK, shortened the crystallization time, and increased the tensile strength of PEEK blends. Additionally, IL has no significant effect on the molecular weight and degradation temperature of PEEK. In summary, adding IL into the PEEK matrix reduces the melt viscosity of PEEK, providing a reference for improving the processing fluidity of PEEK. [ABSTRACT FROM AUTHOR]

Poly(ether ether ketone) (PEEK) was found to form gels in the benign solvent 1,3-diphenylacetone (DPA). Gelation of PEEK in DPA was found to form an interconnected, strut-like morphology composed of polymer axialites. To our knowledge, this is the first report of a strut-like morphology for PEEK aerogels. PEEK/DPA gels were prepared by first dissolving PEEK in DPA at 320 °C. Upon cooling to 50 °C, PEEK crystallizes and forms a gel in DPA. The PEEK/DPA phase diagram indicated that phase separation occurs by solid–liquid phase separation, implying that DPA is a good solvent for PEEK. The Flory–Huggins interaction parameter, calculated as χ12 = 0.093 for the PEEK/DPA system, confirmed that DPA is a good solvent for PEEK. PEEK aerogels were prepared by solvent exchanging DPA to water then freeze-drying. PEEK aerogels were found to have densities between 0.09 and 0.25 g/cm3, porosities between 80 and 93%, and surface areas between 200 and 225 m2/g, depending on the initial gel concentration. Using nitrogen adsorption analyses, PEEK aerogels were found to be mesoporous adsorbents, with mesopore sizes of about 8 nm, which formed between stacks of platelike crystalline lamellae. Scanning electron microscopy and X-ray scattering were utilized to elucidate the hierarchical structure of the PEEK aerogels. Morphological analysis found that the PEEK/DPA gels were composed of a highly nucleated network of PEEK axialites (i.e., aggregates of stacked crystalline lamellae). The highly connected axialite network imparted robust mechanical properties on PEEK aerogels, which were found to densify less upon freeze-drying than globular PEEK aerogel counterparts gelled from dichloroacetic acid (DCA) or 4-chlorphenol (4CP). PEEK aerogels formed from DPA were also found to have a modulus–density scaling that was far more efficient in supporting loads than the poorly connected aerogels formed from PEEK/DCA or PEEK/4CP solutions. The strut-like morphology in these new PEEK aerogels also significantly improved the modulus to a degree that is comparable to high-performance crosslinked aerogels based on polyimide and polyurea of comparable densities.

With the global effort to reduce fossil fuels and to use eco-friendly energy, interest in Li-ion batteries (LIBs) is rapidly increasing. In the LIB system, the separator is an important component for determining the rate performance and safety of cells. Although polyolefin separators are commercially used in LIBs, they still suffer from inferior electrolyte wettability and low thermal stability issues. Here, we introduce a chemical surface modification for polyethylene (PE) separators using a poly(ether ether ketone) (PEEK) coating. The separators were pretreated in a tannic acid solution to enforce the adhesion of the coated layers. Then, PEEK was coated onto the PE surface by a doctor blading method. The separators were examined by infrared spectroscopy, and the surface properties were characterized by electrolyte uptake and contact angle measurements. The treated surface was hydrophilic, and the ionic conductivity of the cell with the modified separator was significantly improved. As a result, the corresponding rate performance was significantly improved. The surface modification strategy proposed here can be applied to polyolefin-based separators as well. [ABSTRACT FROM AUTHOR]

The thermoelectric properties, at temperatures from 30 °C to 100 °C, of melt-processed poly(ether ether ketone) (PEEK) composites prepared with 10 wt.% of carbon nanofibers (CNFs) are discussed in this work. At 30 °C, the PEEK/CNF composites show an electrical conductivity (σ) of ~27 S m−1 and a Seebeck coefficient (S) of −3.4 μV K−1, which means that their majority charge carriers are electrons. The origin of this negative Seebeck is deduced because of the impurities present in the as-received CNFs, which may cause sharply varying and localized states at approximately 0.086 eV above the Fermi energy level (EF) of CNFs. Moreover, the lower S, in absolute value, found in PEEK/CNF composites, when compared with the S of as-received CNFs (−5.3 μV K−1), is attributed to a slight electron withdrawing from the external layers of CNFs by the PEEK matrix. At temperatures from 30 °C to 100 °C, the σ (T) of PEEK/CNF composites, in contrast to the σ (T) of as-received CNFs, shows a negative temperature effect, understood through the 3D variable-range hopping (VRH) model, as a thermally activated hopping mechanism across a random network of potential wells. Moreover, their nonlinear S (T) follows the same behavior reported before for polypropylene composites melt-processed with similar CNFs at the same interval of temperatures. [ABSTRACT FROM AUTHOR]

Sulfonation of poly(ether ether ketone) (PEEK) is an electrophilic substitution reaction that takes place on the aromatic ring flanked by the two ether groups. The degree of sulfonation (DS) reached up to 100% with only one sulfone group is attached to the activated aromatic rings. In the present work, a spectroscopic evidence for the attachment of a second sulfone group on the para position rather the meta position with respect to the first sulfone group in the activated ring is provided. With the help of 1H-, 13C- nuclear magnetic resonance (NMR) and two-dimensional correlation (2D-COS) spectroscopies, it was possible to show that the intensity of the proton in the para position with respect to the newly introduced sulfone group changed before the proton in the meta position with increasing DS. Further evidence was obtained from the analysis of 2D-NMR spectra namely; 1H-1H correlation spectroscopy (1H-1H-COSY), 1H-13C heteronuclear single quantum coherence spectroscopy (1H-13C-HSQC) and 1H-13C heteronuclear multiple bond correlation spectroscopy (1H-13C-HMBC) of highly sulfonated PEEK by the disappearance of proton 12' and the confirmation of the presence of other protons, i.e. 10' and 13'. 2D-COS is a powerful tool to analyze NMR spectra and extract information related to the structure of final products of complicated reactions such as sulfonation of polymers. [ABSTRACT FROM AUTHOR]

This paper introduced the properties of six high-performance resins, including poly(ether ether ketone) (PEEK), poly(phenylene sulfide) (PPS), liquid crystal polymer(LCP), poly(etherimide) (PEI), polysulfone(PSF), and polyimide (PI). The preparation processes and modification methods of the films based on these six respective resins were discussed in detail, and their applications were prospected. [ABSTRACT FROM AUTHOR]

The poly(ether ether ketone) (PEEK) was prepared as organic matrix. ZIF-8 and GO/ZIF-8 were used as fillers. A series of novel new anion exchange membranes (AEMs) were fabricated with imidazole functionalized PEEK and GO/ZIF-8. The structure of ZIF-8, GO/ZIF-8 and polymers are verified by 1H NMR, FT-IR and SEM. This series of hybrid membranes showed good thermal stability, mechanical properties and alkaline stability. The ionic conductivities of hybrid membranes are in the range of 39.38 mS cm−1–43.64 mS cm−1 at 30 °C, 100% RH and 59.21 mS cm−1–86.87 mS cm−1 at 80 °C, 100% RH, respectively. Im-PEEK/GO/ZIF-8-1% which means the mass percent of GO/ZIF-8 compound in Im-PEEK polymers is 1%, showed the higher ionic conductivity of 86.87 mS cm−1 at 80 °C and tensile strength (38.21 MPa) than that of pure membrane (59.21 mS cm−1 at 80 °C and 19.47 MPa). After alkaline treatment (in 2 M NaOH solution at 60 °C for 400 h), the ionic conductivity of Im-PEEK/GO/ZIF-8-1% could also maintain 92.01% of the original ionic conductivity. The results show that hybrid membranes possess the ability to coordinate trade-off effect between ionic conductivity and alkaline stability of anion exchange membranes. The excellent performances make this series of hybrid membranes become good candidate for application as AEMs in fuel cells. [Display omitted] • The hybrid AEMs showed good dimensional stability and excellent alkaline stability. • GO were conducive to ion transport and the construction of ion transport channels. • The imidazole groups in ZIF-8 could effectively increase content of "bulk water". [ABSTRACT FROM AUTHOR]

In this paper, poly(ether ether ketone) (PEEK) scaffold was manufactured using the fused deposition modeling (FDM) technology with a modified platform. The effect of processing parameters of FDM on the porosity and compressive strength of PEEK scaffold with uniform pores (0.8 mm of diameter) was optimized through Taguchi methodology. With the determined parameters, four kinds of PEEK scaffolds with gradient pores (0.4–0.8 mm, 0.6–1.0 mm, 0.8–1.2 mm, and 1.2–2.0 mm) were manufactured. The scaffolds were investigated using scanning electron microscopy. The results showed that the pores of scaffolds were interconnected with rough surface, which can allow the attachment, migration, and differentiation of cells for bone forming. The tensile strength, compressive max strength, and compressive yield strength of scaffolds were between 18 and 35 MPa, 197.83 and 370.42 MPa, and 26 and 36 MPa, respectively. The mechanical properties of the scaffolds can satisfy the loading requirements of human bones. Therefore, the PEEK scaffolds have a potential to be used in tissue engineering as implants.

High‐performance engineering polymers continually challenge existing boundaries of rapidly emerging research areas including electronics, transportation, energy, defense and aerospace. Significant research attention over the past decade highlights the exceptional performance of these polymers due to their superior thermomechanical properties and stability under extreme conditions. Unfortunately, inherent structure–property relationships of high‐performance engineering polymers, which predict this unique complement of physical properties, also describe high‐viscosity melts and high melting temperatures. These processing challenges have steered researchers towards advanced processing methods, such as additive manufacturing, that allow for unprecedented control over part geometry. In addition, additive manufacturing serves to advance application–cost relationships, as part optimization and 3D printing of previous monolithic components allow for less material consumption. Currently, the additive manufacturing materials toolbox only contains a fraction of commercially available high‐performance polymers due to unique processing constraints. This review discusses recent efforts towards the successful additive manufacturing of three high‐performance polymer families, i.e. polysulfones, poly(ether ether ketone)s and polyimides. © 2021 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Glass fiber/poly(ether ether ketone) (GF/PEEK) composite foams with improved compressive strength and heat resistance can be successfully prepared using a simple and environmentally friendly supercritical carbon dioxide (sc‐CO2) foaming technology. The cell morphologies of the foams can be controlled by adjusting the GF content and foaming parameters, including the saturation temperature, saturation time, saturation pressure, and depressurization rate. With a foam density of 0.55 g cm−3, the PEEK‐based composite foam having 30% GF content has a 10% compressive strength of 11.07 MPa, and its density varies negligibly up to 330.0 °C. The GF/PEEK composite foams having high GF contents show significantly better properties than those having low GF contents as a result of the supporting and strengthening effect of the GF in the PEEK cell walls. The GF/PEEK composite foams also show good corrosion resistance. As a result of these properties, the GF/PEEK composite foams are promising high‐performance materials for use in extreme environments. [ABSTRACT FROM AUTHOR]

In this work, poly(ether ether ketone) (PEEK) was synthesized by direct polycondensation reaction. Subsequently, PEEK was functionalized by 1-vinylimidazole to prepare the polymer matrix (Im-PEEK). Cationic UiO-66-NH2 metal-organic frameworks (C-MOF) were synthesized as fillers. The structure of the C-MOF and the morphology of the membranes were verified by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The prepared hybrid membranes exhibited excellent alkali stability, among which Im-PEEK/C-MOF-1% could retain 89.2% of the conductivity compared to the original membrane after immersing in 1 ​mol ​L−1 NaOH solution for 320 ​h at 60 ​°C. In addition, the ionic conductivity of Im-PEEK/C-MOF-1% was 73 ​mS ​cm−1 at 80 ​°C, which was higher than that of pure Im-PEEK under the same condition (44.3 ​mS ​cm−1 at 80 ​°C). The results showed that the hybrid membranes have great potential for application in the field of anion exchange membranes.

Poly(ether ether ketone) is a semicrystalline organic polymer. It has widely been used as high-performance engineering plastic owing to its high melting point (343 °C), excellent mechanical strength, and outstanding chemical resistance. Therefore, poly(ether ether ketone) and its composites have shown lots of applications in aerospace and medical fields. However, its application is restricted due to poor strength at the mechanically joint components. Thus, this scope leads us to study an alternative method of the joint process that will lead to finding a new joining process for poly(ether ether ketone)-based materials. In this study, a solid-state joining process was conducted to join two poly(ether ether ketone) rods by a friction welding process. Here, we statistically optimized the values of forge load, friction load, and friction welding time as 100 N, 450 N, and 8 s, respectively, which have more influence on tensile stress and hardness of the material after the friction welding process. It has been found that the forge load had the highest influence and the forge time had the least influence on tensile strength. Their optimal values were calculated after considering the trend in hardness values by statistical analysis using Minitab software. However, after the optimal values, the above parameter showed a negative effect on the high tensile stress due to the change in crystallinity of the friction welding processed poly(ether ether ketone) as confirmed by X-ray diffraction and thermal analyses. [ABSTRACT FROM AUTHOR]

The present work focuses on the analysis of X-ray photoelectron spectroscopic (XPS) data by two-dimensional correlation spectroscopy (2D-COS). While it is not useful to perform the generalized form of the 2D-COS analysis on the survey spectra, the later could be used to correlate different regions of the spectra with each other. This correlation leads to useful qualitative information, which is consistent with the underlying physics and chemistry of the studied process and related to the mechanism of perturbation effects on the materials. In addition, the effects of the probing incident X-ray beam on the measured samples are explored. Depending on the chemical structure and stability of the measured samples, the effects of X-ray beam varied from net charging effect on helium irradiated PEEK to massive change in the surface composition of amorphous and proton irradiated PEEK samples. XPS is a sensitive surface analysis technique, and care must be paid to avoid misleading results in the analysis of polymer samples. [ABSTRACT FROM AUTHOR]

This work aims to perform a systematic investigation on the crystallization behavior and morphologies of carbon and glass fiber reinforced PEEK. The nonisothermal and isothermal crystallization behavior was investigated by differential scanning calorimetry (DSC). The resultant morphologies were assessed by wide angle X-ray diffraction (WAXD), small angle X-ray scattering (SAXS), and polarized optical microscopy (POM) to provide details on spherulitic level, crystalline structure at unit cell, and lamellar levels. It was found that the crystallization ability of carbon fiber filled PEEK was better than that of neat PEEK, while the behavior of glass fiber filled PEEK was in an opposite trend. The incorporation of carbon fiber (or glass fiber) led to a looser packing of the unit cell or a less crystal perfection of PEEK but did not change its crystal form as well as its long period of lamellae. The isothermal crystallization kinetics was analyzed by the Avrami model, suggesting that the crystallization mechanism of carbon fiber filled PEEK was different from that of neat PEEK and its glass fiber filled composites. Nevertheless, the POM results showed that fiber-induced transcrystallization in PEEK matrix was not evidenced for either carbon or glass fiber filled PEEK. Finally, the effect of carbon and glass fiber on the crystallization of PEEK matrix was discussed to some extent. [ABSTRACT FROM AUTHOR]

To improve the antifouling properties of poly(ether ether ketone) (PEEK) membrane, negatively charged acrylic acid (AA), neutral ethyl hydroxyacrylate (HEA) and positively charged acryloxyethyl trimethylammonium chloride (DAC) as hydrophilic monomers were respectively grafted onto the PEEK hollow fiber membrane surface via ultraviolet irradiation polymerization. The effects of the grafted monomers on surface chemical structure, surface morphology, zeta potential, hydrophilic performance, permeability and the antifouling properties of the membrane were investigated in detail. The results show that the charge state of the membrane surface is closer to the monomer charge characteristic, which obviously affects the permeability and antifouling performance of the membrane. The pure water flux of the membrane grafted with neutral hydrophilic HEA monomer is increased and the antifouling properties to bovine serum albumin (BSA) and sodium alginate (SA) are also enhanced, while the pure water flux of the membranes grafted with negatively charged AA monomer or positively charged DAC monomer is decreased, with different antifouling properties to BSA and SA. Furthermore, the antifouling experiment with BSA under different pH conditions revealed that membrane fouling depends on the pH value, and membrane fouling was the most serious at the isoelectric point of BSA. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Utilizing a novel processing method of PEEK foam that produces hierarchical mesoporosity, we explore the use of hydroxyapatite (HA)/PEEK composites for mimicking the structure of human bone. The effect of HA content and processing parameters on the porosity, and interconnective network are studied with respect to the corresponding morphology, mechanical properties, and ultimately the cell viability. Having achieved hierarchical structuration with pore sizes ranging from approx. a hundred nanometers all the way to a few hundred microns, the HA/PEEK composites produced desirable mechanical properties and promising cell proliferation. A strong correlation was not seen with HA loading and the resulting properties, but a combination of the HA loading and variance in porosity is shown to be significant. The development and analysis of this bone mimic structure opens up the potential for this processing method and material as a treatment to bone injuries and bone diseases. [ABSTRACT FROM AUTHOR]

The impact of poly (ether sulfone) modified graphene (f-GEi) on the non-isothermal crystallization kinetic behavior of PEEK composites was investigated by differential scanning calorimetry at various cooling rates. According to the results, the addition of f-GEi reduced the crystallinity of the PEEK composites and shortened the total crystallization time. The peak temperature and nucleation activity of the f-GEi increased with increasing the mass ratio of PES to GE before declining, those of PEEK/f-GE5 composites were the highest, which suggested the potential of f-GE5 to provide more nucleation sites for PEEK matrix. The addition of f-GEi decreased the temperature gradient required during the crystallization process and reduced the crystallization activation energy. The log(F(T)) values of PEEK/f-GE5 were significantly higher compared to the other PEEK/f-GEi composites, indicating that the interaction between f-GE5 and PEEK matrix was stronger and the mobility of the polymer molecular chain was much difficult.

Poly(ether ether ketone) (PEEK) is a high-performance thermoplastic used for several industrial applications due to its excellent mechanical properties. However, the use of PEEK is limited to dental materials because of its poor implant-bone integration. In the present study, methylated polyrotaxanes (MePRXs) with 4-vinylbenzyl groups, which are supermolecules composed of methylated α-cyclodextrins and poly(ethylene glycol) chains end-capped with 4-vinylbenzyl groups, were covalently tethered onto PEEK surfaces using photo-induced polymerization to improve their osteoblast compatibility. The surface-tethering of MePRXs onto PEEK surfaces was confirmed by analyzing their attenuated total reflectance Fourier transform infrared spectra and contact angles. When mouse preosteoblasts were cultured on the MePRX-PEEK and bare PEEK surfaces, the MePRX-PEEK surfaces showed significantly better proliferation and osteoblast differentiation than the bare PEEK surfaces. These results suggest that surface modification of PEEKs using MePRXs improves their osteoblast compatibility. [ABSTRACT FROM AUTHOR]

This study investigates the effect of pre-coating with methyl methacrylate (MMA) containing ultraviolet (UV) photoinitiators on the bond strength of poly(ether ether ketone) (PEEK). Cylindrical PEEK blocks were irradiated with 365 nm UV light for 5–20 s after they were coated with MMA containing 0.4–3.0 wt% UV photoinitiators: [1-phenyl-1,2-propanedione (PPD)], [diphenyl(2,4,6- trimethylbenzoyl) (TMDPO)], and [phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide (BTMPO)]. Pre-coated PEEKs were bonded to PEEK blocks with a MMA-based adhesive resin. The shear bond strength was measured using a universal testing machine. Secondary electron images were captured to observe failure surfaces. The data were analyzed with one- and two-way ANOVA and Tukey’s post hoc tests (p<0.05). The highest bond strength (20.7±5.1 MPa) was observed for pre-coating with MMA containing 0.4 wt% BTMPO, for 20 s of UV irradiation. Cohesive failure of the adhesive resin was observed. The use of this pre-coating led to improved bonding performance of PEEK. [ABSTRACT FROM AUTHOR]

A series of quaternary ammonium salt poly(ether ether ketone) AEMs containing long ether substituents are successfully prepared, and their chemical structure is confirmed by 1H NMR and FT-IR. The distinct microphase separation morphology of AEMs is observed by TEM. As the content of methylhydroquinone increases, the ion conductivity of AEMs gradually increases. When the content of methylhydroquinone increases to 80%, the hydroxide conductivity of PEEK-DABDA-80 membrane reaches 0.052 S/cm at 80 °C. Meanwhile, it exhibits excellent mechanical properties and anti-swelling ability, with tensile strength of 25 MPa, elongation at break of 8.12% and swelling ratio is only 17.4% at 80 °C. And AEMs also display the better thermal stability. After soaked in 1 M NaOH at 60 °C for 30 days, PEEK-DABDA-80 membrane shows acceptable ion conductivity of 0.021 S/cm at 60 °C. In view of these properties, PEEK-DABDA-x AEMs may display potential application as alkaline AEMs. Image 1 • A series of poly(ether ether ketone) anion exchange membranes were prepared. • Effect of the content of methylhydroquinone on AEMs' properties was studied. • The AEMs showed low swelling ratio, excellent mechanical properties. [ABSTRACT FROM AUTHOR]

Poly(ether ether ketone) (PEEK) is a high-performance thermoplastics with outstanding mechanical properties and thermal resistance (serving temperature up to 250 °C). Although many studies have been performed on the stress–strain behavior and related modeling, less attention has been paid on the structural and orientational evolution of PEEK during tensile deformation. In this work, the orientational and structural evolution during tensile deformation at a wide range of temperatures from 30 to 170 °C was probed ex situ by wide-angle X-ray diffraction and differential scanning calorimetry. The enthalpy of cold crystallization of PEEK as a function of strain, which reflects the content of amorphous fraction and the disorder degree of crystals, presents an interesting dependence on tensile temperature. The evolution of orientation with strain is strongly dependent on the tensile temperature. Oriented PEEK presents much improved modulus and tensile strength compared to that of undrawn PEEK. This finding demonstrated that pre-stretching especially at temperatures above Tg is an effective way to improve the mechanical property of PEEK. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is one of the most promising shape memory polymers with outstanding biocompatibility, while poly(ether ether ketone) (PEEK) is a special engineering plastic with excellent mechanical performance. In this work, PEEK was selected to modify PLA, and a series of PLA blended with different PEEK contents (PLA/PEEK blends) were obtained. The effects of PEEK on thermodynamic, mechanical and shape memory properties of PLA/PEEK blends were investigated. The results showed that the thermal stability of the PLA/PEEK blend was improved with the PEEK content increase. The tensile strength reached the highest value of 20.6 MPa when the PEEK content was 10%. While the best shape memory performance occurred with the PEEK content of 15%, the shape recovery time was less than 2 s, and the shape fixation/recovery ratio was more than 99%. Furthermore, the programmable mimetic flower opening process was achieved by using PLA/PEEK blends with different PEEK content ratios. The above results indicated that the blend of an appropriate proportion of PEEK had positive effects on mechanical and deformation performances of PLA. [ABSTRACT FROM AUTHOR]

Poly(ether ether ketone) (PEEK) was irradiated with 4 MeV O+ and 5 and 10 MeV Au+ ions to the fluences from 1012 to 1014 cm−2 and then treated in 5 M/l water solution of LiCl for one month at room temperature. After drying and removal of LiCl surface contamination, the depth distribution of LiCl embeded in PEEK was measured by the neutron depth profilig method (NDP) sensitive to 6Li isotope. Embeded LiCl is believed to map distribution of water diffusing into PEEK interior. The results show that the PEEK irradiated to the fluences above 1.1013cm−2 is prone to water penetration to the depths of few microns. On the pristine PEEK and that irradiated to lower ion fluences only a surface Li contamination is observed. [ABSTRACT FROM AUTHOR]

This study explores the effect of rapid high-temperature processing on the interface of carbon fibre (CF) reinforced poly-ether-ether-ketone (PEEK). Specimens that have been thermally treated at slower and faster heating rates and specimens that have not been post-manufacturing treated (virgin) are examined with single fibre pull-out tests. A comparison between their interfacial shear strength (IFSS) and their failure modes takes place. Scanning electron microscopy is used to assess the surface morphology of the thermally treated specimens, and partly cross-polarised microscopy is employed to investigate the development of transcrystallinity. Furthermore, to identify the extent of thermal degradation the specimens are examined with attenuated total reflection Fourier transform infrared spectroscopy. At faster heating rates, an improved interfacial adhesion up to 25% is found at temperatures where a low-level thermal damage is induced. At higher temperatures and despite the increased thermal damage, an IFSS increase of up to 10% is still identified. This is due to the beneficial formation of thermal residual stresses upon high-temperature processing, and overall, especially rapid high-temperature processing could effectively serve for enhancing the interface properties of CF/PEEK. [Display omitted] • The CF/PEEK interface is examined in slower and faster high-temperature processing. • High-temperature processing results in thermal residual stresses at CF/PEEK. • At faster heating rates an improved interfacial adhesion up to 25% is found. • At elevated temperatures and despite the increased thermal damage, an improved IFSS of up to 10% is still identified. • Rapid high-temperature processing could serve for enhancing the CF/PEEK interface. [ABSTRACT FROM AUTHOR]

Sulfonated poly(ether ether ketone) (sPEEK) membrane is a promising proton-conducting membrane for fuel cell. However, the performance and lifetime of sPEEK membrane depend on the degree of sulfonation (DS). High DS of sPEEK increases the performance, but the mechanical properties could deteriorate progressively which affect its lifetime. Thus, this study investigated the effect of adding polyvinylidene fluoride (PVDF) into high DS (80%) of sPEEK through solution blending method toward its physicochemical properties and morphology structures. The PVDF concentration was varied to 5, 10, 15, and 20 wt% relative to the sPEEK content. The existence of hydrophobic PVDF in 80% sPEEK improved the mechanical properties where the water uptake and swelling degree of membrane decreased, whereas the tensile strength increased. The sPEEK/PVDF 15 exhibited the highest proton conductivity (46.23 mS cm−1) at 80°C. Incorporating PVDF into high DS of sPEEK enhanced the mechanical properties which can be used as a proton-conducting membrane for fuel cell that may improve the performance and prolong the lifetime of the cell. [ABSTRACT FROM AUTHOR]

Wrinkling patterns were fabricated by sulfonation of ion irradiated poly(ether ether ketone) (PEEK). A variety of wrinkling patterns in the micrometer to sub-micrometer range were observed and were controlled by the adsorbed dose and dose rate of the irradiated ions as well as the sulfonation time. Because of the properties of these micro-textured membranes, they are promising for a broad range of applications. In particular, the cross-linked membranes had a very low permeability of vanadium ions, i.e. 1.5 × 10−7 cm2 min−1 due to their wrinkled structures in combination with the Donnan exclusive effect. [ABSTRACT FROM AUTHOR]

High-performance anion exchange membranes (AEMs) are in need for practical application of AEM fuel cells. Novel branched poly(ether ether ketone) (BPEEK) based AEMs were prepared by the copolymerization of phloroglucinol, methylhydroquinone and 4,4′-difluorobenzophenone and following functionalization. The effects of the branched polymer structures and functional groups on the membrane's properties were investigated. The swelling ratios of all the membranes were kept below 15% at room temperature and had good dimensional stability at elevated temperatures. The branching degree has almost no effect on the dimensional change, but plays a great role in tuning the nanophase separation structure. The cyclic ammonium functionalized membrane showed a lower conductivity but a much better stability than imidazolium one. The BPEEK-3-Pip-53 membrane with the branching degree of 3% and piperidine functionalization degree of 53% showed the best performances. The ionic conductivity was 43 mS cm−1 at 60 °C. The ionic conductivity in 1 M KOH at 60 °C after 336 h was 75% of its initial value (25% loss of conductivity), and the IEC was 83% of its initial value (17% loss of IEC), suggesting good alkaline stability. The peak energy density (60 °C) of the single H 2 /O 2 fuel cell with BPEEK-3-Pip-53 membrane reached 133 mW cm−2 at 260 mA cm−2. • A novel branched poly(ether ether ketone) based AEM was prepared. • The branched AEMs showed high conductivity and low swelling ratio. • A high peak power density was achieved for single cell with the branched AEM. [ABSTRACT FROM AUTHOR]

• Both GNP and C 60 enhanced the modulus of PEEK significantly. • The reinforcing effect of C 60 on PEEK was more pronounced compared to GNP. • The thermal stability of PEEK was improved by the addition of GNP or C 60. • The tan δ peak height of PEEK decreased with increasing the content of GNP. • The tan δ peak height of PEEK kept constant irrespective of the addition of C 60. Poly(ether ether ketone) (PEEK) is a high-performance engineering plastics, being widely used in aerospace, automobile and biomedical applications. In this work, the effect of fullerenes (C 60) and graphene nanoplatelets (GNP) on the properties of PEEK was compared. It was found that both C 60 and GNP enhanced the modulus of PEEK significantly and the reinforcing effect was more pronounced for C 60. Most interestingly, the tan δ peak height of PEEK kept constant irrespective of the addition of C 60 , while it decreased gradually with increasing the content of GNP. This study suggests that C 60 appears to be the best filler of PEEK if the damping property of the materials is a critical concern. [ABSTRACT FROM AUTHOR]

Poly(ether ether ketone) (PEEK) is an alternative material to metals for orthopedic applications. However, the compatibility of PEEK with hard tissues needs to be improved. To address this issue, this study proposes a novel technique for PEEK surface modifications. A polyphosphodiester macromonomer (PEPMA·Na) was synthesized via the demethylation of polyphosphotriester macromonomer obtained via the ring-opening polymerization of cyclic phosphoesters using 2-hydroxypropyl methacrylamide as the initiator. The surface modification of PEEK was performed via photoinduced and self-initiated graft polymerization of PEPMA·Na without using any photoinitiators. The amount of phosphorus due to poly(PEPMA·Na) immobilized on PEEK increased with an increase in the photoirradiation time. The PEEK surface turned hydrophilic due to poly(PEPMA·Na) grafting, with almost similar advancing and receding contact angles, implying that the modified PEEK surface (PEEK-g-poly(PEPMA·Na)) was homogeneous. Specimens were mineral coated by simple static soaking in ×1.5 simulated body fluid (1.5SBF) and by an alternative process that included additional soaking steps in 200 mM CaCl2 aq. and 200 mM K2HPO4 aq. before static soaking in 1.5SBF. Specimens were immersed in 1.5SBF for 28 days in simple static soaking, after which the PEEK-g-poly(PEPMA·Na) surface was completely covered with spherical cauliflower-like mineral deposits that resembled octacalcium phosphate (OCP). Their structural similarities were confirmed via X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDS), and X-ray fluorescence (XRF) analyses. However, these mineral deposits were not observed on the bare PEEK surface. Due to the additional soaking steps (alternative soaking) undertaken before the static soaking of the specimens in 1.5SBF, the mineral coating on the PEEK-g-poly(PEPMA·Na) was dramatically accelerated and the surface was fully covered with mineral deposits in only one day of soaking. The mineral deposits resulting from both the soaking processes had similar structures. Compared with bare PEEK, osteoblastic MC3T3-E1 cells proliferated more actively on mineral-coated PEEK-g-poly(PEPMA·Na). Thus, the surface immobilization of poly(PEPMA·Na) on a PEEK surface is effective for mineral coating and may be useful to provide hard-tissue compatibility on PEEK. [ABSTRACT FROM AUTHOR]

The motivation of this study was to investigate the stability of poly(ether ether ketone) (PEEK) at conditions close to real processing: fast cycles (below 300 s), temperatures higher than 400 °C and oxygen-containing atmosphere. Such conditions significantly affect the consolidation ability of PEEK and its further processability. The overall quality of the polymer after the degradation cycles was investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Significant morphological changes were detected by increasing crosslinking density and decrease in crystallinity with temperature and time. Moreover, the through-thickness polymer degradation was studied in order to understand the local polymer quality. The samples were examined via Fourier transform infrared (FTIR) spectroscopy and light transmission microscopy. The formation of a dark coloured boundary layer by the way of an oxygen diffusion-controlled process on the surface of the polymer was observed. For temperatures below 400 °C, the boundary layer increased constantly with time. In contrast, high processing temperatures resulted in a concentrated barrier layer which acted as protecting cover. • The thermal history in air significantly affects the processing properties of PEEK, espe-cially at the surface. • The boundary layer formed has been studied by DSC and FT-IR. • For temperatures below 400 °C, the boundary layer increased constantly with time. • Above 400 °C, the dark layer is not linearly dependent on t and T and leads to the formation of a protecting cover. [ABSTRACT FROM AUTHOR]

• PEEK capillary was used in CE-MS for tolerance to organic solvents. • PEEK capillary showed excellent stability in commonly used organic solvents. • PEEK capillary showed good separation performance in NACE and organic-aqueous CE. • This method was successfully used to quantitative analysis of peimine and peiminine. Nonaqueous capillary electrophoresis (CE) and organic-aqueous CE using high content of organic solvents are common techniques in capillary electrophoresis-mass spectrometry (CE-MS) due to various advantages. However, the long-term stability of commonly used polyimide coated fused silica capillary remains a major problem that polyimide coating is prone to swelling in organic solvents and aminolysis in alkaline buffer, which cause serious problems like irregular electrospray, current drop or clogging event. In this work, robust PEEK capillary was used as separation capillary for tolerance to high content of organic solvents in CE-MS system. It is interesting that the high mechanical and chemical stability of PEEK capillary ensured stable CE separation and electrospray when used in CE-MS. All quantitative experiments were accomplished by single PEEK capillary. In addition, the using of organic solvents as running buffer reduced adsorption of hydrophobic compounds on PEEK capillary wall and improved the symmetry of peak shape. The PEEK-based CE-MS method showed good separation performance in analysis of several groups of active alkaloids in traditional Chinese medicines and was applied for quantitative analysis of peimine and peiminine in Bulbus Fritillariae thunbergii herb with high sensitivity. Based on the advantages like simple pretreatment, easy to cut, stable and good separation performance of PEEK column in CE-MS, this study provides an effective way for improving the stability and employment of high content of organic solvents in CE-MS analysis. [ABSTRACT FROM AUTHOR]

Abstract Poly(ether ether ketone) (PEEK), with its superb mechanical properties, excellent chemical resistance and high thermo-oxidative stability is one of the most important engineering thermoplastics for high-end applications. In this work, we investigate the elastic and viscoelastic properties along with the creep mitigation of two sets of samples: PEEK reinforced with graphene nanoplatelets (GNPs) and PEEK reinforced with a hybrid graphene/short carbon fibre (CF) filler. The melt viscosity of the PEEK nanocomposites was found to increase with increasing GNPs content; however, the viscosity of the hybrid CF-GNP samples with the highest filler content was equal to the one of the samples filled only with GNPs at low shear rates. This processability shows the advantage of GNPs over other nano and conventional fillers in the ability to use meaningful loadings. The introduction of GNPs improved significantly the stiffness and the storage modulus of the materials in both PEEK-GNP and PEEK-CF-GNP composites. Moreover, the presence of GNPs within the composites led to a restriction of the mobility of the macromolecular chains of PEEK, which resulted in enhanced creep properties at both room temperature and elevated temperatures. Overall, the nanocomposites produced displayed properties that make them attractive in applications where high stiffness and structural integrity at elevated temperatures are required. [ABSTRACT FROM AUTHOR]

Improved thromboresistance of mechanical valves is desired to decrease the risk of thromboembolism and thrombosis and reduce the dosage of anticoagulation with a vitamin K antagonist (e.g., warfarin). For several mechanical valves, design‐related features are responsible for their improved thromboresistance. However, it remains unclear whether material‐related features provide a practical level of thromboresistance to mechanical valves. Here, we studied the effect of a bileaflet valve made of poly(ether ether ketone) (PEEK) with a poly(2‐methacryloyloxyethyl phosphorylcholine) (PMPC)‐grafted surface (PEEK‐g‐PMPC). PMPC is a well‐known thromboresistant polymeric material. A short‐term (<26 h) porcine aortic valve replacement model using neither an anticoagulant nor an antiplatelet agent showed that the PEEK‐g‐PMPC valve opened and closed normally with an allowable transvalvular gradient. Unlike an untreated PEEK valve, no thrombus formed on the PEEK‐g‐PMPC valves on gross anatomy examination in addition to the absence of traveled thrombi in the kidney and lung tissues. Material (PEEK‐g‐PMPC)–related thromboresistance appeared to decrease the risk of thromboembolism and thrombosis for patients with mechanical valves. However, thromboresistance of the PEEK‐g‐PMPC valve requires improvement because fibrous fouling was still observed on the leaflet. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1052–1063, 2019. [ABSTRACT FROM AUTHOR]

Poly(ether ether ketone) s with terminal propargyl groups (PEEK‐PR) were synthesized from hydroxyl terminated PEEK (PEEKTOH) and characterized. The heat‐triggered polymerization of PEEK‐PR to poly bischromenes having PEEK backbone was confirmed by Fourier transform infrared spectroscopy and differential scanning calorimetric studies. PEEK‐PR was blended with a bisphenol based epoxy resin‐diamino diphenylsulphone system in different proportions and cured to form PEEK‐bischromene‐interpenetrated‐epoxy‐amine networks. Tensile strength and elongation of the cured blends increased up to 10‐phr loading of PEEK‐PR and then declined. Tensile moduli of all formulations were comparable. Fracture toughness increased by a maximum of 33%, and the fractured surface morphology showed a ductile fracture. The blends exhibited slightly lower glass transition temperature to that of the neat epoxy‐amine system. A reference sample of epoxy‐amine was processed with the optimum loading of the precursor polymer, PEEKTOH, and compared its properties with the PEEK‐PR incorporated epoxy systems. In this way, it is found that the incorporation of addition curable propargylated PEEK increases the strength characteristics with adequate thermal stability and fracture toughness for high‐performance structural applications. [ABSTRACT FROM AUTHOR]

Abstract Side-chain-type quaternized aromatic polyelectrolytes named QBz-PEEK-x have been synthesized via one-step benzylation modification of commercial poly(ether ether ketone) (PEEK). By controlling the molar ratio between the benzylation reagent and PEEK, the substitution degree x could be tuned in a wide range (51.1%~ 91.6%). A series of five anion exchange membranes (AEMs) with high mechanical strength were facilely prepared via solution-casting of QBz-PEEK-x. Water uptake, swelling ratio and ion conductivity of these AEMs were investigated in detail. Of particular interest is that, at 60 °C, the AEM of QBz-PEEK-76.0% exhibited a moderate water uptake of 56%, a low swelling ratio of 15%, and an exceptionally high OH– conductivity of 155 mS cm−1 which was comparable to the top values ever reported. Moreover, a promising peak power density of 391 mW cm−2 was achieved when assembling QBz-PEEK-76.0% AEM in a H 2 /O 2 single cell operated at 70 °C. This unprecedented "benzylation" method opens a new door to novel high performance side-chain-type AEMs. Graphical abstract Unprecedented one-step benzylation modification of commercial poly(ether ether ketone) (PEEK) yielded high performance AEMs. fx1 Highlights • One-step benzylation modification of PEEK yielded soluble polyelectrolytes. • An AEM exhibited an exceptionally high OH– conductivity of 155 mS cm−1 at 60 °C. • A promising peak power density of 391 mW cm−2 was achieved in a H 2 /O 2 single cell. [ABSTRACT FROM AUTHOR]

• Response tolerance to the high dose (500 kGy) irradiation in air and water of highly sulfonated SPEEK is demonstrated. • Thermal and mechanical properties for SPEEK with degree of sulfonation up to 70 % remain stable after high dose irradiation compared to nonirradiated SPEEK membranes. • Irradiation in water enhances reduction of molecular arrangement at the DS > 70 % causing membrane dissolution in water. • Improved molecular arrangement due to the physical interaction of sulfonated groups affects mechanical stiffness of SPEEK60-70 membranes after irradiation in water. Sulfonated poly(ether ether ketones) (SPEEK) have raised interest as a replacement of Nafion® proton exchange membranes (PEM) for the application in harsh environments involving material exposure to ionizing radiation, for example, radioactive hydrogen isotope separation from water. This study is dedicated to evaluate the effects of high dose (500 kGy) electron beam irradiation on the physico-chemical and thermomechanical properties of highly sulfonated (degree of sulfonation 60–90 %) SPEEK membranes irradiated in air and water. Spectrometric and thermogravimetric analysis indicated slight changes in the material properties after irradiation with increase of the degree of sulfonation (DS). Tensile tests and thermomechanical analysis of irradiated samples indicated notable deterioration of properties at higher DS values. Results demonstrate that SPEEK membranes with DS around 70 % could be a replacement of the traditional PEM for the applications where exposure to ionizing radiation occurs. [ABSTRACT FROM AUTHOR]

The binder effect was investigated on the interfacial stability and the cell performance of membrane electrode assembly (MEA), when Nafion® and sulfonated poly(ether ether ketone) (sPEEK) ionomers were used as binders. When sPEEK membrane was employed in the MEA fabrication, sPEEK ionomer illustrated better cell performance with lower electric-surface resistance than Nafion® ionomer under the 30% relative humidity (RH), whereas the outcome is vice versa at 100% RH. This different result was caused by the interfacial stability between the catalyst and membrane via binder as well as the proton conductivity of binder. Even though the proton conductivity of Nafion® ionomer was higher than that of sPEEK, the compatibility between sPEEK membrane and sPEEK ionomer was better than that between sPEEK membrane and Nafion® ionomer. At 30% RH, this interfacial stability, rather than proton conductivity of the ionomer, has more significant effect on the cell performance, as the SEM-morphology analysis showed that application of the Nafion® ionomer resulted in the delamination of the membrane from the catalyst layer. At the 100% RH, the proton conductivity of the binder was the main contribution to the cell performance, as an interfacial problem was not evident between the two layers. [ABSTRACT FROM AUTHOR]

Abstract Poly(ether ether ketone) (PEEK) is a relevant thermoplastic in industry and in the biomedical sector. In this work, the lubricant capability of graphene nanoplatelets (GNPs) is used for improving the PEEK wear properties. Nanocomposites were prepared by solvent-free melt-blending and injection molding at various compositions between 1 and 10 wt. % of GNPs. The Raman G band shows a progressive increment proportional to the bulk GNP percentage. From calorimetric data, the polymer matrix structure is interpreted in terms of a 3-phase model, in which the crystalline phase fluctuates from 39 to 34% upon GNP addition. Thermal conductivity varies in accordance with the polymer crystallinity. Tensile and flexural tests show a progressive increase in the modulus, as well as a decrease in the fracture strength and the work of fracture. Most important, the composite surface undergoes a substantial improvement in hardness (60%), together with a decrease in the coefficient of friction (−38%) and a great reduction in the wear factor (−83%). Abrasion and fatigue wear mechanisms are predominant at the lowest and highest GNP concentrations respectively. In conclusion, GNPs are used without any chemical functionalization as the filler in PEEK-based materials, improving the surface hardness and the tribological properties. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Phosphate-modified PEEK is successfully prepared. • Phosphate-modified PEEK enhances bone marrow stromal cells responses. • Phosphate-modified PEEK mitigates inflammatory responses by macrophage. • Phosphate modification can significantly improve implant-bone bonding strength in vivo. Abstract Poly(ether ether ketone) (PEEK) has emerged as an alternative endosseous material to metal implants mainly because of its lack of allergic sensitivity and radiolucency, while maintaining similar mechanical properties with bone. However, a disadvantage of PEEK is its weak osseointegration ability compared with metal implants. To overcome this, we prepared a phosphate group-modified PEEK by plasma treatment and subsequent phosphorylation reaction. Plasma treatment and phosphate modification of PEEK changed its hydrophobic surface to a hydrophilic surface while maintaining the original surface topography and roughness. Phosphate modification increased the bioactivity of rat bone marrow stromal cells (BMSCs), including proliferation, alkaline phosphatase activity, and bone-like nodule formation; however, this effect was negligible in plasma-treated PEEK. In addition, phosphate modification attenuated the phenotypic polarization of lipopolysaccharide-primed RAW264.7 macrophages to an inflammatory phenotype, based on the finding that macrophages on phosphate-modified PEEK produced decreased levels of the inflammatory cytokine and increased levels of the anti-inflammatory cytokine. Finally, in an animal study, phosphate-modified PEEK exhibited a doubled pullout force from the femur bone cavity compared with bare PEEK. Thus, we conclude that phosphate modification can significantly improves the implant-bone bonding strength of PEEK by enhancing BMSCs activity and reducing excessive inflammation. [ABSTRACT FROM AUTHOR]

Preparation of stir bar extraction (SBSE) device with high physical and chemical stability is important and challenging by date. A novel poly (ether ether ketone) (PEEK) tube with excellent mechanical property and chemical stability was firstly used as jacket of metal bar for preparation of stir bar. By employing covalent modification method, the inherent chemical resistant problem of PEEK which restricts the modification of sorbents was well solved. After functionalization, plenty of benzoic acid groups were formed onto the PEEK jacket. Metal organic frameworks of aluminium-based Materials of Institute Lavoisier-68 (MIL-68) was in situ immobilized onto the PEEK surface (MIL-68@PEEK) by the bonding with benzoic acid groups. Afterwards, a facile dumbbell-shaped structure was designed for reducing the friction between sorbents and bottom of container. Due to superior property of the PEEK jacket and the covalent modification method, the MIL-68 modified PEEK jacket SBSE device showed good robustness. After coupling with HPLC-MS/MS, the MIL-68@PEEK-based SBSE device was used to analyse of three parabens including methyl paraben, ethyl paraben and propyl paraben. The method had low limit detection up to 1 pg mL −1 with good linearity (R 2  ≥ 0.9978) and good reproducibility (relative standard deviation ≤ 9.74%). The method has been applied to the detection of parabens in cosmetics and rabbit plasma after painted with cosmetics with recoveries between 73.25% and 104.23%. [ABSTRACT FROM AUTHOR]

Poly(ether ether ketone) (PEEK) has emerged as a candidate to replace metal implants because of its satisfactory mechanical properties, radiolucency, and lack of metal allergy. However, PEEK lacks osseointegration ability limiting its clinical applications. To overcome this problem, we prepared PEEK with a micro-rough surface using the sandblast method to modulate its osseointegration property; the sandblast method is simple, cost-effective, and is already applied to clinical metal implants. The surface roughness of the sandblasted PEEK was about 2.3 µm, whereas that of mirror-polished PEEK was 0.06 µm. Rat bone marrow-derived mesenchymal stem cells (RMSCs) showed higher proliferation, osteocalcin (OC) expression and bone-like nodule formation on micro-roughened PEEK compared with those cultured on mirror-polished PEEK, suggesting that micro-roughening facilitated RMSCs proliferation and differentiation. The micro-roughened surface slightly mitigated secretion of inflammatory C-C motif chemokine 2 (CCL-2) from lipopolysaccharide (LPS)-stimulated macrophages, but not of tumor necrosis factor a (TNFa) and interleukin-6 (IL-6). Finally, to compare osseointegration, specimens were implanted in rat femur bone marrow cavities, and then the pull-out force was measured. The pull-out force of micro-roughened PEEK was about four times higher than that of the mirror-polished PEEK. These results showed that micro-roughening of PEEK using the sandblast method was able to improve osseointegration, partly through elevating proliferation and differentiation of RMSCs. [ABSTRACT FROM AUTHOR]