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The absorption-dominated graphene porous materials, considered ideal for mitigating electromagnetic pollution, encounter challenges related to intricate structural design. Herein, petal-like graphene porous films with dendritic-like and honeycomb-like pores are prepared by controlling the phase inversion process. The theoretical simulation and experimental results show that PVP K30 modified on the graphene surface via van der Waals interactions promotes graphene to be uniformly enriched on the pore walls. Benefiting from the regulation of graphene distribution and the construction of honeycomb pore structure, when 15 wt % graphene is added, the porous film exhibits absorption-dominated electromagnetic shielding performance, compared with the absence of PVP K30 modification. The total electromagnetic shielding effectiveness is 24.1 dB, an increase of 170%; the electromagnetic reflection coefficient reduces to 2.82 dB; The thermal conductivity reaches 1.1 W/(m K), representing a 104% increase. In addition, the porous film exhibits improved mechanical properties, the tensile strength increases to 6.9 MPa, and the elongation at break increases by 131%. The method adopted in this paper to control the enrichment of graphene in the pore walls during the preparation of honeycomb porous films by the phase inversion method can avoid the agglomeration of graphene and improve the overall performance of the porous graphene porous films.

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BACKGROUND: This systematic review and meta-analysis aimed to evaluate the efficiency and safety of percutaneous nephrolithotomy (PCNL) between flank position and prone position for the treatment of renal stones. METHODS: PubMed, Embase, OVID, and Cochrane Library were comprehensively searched from their inception to Jul 2024. Randomized and nonrandomized trials evaluating renal calculi patients who underwent PCNL via flank position or prone position were included. Data extraction and quality assessment were conducted by two independent reviewers. The outcomes and complications of both groups were compared in this meta-analysis. RESULTS: This review involved five articles (554 patients). Specifically, four articles were randomized controlled trials, and the remaining publication was prospective cohort study. No significant difference was found in stone-free rate between the flank group and prone group after the PCNL procedure. Similarly, the percutaneous access time, operative time, and hospital stay of flank position had no significant difference compared with the prone group. There was no significant difference in the comparison of complication rates between the flank group and the prone group. Although further analysis indicated that patients in the prone position suffered more hemoglobin drop than the flank group, no significant difference was found in the hemorrhage and blood transfusion rates. CONCLUSIONS: Both surgical positions were appropriate for most PCNL procedures and had shown similar efficacy and safety. In practice, the optimal choice should be made according to the patients' conditions and urologists' acquaintance.

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We report for the first time using zinc hydroxyfluoride (ZnOHF) for efficient NO2 gas detection. The prepared ZnOHF had a unique flower-like architecture self-assembled by nanorods with a diameter of 150 nm and length of 2-3 µm. The sensing performance toward NO2 detection indicated that the prepared ZnOHF exhibited high response (82.71), short response/recovery time (13 s/35 s) to 10 ppm of NO2, and excellent selectivity at 200 °C, greatly outperforming the ZnO raw material. ZnOHF could work in a wide detection window ranging from 100 ppb to 50 ppm, implying its practical application prospects in both industry and daily life. The excellent sensing behavior of ZnOHF originated mainly from the negligible oxygen ions adsorbed on the material surface, which was caused by the higher work function of ZnOHF. Therefore, almost all conduction band electrons can be used in the NO2 gas sensing.

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Supramolecular polymers have the combined properties of both traditional polymers and supramolecules. They are generally formed via the self-assembled polymerization driven noncovalent interactions such as hydrogen bonding, π-π stacking, metal coordination, and host-guest interaction between building blocks. The driving force for the formation of supramolecular polymers has changed from single noncovalent interactions to multiple noncovalent interactions. The advantages of multiple noncovalent interactions driving the formation of supramolecular polymers are reviewed from four aspects: polymer construction, the enhancement of bonding strength, properties and topological structure. The applications are illustrated with detailed examples including self-healing, drug delivery, bioimaging, biomedicine, environmental sensing and electronics.

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A novel composite film of hydroquinone/resorcinol-based poly(arylene ether nitrile) (HQ/RS-PEN) improved by bisphenol A based poly(arylene ether nitrile) (BPA-PEN) was prepared, in which BPA-PEN acts as a plasticizer, leading to improved fluidity of the material, thereby favoring the crystallinity of HQ/RS-PEN. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and mechanical and rheological tests have shown that the composites exhibited outstanding thermal and mechanical properties as well as improved fluidity and processing applicability compared with HQ/RS-PEN. At the same time, the crystallization of the poly(arylene ether nitrile) blends with 5 wt % BPA-PEN could be promoted under both static and shear flow fields. Polarizing microscope (POM) and scanning electron microscopy (SEM) showed that the crystalline morphology of HQ/RS-PEN was converted from spherulites to fibrous crystals under shearing. DSC, X-ray diffraction (XRD), and dynamic storage modulus results proved that the crystallization rate and crystallinity of HQ/RS-PEN increased significantly under the shear field. The crystallinity enhanced to a maximum of 20.1% and the melting enthalpy increased to 33.4 J/g at 310 °C under the frequency of 0.01-100 Hz for 20 min.

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In this paper, barium titanate@zinc phthalocyanine (BT@ZnPc) and graphene oxide (GO) hybrids (BT@ZnPc-GO) connected by calcium ions are prepared by electrostatic adsorption, and then introduced into polyarylene ether nitrile (PEN) to obtain composites with enhanced dielectric and crystallization properties. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) results confirm the successful fabrication of the BT@ZnPc-GO. BT@ZnPc-GO and PEN composites (BT@ZnPc-GO/PENs) are obtained through the solution-casting method. BT@ZnPc-GO demonstrates well compatibility with PEN due to its unique structure and the organic layer of ZnPc at the periphery of BT. On the other hand, BT and GO contribute a high dielectric constant of the composites obtained. In addition, the BT@ZnPc-GO can be used as a nucleating agent to promote the crystallization of the nanocomposites. As a result, The BT@ZnPc-GO/PEN exhibits a dielectric constant of 6.4 at 1 kHz and crystallinity of 21.03% after being isothermally treated at 280 °C for 2 h at the GO content of 0.75 wt %. All these results indicate that the hybrid nanofiller BT@ZnPc-GO can be an effective additive for preparing high-performance PEN-based nanocomposites.

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Excellent thermal resistance and thermal conductivity are preconditions of materials to be used at elevated temperatures. Herein, boron nitride and polyarylene ether nitrile hybrids (PEN-g-BN) with excellent thermal resistance and thermal conductivity are fabricated. Phthalonitrile-modified BN (BN-CN) is prepared by reacting hydroxylated BN with isophorone diisocyanate (IPDI) and 3-aminophxylphthalonitrile (3-APN), and then characterized by FT-IR, UV-Vis, and X-ray photoelectron spectroscopy (XPS). The obtained BN-CN is introduced to a phthalonitrile end-capped PEN (PEN-Ph) matrix to prepare BN-CN/PEN composites. After curing at 340 °C for 4 h, PEN-g-BN hybrids are fabricated by a self-crosslinking reaction of cyano groups (-CN) from BN-CN and PEN-Ph. The fabricated PEN-g-BN hybrids are confirmed through FT-IR, UV-Vis, SEM and gel content measurements. The PEN-g-BN hybrids demonstrate excellent thermal resistance with their glass transition temperature (Tg) and decomposition temperatures (Td) being higher than 235 °C and 530 °C, respectively. Additionally, the thermal conductivity of the prepared PEN-g-BN hybrids is up to 0.74 W/(m·k), intensifying competitiveness of PEN-g-BN hybrids for applications at elevated temperatures.

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Enhanced dielectric and mechanical properties of polyarylene ether nitrile (PEN) are obtained through secondary dispersion of polyaniline functionalized barium titanate (PANI-f-BT) by hot-stretching. PANI-f-BT nanoparticles with different PANI content are successfully prepared via in-situ aniline polymerization technology. The transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopic instrument (XPS) and Thermogravimetric analysis (TGA) results confirm that the PANI layers uniformly enclose on the surface of BaTiO3 nanoparticles. These nanoparticles are used as functional fillers to compound with PEN (PEN/PANI-f-BT) for studying its effect on the mechanical and dielectric performance of the obtained composites. In addition, the nanocomposites are uniaxial hot-stretched by 50% and 100% at 280 °C to obtain the oriented nanocomposite films. The results exhibit that the PANI-f-BT nanoparticles present good compatibility and dispersion in the PEN matrix, and the hot-stretching endows the second dispersion of PANI-f-BT in PEN resulting in enhanced mechanical properties, crystallinity and permittivity-temperature stability of the nanocomposites. The excellent performances of the nanocomposites indicate that a new approach for preparing high-temperature-resistant dielectric films is provided.

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Barium titanate (BT) and polyarylene ether nitrile (PEN) nanocomposites with enhanced dielectric properties were obtained by using carboxylatedzinc phthalocyanine (ZnPc-COOH) buffer as the plasticizer. Carboxylated zinc phthalocyanine, prepared through hydrolyzing ZnPc in NaOH solution, reacted with the hydroxyl groups on the peripheral of hydrogen peroxide treated BT (BT-OH) yielding core-shell structured BT@ZnPc. Thermogravimetric analysis (TGA), transmission electron microscopy (TEM), TEM energy dispersive spectrometer mapping, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) demonstrated successful preparation of BT@ZnPc. The fabricated BT@ZnPc was incorporated into the PEN matrix through the solution casting method. Rheological measurements demonstrated that the ZnPc-COOH buffer can improve the compatibility between BT and PEN effectively. With the existence of the ZnPc-COOH buffer, the prepared BT@ZnPc/PEN nanocomposites exhibit a high dielectric constant of 5.94 and low dielectric loss (0.016 at 1000 Hz). BT@ZnPc/PEN dielectric composite films can be easily prepared, presenting great application prospects in the field of organic film capacitors.

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A series of polymers containing nunchaku-like unit with an azo chromophore and a mesogen group was successfully prepared and photoinduced anisotropy of the obtained polymers was minutely investigated. Firstly, monomers containing nunchaku-like unit with an azo chromophore and a mesogen group linked by flexible group were synthesized. The structure of the monomers was confirmed via NMR COSY spectra. Subsequently, the obtained monomers were polymerized into corresponding polymers through RAFT polymerization. The prepared polymer samples were characterized through NMR, FTIR, gel permeation chromatography (GPC), and UV-vis testing while the thermal properties of the samples were investigated through differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) measurements. The photoinduced isomerization of the polymers, which was researched in situ via measuring UV-vis spectra of the polymer solutions and spin-coated films under irradiation with 450 nm light or putting in darkness, demonstrated the rapid trans-cis-trans isomerization of the polymers. When irradiated with a linearly polarized light, significant photoinduced birefringence and dichroism were observed, suggesting photoinduced isomerization of azobenzene can drive orientation of mesogen in the system. This study blazes a way to design the optical materials with light-controllable birefringence and dichroism.

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Conductive Nb12O29 hierarchical microspheres with nanosheet shells were synthesized based on a hydrothermal process and a high-temperature hydrogen reduction treatment. The obtained materials demonstrated comprehensively good electrochemical properties, including a significant pseudocapacitive contribution, safe operating potential, high reversible capacity, superior initial coulombic efficiency, increased rate capability, and durable cycling stability.

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Chemical energy conversion/storage through water splitting for hydrogen production has been recognized as the ideal solution to the transient nature of renewable energy sources. Solid polymer electrolyte (SPE) water electrolysis is one of the most practical ways to produce pure H2 . Electrocatalysts are key materials in the SPE water electrolysis. At the anode side, electrode materials catalyzing the oxygen evolution reaction (OER) require specific properties. Among the reported materials, only iridium presents high activity and is more stable. In this Minireview, an application overview of single iridium metal and its oxide catalysts-binary, ternary, and multicomponent catalysts of iridium oxides and supported composite catalysts-for the OER in SPE water electrolysis is presented. Two main strategies to improve the activity of an electrocatalyst system, namely, increasing the number of active sites and the intrinsic activity of each active site, are reviewed with detailed examples. The challenges and perspectives in this field are also discussed.

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Multi-walled carbon nanotube (MWCNT) filled with poly(arylene ether nitrile) (PEN) (PEN-in-MWCNT) is used as additive to improve the physical performances of PEN matrix. The influences of PEN-in-MWCNT on the crystallization, mechanical, dielectric and thermal properties of PEN are investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier Transform Infrared Spectoscopy (FT-IR), dielectric testing, mechanical testing and scanning electron microscope (SEM) observation. The filling of the PEN into the MWCNT is confirmed by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) observation, FT-IR spectra, TGA and DSC curves. TGA results indicate that the mass fraction of PEN filled in the MWCNT is 61.56 wt% and the thermal property of PEN-in-MWCNT is significantly enhanced after the filling of PEN. Comparing with MWCNT, the oxidation temperature of PEN-in-MWCNT increases more than 180 °C. DSC results demonstrate that PEN-in-MWCNT is a better nucleating agent for PEN than MWCNT, as it can promote the crystallinity of PEN at relative lower concentration. When the concentration of MWCNT is 0.5 wt%, the melting enthalpy of the composite PEN-in-MWCNT/PEN5 is 41.13 J/g. The tensile strength of the obtained composite PEN-in-MWCNT/PEN10 enhances by 34% after 1.0 wt% of MWCNT is incorporated. Improved dielectric properties are also observed when PEN-in-MWCNT is incorporated into the PEN matrix. The PEN-in-MWCNT appears to be an excellent additive candidate for PEN.

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The core-shell structured polyaniline-functionalized-BaTiO3 (BT@PANI) nanoparticles with controllable shell layer thicknesses are developed via in-situ aniline polymerization technology and characterized in detail. The results prove that the PANI shell layer with the adjustable and controllable thicknesses of 3⁻10 nm are completely stabilized on the surface of the BaTiO3 core. In addition, the BT@PANI nanoparticles are regarded as the hybrid nanofillers to prepare PEN/BT@PANI nanocomposite films with a PEN matrix. The research results indicate that the surface functionalized nanoparticles facilitate the compatibility and dispersibility of them in the PEN matrix, which improves the properties of the PEN/BT@PANI nanocomposites. Specifically, the PEN/BT@PANI nanocomposites exhibit thermal stability, excellent permittivity-frequency, and dielectric properties-temperature stability. Most importantly, the energy density of nanocomposites is maintained at over 70% at 180 °C compared with that at 25 °C. All these results reveal that a new way to prepare the high-performance PEN-based nanocomposites is established to fabricate an energy storage component in a high temperature environment.

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A novel phthalonitrile-terminated polyaryl ether nitrile (PEN-Ph) was synthesized and characterized. The crystallization behavior coexisting with the crosslinking behavior in the PEN-Ph system was confirmed by rheological measurements. DSC was applied to study the crystallization kinetics and crosslinking reaction kinetics. Through the Avrami equation modified by Jeziorny, the nonisothermal crystallization kinetics were analyzed, and the Avrami exponent of about 2.2 was obtained. The analysis results of more intuitive polaring optical microscopy (POM) and SEM indicated that the shape of the crystals is similar to spherical. Moreover, the activation energy of the crystallization behavior and crosslinking behavior were obtained by the Kissinger method, and the values were about 152.7 kJ·mol-1 and 174.8 kJ·mol-1, respectively. This suggests that the activation energy of the crystallization behavior is lower than that of the crosslinking behavior, indicating that the crystallization behavior is more likely to occur than the crosslinking behavior and the crystals of PEN-Ph can be self-crosslinked to form single-polymer composites.

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Highly ordered nitrogen-doped graphene multilayer films with large interlayer void are successfully fabricated by thermal annealing of the compact stacking graphene oxide/copper phthalocyanine (GO/CuPc) multilayer films. Scanning electron microscopic (SEM), X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopic (XPS), and electrical conductivity measurements indicate that the breakaway of oxygen functional groups on/in the GO sheets at high temperature and the in situ pyrolysis of CuPc molecules in the interlayer of graphene sheets synergistically facilitate the restoration of GO in graphitization, the effective nitrogen doping by replacing carbon atoms in graphene frameworks, the retention of layer-by-layer stacking structure of graphene sheets in plane, and the formation of interlayer voids, leading to the enhancement in the electrical conductivity (3.64 × 103 S/m). In addition, due to the formation of a Fabry-Pérot resonance cavity in the unique layer-by-layer stacking structure with larger interlayer voids, constructive interference of internal reflections aligned between parallel reflecting planes endows the fluffy graphene multilayer films with excellent electromagnetic interference (EMI) shielding effectiveness (exceeds 25 dB in all X-bands). The optimal shielding effectiveness is up to 55.2 dB with a smaller thickness of 0.47 mm, which makes it possible to become a practical EMI shielding material with a distinct competitive advantage.

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We report the fabrication and improved properties of crosslinked polyarylene ether nitrile (CPEN) interpenetrating with a zinc ion bridged graphene sheet (GS) and carbon nanotube (CNT) network (GS-Zn-CNT) (CPEN/GS-Zn-CNT). Graphene oxide (GO) and acidulated CNT were firstly prepared and then coordinated with zinc ions to form the zinc ion bridged GO and CNT network (GO-Zn-CNT). The mass ratio of GO and acidulated CNT in GO-Zn-CNT was controlled to be 1:3 and the optimized content of Zn2+ was Zn2+/C = 0.01 mmol/mg (mole of zinc acetate/total weight of GO and acidulated CNT). Phthalonitrile end-capped polyarylene ether nitrile (PEN-Ph) permeated into the GO-Zn-CNT in N-methyl-2-pyrrolidone (NMP) and the corresponding composite PEN/GO-Zn-CNT was fabricated through the solution-casting method. After thermal annealing at 230 °C for 1 h and further curing at 320 °C for 2 h, the GO in GO-Zn-CNT was partly reduced into GS, and PEN-Ph was crosslinked, offering the CPEN/GS-Zn-CNT. The mechanical, thermal, and electrical properties of the obtained CPEN/GS-Zn-CNT were investigated in detail. The glass transition temperature, relative permittivity, and tensile strength of CPEN/GS-Zn-CNT with 2.0 wt % GS-Zn-CNT, compared to that of PEN, were increased by 18%, 181%, and 27%, respectively. The CPEN/GS-Zn-CNT based composite is a potential candidate as material in high performance electronic devices.

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Dielectric film with ultrahigh thermal stability based on crosslinked polyarylene ether nitrile is prepared and characterized. The film is obtained by solution-casting of polyarylene ether nitrile terminated phthalonitrile (PEN-Ph) combined with post self-crosslinking at high temperature. The film shows a 5% decomposition temperature over 520 °C and a glass transition temperature (Tg) around 386 °C. Stable dielectric constant and low dielectric loss are observed for this film in the frequency range of 100-200 kHz and in the temperature range of 25-300 °C. The temperature coefficient of dielectric constant is less than 0.001 °C-1 even at 400 °C. By cycling heating and cooling up to ten times or heating at 300 °C for 12 h, the film shows good reversibility and robustness of the dielectric properties. This crosslinked PEN film will be a potential candidate as high performance film capacitor electronic devices materials used at high temperature.

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OBJECTIVE: (18)F-Fluorodeoxyglucose ((18)F-FDG), (18)F-fluoro-3'-deoxy-3'-L-fluorothymidine ((18)F-FLT), (18)F-fluoromisonidazole ((18)F-FMISO), and (18)F-AlF-NOTA-PRGD2 ((18)F-RGD) are all commonly used PET tracers for tumor diagnosis based on different mechanisms of tissue uptake. This study compared the ex-vivo biodistribution and PET/computed tomography (CT) imaging studies of these four PET tracers in a xenograft prostate tumor-bearing mouse model. MATERIALS AND METHODS: Nude mice were inoculated with 5 × 10 PC-3 cells in the right armpit. The ex-vivo biodistribution of (18)F-FDG, (18)F-FLT, (18)F-FMISO, and (18)F-RGD at 30, 60, 90, and 120 min after injection was compared. Micro-PET/CT images of (18)F-FDG, (18)F-FLT, and (18)F-RGD were acquired at 60 min, whereas (18)F-FMISO images were acquired at 90 min after injection. RESULTS: The tumors were clearly visualized by micro-PET/CT using all four PET tracers. Ex-vivo biodistribution results showed highest tumor accumulation and tumor-to-muscle ratio of (18)F-FDG at each time point, accompanied by physiologically high uptakes in the brain, heart, and intestinal tract. Modest uptake of (18)F-FLT and (18)F-FMISO in tumors was observed at 60 and 90 min after injection, with less interference from other tissues compared with (18)F-FDG. Besides, (18)F-RGD also exhibited high tumor specificity; however, relatively low uptake was observed in the tumor. CONCLUSION: Our results demonstrated the potential of (18)F-FMISO and (18)F-FLT in the diagnosis of xenograft prostate cancer.

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Nematic liquid crystalline elastomer (LCE) microactuators are developed, showing simultaneous thermomechanical deformation and photoluminescence (PL) emission variation functions. The microactuators are prepared by a method combining soft-lithography and photo-polymerization/crosslinking. 1,4-Bis(α-cyano-4-methoxystyryl)benzene as the PL dye is synthesized, characterized, and introduced into LCEs as a dopant in the preparation process. During the heating process, PL emission of the LCE micropillars under blue light excitation becomes significantly weak when the micropillars contract. When cooling down, the emission completely recovers as the micropillars stretches back to their original shape. The PL intensity variation at the transition is proved to be related to the thermomechanical deformation.

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