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Theoretically, separating the positive and negative charge centers of the chain segments of dielectric elastomers (DEs) is a viable alternative to the conventional decoration of chain backbone with polar handles, since it can dramatically increase the dipole vector and hence the dielectric constant (ε′) of the DEs while circumvent the undesired impact of the decorated polar handles on the dielectric loss (tan δ). Herein, a novel and universal method is demonstrated to achieve effective separation of the charge centers of chain segments in homogeneous DEs by steric hindrance engineering, i.e., by incorporating a series of different included angle‐containing building blocks into the networks. Both experimental and simulation results have shown that the introduction of these building blocks can create a spatially fixed included angle between two adjacent chain segments, thus separating the charge center of the associated region. Accordingly, incorporating a minimal amount of these building blocks (≈5 mol%) can lead to a considerably sharp increase (≈50%) in the ε′ of the DEs while maintaining an extremely low tan δ (≈0.006@1 kHz), indicating that this methodology can substantially optimize the dielectric performance of DEs based on a completely different mechanism from the established methods. [ABSTRACT FROM AUTHOR]

As a promising innovative energy storage material, phase change fibers (PCFs) have been widely studied. PCFs are equipped with the ability of temperature regulation by introducing phase change materials (PCMs) and have been successfully prepared by melt spinning, wet spinning and electrospinning. With the rapid development of PCM and fibrous preparation technology, the combination of different processes of PCF preparation has been explored and developed. In this paper, the research progress of the preparation methods of PCFs is reviewed. Firstly, the preparation methods are classified according to the different loading forms of PCMs, and the fibrous maceration method, composite method and microcapsule method are introduced. Then, the special preparation methods and characteristics of PCF are elaborated. Finally, the research hot spots and development of PCFs are summarized for providing guidance for fabricating PCFs with desired comprehensive properties; among them, with the continuous innovation of smart fibers, the single function of PCFs will cause limited use, so the multi-functionality of PCFs is also discussed in detail for various applications. [ABSTRACT FROM AUTHOR]

In this work, a temperature‐regulating and antimicrobial–antioxidant fiber membrane was fabricated using coaxial electrospinning technology. The tea tree oil (TTO) emulsion used as the core solution, polyvinyl alcohol (PVA) as the shell solution for coaxial electrospinning, has been demonstrated. Compared with the original PVA fibers, the average diameter of the fibers is increased after coaxial electrospinning, and the diameter increases with the core flow rate. The diameters corresponding to core flow rates of 0.05, 0.1, and 0.15 mL/h are 561, 597, and 849 nm, respectively. Via in vitro release experiment demonstrated that the quantity of TTO released from the composite membrane increased with the elevation of temperature. The inclusions TTO and polyethylene glycol give the film excellent antibacterial–antioxidant properties and a delayed thermal response. More intriguingly, core–shell fiber membranes containing TTO in the core part are effective in slowing down the formation of oxidation spots on the surface of banana compared with pure PVA membranes. Seven days after wrapping bananas with different membranes, the surface of banana in pure PVA film was full of oxidized spots, whereas banana in PVA core–shell fibers showed only one obvious spot. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Delayed intestinal perforation has various manifestations. For peritonitis with delayed treatment and multi‐bacterial peritonitis, we should be alert to the occurrence of this rare complication. Abdominal CT examination and imaging results judgment based on clinical conditions are particularly important for diagnosis. Delayed intestinal perforation of peritoneal dialysis catheter is a rare but serious complication. We reported a 49‐year‐old patient who had been hospitalized twice within 3 months due to poor drainage of the peritoneal dialysis catheter. During the first hospitalization, peritoneal dialysis‐related peritonitis was diagnosed, and a variety of bacterial infections were cultivated. However, at that time, the actual peritoneal dialysis catheter‐related intestinal perforation was missed, and he was discharged after anti‐infection treatment until a clinical cure was met. After more than 2 months of normal peritoneal dialysis after returning home, the patient again had poor drainage of the peritoneal dialysis catheter, accompanied by the outflow of yellowish‐brown sediment. It was found that the peritoneal dialysis catheter had evidence of intestinal perforation. After the removal of the catheter and intestinal repair, he recovered and was discharged from the hospital and received long‐term hemodialysis treatment. In the case of delayed intestinal perforation, peritoneal dialysis was maintained normally for more than 2 months, which was an unprecedented situation in previous case reports. In addition, we should be alert to the occurrence of this rare complication, especially when we find the occurrence of polybacterial Peritonitis. Abdominal CT examination and imaging results judgment based on clinical conditions are particularly important for diagnosis. [ABSTRACT FROM AUTHOR]

Reinforcement and cross-linking are two critical issues in the rubber industry. However, carbon black (CB) as the most dominant reinforcing filler is derived from fossil resource-derived chemicals. And currently adopted cross-linking strategies would result in difficulties in the recycling of end-of-life rubbers. Herein, lignin, the most abundant renewable aromatic polymer, was developed as an effective reinforcing filler of rubber. The butadiene–styrene–vinylpyridine rubber (VPR) was selected as the rubber matrix, and a facile and cost-effective strategy was provided to improve the compatibility and interfacial interaction between lignin and the non-polar rubber matrix. Based on the Zn2+–pyridine coordination between the pyridine groups in the VPR chains and phenoxy groups in the lignin molecules, the lignin particles could obtain fine dispersion in the rubber matrix, exhibiting an excellent reinforcing effect. Moreover, the pyridine groups in the VPR chains were developed as cross-linking points, and the VPR could be effectively cross-linked based on the chemical reaction between the pyridine group and alkyl halide, producing quaternized pyridine groups. Due to the existence of the exchange reaction via the C–N transalkylation of the quaternized pyridine groups, the lignin/VPR composites could show vitrimer-like properties and are endowed with good reprocessability at high temperatures. Additionally, due to the photothermal conversion capability of lignin, the lignin/VPR composites could exhibit good photothermal performance triggered by 808 nm near-infrared light, and further possess light-driven shape memory properties. Hence, we envisage that this work can provide an avenue to design and fabricate green, sustainable, and recyclable elastomer materials with lignin as a renewable bio-filler. [ABSTRACT FROM AUTHOR]

In the face of changing outdoor environments, it is necessary for us to develop advanced textiles with thermal regulation and hydrophobic properties. In order to create a fabric with both temperature control and waterproof properties, the study adjusted the ratio of polystyrene (PS) and polyvinylidene fluoride (PVDF) to produce nanofiber membranes with excellent morphology and dirt resistant properties. Furthermore, the hydrophobicity of the nanofibers was further improved by adding SiO2 to the spinning solution. Based on this, a core solution of octadecane (Oct) was used to give it thermal regulation functionality through coaxial electrospinning technique. The resulting composite nanofiber membrane exhibited excellent hydrophobicity and thermal regulation performance. The measurement results obtained from Differential Scanning Calorimetry (DSC) indicate that the maximum Oct encapsulation rate of the PS/PVDF/SiO2@Oct nanofiber membrane is 58.36%. The latent heat of the composite nanofiber membrane is 148.84 J/g, and the water contact angle (WCA) is 135°. The multifunctional composite nanofiber has great potential for applications in outdoor protective clothing and outdoor electronic device protection. [ABSTRACT FROM AUTHOR]

At present, it is still challenging to design high-performance and low-cost non-noble mental catalysts. In this work, nickel phosphide (Ni5P4) was combined with FeV LDH via an in situ growth approach to form porous nanosheet arrays. Benefiting from the synergistic effect of atoms between Ni5P4 and FeV LDH, the hybrid electrocatalyst displays significantly enhanced electro-catalytic properties for the anodic reaction. Impressively, the Ni5P4@FeV LDH material delivers 10, 50 and 100 mA cm−2 with an overpotential of only 204, 250 and 416 mV for the oxygen evolution reaction (OER), respectively. Additionally, it also exhibits superior properties for the urea oxidation reaction (UOR) with a low cell voltage of 1.44 V at 50 mA cm−2 and retains stability for at least 15 h in the alkaline electrolyte with 0.33 M urea. This strategy provides a new idea for the design and synthesis of transition metal phosphides that can be used as an efficient electrocatalyst for electrolysis of water and wastewater treatment. [ABSTRACT FROM AUTHOR]

Catalysts with high catalytic activity and low cost are extremely significant for hydrogen production by water cracking. In this work, through simple electrospinning and carbonization methods, Ru with excellent catalytic activity is dispersed onto Fe4C to form Ru–Fe4C nanoparticles loaded on N-doped carbon nanofibers (Ru–Fe4C/NCNF), so that Ru can expose more active sites and thus improve HER catalytic activity. Meanwhile, the addition of low-cost Fe can reduce the use of noble metal Ru, thereby reducing the catalyst cost. On the other hand, the prepared Ru–Fe4C/NCNF can be used as a self-supporting working electrode and shows good stability. The experimental results show that the prepared Ru–Fe4C/NCNF can drive a current density of 10 mA cm−2 with only 106 mV in 1 M KOH, and more importantly, only 254 mV can produce a current density of 100 mA cm−2. At the same time, it shows excellent stability after continuously working for 100 h at a current density of 100 mA cm−2. This work provides a new thought to synthesize economical catalysts with high catalytic activity. [ABSTRACT FROM AUTHOR]

Constructing dynamic covalent bonds (DCBs) in rubbers provides a promising avenue to resolve the trade‐offs between chemical crosslinking and recyclability. The reinforcement of dynamic covalent networks by nanofilling is widely adopted, which, however, inevitably hinders the exchange reaction of DCBs and network rearrangement due to the restrictions on chain mobility imposed by fillers. To date, the reinforcement of dynamic covalent networks without affecting the dynamic properties remains challenging. In this work, we report a dual dynamic crosslinking strategy by engineering reversible noncovalent bonds into dynamic covalent rubbers to improve mechanical performance and simultaneously maintain desirable malleability and reprocessability. Specifically, dynamic boronic ester‐crosslinked styrene–butadiene rubber is firstly prepared and then modified through triazolinedione (TAD) click reaction. The grafted urazole groups can form hydrogen bond interactions that further aggregate to form clusters and phase‐separation structure in the networks. Due to the reversible nature of hydrogen bonds, they can act in a sacrificial manner to dissipate mechanical energy, leading to a combination of improved strength, modulus and toughness of the networks. More importantly, the hydrogen‐bonded clusters are dissociated at elevated temperatures, enabling the network dynamic properties to be largely preserved. In addition, the dynamic features of the dual crosslinks (hydrogen bonds and boronic esters) endow the TAD‐modified networks with reconfigurable shape memory effect. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Decorating diene rubbers with functional handles through copolymerization with polar monomers or post-modification of the chain backbone still struggles with some stubborn problems, including the dependence on specific catalytic systems, inescapable side reactions and poor tunability. Herein, we pioneer a brand-new methodology to rationally design functionalized diene rubbers with tunable chain structures. More specifically, by adopting the disulfide/polysulfide linkages in vulcanizates as reactive substrates, these linkages can be cleaved into active sulfur radicals upon solvothermal pyrolysis, which not only enable network disintegration but initiate the direct insertion of functional vinyl monomers into the rubber skeleton through a dynamic covalent polymerization mechanism. Accordingly, the local polarity of the functionalized chain segments increases, which reduces compatibility with the pristine components and hence facilitates the high-yield separation (∼98 wt%) of these functionalized rubbers from the network architecture. The chain structure of the obtained functionalized rubbers can be facilely tuned by regulating the pyrolysis conditions (time and temperature) and monomer content. More importantly, it is demonstrated that this methodology is versatile for obtaining functionalized rubbers with desired handles from various vulcanizates and vinyl monomers. Therefore, we envision that the present methodology will have important scientific and economic significance, since it exploits a feasible alternative for custom-made functionalized rubbers that will have broad application prospects, such as functional coupling agents, and self-healing and shape memory materials. [ABSTRACT FROM AUTHOR]

Polydopamine (PDA) is a natural melanin derived from marine mussels that has good biocompatibility, biodegradability, and photothermal conversion ability. As a new coating material, it offers a novel way to modify the surface of various substances. The drug loading capacity and encapsulation efficiency of PDA are greatly improved via the use of mesoporous materials. The abundant pore canals on mesoporous polydopamine (MPDA) exhibit a uniquely large surface area, which provides a structural basis for drug delivery. In this review, we systematically summarized the characteristics and manufacturing process of MPDA, introduced its application in the diagnosis and treatment of cancer, and discussed the existing problems in its development and clinical application. This comprehensive review will facilitate further research on MPDA in the fields of medicine including cancer therapy, materials science, and biology. [ABSTRACT FROM AUTHOR]

Background: Tumor glycolysis is a critical event for tumor progression. Docetaxel is widely used as a first-line drug for chemotherapy and shown to have a survival advantage. However, the role of docetaxel in tumor glycolysis remained poorly understood. Methods: The effect of Docetaxel in tumor glycolysis and proliferation were performed by CCK-8, Western blotting, real-time PCR, glucose, and lactate detection and IHC. ChIP and luciferase assay were used to analyze the mechanism of Docetaxel on Smad3-mediated HIF-1α transactivity. Results: In this study, we showed that docetaxel treatment led to a significant inhibition of cell proliferation in prostate cancer cells through PFKP-mediated glycolysis. Addition of lactate, a production of glycolysis, could reverse the inhibitory effect of docetaxel on cell proliferation. Further analysis has demonstrated that phosphorylation of Smad3 (Ser213) was drastically decreased in response to docetaxel stimulation, leading to reduce Smad3 nuclear translocation. Luciferase and Chromatin immunoprecipitation (ChIP) analysis revealed that docetaxel treatment inhibited the binding of Smad3 to the promoter of the HIF-1α gene, suppressing transcriptional activation of HIF-1α. Moreover, ectopic expression of Smad3 in prostate cancer cells could overcome the decreased HIF-1α expression and its target gene PFKP caused by docetaxel treatment. Most importantly, endogenous Smad3 regulated and interacted with HIF-1α, and this interaction was destroyed in response to docetaxel treatment. What's more, both HIF-1α and PFKP expression were significantly reduced in prostate cancer received docetaxel treatment in vivo. Conclusion: These findings extended the essential role of docetaxel and revealed that docetaxel inhibited cell proliferation by targeting Smad3/HIF-1α signaling-mediated tumor Warburg in prostate cancer cells. -FEhS87GPJvKiophzuvDRW Video Abstract [ABSTRACT FROM AUTHOR]

Ordinary packaging film only has the functions of storing food and transporting food, while the external environment can affect the storage period of food. In this study, a common degradable material, polylactic acid (PLA), was chosen as the base material, and the material was endowed with antibacterial function by adding curcumin (Cur). Coaxial electrostatic spinning technology has a unique advantage in the preparation of core‐sheath structured fibers, and a PLA/Cur/n‐octadecane (OD) phase change thermoregulation fiber was prepared by selecting OD as the core material, which gives the fiber film thermoregulation function. The fiber structure, mechanical properties, and thermal properties were characterized. The antibacterial activity of the composite films against Escherichia coli and Staphylococcus aureus was investigated. The temperature regulation function of the composite film was evaluated, and the unique core‐sheath structure endowed the fiber film with a temperature regulation function. The storage of bananas was studied in which to explore the effect on food preservation. The composite films showed excellent bactericidal as well as antioxidant properties and successfully delayed the warming phenomenon. [ABSTRACT FROM AUTHOR]

Developing high-performance and earth-abundant electrocatalysts for hydrogen production by electrolysis of freshwater/seawater is desirable but remains a huge challenge, especially in seawater solution. Herein, we report an efficient catalyst for a cathode consisting of three-dimensional standing arrays of Mo-Ni2P/CC nanosheets uniformly grown on carbon cloth, in which the Mo doping improved the HER properties of Ni2P by providing applicable morphology, electronic properties and active sites. It is found that the as-obtained catalyst shows superior HER activity with a low overpotential of 113 and 154 mV at 10 mA cm−2 in 1 M KOH and simulated alkaline seawater solution, respectively. Moreover, the Mo–Ni2P/CC catalyst exhibits favorable stability in 5000 CV cycles in 1 M KOH and reasonable stability in a 20 h stability test in alkaline, simulated seawater and alkaline seawater solution. This work may provide a feasible insight into the construction and development of high-efficiency HER electrocatalysts for freshwater/seawater electrolysis. [ABSTRACT FROM AUTHOR]

Background: Roxadustat is a new oral anti-renal anemia medication that works by stabilizing hypoxia-inducible factor (HIF) which can activate the expression of more than 100 genes in addition to genes related to anemia. However, the more potential molecular targets of roxadustat are not completely clear. Therefore, it is essential to further reveal its molecular targets to guide its clinical applications. Methods: We performed label-free quantification and LC-MS/MS to study the proteomic alterations in serum exosome of renal anemia patients before and after roxadustat therapy. Results were validated by PRM. Results: A total of 30 proteins were significantly changed after treatment with roxadustat. Among these proteins, 18 proteins were up-regulated (and 12 were down-regulated). The results are statistically significant (P < 0.05). Then, we validated the result by PRM, the results confirmed that TFRC, HSPA8, ITGB3, COL1A2, and YWHAZ were markedly upregulated, while ITIH2 and CFH were significantly downregulated upon treatment with roxadustat. Conclusions: TFRC and HSPA8 could be an important target of the action of roxadustat, and roxadustat may increase cardiovascular risk through its influence on platelet activation. Our results provide a theoretical basis for its wider clinical application and preventing expected side effects. [ABSTRACT FROM AUTHOR]

The first step in the mainstream end‐of‐life management of discarded silicone‐rubber‐based composite insulators involves grinding and modification of them into fine silicone rubber powders (SRPs). However, significant knowledge gaps have prevented researchers from developing direct efficient surface treatments for SRPs that do not involve time‐consuming and multi‐step processes. Herein, we report a straightforward method for the efficient modification of discarded SRPs through a microwave‐assisted alcoholysis process. Specifically, the siloxane moieties of the SRPs were cleaved using nucleophilic geraniol as a modifier, thereby facilitating the introduction of abundant alkoxysilyl groups on SRPs surface. During sulfur crosslinking, the intrachain vinyl functionalities of the modified SRPs co‐crosslinked with the rubber matrix via sulfur bridges, thereby improving the dispersion state of the SRPs and the interfacial adhesion between the SRPs and the rubber matrix. Accordingly, even for a high SRP loading (200 phr, parts per hundreds of gum), the mechanical performance of the resulting systems, and in particular the tensile strength and extensibility were significantly higher than those of the rubber matrix. Moreover, the interfacial adhesion of the resulting systems was improved, and the resulting systems presented remarkable damping performance (tan δ ≥ 0.3) over a broad temperature range (≥80°C). [ABSTRACT FROM AUTHOR]

With the development of power industry, the recycling of waste insulator silicone rubber (WSR) remains a significant challenge. Herein, an efficient alcoholysis strategy for the surface modification of WSR was explored by using nerol as alcoholysis reagent, and then the nerol modified WSR (Nerol-WSR) was utilized in polypropylene toughening. FTIR spectra indicate that nerol can served as nucleophilic reagent to cleave the Si–O bonds in WSR, resulting in an efficient surface grafting of nerol moieties on WSR. The grafting content of nerol moieties gradually increases with alcoholysis times. Morphology investigation demonstrates that with the increase of alcoholysis time, the dispersion state of Nerol-WSR particles in PP matrix is significantly improved, along with a much smaller particle size. Accordingly, with the addition of 10 wt.% of Nerol-WSR, the resulting PP composites can achieve a remarkable increase of approximately 200% in impact strength. This should be due to the grafted nerol moieties can substantially improve the interfacial adhesion of the composites and hence facilitate the dispersion of WSR particles in PP matrix. Therefore, the stress concentration of PP can also be effectively delivered to the adjacent Nerol-WSR and thus retard the propagation of cracks. In addition, the addition of Nerol-WSR can also increase the loss tangent values of the composites, which indicates its potential application in polymer damping. [ABSTRACT FROM AUTHOR]

A series of co-doped TiO2 ceramics named (Re0.5Nb0.5)0.005Ti0.995O2 (Re = La, Nd, Sm, Gd) were prepared by a solid-state reaction method. The microstructure, dielectric properties, and impedance spectra of (Re0.5Nb0.5)0.005Ti0.995O2 ceramics were systematically investigated in detail. The co-doped TiO2 with rutile structure ceramics possessing CP and low dielectric loss (<0.05) have been gotten. Low dielectric loss is attributed to enhancing grain boundary resistance and suppressing Maxwell–Wagner polarization This work maybe give us enlightenment about how to find low dielectric loss in co-doped TiO2 CP ceramics. [ABSTRACT FROM AUTHOR]

Crosslinking of diene rubbers by the traditional sulfur-based curing package inevitably utilizes toxic activators and accelerants, which causes potential dangers and environmental pollution. Herein, we report on the rapid synthesis of sulfur co-polymers by inverse vulcanization of S8 and styrene through a nucleophilic activation mechanism and demonstrate that the inverse vulcanised co-polymer is highly efficient in crosslinking diene rubbers in a green manner. Compared with the traditional sulfur-cured counterpart, the sulfur co-polymer-cured sample with an identical crosslinking density exhibits a remarkably larger breaking strain and a higher elasticity. [ABSTRACT FROM AUTHOR]

It is still a challenge to integrate multiple dynamic covalent bonds (DCBs) into one network, so the effects of DCB multiplicity on the performance of covalent adaptable networks (CANs) are still unclear. In this contribution, based on the versatility of vanillin chemistry, we realized the construction of CANs containing different DCB multiplicities, and thus the influences of DCB multiplicity on the vitrimeric performance of the networks are fairly investigated. It turns out that, with increasing DCB multiplicity, the relaxation time of the networks can be reduced significantly because the dynamic performance of the CANs with double or triple DCBs is determined by not only the activation energy but the synergistic effect of different DCBs. A plausible method was first proposed to quantify the synergistic effect of DCB multiplicity. We envisage that the disclosed findings will provide significant insight into the optimized design of CANs with tunable dynamic performance. [ABSTRACT FROM AUTHOR]

Dielectric spectroscopy was carried out for reduced and stoichiometric La0.0025Nb0.0025Ti0.995O2 ceramics synthesized by sintering in different atmospheres. A giant permittivity (~1 × 104) was obtained at a frequency of 100 MHz and temperature range from 170 to 350 K. Three dielectric relaxation mechanisms were observed within the temperature range of 10‐300 K via dielectric spectroscopy. A low temperature dipole relaxation peak (in the temperature range of 10‐30 K) in the spectra was identified to be associated with the giant permittivity specifically measured at 100 MHz. The origin of such giant permittivity was attributed to dipole orientation polarization. Hopping polaron and interfacial effect contributed to giant permittivity. After annealing treatment, all the relaxation contributions were weakened. Low dielectric loss was attributed to high resistance of grain and grain boundaries. Annealing in ambient conditions led to decreased relaxation times which gives the signature of decreased concentration of oxygen vacancies and Ti3+. Dipoles which were related to oxygen vacancies and Ti3+, resulted in giant permittivity up to 100 MHz. [ABSTRACT FROM AUTHOR]

(In0.5Nb0.5)0.005(Ti1‐xZrx)0.995O2 (INZT, x = 0‐0.10) ceramics were synthesized using a conventional sintering method, and the effects of Zr content on the microstructures, dielectric properties and electron‐pinned defect‐dipoles (EPDD) polarization of the resultant products were investigated. The solubility limit of INZT was x = 0.075, and a secondary ZrTiO4 phase appeared at x = 0.10. Ceramics with x = 0‐0.10 exhibited excellent dielectric properties, ie, colossal permittivity (CP, εʹ > 103) and low dielectric loss (tanδ < 0.1), over a wide range of frequencies (100‐106 Hz at 300 K) and temperatures (50‐350 K at 1 kHz). The dielectric spectra and XPS results confirmed that the CP property of the ceramics could be ascribed to their EPDD polarization. The activation energy (Ea) for EPDD polarization was continuously enhanced by increasing x values. EPDD relaxation parameters at different x values were revealed using Cole‐Cole equation fitting. Moreover, α, which characterize the relaxation time τ distribution, increased with x values, thus indicating that Zr was involved in and affected electron localized states. The high Ea, temperature Tp of the peak εʹʹ at 1 kHz, and dielectric relaxation time τp at 30 K were related to increases in hopping distance of electrons among defect clusters with Zr addition. [ABSTRACT FROM AUTHOR]

Low dielectric loss (tanδ < 0.05) within a frequency range of 20 Hz–2 MHz and a temperature range of 25–350 K was obtained through an optimized annealing process in colossal permittivity (CP) (εʹ > 104) (La0.5Nb0.5)0.005Ti0.995O2 ceramics. The effects of annealing on two important dielectric relaxations, electron-pinned defect-dipole (EPDD), and Maxwell–Wagner polarization were explored. An enhancement of activation energy (Ea) value and a large distribution of relaxation time τ were detected in EPDD relaxation for the ceramics annealed at 1123 K. The EPDD polarization was destroyed, accompanied by the disappearance of CP in the high annealing temperature range (> 1273 K). Impedance spectroscopy analysis suggested that grain boundary impedance could greatly enhanced as the ceramics were annealed at 1123 K. Strong electrode-material-dependent dielectric properties were detected, and a high tanδ was observed after the insulating surface layer was removed. The CP and low tanδ were ascribed to the maintenance of EPDD polarization, the enhancement of grain boundaries resistance, and the formation of an insulating surface layer through appropriate annealing. [ABSTRACT FROM AUTHOR]

Vitrimers can undergo network reshuffling via exchange reactions, endowing the covalently crosslinked polymers with malleability and reprocessability. Elastomeric vitrimers usually suffer from poor mechanical properties and undergo undesired creep at service temperature. Thus far, the incorporation of fillers and introduction of static cross-links are feasible solutions to improve mechanical properties and creep resistance, which, however, inevitably hampers network arrangement and deteriorates the dynamic properties. Herein, we demonstrate a rational design of elastomeric vitrimers with an integration of unparalleled mechanical properties, improved creep resistance and retained malleability by engineering Zn2+–imidazole complexes into the network. Specifically, commercially available styrene-butadiene rubber (SBR) grafted with 2-(2-benzimidazolyl)ethanethiol is covalently crosslinked with the dithiol-containing boronic ester cross-linker through thiol-ene "click" chemistry reaction. Afterwards, Zn2+–imidazole complexes are introduced and lead to the formation of a micro-phase separated structure. Zn2+–imidazole complexes can function as sacrificial units through reversible breaking and reforming events, leading to significant enhancements on the modulus, strength and toughness while maintaining the extensibility of the networks. In addition, the creep resistance at service temperature is improved as the Zn2+–imidazole complexes can act as cross-links to restrict segment mobility, whereas, the network arrangement at elevated temperatures is not affected due to the dissociation of Zn2+–imidazole complexes, allowing the networks to be reshaped and recycled. [ABSTRACT FROM AUTHOR]

Introduction: The aim of the study was to further explore the pathogenesis of idiopathic membranous nephropathy (IMN), gene-sequencing was used to analyze the differentially expressed circRNAs in exosomes of patients with IMN, which may lay the foundation for the research of circRNAs as a new class of exosome-based IMN diagnosis biomarkers.Material and Methods: Ten patients with IMN and ten normal controls were recruited as experimental subjects in our study. The exosomes were extracted from the collected serum and urine. Then, pure circRNAs were extracted from the exosomes with a series of enzymatic reactions. Afterwards, the significantly differentially expressed circRNAs were chosen by the method of gene-sequencing.Results: Compared with normal controls, the circRNAs were reduced in the exosomes from serum of patients with IMN, which mostly originated from intron gene regions. Meanwhile, a total of 89 circRNAs were significantly differentially expressed, which were also mostly derived from intron gene regions, including 49 up-regulated and 40 down-regulated genes. However, the species were increased in the exosomes from the urine of patients with IMN compared to normal controls, and they mainly originated from exon gene regions. Simultaneously, 60 circRNAs were significantly differentially expressed, which primarily belonged to intron gene regions, including 54 up-regulated and 6 down-regulated regions.Conclusions: The significant differential and specific expression of circRNAs in the exosomes from patients with IMN were observed. For example, MUC3A, which originated from chr7:100550808|100551062, could be considered a potential diagnostic biomarker of IMN. Furthermore, these figures may be used as a reference or supplement in the research of the pathogenesis of IMN. [ABSTRACT FROM AUTHOR]

Cross-linked elastomers are widely used in daily life; however, they become a stubborn environment problem at the end of their service life due to their thermosetting nature. Vitrimers, as a new class of materials with dynamic covalent networks that rely on associative exchange mechanisms, have been recently exploited for the development of covalently cross-linked recyclable elastomers. Herein, we report a facile strategy to achieve elastomeric vitrimers with mechanical robustness, malleability and recyclability by implementing dynamic covalent networks afforded by the interfacial silyl ether motifs in elastomer/silica hybrids. By virtue of its abundant surface silanol moieties, silica acts as both a reinforcement and cross-linker to endow the networks with chemical and mechanical robustness. Moreover, these permanent networks can reshuffle the topological structure upon temperature-induced trans-oxyalkylation reactions in the elastomer–silica interphase, enabling malleability and recyclability to the resultant materials. Since a wide variety of epoxy polymers and silanol-containing nanoparticles are easily accessible, we envisage that the present strategy can be a facile and universal avenue towards organic/inorganic hybrid vitrimers integrated with robustness, malleability and recyclability through the implementation of interfacial silyl ether-based networks. [ABSTRACT FROM AUTHOR]

Recycling of sulfur-cured scrap rubber is of growing importance worldwide due to the scarcity of rubber resources and environmental pollution. Herein, we report a feasible way to recycle sulfur-cured rubber by utilizing transalkylation exchange of C–S bonds, which enables the cross-linked rubber network rearrangement and thus confers the materials with the ability to be reprocessed. [ABSTRACT FROM AUTHOR]

Waste tire elastomers generate serious resource and environmental problems. Herein, a generic avenue was exploited by implementing exchangeable β-hydroxyl ester linkages between natural rubber and carbon black, which integrated covalent adaptable networks, mechanical robustness and reprocessability into a commercial rubber formulation by excluding the employment of toxic rubber additives. [ABSTRACT FROM AUTHOR]

The pure phase Li4Mg3Ti2O9 with nanopowders of 37 nm was prepared by a sol-gel method and calcinated at 600, 450 °C lower than that by a conventional solid-stated method. The sintering temperature of Li4Mg3Ti2O9 with addition of LiF (≥ 2 wt%) was reduced from 1275 to 800 °C with enhancement of density and microwave dielectric properties, related to the substitution of F− ion for O2− ion in Li4Mg3Ti2O9 compound at low temperature. Addition of LiF broadened the sintering window (800-1000 °C). The Li4Mg3Ti2O9-4 wt% LiF ceramic sintered at 850 °C exhibited good microwave dielectric properties of εr = 17.5, Q × f = 89,320 GHz (at 9.1 GHz), and τf = − 37.4 ppm/°C. Such samples were compatible with Ag electrodes, promising to be a candidate material for low-temperature co-fired ceramics technology application. [ABSTRACT FROM AUTHOR]

Rubbers are widely applied in tires, seals, biomedical materials and aerospace applications because of their unique high elasticity. However, combining high self-healing capability and excellent mechanical performance in a rubber remains a formidable challenge. In this work, inspired by the energy dissipation mechanism and the recoverability of sacrificial bonds, the authors describe a dual-dynamic network design of a high-performance elastomer in which weaker multiple hydrogen bonds and stronger Zn–triazole coordination have been engineered into an unvulcanized cis-1,4-polyisoprene (IR) matrix. Accordingly, the elastomer obtains high tensile strength (21 MPa) and toughness (60 MJ m−3). The facilitated chain orientation in such a dual-dynamic network is finely substantiated by the molecular dynamics simulation results. Significantly, this dual-dynamic network design enables a fully cut elastomer to be healed at mild temperature. Under healing at 80 °C for 24 h, the healed elastomer regains excellent mechanical properties (tensile strength of 15.5 MPa and fracture energy of 42.8 MJ m−3). We envision that this design concept can not only develop a new network construction method in rubbers instead of vulcanization, but also provide inspiration for preparing advanced elastomers with the combination of excellent mechanical performance and high self-healing capability. [ABSTRACT FROM AUTHOR]

Mimicking natural structures has been highly pursued in the fabrication of synthetic polymeric materials due to its potential in breaking the bottlenecks in mechanical properties and extending the applications of polymeric materials. Recently, it has been revealed that the energy dissipating mechanisms via sacrificial bonds are among the important factors which account for strong and tough attributes of natural materials. Great progress in synthesis of polymeric materials consisting of sacrificial bonds has been achieved. The present review aims at (1) summarizing progress in the mechanics and chemistry of sacrificial bond bearing polymers, (2) describing the mechanisms of sacrificial bonds in strengthening/toughening polymers based on studies by single-molecule force spectroscopy, chromophore incorporation and constitutive laws, (3) presenting synthesis methods for sacrificial bonding including dual-crosslink, dual/multiple-network, and sacrificial interfaces, (4) discussing the important advances in engineering sacrificial bonding into hydrogels, biomimetic structures and elastomers, and (5) suggesting future works on molecular simulation, viscoelasticity, construction of sacrificial interfaces and sacrificial bonds with high dissociative temperature. It is hoped that this review will provide guidance for further development of sacrificial bonding strategies in polymeric materials. [ABSTRACT FROM AUTHOR]

(Pb0.87Ba0.10La0.02)(Zr0.60Sn0.40-xTix)O3(PLBZST) (x = 0–0.20) bulk ceramics were prepared by the conventional solid state method, and the dependence of phase transformation, ferroelectric properties and energy storage properties on x values has been investigated. When x = 0.12, the unit cell volume significant change indicted the phase transformation of the ceramics. As x = 0.04–0.10, the PLBZST ceramics possess anti-ferroelectric phase with high recoverable energy storage density 0.8–1.3 j/cm3and when x = 0.12–0.20, the ceramics with ferroelectric phase have lower density values about 0.2–0.3 j/cm3. The phase switching electric field, saturation polarization and test temperature have an important influence on energy storage density and efficiency. As a result, the PLBZST bulk ceramics exhibit the largest recoverable energy density of 1.3 j/cm3with efficiency of 77.4% at 20°C. [ABSTRACT FROM AUTHOR]

It is a significant but challenging task to simultaneously reinforce and functionalize diene rubbers. Inspired by 'sacrificial bonds', the authors engineer sacrificial hydrogen bonds formed by pendent urazole groups in crosslinked solution-polymerized styrene butadiene rubber (SSBR) via triazolinedione click chemistry. This post-crosslinking modification reveals the effects of the sacrificial bonds based on a consistent covalent network. The 'cage effect' of the pre-crosslinked network facilitates the heterogeneous distribution of urazole groups, leading to the formation of hydrogen-bonded multiplets. These multiplets further aggregate into clusters with vicinal trapped polymer segments that form microphase separation from the SSBR matrix with a low content of urazole groups. The clusters based on hydrogen bonds, serving as sacrificial bonds, promote energy dissipation, significantly improving the mechanical properties of the modified SSBR, and enable an additional wide transition temperature region above room temperature, which endows the modified SSBR with promising triple-shape memory behavior. [ABSTRACT FROM AUTHOR]

A novel and non-cytotoxic self-healing supramolecular elastomer (SE) is synthesized with small-molecular biological acids by hydrogen-bonding interactions. The synthesized SEs behave as rubber at room temperature without additional plasticizers or crosslinkers, which is attributed to the phase-separated structure. The SE material exhibits outstanding self-healing capability at room temperature and essential non-cytotoxicity, which makes it a potential candidate for biomedical applications. [ABSTRACT FROM AUTHOR]

ABSTRACT Reversible plasticity shape memory (RPSM) polymers have been emerging as new smart materials with distinctions compared with conventional SMPs, such as easier shaping programming, stronger recovery stress, and higher recovery strain. For purposeful control of the structure, and therefore the physical and mechanical properties, a full understanding of the deformation habits of such materials under different conditions is essential. This perspective provides the context as to how the deformation temperature and fixing conditions influence the fixity and recovery behavior of RPSM polymers and what are the optimized conditions for RPSM. We hope that this will afford useful information for fabricating RPSM polymers with better memory properties and promote the technical development of new design methods of such materials for advanced applications © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 1295-1299 [ABSTRACT FROM AUTHOR]

It remains a huge challenge to create advanced elastomers combining high strength and great toughness. Despite enhanced strength and stiffness, elastomeric nanocomposites suffer notably reduced extensibility and toughness. Here, inspired by the concept of sacrificial bonding associated with many natural materials, a novel interface strategy is proposed to fabricate elastomer/graphene nanocomposites by constructing a strong yet sacrificial interface. This interface is composed of pyridine-Zn2+-catechol coordination motifs, which is strong enough to ensure uniform graphene dispersion and efficient stress transfer from matrix to fillers. Moreover, they are sacrificial under external stress, which dissipates much energy and facilitates chain orientation. As a result, the strength, modulus, and toughness of the elastomeric composites are simultaneously strikingly enhanced relative to elastomeric bulk. This work suggests a promising methodology of designing advanced elastomers with exceptional mechanical properties by engineering sacrificial bonds into the interface. [ABSTRACT FROM AUTHOR]

ABSTRACT It poses a huge challenge to create nonpolar rubber with high fracture toughness. In the present letter, inspired by the concept of sacrificial bonding associated with many biological materials, we propose that a small fraction of additional sacrificial network can strikingly improve the fracture toughness of nonpolar rubbers. As a proof of concept, we created the additional 'fragile' epoxidized natural rubber (ENR) network in commercially available SBR rubber in a facile process. With addition of only 10 phr ENR, the SBR/ENR double network (DN) exhibits a fracture energy nearly fourfold higher than that for the neat SBR. The formation of DN formation and the correlation between the high toughness and presence of the second brittle network have been fully discussed. This is the first time sacrificial networks are created in diene-based rubber towards high toughness elastomers in a facile and efficient way. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 781-786 [ABSTRACT FROM AUTHOR]

Li2MgTiO4ceramics were prepared with Li2CO3, TiO2and MgO by high energy ball mill method. After mixtures ball-milling 30 h and calcining at 700°C, the homogenate Li2MgTiO4powders with average particle size of 160 nm were obtained. The pure phase obtained temperature was about 300°C lower than that by a conventional solid-state reaction process. Due to Li+evaporation, the Li2MgTiO4ceramics sintered at high temperature existed with some Mg2TiO4. The Li2MgTiO4ceramics at 1250°C had an excellent microwave dielectric propertiesϵr= 12.17, Q × f = 42000 GHz and an τf= −23 ppm/°C [ABSTRACT FROM AUTHOR]

Separating the effects of interfacial interaction on rubber performance from those of the dispersion state remains challenging, as an improvement in both properties is often observed upon addition of an interfacial modifier. In this work, 4-(chloromethyl) phenyltrimethoxysilane, a silane-bearing benzyl chloride, is used as the model substance to modify a SBR/silica composite. Although an improvement in dispersion, as indicated by morphological observations and rheological measurements, is achieved, the dynamic property indicated by the mechanical loss and heat build-up, deteriorates. Such outcomes are attributed to the inferior interfacial interaction and decreased crosslink density. As a comparison, the counterpart modified by bis(triethoxysilylpropyl) tetrasulfide possesses a superior dynamic property which is attributed to the simultaneous improvements in the dispersion and interfacial interaction. This work provides new insights for the design of high performance rubbers used under dynamic circumstances. POLYM. COMPOS., 37:446-454, 2016. © 2014 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The MgNbO co-doped with 20 wt% TiO (MNT) and x wt% LiF (1 ≤ x ≤ 8) composite ceramics were prepared by a solid-state reaction method for developing ultralow-fired (≤800 °C) microwave dielectric ceramics. The sintering temperatures of MNT ceramics were successfully lowered to 750 °C due to the formation of liquid phase (LiF). A secondary phase of MgTiO was observed at above 700 °C for MNT-8 wt% LiF ceramics. All the composite ceramics have the optimal bulk densities at 800 °C, which corresponds to the maximum Q × f value of 32,000 GHz and ɛ value of 15.7. The well microwave dielectric properties of ɛ = 15.6, Q × f = 25,000 GHz, and τ = −56 ppm /°C were obtained at 750 °C for 5 h for MNT-8 wt% LiF ceramics. This material is compatible with Ag electrodes, suitable for low-temperature co-fired ceramics applications. [ABSTRACT FROM AUTHOR]

Although various shape memory polymers (SMPs) or diverse applications have been widely reported, the SMPs based on rubbers have been rarely realized due to the low triggering temperature of rubbers. In another aspect, the SMPs based on sustainable substances are highly desired for the growing shortage in fossil resources. In the present study, we accordingly developed the sustainable SMPs with tunable triggering temperature, based on natural rubber (NR) and ferulic acid (FA) as the raw materials. Specifically, the SMPs are based on a crosslinked network of epoxidized natural rubber (ENR) crosslinked byin situformed zinc ferulate (ZDF) via oxa-Michael reaction. The excellent shape memory effect (SME) is found in these SMPs, as evidenced by the high fixity/recovery ratio and the tunable triggering temperature. With the incorporation of natural halloysite nanotubes (HNTs), the stress and recovery rate of the SMPs are found to be tunable, which widens the application of this kind of SMPs. The combination of adoption of sustainable raw materials, and the excellent and tunable SME makes these SMPs potentially useful in many applications, such as various actuators and heat-shrinkable package materials. [ABSTRACT FROM AUTHOR]

Sulphur-cured diene-based rubbers generally suffer from insufficient anti-ageing properties, and the curing process involves the use of toxic additives. Renewable conjugated acids are demonstrated to effectively cure epoxidized natural rubber into a high-performance elastomer, without the use of any toxic accelerators or antioxidants. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, nanosheets including graphene oxide (GO) and reduced graphene oxide (rGO), were incorporated into natural rubber (NR), to study the effects of substituting GO or rGO for carbon black (CB) on the structure and performance of NR/CB composites. The morphological observations revealed the dispersion of CB was improved by partially substituting nanosheets for CB. The improvements in static and dynamic mechanical properties were achieved at small substitution content of GO or rGO nanosheets. With substitution of rGO nanosheets, significant improvement in flex cracking resistance was achieved. NR/CB/rGO (NRG) composites has a much lower heat build-up value compared with NR/CB/GO (NG) composites at a high load of nanosheets. However, both GO and rGO tended to aggregate at a high concentration, which led to the poor efficiency on enhancing the dynamic properties, or even deteriorate the performance of rubber composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41832. [ABSTRACT FROM AUTHOR]