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Recently, passive radiative cooling (PRC) that realizes thermal management without consuming any energy has attracted increasing attention. However, few studies focus on low‐cost and robust PRC film fabricated by a facile and environmentally friendly method. In this study, via coextrusion blow film molding and water leaching, sandwiched PRC film (SPRCF) is efficiently prepared, and its skin and core layer are respectively high‐density polyethylene (HDPE) film and oriented ZnO@HDPE microfiber layer. Of note, such a sandwiched structure enables SPRCF to possess remarkable mechanical properties, abrasion, and weather resistance. Moreover, with the introduction of ZnO, SPRCF shows lower sunlight transmittance (≈3.8%) but higher mid‐infrared transmittance (≈88.8%), endowing it with remarkable PRC performance (the maximum cooling power of daytime and nighttime are respectively 73.8 and 96.7 W m−2). Furthermore, the decent self‐cleaning performance of SPRCF‐45 endows it with maintenance‐free features outdoors. This work proposes a facile and environmentally friendly method for preparing low‐cost and robust SPRCF, opening a new pathway to develop PRC film following the concept of polymer "structuring" processing. [ABSTRACT FROM AUTHOR]

Despite great progress in the construction of non‐equilibrium systems, most approaches do not consider the structure of the fuel as a critical element to control the processes. Herein, we show that the amino acid side chains (A, F, Nal) in the structure of abiotic phosphates can direct assembly and reactivity during transient structure formation. The fuels bind covalently to substrates and subsequently influence the structures in the assembly process. We focus on the ways in which the phosphate esters guide structure formation and how structures and reactivity cross regulate when constructing assemblies. Through the chemical functionalization of energy‐rich aminoacyl phosphate esters, we are able to control the yield of esters and thioesters upon adding dipeptides containing tyrosine or cysteine residues. The structural elements around the phosphate esters guide the lifetime of the structures formed and their supramolecular assemblies. These properties can be further influenced by the peptide sequence of substrates, incorporating anionic, aliphatic and aromatic residues. Furthermore, we illustrate that oligomerization of esters can be initiated from a single aminoacyl phosphate ester incorporating a tyrosine residue (Y). These findings suggest that activated amino acids with varying reactivity and energy contents can pave the way for designing and fabricating structured fuels. [ABSTRACT FROM AUTHOR]

The lack of a robust phylogenetic backbone has posed significant challenges to proposing an infrageneric taxonomic classification of the pear genus, Pyrus, a widely distributed Eurasian lineage of Rosaceae. This issue has been exacerbated by limited informative loci and inaccessible taxon sampling. To address these limitations, we conducted extensive taxon sampling, encompassing 78 Pyrus ingroup individuals representing 32 species, along with 4 outgroup species. This comprehensive sampling strategy covers a wide range of morphological and geographical variations. To enable accurate phylogenomic inference, we assembled 801 single‐copy nuclear genes and 72 plastid coding sequences from deep genome skimming (DGS) data. Additionally, we employed a tree‐based method for nuclear orthology inference, which led to the generation of three orthologous datasets: one‐to‐one orthologs (1to1), monophyletic outgroups (MO), and rooted ingroups (RT). The results yielded from both nuclear and plastid analyses consistently support the monophyly of Pyrus, and two well‐supported clades, the Occidental and Oriental clades, were recovered in nine nuclear and three plastid trees. Integrating evidence from morphology and phylogenomics, we propose an updated infrageneric classification of Pyrus, which consists of two subgenera: P. subg. Pyrus and P. subg. Pashia stat. nov. This revised classification provides a more robust framework for understanding the evolutionary relationships within the pear genus. [ABSTRACT FROM AUTHOR]

Unprecedented levels of seismicity have been seen in southern Sichuan, China, since the large‐scale exploitation of shale gas. Fluid and pore pressure transported through hydrological channel are thought as pivotal elements in the induction of earthquakes. Our high‐resolution tomography results reveal two inclined seismic anomalies featured by low Vs and high Vp/Vs at different depth range. The deeper anomaly extends 15 km from NE to SE and connects the well g048 from 3 km depth to the vicinity of the Ms 4.7 Gongxian earthquake 5.4 km deep, which is hinted to be a hydrological channel inferred from the high fluid overpressure of 28 Mpa calculated from focal mechanism solution. The injection operation of multiple shale gas wells along the channel may potentially accumulate the pore pressure and cause the fault near the end of the channel to reach critical stress state through various mechanisms. Plain Language Summary: Increasing seismicity in southern Sichuan is suspected to be linked to hydraulic fracturing stimulation for shale gas extraction. Induced earthquakes resulting from fracturing operations at nearby wells can be verified using in‐situ fracturing data, while remote‐induced factors are hard to prove. In this study, a seismic anomaly of low Vs and high Vp/Vs inferred to be a long‐distance hydrological channel connecting the 2021 Ms 4.7 Gongxian earthquake to the active shale gas well 15 km away. Our results indicate that pore fluid pressure generated by hydraulic fracturing in multiple wells may continuously accumulated at the end of the channel, ultimately resulting in high pore pressure and triggering the fault rupture. Therefore, it is urgent to plug this channel and prevent the filtration loss. Key Points: Two long‐distance hydrological channels were observed in southern SichuanThe injection operation of multiple wells along the channel may increase the pore pressure in the hydrological channelThe accumulation of pore pressure at the end of the hydrological channel was confirmed by the occurrence of Ms 4.7 Gongxian earthquake [ABSTRACT FROM AUTHOR]

In this comprehensive study, based on extensive taxon sampling, we performed phylogenomic analyses of plastome and nuclear ribosomal DNA (nrDNA) datasets. We employed multiple inference methods, including concatenated and coalescent‐based strategies, to generate an accurate phylogeny of the woody Rosaceae genus Pourthiaea. The nrDNA phylogeny of Pourthiaea strongly supports three major clades, which are consistent with morphology. However, the plastid tree provides an alternative phylogenetic topology, indicating cytonuclear discordance which could be explained by frequent hybridizations between and among the species of Pourthiaea. Considering evidence from morphology and phylogenomic data, we propose a new infrageneric classification for Pourthiaea, consisting of three sections: P. sect. Pourthiaea, P. sect. Amphidoxae sect. nov., and P. sect. Impressivenae sect. nov. [ABSTRACT FROM AUTHOR]

The development of flexible and adaptable multifunctional sensing systems for human–machine interaction, especially for animal voice‐emotion identification, is highly desirable yet quite challenging. Herein, a multifunctional triboelectric nanogenerator (TENG) based on ordered hierarchical microhump arrays is proposed and fabricated by template‐assisted electrospinning with a facile, low‐cost, and expandable manufacturing process. Performances of a single‐electrode TENG based on the patterned nanofiber films with microhump arrays (NFM‐TENG) are studied in detail by varying mesh number of the template. Electric field structure of the collector is altered by pore sizes, wire diameters, and protrusions of the receiving templates subjected to different mesh numbers, generating different degrees of microhump arrays on the surface of the nanofiber film. NFM‐TENG demonstrates high sensitivity (15.94 mV Pa−1), fast response and recovery time (76 and 58 ms), a large power density of 122 mW m−2, and excellent ability of structural retention. Integrated with four functions of energy harvesting, pressure sensing, human physiological sensing, and animal voice‐emotion identification, NFM‐TENG achieves real‐time monitoring of human physiological, motion, handwriting, and animal voice‐emotion signals without an external power supply. This study shows significant application strategies for self‐powered human–machine interaction devices, novel animal voice‐emotion identification, biodiversity conservation, and so on. [ABSTRACT FROM AUTHOR]

Saikosaponin A (SSA) has been revealed to have anti‐breast cancer (BC) effect. However, the association between SSA and BC glycolysis is obscure. We want to probe the function and mechanism of SSA on BC glycolysis. Kaplan–Meier plotter revealed the relationship between STAT3 and the survival curve of BC. The protein kinase B (Akt)/signal transducer and activator of transcription 3 (STAT3) pathway and the viability in cells treated with or without 0, 5, 10, and 15 μM SSA were assessed by Western blot and cell counting kit‐8. The biological behaviors, lactate, and ATP contents, glucose uptake, and Akt/STAT3 pathway‐related markers in BC cells treated with colivelin or SSA were evaluated using cell function experiments, kit, and Western blot. Then, the impacts of colivelin and SSA on BC cells were tested again. The overexpressions of p‐STAT3 and p‐Akt in BC cells were weakened by 5, 10, and 15 μM SSA. Colivelin boosted the BC cell viability and proliferation and impeded apoptosis, while SSA did the opposite. Meanwhile, colivelin intensified lactate and ATP contents, glucose uptake, and Akt/STAT3 pathway‐related markers level in BC cells, while SSA was the opposite. The modulation of SSA on the biological behavior, lactate and ATP productions, glucose uptake, and Akt/STAT3 pathway was rescued by colivelin. Our research unveiled new insights into SSA as a valuable candidate therapeutic agent for weakening glycolysis, and protruded the Akt/STAT3 pathway as a latent molecular target for SSA and glycolysis modulation. [ABSTRACT FROM AUTHOR]

The September 2022 Ms 6.8 Luding earthquake broke more than 230 years of seismic calm on the Moxi fault, providing a unique opportunity to understand its seismogenic environment, rupture dynamics, and seismic hazard. Using teleseismic body waves, regional strong‐motion observations, GNSS, and InSAR data, we decipher the spatiotemporal rupture evolution of the mainshock. Combining the elastic dislocation model with surface creep, we find that the coseismic slip correlates closely with a locked patch with a loading rate of 9.7 mm/yr, but the creeping rate is insufficient to make up the shallow slip deficit. Notably, the Luding earthquake ruptured only ∼1/4 of the Moxi seismic gap, and it further increased the stress in the unruptured northern part. We thus argue that the Moxi fault has the potential for magnitude 7+ earthquakes in the near future, although geodetic prediction may overestimate the actual seismic moment released by the coseismic rupture. Plain Language Summary: The Xianshuihe fault is an area of intense tectonic activity on the Tibetan Plateau and plays an important role in accommodating the postcollisional convergence of the Eurasian and Indian plates. However, the Moxi fault, at the southeastern end of the Xianshuihe fault, has remained seismically quiescent since the last Ms 7.75 event in 1786. In September 2022, a Ms 6.8 Luding earthquake struck the Moxi seismic gap, resulting in destructive landslide damage, with 93 people dead and 25 missing. Using seismic and geodetic recordings, we recover its space‐time rupture process in detail. Our model reveals an asymmetric bilateral rupture with dominant propagation and maximum slip to the SSE. It is important to note that the 2022 Luding earthquake ruptured only the southern Moxi seismic gap, leaving the northern part unruptured. Based on the departure time of the last major earthquake and the slip rate obtained from the elastic dislocation model, we estimate the unreleased seismic energy of the Moxi fault, indicating that it still has the potential for strong earthquakes. Besides, the Luding earthquake further increased its seismic hazard through stress transfer. Therefore, we should pay great attention to the kinematic state of the Moxi fault at this time. Key Points: The kinematic evolution of the Luding earthquake is revealed by seismic and geodetic observationsThe coseismic slip asperity from 3 to 20 km depth correlates closely with the preseismic surface creep and locked patchThe unruptured Moxi seismic gap still has the potential for magnitude 7+ earthquakes and deserves further attention [ABSTRACT FROM AUTHOR]

An elastic masterbatch and elastic melt blown nonwovens are prepared based successively on styrene‐ethylene/butylene‐styrene (SEBS) and polypropylene (PP) blend. The phase separation morphology, rheological properties and crystal structure of the elastic masterbatch are investigated. The results show that a compatible and stable structure is obtained in molten SEBS and PP blend with excellent mobility in the temperature range of 210–230°C. The crystallization of PP slows down resulting in a finer structure due to the restriction of the SEBS network structure with rarely change of crystalline structure. The relationship between process parameters and properties of the elastic nonwoven is also studied in detail. Air pressure and die to collector distance (DCD) have discernible effects on fiber diameter and bonding between fibers, further influencing the performances of nonwovens including porosity, tensile strength and elastic recovery. Elastic recovery is shown to be significantly more affected by DCD than by air pressure. [ABSTRACT FROM AUTHOR]

A facile benzylic alkylation of indenes and other arenes was developed from readily available primary and secondary alcohols using our newly investigated CCC pincer IrIII catalyst (SNIr−H). Excellent regioselectivity and yield (89 %) of the C3‐alkylated indenes were obtained. Additionally, the challenging sp2C‐alkylation was readily accomplished. This method could be utilized for the synthesis of the analogs of a histamine H1 receptor antagonist and the functional material template molecule, indeno[2,1‐a]indene. A hemilabile IrIII‐dihydride intermediate was proposed based on control experiments and previous density functional theory (DFT) calculations for the borrowing hydrogen mechanism and is key to the success of this IrIII catalyst in the reduction of unactivated multi‐substituted olefin intermediates. [ABSTRACT FROM AUTHOR]

Flexible transparent conductive films (FTCFs) are critically important for the emerging flexible electronic devices. To this end, FTCFs with conductive gratings have drawn more interests in the past decades. However, there are great challenges to fabricate such FTCFs containing conductive gratings in a facile way. Borrowing the idea from traditional farming, a homemade roll‐to‐roll plowing technique combined with blade coating is proposed to fabricate silver grating FTCFs with anisotropic conductivity in a continuous, cost‐effective, and environmental friendly way. The as‐prepared FTCFs exhibit satisfied optical and electrical properties (i.e., transmittance is 78.2% and sheet resistance is 3.1 Ω □–1). After coated with thin polyvinyl butyral layer through hot‐pressing, it shows a higher transmittance of 84.2% and remarkable mechanical flexibility. Based on the FTCFs with anisotropic conductivity, flexible transparent heater and capacitive keyboard are successfully fabricated. Furthermore, based on such flexible capacitive keyboard, smart wireless controlled human–machine interface system is developed to wirelessly control tablet personal computer working and quadrotor flying. This study provides a promising strategy to fabricate high‐performance FTCFs with anisotropic conductivity via a continuous, cost‐effective, and environmental friendly way. [ABSTRACT FROM AUTHOR]

The developed JO‐IEX technology was applied to continuously separate four 5′‐ribonucleotides here. The unit contained seven columns with three separation steps, among which three columns were for the quaternary separation and the others for regeneration of resins. The operating conditions, that is, the critical flow rates in three separation steps were preliminarily designed according to the equilibrium theory and optimized by a three‐dimensional theoretical separation region approach. The feasibility of the JO‐IEX process and the separation performances were validated by four runs using the actual 5′‐ribonucleotides' enzymatic hydrolysate as feed solutions. The purities and yields of 5′‐ribonucleotides could reach above 97%. The productivity was enhanced to be 0.91 g/(kg h), and the desorbent consumption was reduced to be 1.01 L/g, compared to those of 0.70 g/(kg h) and 1.75 L/g in the fixed‐bed process. The technology proposed could be a potential technique in the continuous multicomponent ion‐exchange separation process. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA) and polyacrylamide (PAM) hydrogels as well as silver particles (Ag) composites are prepared by compound gelation. The structure and properties of the composites, which are controlled by the reaction of acrylamide in the hydrogel, are analyzed and the feasibility of their application in strain sensors are explored. The effects of different PVA concentration, content, and particle size of Ag on the mechanical properties, rheological properties of the composites are studied. PVA/PAM/Ag composites are selected as the substrate of the strain sensor, when the concentration of PVA is 0.08 g/ml, the particle size of Ag is 60 nm and the addition amount is 0.15 wt%. The strain sensing performance of the composites under low strain (5%, 20%, and 50%) and high strain (100% and 200%) are tested respectively. The hydrogel composite sensor shows sensitive and stable response to human motion, and it has the ability of distinguish the movement of different human body joints. [ABSTRACT FROM AUTHOR]

Conductive hydrogels (CHs) have been highlighted in the design of flexible strain sensors and stretchable triboelectric nanogenerators (TENGs) on the basis of their excellent physicochemical properties such as large stretchability and high conductivity. Nevertheless, the incident freezing and drying behaviors of CHs by using water solvent as the dispersion medium limit their application scopes significantly. Herein, an environment tolerant and ultrastretchable organohydrogel is demonstrated by a simple solvent‐replacement strategy, in which the partial water in the as‐synthesized polyacrylamide/montmorillonite/carbon nanotubes hydrogel is replaced with the glycerol, leading to excellent temperature toleration (−60 to 60 °C) and good stability (30 days under normal environment) without sacrificing the stretchability and conductivity. The organohydrogel exhibits an ultrawide strain sensing range (0–4196%) with a high sensitivity of 8.5, enabling effective detection and discrimination of human activities that are gentle or drastic under various conditions. Furthermore, the organohydrogel is assembled in a single‐electrode TENG, which displays excellent energy harvesting ability even under a stretchability of 500% and robustness to directly power wearable electronics in harsh cold conditions. This work inspires a simple route for multifunctional organohydrogel and promises the practical application of flexible and self‐powered wearable devices in extreme environments. [ABSTRACT FROM AUTHOR]

Objectives: Sarcopenia and systemic inflammation can affect survival of advanced‐stage oral squamous cell carcinoma (OSCC) patients; however, their reciprocal associations with survival outcomes are yet to be investigated. Study Design: Retrospective review at a tertiary cancer center. Methods: Patients with stage III‐IVB OSCC that underwent surgery and (chemo)radiotherapy at our institution between 2010 and 2015 were reviewed. Skeletal muscle index (SMI) was assessed using computed tomography scans at the C3 vertebra. Sarcopenia was defined at the lowest sex‐specific tertile for SMI. Systemic inflammation was estimated using the modified Glasgow prognostic score (mGPS), which ranges from 0 to 2 based on serum C‐reactive protein and albumin levels. The predictors of overall survival (OS) were evaluated using Cox regression models. Results: A total of 174 patients were included in the study. The cut‐off values for sarcopenia were set at SMI <52.4 cm2/m2 (men) and < 36.2 cm2/m2 (women) corresponding to the lowest sex‐specific tertile. An mGPS 1–2 was independently associated with sarcopenia (odds ratio: 2.05; 95% confidence interval: 1.06–3.97; P =.03). On multivariate analysis for OS, sarcopenia and mGPS 1–2 independently predicted OS (hazard ratio: 2.12; 95% confidence interval: 1.17–3.85; P =.01 and hazard ratio: 7.85; 95% confidence interval: 3.7–16.65; P <.001, respectively). Patients with both sarcopenia and mGPS 1–2 (vs. neither) had worse OS (hazard ratio: 16.80; 95% confidence interval: 6.01–46.99; P <.001). Conclusions: Sarcopenia and systemic inflammation may exert a negative synergistic prognostic impact in advanced‐stage OSCC patients. Level of Evidence: 4 Laryngoscope, 131:E1530–E1538, 2021 [ABSTRACT FROM AUTHOR]

Wearable strain sensors based on flexible conductive polymer composites (FCPCs) have attracted great attention due to their applications in the fields of human–machine interaction, disease diagnostics, human motion detection, and soft robotic skin. In recent decades, FCPC‐based strain sensors with high stretchability and sensitivity, short response time, and excellent stability have been developed, which are expected to be more versatile and intelligent. Smart strain sensors are required to provide wearable comfort, such as breathability, self‐cooling ability, and so forth. To adapt to the harsh environment, wearable strain sensors should also be highly adaptive to protect the skin and the sensor itself. In addition, portable power supply system, multisite sensing capability, and multifunctionality are crucial for the next generation of FCPC‐based strain sensor. [ABSTRACT FROM AUTHOR]

The rupture process of the 2018 Mw 7.9 offshore Kodiak (Alaska) earthquake is still in hot dispute because of a lack of offshore observations, thus causing difficulties for understanding seismogenic tectonics and tsunami hazards. In this study, teleseismic body waves, high‐rate GPS, seismic waves preceding tsunami waves, static GPS, and tsunami data are jointly used to resolve the faulting geometry and coseismic slip distribution of the offshore Kodiak earthquake. Tests of a series of finite fault rupture models illustrate that an optimal five‐fault model can reconcile all available data sets well. The results reveal that the asperity on each fault segment is located near the hypocenter, with peak slip of ~7.8 m. The aftershock loci appear to be complementary to the mainshock slips, demonstrating the velocity‐strengthening regions that predominantly slip aseismically. Based on a tectonic stress field analysis, we propose that the 2018 Kodiak earthquake is attributed to a combination of enhanced tensional stress following the 1964 Mw 9.2 Alaska earthquake and compressional stress produced by the collision of the Yakutat terrane with North America. Key Points: A complex quasi‐orthogonal strike‐slip fault system is revealed by seismic, geodetic, and DART dataNear‐field high‐rate GPS and DART data are involved in the joint inversion to improve the rupture modelShear stress between the 1964 Mw 9.2 Alaska earthquake and collision of the Yakutat terrane with North America favors strike‐slip events [ABSTRACT FROM AUTHOR]

N,N,N′,N′,N",N"‐hexaalkylnitrilotriacetoamide (HRNTA) derivatives were found to be promising for the separation of trivalent actinides from lanthanides, which is a burning topic in the back end of the nuclear fuel cycle. In the present work, separation of Am3+ from Eu3+ was studied using the N,N,N',N',N",N"‐hexa‐2‐ethylhexylnitrilotriacetamide (H2EHNTA) derivative and the role of the diluent medium to control the extractable complex was demonstrated. The effect of alkyl chain length and branching in the alkyl chain of different HRNTA (R=methyl, n‐butyl, n‐hexyl, n‐dodecyl and 2‐ethylhexyl) derivatives on their complexation with Eu3+ were investigated using steady‐state and time‐resolved luminescence studies. Different species formed at different ligand to metal ratios were identified from the luminescence titration experiments and their lifetime values measured. The experimental results were corroborated with the help of density functional theoretical (DFT) calculations on Am3+ and Eu3+ complexes of HRNTA derivatives with varying alkyl chain length and branching. [ABSTRACT FROM AUTHOR]

Electrically conductive carbon black (CB)/polypropylene (PP) nanocomposites with a segregated structure are fabricated by localizing CB particles at the interfaces among the PP granules. Interesting double-peak positive temperature coefficient (PTC) effect when exposed to temperature field is observed and ascribed to the breakage of unique segregated conductive network due to the volume expansion stemming from the crystal melting of interfacial PP and the bulk PP matrix. With extending thermal treatment time, the PTC intensity first increases and then decreases obviously. Long treatment time is required for the composites with high CB loadings to reach the PTC intensity maximum value. This phenomenon is attributed to the evolution of segregated microstructure during the thermal treatment, which is traced visually in situ through an optical microscope (OM). The diffusion due to the concentration gradient and the subsequent aggregation of CB particles lead to this behavior. A model based on the OM observation is proposed to reveal the origin of this novel resistivity-temperature behavior. [ABSTRACT FROM AUTHOR]

The mechanical properties and microstructure of injection molded isotactic polypropylene parts with high orientation before and after annealing are analyzed. The mechanical properties of the annealed samples are improved effectively. Through thorough analysis of various structural characterizations, a microstructural model based on the fact that the total length of long period kept constant to analyze the variation of mechanical properties is proposed. It is suggested that the increase of overall crystallinity, the recombination of crystalline phase, and the increase of amorphous phase, respectively, are beneficial for the improvements of the strength, stiffness, and toughness of annealed samples. [ABSTRACT FROM AUTHOR]

ABSTRACT Up to now, research on the dynamic process of conductive network formation has tended to focus on composite particles with one-dimensional geometry, such as carbon black and carbon nanotubes. However, studies on this subject based on fillers with two-dimensional structure, such as graphite, are rare in the literature. In this work, the dynamic percolation and rheological properties of poly(methyl methacrylate) (PMMA)-graphite composites under an electric field were investigated. The activation energies of conductive network formation and polymer matrix mobility were calculated from the temperature dependence of the percolation time and the zero-shear viscosity. It was found that the activation energy calculated from the zero-shear viscosity was not influenced by the electric field in the concentration range investigated, but the electric field had an effect on the activation energy calculated from the percolation time. This finding emphasizes that the electrical and rheological properties have different physical origins. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43810. [ABSTRACT FROM AUTHOR]

ABSTRACT Polymer processing methods generally play a crucial role in determining the development of microstructure in the fabricated product. In this study, isotactic polypropylene (iPP) melt containing 0.05 wt % β-nucleating agent (β-NA) was extruded via a melt flow rate indicator. The molten extrudate was stretched into a fiber upon various take-up velocities (TVs). The microstructures of the fiber were investigated by differential scanning calorimeter, two-dimensional wide-angle X-ray diffraction, and small-angle X-ray scattering. Also, its tensile properties (including tensile strength, modulus, elongation at break, and toughness) were measured by tensile test. Interestingly, the tensile strength (135.0 MPa) of a melt-spun β-nucleated iPP fiber fabricated at 400 cm/min was enhanced by 115.2%, compared with that (62.7 MPa) prepared at 100 cm/min, with a considerable increment in toughness (from 661 to 853 MJ/m3). The enhancement mechanism for tensile properties was discussed based on the microstructures. This work offers a simple approach to prepare β-nucleated iPP fibers with excellent strength and toughness. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43454. [ABSTRACT FROM AUTHOR]

Electrospun polyamide PA 66 nanofiber bundles were mechanically strengthened via compositing with polyvinyl alcohol (PVA). The highest tensile strength (126.4 MPa) was achieved for the bundles immersed in the solution with 5.0 wt% PVA, indicating sufficient PVA filling between nanofibers after drying the impregnated nanofiber bundles. The disappearance of voids for the bundles immersed in the PVA solution indicated a superb interface adhesion, which was responsible for the excellent mechanical properties of the composite bundles. Furthermore, the step-cycle and stress relaxation tests were carried out to shed light on the deformation evolution and the viscous stress of the bundles. The results further demonstrated the excellent mechanical properties of the composite bundles. [ABSTRACT FROM AUTHOR]

In this work, isotactic-polypropylene (iPP) specimens were prepared by a modified injection molding machine, in which high temperature preshear (HTPS) can be imposed on the molten polymer during the plasticizing stage. The effect of HTPS on the microstructure and mechanical property of iPP was investigated. It was found that spherulite size in core region of iPP part decreased steadily with the increasing HTPS duration, indicating that HTPS could substantially enhance iPP nucleation. Moreover, β-iPP formation correlated strongly with HTPS duration. That is, in the absence of HTPS, β-iPP existed only in intermediate region; with moderate HTPS duration, β-iPP could be unexpectedly formed in core region; however, long HTPS duration inhibited β-iPP formation in both intermediate region and core region. Based on the relationship between β-iPP formation and HTPS duration, metastable nuclei, instead of α-row nuclei, were proposed to be responsible for the development of β-iPP. Notched Izod impact test showed that moderate HTPS duration enhance the impact strength of injection molded iPP by decreasing the thickness of shear region and elevating β-iPP crystallinity in core region. Dynamic mechanical test indicated that with the increase of HTPS duration, the storage modulus of injection-molded iPP improves drastically. [ABSTRACT FROM AUTHOR]

Liquid-sensing behaviors of carbon black (CB)/polypropylene (PP) and carbon nanotubes (CNTs)/PP-conductive polymer composites (CPCs) were studied in detail. It was found that the CB/PP showed a higher liquid-sensing intensity but a poorer reproducibility toward the 'good solvent' xylene. The main origin is that the conductive works formed by CB, the zero-dimensional filler, are vulnerable to the swelling effect of PP during the immersion-drying runs (IDRs), whereas CNTs in the CNTs/PP with a large aspect ratio have better capacity in maintaining the conductive networks. To investigate the influence of the remaining solvent on the evolution of conductive networks, liquid-sensing tests of the two composites after long-term immersion in xylene were investigated. Results showed that the liquid-sensing behaviors of CNTs/PP changed less weakly compared with that of the CB/PP. Liquid-sensing behaviors of the two composites, cyclohexane and tetrachloromethane, to the 'poor solvents' were also studied. The results of this article indicate that liquid-sensing behaviors of the CPCs were affected by the microstructure of the conductive filler, the solubility parameter, and the molar volume of the solvent significantly. POLYM. COMPOS., 36:205-213, 2015. © 2014 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

High density polyethylene (HDPE) was molded by a new polymer processing method, that is, water-assisted injection molding (WAIM), and its hierarchical structure was studied by two-dimensional small angle X-ray scattering (SAXS). For comparison, the hierarchical structure of HDPE molded by conventional injection molding (CIM) was also characterized. The result shows that the WAIM part exhibits a distinct skin-core-water channel structure which is different from the skin-core structure for the CIM part. In the skin layer of both WAIM and CIM parts, the shish-kebab structure was formed due to the shear stress brought by melt filling, but the lamellar orientation parameter of CIM part is smaller than that of WAIM part. The spherulites with random lamellar orientation are dominant at the core of both parts owing to the low cooling rate and feeble shear stress therein. Interestingly, the shish structure and the lamellae with low level of orientation can be found at the water channel layer of WAIM part. They are attributed to the shear stress brought by water penetration. Moreover, the lamellar orientation parameter in water channel layer is smaller than that of skin layer. In addition, the long period of WAIM part first increases and then decreases with the elevating distance from the skin surface, while that of CIM part tends to increase monotonously. In a word, one can conclude that the rapid cooling rate and shear brought by the injected water have significant influence on the structural evolution for the WAIM part. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

This article reports the positive temperature coefficient (PTC) and negative temperature coefficient (NTC) effects of a carbon black (CB)-filled electrically conductive microfibrillar poly(ethylene terephthalate) (PET)/polyethylene (PE) composite (FCMC). The composite contains in situ polymer microfibrils in the matrix of another polymer with CB particles selectively localized at microfibrils' surfaces. Anomalous attenuations of PTC and NTC intensities ( IPTC and INTC) of FCMC were observed during heating-cooling runs (HCRs) and long-term isothermal treatments. Particularly, when the isothermal treatment time was 32 h, the IPTC decreased from 5.5 in the original sample to only 0.5, showing a tremendous attenuation ratio of up to 91%, and the NTC effect was completely eliminated. On the contrary, attenuations of PTC and NTC effects in a common conductive polymer composite (CCPC) were so weak as to be negligible through the same thermal treatments. Microstructural changes of the conductive network by Brownian motion and large size of the conductive component-CB coated PET microfibrils are both responsible for the great reductions in IPTC and INTC. The present results strongly suggest that thermal field induced microstructural transformation by Brownian motion helps to reveal the origin of PTC and NTC effects. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

This article reports the organic liquid stimuli-response behaviors of carbon black (CB)-filled electrically conductive microfibrillar poly(ethylene terephthalate) (PET)/polyethylene (PE) composite (FCMC) with CB particles selectively localized at PET microfibrils' surfaces. It was found that FCMC's thickness and CB concentration affected its responsivity significantly, a thinner FCMC film with a high CB content exhibited higher responsivity and better signals. In immersion-drying tests, FCMC displayed high and stable responsivities after six immersion-drying runs, indicating that the solvent absorption/desorption equilibrium state was achieved. After long-term immersion, FCMC showed obviously different organic liquid stimuli-response behaviors with faster response rate in immersion and higher terminal resistivity platform in drying, compared with samples without immersion treatment. Conductive network's microstructural changes induced by the long-term immersion and evident capillary effect, which resulted in slow evaporation of remaining solvent in FCMC's interfaces, are the reasons for the phenomenon. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

An anisotropically conductive polymer composite (ACPC) based on conductive carbon black (CB) and binary polymer blend of polyethylene (PE) and polyethylene terephthalate (PET) was successfully fabricated under shear and elongational flow fields. The PET phase formed in situ the aligned conductive microfibrils whose surfaces were coated by CB particles. This ACPC material exhibited a strong electrical anisotropy within a broad temperature range. When the ACPC samples were subjected to isothermal treatment (IT), they showed anomalous variations of the positive temperature coefficient (PTC) and negative temperature coefficient (NTC) effects. The PTC intensity was attenuated gradually with the increase of the IT time, and the NTC intensity was nearly eliminated after IT of 8 or 16 h. Beyond 16 h, the resistivity in the NTC region rose anomalously with the temperature after the elimination of NTC effect, which was the result of much transformation from the potential pathways to the intrinsic pathways due to the disordering of oriented conductive microfibrils. When the amount of potential pathways was very small, the effect of the intrinsic pathway separation surmounts that of the potential pathways, leading to the anomalous resistivity increase in the NTC region. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

The nucleated isotactic polypropylene (iPP) was molded by water-assisted injection molding. The crystalline morphology and orientation distribution were studied. The results show that shear brought by melt filling and pressurized water penetration can separately induce the formation of oriented structures in skin region (i.e., the region near mold cavity wall) and the water channel region. For virgin iPP, slightly oriented lamellae appear exclusively in the above aforementioned regions. However, shish-kebab structure occurs not only in skin and water channel region of the iPP containing moderate content of nucleator (0.2 wt%) but also in the whole region of the iPP containing a higher content of nucleator (1 wt%). It is well known that nucleator cannot directly induce the development of shish-kebab in the absence of shear, thus the results indicate: shear flow actually distributes over a much broader range than expected; in shear field, nucleator is significantly helpful for the shear which is not sufficient to solely induce oriented structure to promote the formation of the oriented structure. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

At an extremely small extrusion rate, an isotactic polypropylene melt was extruded through a slit die of an extruder. Simultaneously, the extruded melt was stretched at various stretching rates (SRs) at the die exit. The oriented structure and its subsequent recrystallization via self-seeding were investigated using polarized optical microscopy, two-dimensional wide-angle X-ray scattering and small-angle X-ray scattering. As expected, much slenderer and denser oriented structures were formed at larger SR, which indicates that orientation is preferably promoted with increasing SR. In the case of the crystalline morphology developed during recrystallization, a shish kebab-like structure was retrieved via the surviving oriented structure after annealing. Unexpectedly, for the sheet stretched at higher SR, a mainly sparse and short shish kebab structure was observed. For the sheet stretched at lower SR, a dense and long shish kebab structure was observed. This suggests that the oriented structure in the sheet stretched at lower SR has a better thermal stability than that in the sheet stretched at higher SR. This is discussed based on the relaxation of entangled junctions in the stretched networks with respect to varying chain length. Copyright © 2011 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The article reports on a study of the carbon nanotubes/ultrahigh molecular weight polyethylene (CNTs/UHMWPE) conductive composite with a low percolation threshold. It was shown that the resistivity decreased during isothermal treatment above the melting point of UHMWPE. This relaxation was proven as a function of time, temperature, filler concentration, and heating rate.

Enhancing the piezoelectricity of polymers while maintaining all components organic is still challenging but significantly important for developing flexible wearable energy harvesters and self‐powered devices. Here, a novel and versatile strategy is introduced to construct mixed‐dimensional all‐organic polymer heterostructures (MPHs) for enhanced piezoelectricity. By combining all‐polymer 1D nanofibers (NFs) with 2D crystals through epitaxial crystallization‐driven assembly (ECA), MPHs are engineered to capitalize on the synergistic effects of both dimensional nanostructures. The intrinsic piezoelectric activity of 1D NFs is amplified by the growth of 2D crystals, enhancing force‐sensitivity and overall piezoelectricity. The mixed‐dimensional assembly not only enables controlled in‐situ growth of MPHs, but also simultaneously induces preferential formation of electroactive phases through solvent‐induced phase transition. By modulating the epitaxial growth of 2D crystals on 1D NFs, effective tuning of MPH growth amount and morphology is achieved, resulting in significant improvements in deformability, dipole polarization, and durability. MPHs exhibit remarkable piezoelectric improvements, achieving higher output under lower‐level forces with a record‐high sensitivity of ≈670 mV kPa−1. Their superior responsivity enables the development of self‐powered wireless wearable motion‐monitoring systems for real‐time physiological movement detection and analysis. This work inspires the development of all‐organic piezoelectric devices for innovative flexible energy‐harvesting and sensing applications. [ABSTRACT FROM AUTHOR]

As a part of continuous efforts to systematically understand the morphological development in water-assisted injection molding, high density polyethylene with different molecular weights was molded in this study. Unexpectedly, it was found that shish kebab with high lamellar and molecular orientations was formed in the sample with a lower molecular weight (LMW) rather than in the higher one, especially in the water channel layer. Present finding is obviously inconsistent with the general consensus, that is, higher molecular weight (HMW) polymer is much easier to form preferential orientation in flow field than LMW one. Such anomalous phenomenon is explained by the fact that even though melts experienced the same processing, lower shear rate is practically achieved in HMW sample due to its high viscosity. The result indicates that the flow history in industrial processing method is far from that in laboratory one. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Stretchable, flexible, and strain‐sensitive hydrogels have gained tremendous attention due to their potential application in health monitoring devices and artificial intelligence. Nevertheless, it is still a huge challenge to develop an integrated strain sensor with excellent mechanical properties, broad sensing range, high transparency, biocompatibility, and self‐recovery. Herein, a simple paradigm of stretchable strain sensor based on multifunctional hydrogels is prepared by constructing synergistic effects among polyacrylamide (PAM), biocompatible macromolecule sodium alginate (SA), and Ca ion in covalently and ionically crosslinked networks. Under large deformation, the dynamic SA‐Ca2+ bonds effectively dissipate energy, serving as sacrificial bonds, while the PAM chains bridge the crack and stabilize the network, endowing hydrogels with outstanding mechanical performances, for instance, high stretchability and compressibility, as well as excellent self‐recovery performance. The hydrogel is assembled to be a transparent and wearable strain sensor, which has good sensitivity and very wide sensing range (0–1700%), and can precisely detect dynamic strains, including both low and high strains (20–800% strain). It also exhibits fast response time (800 ms) and long‐time stability (200 cycles). The sensor can monitor and distinguish complicated human motions, opening up a new route for broad potential applications of eco‐friendly flexible strain‐sensing devices. [ABSTRACT FROM AUTHOR]

As a crucial element for wearable devices, high‐performance strain sensors have been spotlighted as an ideal strategy to develop machine‐human interfaces and healthcare systems. It still remains a huge challenge to construct flexible strain sensors with equational response in a broad range. Herein, highly stretchable multi‐walled carbon nanotubes (MWCNTs)–decorated thermoplastic polyurethane (TPU) fibers with a porous microstructure are produced through a scalable and facile strategy by wet‐spinning and ultra‐sonication. The fiber is composed of pure TPU fibers with MWCNTs decorated on the surface. The porous fiber is then assembled as a strain sensor. Interestingly, the effective MWCNTs distribution on the TPU fiber enables exponential sensing over the whole strain range. The sensor possesses a high gauge factor (GF, 102 at 300% strain), very large workable sensing range (300% strain), excellent durability (10 000 cycles), light weight (0.85 g cm−3), and fast response (200 ms). The as‐prepared strain sensor exhibits excellent insensitive properties toward buckling, torsion, temperature, and humidity stimuli. Based on the high sensing performance, the fiber‐shaped strain sensor detects human movements precisely by directly attaching to skin or embedding in garments, demonstrating huge potential in human–machine interfaces, health monitoring application, etc. [ABSTRACT FROM AUTHOR]

Polypropylene conductive composites with carbon black selectively distributed at the interfaces between polypropylene matrixes are described by Kun Dai, Zhanhu Guo, and co‐workers in article number 1700265. This segregated conductive network is damaged and constructed by thermal diffusion and aggregation of carbon black, leading to an increasing and then decreasing positive temperature coefficient (PTC) effect. [ABSTRACT FROM AUTHOR]