Modulation of Free Carbon Structures in Polysiloxane-Derived Ceramics for Anode Materials in Lithium-Ion Batteries.

Polymer-derived silicon oxycarbide (SiOC) ceramics have garnered significant attention as novel silicon-based anode materials. However, the low conductivity of SiOC ceramics is a limiting factor, reducing both their rate capability and cycling stability. Therefore, controlling the free carbon content and its degree of graphitization within SiOC is crucial for determining battery performance. In this study, we regulated the free carbon content using divinylbenzene (DVB) and controlled the graphitization of free carbon with the transition metal iron (Fe). Through a simple pyrolysis process, we synthesized SiOC ceramic materials (CF) and investigated the impact of Fe-induced changes in the carbon phase and the amorphous SiOC phase on the comprehensive electrochemical performance. The results demonstrated that increasing the DVB content in the SiOC precursor enhanced the free carbon content, while the addition of Fe promoted the graphitization of free carbon and induced the formation of carbon nanotubes (CNTs). The electrochemical performance results showed that the CF electrode material exhibited a high reversible capacity of approximately 1154.05 mAh g-1 at a low current density of 100 mA g-1 and maintained good rate capability and cycling stability after 1000 cycles at a high current density of 2000 mA g-1.

Constructing a Novel Moderately Modulus "Rigid-Flexible" Structure with Synergistic Reinforcement on the Carbon Fiber Surface to Enhance the Mechanical Properties of Carbon Fiber/Epoxy Composites at Elevated Temperatures.

To improve the mechanical performance of carbon fiber (CF)/epoxy composites in high-temperature environments, a moderately modulus gradient modulus interlayer was constructed at the interface phase region of composites. This involved the design of a "rigid-flexible" synergistic reinforcement structure, incorporating rigid nanoparticle GO@CNTs and a flexible polymer polynaphthyl ether nitrile ketone onto the CF surface. Notably, at 180 °C, compared to commercial CF composites, the CF-GO@CNTs-PPENK composites displayed a remarkable improvement in their mechanical characteristics (interfacial shear, interlaminar shear, flexural strength, and modulus), achieving enhancements of 173.0, 91.5, 225.7, and 376.4%, respectively. The principal reason for this the moderately modulus interface phase composed of GO@CNTs-PPENK (where GO and CNTs predominantly consist of carbon atoms with sp2-hybridized orbitals, forming highly stable C-C structures, while PPENK possesses a "twisted non-coplanar" structure), which exhibited resistance to deformation at high temperatures. Moreover, it greatly improved the mechanical interlocking, wettability, and chemical compatibility between CF and the epoxy. It also played a crucial role in balancing and buffering the modulus disparity. The interface failure behavior and reinforcement mechanisms of the CF composites were analyzed. Furthermore, validation of the presence of a moderately modulus gradient interlayer at the interface phase region of CF-GO@CNTs-PPENK composites was performed by using atomic force microscopy. This study has established a theoretical foundation for the development of high-performance CF composites for use in high-temperature fields.

A Small-Molecule Organic Cathode with Extended Conjugation toward Enhancing Na+ Migration Kinetics for Advanced Sodium-Ion Batteries.

Organic cathode materials show excellent prospects for sodium-ion batteries (SIBs) owing to their high theoretical capacity. However, the high solubility and low electrical conductivity of organic compounds result in inferior cycle stability and rate performance. Herein, an extended conjugated organic small molecule is reported that combines electroactive quinone with piperazine by the structural designability of organic materials, 2,3,7,8-tetraamino-5,10-dihydrophenazine-1,4,6,9-tetraone (TDT). Through intermolecular condensation reaction, many redox-active groups C═O and extended conjugated structures are introduced without sacrificing the specific capacity, which ensures the high capacity of the electrode and enhances rate performance. The abundant NH2 groups can form intermolecular hydrogen bonds with the C═O groups to enhance the intermolecular interactions, resulting in lower solubility and higher stability. The TDT cathode delivers a high initial capacity of 293 mAh g-1 at 500 mA g-1 and maintains 90 mAh g-1 at an extremely high current density of 70 A g-1. The TDT || Na-intercalated hard carbon (Na-HC) full cells provide an average capacity of 210 mAh g-1 during 100 cycles at 500 mA g-1 and deliver a capacity of 120 mAh g-1 at 8 A g-1.

Advanced Polymers in Cathodes and Electrolytes for Lithium-Sulfur Batteries: Progress and Prospects.

Lithium-sulfur (Li-S) batteries, which store energy through reversible redox reactions with multiple electron transfers, are seen as one of the promising energy storage systems of the future due to their outstanding advantages. However, the shuttle effect, volume expansion, low conductivity of sulfur cathodes, and uncontrollable dendrite phenomenon of the lithium anodes have hindered the further application of Li-S batteries. In order to solve the problems and clarify the electrochemical reaction mechanism, various types of materials, such as metal compounds and carbon materials, are used in Li-S batteries. Polymers, as a class of inexpensive, lightweight, and electrochemically stable materials, enable the construction of low-cost, high-specific capacity Li-S batteries. Moreover, polymers can be multifunctionalized by obtaining rich structures through molecular design, allowing them to be applied not only in cathodes, but also in binders and solid-state electrolytes to optimize electrochemical performance from multiple perspectives. The most widely used areas related to polymer applications in Li-S batteries, including cathodes and electrolytes, are selected for a comprehensive overview, and the relevant mechanisms of polymer action in different components are discussed. Finally, the prospects for the practical application of polymers in Li-S batteries are presented in terms of advanced characterization and mechanistic analysis.

PDA-BPs integrated mussel-inspired multifunctional hydrogel coating on PPENK implants for anti-tumor therapy, antibacterial infection and bone regeneration.

Currently, many cancer patients with bone defects are still threatened by tumor recurrence, postoperative bacterial infection, and massive bone loss. Many methods have been studied to endow bone implants with biocompatibility, but it is difficult to find an implant material that can simultaneously solve the problems of anticancer, antibacterial and bone promotion. Here, a multifunctional gelatin methacrylate/dopamine methacrylate adhesive hydrogel coating containing 2D black phosphorus (BP) nanoparticle protected by polydopamine (pBP) is prepared by photocrosslinking to modify the surface of poly (aryl ether nitrile ketone) containing phthalazinone (PPENK) implant. The multifunctional hydrogel coating works in conjunction with pBP, which can deliver drug through photothermal mediation and kill bacteria through photodynamic therapy at the initial phase followed by promotion of osteointegration. In this design, photothermal effect of pBP control the release of doxorubicin hydrochloride loaded via electrostatic attraction. Meanwhile, pBP can generate reactive oxygen species (ROS) to eliminate bacterial infection under 808 nm laser. In the slow degradation process, pBP not only effectively consumes excess ROS and avoid apoptosis induced by ROS in normal cells, but also degrade into PO43- to promote osteogenesis. In summary, nanocomposite hydrogel coatings provide a promising strategy for treatment of cancer patients with bone defects.

Improving the comprehensive properties of chitosan-based thermal insulation aerogels by introducing a biobased epoxy thermoset to form an anisotropic honeycomb-layered structure.

Naturally-derived aerogels have attracted considerable attention owing to their good biocompatibility, biodegradability and sustainability, but their weak mechanical properties largely limit their applications in various fields. Herein, we proposed the use of a directional freeze-drying method to prepare an anisotropic honeycomb three-dimensional porous aerogel with water-soluble chitosan (CS) as a rigid skeleton and water-soluble biobased epoxy resin as cross-linked hard segments, which had low volume shrinkage and density of 13.9 % and 34.3 mg/cm3, respectively. The resultant aerogel had anisotropic mechanical properties, such as rigidity in the axial direction with a maximum axial modulus of 6.71 MPa, which was 51.6 times larger than that of the pure chitosan aerogel, demonstrating a good compressive elasticity in the radial direction. It also had anisotropic thermal management properties, with a lower thermal conductivity in the radial direction than in the axial direction, down to 0.029 W/mK. The introduction of biobased epoxy resin improved the overall thermal stability, flame retardancy, and increased the biomass content in the aerogel, reducing the carbon footprint of the material. This study paves the way for the construction of a special graded porous, structurally and functionally integrated thermal insulation aerogel, which is of great significance for the development of new thermal insulation materials.

A New Strategy to Improve the Toughness of Epoxy Thermosets-By Introducing Poly(ether nitrile ketone)s Containing Phthalazinone Structures.

As high brittleness limits the application of all epoxy resins (EP), here, it can be modified by high-performance thermoplastic poly(ether nitrile ketone) containing phthalazinone structures (PPENK). Therefore, the influence of different PPENK contents on the mechanical, thermal, and low-temperature properties of EP was comprehensively investigated in this paper. The binary blend of PPENK/EP exhibited excellent properties due to homogeneous mixing and good interaction. The presence of PPENK significantly improved the mechanical properties of EP, showing 131.0%, 14.2%, and 10.0% increases in impact, tensile, and flexural strength, respectively. Morphological studies revealed that the crack deflection and bridging in PPENK were the main toughening mechanism in the blend systems. In addition, the PPENK/EP blends showed excellent thermal and low-temperature properties (-183 °C). The glass transition temperatures of the PPENK/EP blends were enhanced by approximately 50 °C. The 15 phr of the PPENK/EP blends had a low-temperature flexural strength of up to 230 MPa, which was 46.5% higher than EP. Furthermore, all blends exhibited better thermal stability.

Low Dielectric Constant Photocurable Fluorinated Poly (Phthalazinone Ether) Ink with Excellent Mechanical Properties and Heat Resistance.

The photosensitive resins for 3D printing technology have been widely applied throughout the advanced communication field due to their merits of high molding accuracy and fast processing speed. Regardless, they, in particular, should have better mechanical properties, heat resistance, and dielectric properties. Herein, photocurable fluorinated poly (phthalazinone ether) (FSt-FPPE) was utilized as a prepolymer to improve the performance of photosensitive resin. A series of UV-curable inks named FST/DPGs were prepared with FSt-FPPE and acrylic diluents of different mass fractions. The FST/DPGs were cured into films by UV curing and post-treatment. After curing, their properties were characterized in detail. In terms of heat resistance, glass transition temperature (Tg) could reach 233 °C and the 5% thermal decomposition temperature (Td5%) was 371 °C. The tensile strength surprisingly reached 61.5 MPa, and the dielectric constant (Dk) could be significantly reduced to 2.75. Additionally, FST/DPGs were successfully employed in UV-assisted direct writing (DIW) to print 3D objects that benefited from their commendable fluidity and rapid curing speed. A stiff cylinder sample with a smooth surface and distinct pattern was ultimately obtained, indicating their remarkable 3D printing adaptation. Such photosensitive resin for UV-assisted DIW exhibits tremendous potential in the electronic industry.

Large and Tunable Ranking Shift in Triboelectric Series of Polymers by Introducing Phthalazinone Moieties.

Regulating the ranking of polymer in triboelectric series over a wide range is of great help for material's selection of triboelectric nanogenerators (TENGs). Herein, fluorinated poly(phthalazinone ether)s (FPPEs) with tunable molecular structure and aggregate structure are synthesized by co-polycondensation, while the large positive ranking shift in the triboelectric series can be achieved by introducing phthalazinone moieties with strong electron donating capability. FPPE-5, which includes abundant phthalazinone moieties, is more positive than all of the previously reported triboelectric polymers. Hence, the regulating range of FPPEs in this work updates a new record in triboelectric series, which is wider than that of previous works. A peculiar crystallization behavior, capable of trapping and storing more electrons, has been observed in FPPE-2 with 25% phthalazinone moieties. Correspondingly, FPPE-2 is more negative than FPPE-1 without a phthalazinone moiety, which is an unexpected shift against the common changing tendency in triboelectric series. With FPPEs films as the probing material, a tactile TENG sensor is applied to enable material identification via electrical signal polarity. Hence, this study demonstrates a strategy to regulate the series of triboelectric polymers by copolymerization using monomers with distinct electrification capabilities, where both the monomer ratio and the peculiar nonlinear behavior can control triboelectric performance.

Stabilization of Apatite Coatings on PPENK Surfaces by Mechanical Interlocking to Promote Bioactivity and Osseointegration In Vivo.

Apatite coatings with high stability can effectively improve the surface bioactivity and osteogenic activity of implant materials. In clinical practice, the ability of apatite coatings to bond with the substrate is critical to the effect of implants. Here, we propose a strategy to construct a three-dimensional (3D) nanoporous structure on the surface of a poly(phthalazinone ether nitrile ketone) (PPENK) substrate and introduce a polydopamine (PDA) coating with grafted phosphonate groups to enhance the overall deposition of a bone-like apatite coating in the 3D nanoporous structure during mineralization. This method leads to a mechanical interlocking between the apatite coating and the substrate, which increases the stability of the apatite coating. The apatite coating confers a better bioactive surface to PPENK and also promotes osteogenic differentiation and adhesion of MC3T3-E1 osteoblasts in vitro. The samples are then implanted into rat femurs to characterize in vivo osseointegration. Micro-CT data and histological staining of tissue sections reveal that PPENK with a stable apatite coating induces less fibrous capsule formation and no inflammatory response and promotes osteogenic differentiation and bone-bonding strength. This enhances the long-term use of PPENK implant materials and shows great potential for clinical application as orthopedic implants.

Advanced Nanostructured Materials for Electrocatalysis in Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are considered as among the most promising electrochemical energy storage devices due to their high theoretical energy density and low cost. However, the inherently complex electrochemical mechanism in Li-S batteries leads to problems such as slow internal reaction kinetics and a severe shuttle effect, which seriously affect the practical application of batteries. Therefore, accelerating the internal electrochemical reactions of Li-S batteries is the key to realize their large-scale applications. This article reviews significant efforts to address the above problems, mainly the catalysis of electrochemical reactions by specific nanostructured materials. Through the rational design of homogeneous and heterogeneous catalysts (including but not limited to strategies such as single atoms, heterostructures, metal compounds, and small-molecule solvents), the chemical reactivity of Li-S batteries has been effectively improved. Here, the application of nanomaterials in the field of electrocatalysis for Li-S batteries is introduced in detail, and the advancement of nanostructures in Li-S batteries is emphasized.

Synthesis and Characterization of Schiff Base Polymers via Metal Coordination and Its Application in Infrared Stealth Coating.

In order to reduce the infrared emissivity to meet the requirements of modern warfare for infrared stealth materials, we prepared the polymers containing Schiff base moieties using polyetheramine and 2,6-pyridinedicarboxaldehyde by solution polycondensation and coordinated with Ni2+, Cu2+, and Sm3+ ions to prepare organic coatings. The structure and the thermal and mechanical properties of the coatings were studied in detail. Meanwhile, the effect of the conductivity change of coordination polymers on infrared emissivity was studied systematically. The results showed the polymer coordinated with Sm3+ ions had the lowest energy band gap, which was 2.99 eV, and the best electrical conductivity of 3.54 × 10-4 S/cm compared with Ni2+ and Cu2+ coordination polymers. The infrared emissivity was the lowest in the 2-22 µm infrared waveband range, which reached 0.58, suggesting the polymers containing Schiff base moieties and their coordination polymers may have a great potential to be applied as infrared stealth materials in military applications.

Synthesis and Characterization of a Self-Polycondensation Diazaphthalanone Monomer and Its Polymers from Polycondensation Reactions.

Polyether ketone (PEK) plastics are linear thermoplastic polymers connected by at least one ether bond and at least one ketone bond on the aryl group. The reason for their excellent heat resistance, rigidity, and mechanical strength is that their main molecular chain contains plenty of aromatic rings and polar carbonyl groups, and their molecular chain presents a large rigidity and strong intermolecular force. In addition, the main chain contains a considerable number of ether bonds, resulting in a certain toughness. However, polyether ketone materials have the disadvantage of poor solubility because of their excellent rigidity. To improve the solubility of polyether ketone, the preparation method of a novel nitrogenous heterocyclic polyaromatic ether monomer, 2-(4-chlorophenyl)-2,3-dihydrophthalazine-1,4-dione (CDD), was proposed, and its activity of polymerization was studied. The average molecular weight of the poly(aryl ether ketone) containing a nitrogenous heterocyclic polyaromatic ether group obtained by self-polycondensation of CDD was 4.181 × 103 kg/mol, and the yield was 90.5%. In order to further explore the activity of monomers, novel copolymerized poly(aryl ether ketone) (PBCD) containing a nitrogenous heterocyclic polyaromatic ether structure was prepared by ternary copolymerization with 4,4-difluorobenzophenone (DFBP) and bisphenol fluorene (BHPF) with high activity. The average molecular weight of PBCD was 72.793 × 103 kg/mol, the molecular weight distribution was 2.344, and the yield was 88.1%. Fourier transform infrared spectroscopy (FT-IR) and 1H NMR were used to confirm the structure of the obtained polymer. Through thermogravimetric analysis (TGA), the determined weight loss temperature of 5% under nitrogen was higher than 500 °C, indicating excellent thermal stability. Compared with the solubility of the binary copolymer containing fluorenyl poly(aryl ether ketone) (PBD), the polymer showed reasonable solubility in selective solvents such as chloroform and N,N-dimethylacetamide.

Highly Enhancing the Interfacial and Mechanical Properties of Basalt Fiber/Poly(phthalazinone ether nitrile ketone) Composite by Thermoplastic Sizing Agents with Different Structures.

The interfacial modification of basalt-fiber-reinforced polymer (BFRP) composites is an essential research field and many techniques have been developed to improve the adhesion between basalt fiber (BF) and the matrix. However, most studies were based on the matrixes of general plastics and epoxy resins. In this work, five different chain structures of thermoplastic sizing agents were used to improve the interfacial properties of unidirectional BF-reinforced soluble and high-temperature-resistant poly(phthalazinone ether nitrile ketone) (BF/PPENK) composites. DMA results showed that the poly(ether nitrile) (PEN)-sized BF/PPENK (BF-PEN/PPENK) composite exhibited the optimal interfacial performance, with a storage modulus (E') and glass transition temperature (Tg) up to 50 GPa and 288 °C, respectively. Moreover, the tensile strength, compressive strength, flexural strength, and interlaminar shear strength of the BF-PEN/PPENK composite reached 778 MPa, 600 MPa, 1115 MPa and 57 MPa, respectively, and increased by 42%, 49%, 20% and 30% compared with the desized BF/PPENK composite. This study provides some suggestions for the design of sizing agents to modify the interface of BF and high-performance thermoplastic resin.

Tunicate inspired gelatin-based tough hydrogel wound dressing containing twisted phthalazinone with adhesive, self-healing and antibacterial properties.

As a hydrolytic product of collagen, gelatin is a polypeptide of biological origin. Gelatin hydrogels emerge as promising material candidates for traditional dressings due to good biocompatibility and the ability to keep wounds moist. However, it is difficult to simultaneously achieve gelatin hydrogel with robust mechanical property for long-term usage, reliable tissue adhesion, self-healing and antibacterial properties. Herein, we propose a simply synthesized strategy of a multifunctional gelatin hydrogel dressing, which is constructed by conjugating a newly synthesized 2-(4'-aldehydephenyl)-4-(2',3',4'-trihydroxyphenyl)-2,3-phthalazine-1(2H)-one (THPZB) to gelatin with Schiff base and chelating with Fe3+ ions (termed G/THPZB/Fe hydrogel). The twisted structure of phthalazinone in THPZB leads to entanglement of gelatin molecular chains, which resolves the stiffness-toughness conflict of the hydrogel. Furthermore, the strong tissue adhesion and fast self-healing capability mainly originate from the hydrogen bonding of the pyrogallol in THPZB. In vitro study shows that the hydrogels possess good biocompatibility with L929 cells, hemostatic and antibacterial activity. In the rat model of skin infection, the hydrogel dressing not only have no adverse effects on vital organs, but also can effectively promote wound healing of bacterial infection. Considering that it has multiple functions, G/THPZB/Fe hydrogel can be used as a promising wound dressing for biomedical applications.

Preparation and Properties of Sulfonated Poly(phthalazinone ether ketone) Membranes for Electrodialysis.

Sulfonated poly(phthalazinone ether ketones) (SPPEK) with ion exchange capacities from 0.77 to 1.82 mmol·g-1 are synthesized via an electrophilic substitution reaction. Nuclear magnetic resonance and infrared absorption spectroscopy are used to characterize the chemical structure of the obtained polymers for confirming the successful introduction of sulfonic groups. SPPEKs show excellent thermal stability; their temperature required to achieve 5% weight loss is about 360 °C. Accordingly, the obtained membranes possess high ion perm-selectivity, proton conductivity, and low area resistance. Regarding the electrodialysis-related performance of the membranes, the SPPEK-4 membrane has the highest limiting current density (39.8 mA·cm2), resulting from its high content of sulfonic groups. In a desalination test of standard solution, SPPEK-3 and SPPEK-4 membranes exhibit both better salt removal rate and acceptable energy consumption than commercial membrane. Additionally, SPPEK-3 membrane shows outstanding performance in terms of high concentration rate and low energy consumption during saline water treatment, which indicates the feasibility of novel membranes in electrodialysis application.

Investigation into the performance decay of proton-exchange membranes based on sulfonated heterocyclic poly(aryl ether ketone)s in Fenton's reagent.

Sulfonated N-heterocyclic poly(aryl ether) proton-exchange membranes have potential applications in the fuel-cell field due to their favorable proton conduction capacity and stability. This paper investigates the changes in mass and performance decay, such as proton conduction and mechanical strength, of sulfonated poly(ether ether ketone)s (SPEEKs) and three sulfonated N-heterocyclic poly(aryl ether ketone) (SPPEK, SPBPEK-P-8, and SPPEKK-P) membranes in Fenton's oxidative experiment. The SPEEK membrane exhibited the worst oxidative stability. The oxidative stability of the SPPEK membrane is enhanced due to the introduction of phthalazinone units in the chains. The SPPEKK-P and SPBPEK-P-8 membranes exhibit better radical tolerance than the SPPEK membrane, with proton conductivity retention rates of 66% and 73% for 1 h oxidative treatment, respectively. In addition, the molecular chains of SPPEKK-P and SPBPEK-P-8 exhibit relatively little disruption. The pendant benzenesulfonic groups enhance the steric effects for reducing radical attacks on the ether bonds and reduce the hydration of molecular chains. The introduction of phthalazinone units decreases the rupture points in the main chain. Therefore, the radical tolerance of the membranes is improved. These results provide a reference for the design of highly stable sulfonated heterocyclic poly(aryl ether) membranes.

Sulfur-Rich Polymers Based Cathode with Epoxy/Ally Dual-Sulfur-Fixing Mechanism for High Stability Lithium-Sulfur Battery.

Lithium-sulfur (Li-S) batteries have attracted a great deal of attention for the next-generation energy storage devices due to their inherently high theoretical energy density, high natural abundance, and low cost. However, the dissolution of polysulfides in electrolytes and their undesirable shuttle behavior lead to poor cycling performance, which obstructs practical application. Herein, we report a dual-sulfur-fixing mechanism of epoxy/allyl compound/sulfur system to prepare poly(sulfur-random-4-vinyl-1,2-epoxycyclohexane) (SVE) copolymers as powerful cathode materials. Benefiting from the stable C-S bond and a uniform distribution of ultrafine Li2S/S8 in the SVE-based polymer matrix, the SVE electrodes exerted an embedding effect to reduce polysulfides migration. The thiosulfate/polythionate protective layer derived from the terminal hydroxyl group of SVE also ensured the cycle stability of SVE electrodes during cycling. As a result, optimized SVE electrodes deliver a high reversible specific capacity of 1248 mA h g-1 at rates of 0.1 C, together with a stable cycling performance of no capacity decay per cycle over more than 400 cycles. This work provides an effective strategy for the practical application of organosulfur polymers Li-S batteries and inspires the exploration of the reaction mechanism of epoxy/allyl compound/sulfur system.

Apatite Formation Induced by Chitosan/Gelatin Hydrogel Coating Anchored on Poly(aryl ether nitrile ketone) Substrates to Promote Osteoblastic Differentiation.

Bone-like apatite is a promising coating of poly(ether ether ketone) (PEEK) for bone implantation. Poly(aryl ether nitrile ketone) containing phthalazinone moiety (PPENK) is a novel alternative for its easy synthesis. Here, chitosan/gelatin hybrid hydrogel coating is applied to induce the formation of apatite on the surface of PPENK substrate through biomineralization to improve its biocompatibility and osteogenic property. PPENK possessing allyl groups (PPENK-d) are synthesized and spin-coated on PPENK substrate to impart reactive groups. The hydrogel coating is prepared by the ultraviolet crosslinking of gelatin methacrylate (GelMA) and chitosan methacrylate (CSMA) on PPENK substrate. PPENK-d, GelMA, and CSMA are characterized by 1 H-NMR to confirm the designed structures. The presence of chitosan increases the chelation of calcium ions and thus induces the nucleation of apatite. The microstructural and compositional results reveal that the chitosan-containing hydrogel coating induced apatite coating yields a higher apatite quantity compared to the gelatin hydrogel coating. The apatite coatings on PPENK substrate promote the cytocompatibility and osteogenesis of MC3T3-E1 preosteoblasts in vitro.

Enhancing Tissue Adhesion and Osteoblastic Differentiation of MC3T3-E1 Cells on Poly(aryl ether ketone) by Chemically Anchored Hydroxyapatite Nanocomposite Hydrogel Coating.

Tissue adhesion to bone implant and osteoblastic differentiation are the key factors to achieve poly(aryl ether ketone) (PAEK) implant osseointegration. However, physical interaction of implant with tissue and hydroxyapatite coating suffers from slow implant tissue integration and lack of long-term stability. In this study, a novel poly(phthalazinone ether sulfone ketone) containing allyl groups (APPBAESK) is coated onto PPBESK sheet for reacting with the allyl groups of the hydrogel coating to enhance its stability. N-Succinimidyl (NHS)-ester activated group and nano-hydroxyapatite (nano-HA) are introduced into the hydrogel synthesized from gelatin methacrylate (GelMA) and acrylic acid to construct a nanocomposite hydrogel coating on PPBESK which is a promising PAEK implant material. The hydrophilicity of the PPBESK sheet is improved by the hydrogel coating. The chemical components of the nanocomposite hydrogel coating are confirmed by X-ray photoelectron spectroscope, Attenuated total reflection infrared, and X-ray powder diffraction. The tissue shear adhesion strength of the hydrogel coating toward pig skin is enhanced due to the synergism of NHS-ester activated group and nano-HA. The osteogenic differentiation of MC3T3-E1 preosteoblasts is promoted by nano-HA in nanocomposite hydrogel coating. Therefore, the bifunctional nanocomposite hydrogel coating provides a great application prospect in the surface modification of PAEK implants in bone tissue engineering.