Polymer electrolytes have been studied extensively because uniquely they combine ionic conductivity with solid yet flexible mechanical properties, rendering them important for all-solid-state devices including batteries, electrochromic displays and smart windows. For some 30 years, ionic conductivity in polymers was considered to occur only in the amorphous state above Tg. Crystalline polymers were believed to be insulators. This changed with the discovery of Li(+) conductivity in crystalline poly(ethylene oxide)(6):LiAsF(6). However, new crystalline polymer electrolytes have proved elusive, questioning whether the 6:1 complex has particular structural features making it a unique exception to the rule that only amorphous polymers conduct. Here, we demonstrate that ionic conductivity in crystalline polymers is not unique to the 6:1 complex by reporting several new crystalline polymer electrolytes containing different alkali metal salts (Na(+), K(+) and Rb(+)), including the best conductor poly(ethylene oxide)(8):NaAsF(6) discovered so far, with a conductivity 1.5 orders of magnitude higher than poly(ethylene oxide)(6):LiAsF(6). These are the first crystalline polymer electrolytes with a different composition and structures to that of the 6:1 Li(+) complex.

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Three-dimensional (3D) printing has received extensive attention due to its unique multidimensional functionality and customizability and has been recognized as one of the most revolutionary manufacturing technologies. Functional 3D printed products represent an important orientation for next-generation manufacturing and attract a great spotlight for the application in sensors, actuators, robots, electronics, and medical devices. However, the lack of functions of printing polymeric materials dramatically limits the development of functional 3D printing. Different from traditional processing, the physical properties, such as geometry and rheological behavior, of the polymeric materials must match the printing process, making the selection of printable materials limited. More importantly, challenges in large-scale production of such materials further stifle the development of functional 3D printing industry. In this review, we aim to outline recent advances in polymeric materials and methodologies for the functional 3D printing technology. The reports are classified based on functionalities, including electronic conductive, thermally conductive, electromagnetic interference shielding, energy storage, and energy harvesting materials. This study attempts to provide a comprehensive overview of the challenges and opportunities for 3D printing functional polymeric materials/devices, also seeks to enlighten the orientation of future research in this field.

Hypoxia-inducible factor (HIF) is a main heterodimeric transcription factor that regulates the cellular adaptive response to hypoxia by stimulating the transcription of a series of hypoxia-inducible genes. HIF is frequently upregulated in solid tumors, and the overexpression of HIF can promote tumor progression or aggressiveness by blood vessel architecture and altering cellular metabolism. In this review, we focused on the pivotal role of HIF in tumor angiogenesis and energy metabolism. Furthermore, we also emphasized the possibility of HIF pathway as a potential therapeutic target in cancer.

The growing demand for safe and renewable energy storage systems has driven the recent renaissance of Zn‐ion batteries (ZIBs). Nevertheless, the intrinsic drawbacks of inhomogeneous electric distribution and sluggish ion replenishment worsen the Zn dendrite issues that seriously impede their practical application. Herein, for the first time, a functional 3D printed reservoir‐integrated N‐doped carbon host (3DP‐NC) is designed to remodel the electric/ionic fields. The customized 3D printed structure equipped with regular micron‐sized holes induces reduced local current density and homogeneous electric distribution. The micron‐sized holes function as reservoirs to ensure unobstructed ion diffusion and quasi‐steady‐state ionic supplements. A N‐doping interfacial modification strategy is further employed to encourage a highly zincophilic surface, hence reducing the nucleation energy barrier and motivating uniform Zn nucleation. As a result, the Zn‐deposited 3DP‐NC electrode (3DP‐NC@Zn) affords dendrite‐free morphology and highly reversible Zn plating/stripping with an ultra‐small overpotential of 15.3 mV even at 10 mA cm−2. Additionally, these appealing features also endow the 3DP‐NC@Zn electrode with an outstanding lifespan over 380 h at 1 mA cm−2 and 1 mAh cm−2. The thrilling performance establishes a new roadmap that advances the development of dendrite‐free and durable metal batteries by exploiting this unique 3D printing technique.

printing technologies have unparalleled advantages in constructing piezoelectric devices with three-dimensional structures, which are conducive to improving the efficiency of energy harvesting. Among them, fused deposition modeling (FDM) is the most widely used thanks to its low cost and wide range of molding materials. However, as the best piezoelectric polymer, a high electroactive β-phase poly(vinylidene fluoride) (PVDF) piezoelectric device cannot be directly obtained by FDM printing because the β-crystal is unstable at the molten state. Herein, we develop for the first time ionic liquid (IL)-assisted FDM for direct printing of β-PVDF piezoelectric devices. An IL can induce and maintain β crystals during melt extrusion and FDM printing, ensuring that the β-crystal in the printed PVDF device is as high as 98.3%, which is the highest in 3D-printed PVDF as far as we know. Furthermore, the shearing force provided by the FDM facilitates the directional arrangement of the dipoles, resulting in the printed PVDF device having selfpolarization characteristics without poling. Finally, the piezoelectric output voltage of the 3D-printed PVDF device is 4.7 times that of the flat PVDF device, and its area current density (17.5 nA cm −2 ) is more than that of the reported 3D-printed PVDF piezoelectric device in the literature by two orders of magnitude. The one-step 3D printing strategy proposed in this paper can realize the rapid preparation of complex-shaped and lightweight self-polarized β-PVDF-based piezoelectric devices for energy harvesting.

The local dynamics of poly(dimethylsiloxane) (PDMS) has been investigated by quasi-elastic neutron scattering (QENS). Methyl group reorientations dominate the QENS spectra up to 215 K (i.e., below the melting temperature, T m ≈ 235 K). The dynamics of the CH3 groups is interpreted in terms of a model function consisting of elastic and quasi-elastic components, the latter given by a Gaussian distribution of Lorentzian lines. Above T m, the QENS spectra are analyzed considering two processes: (a) the methyl group rotation and (b) the segmental motion. The activation energy for the latter is 14.6 kJ/mol, in excellent agreement with rheological data. Moreover, in agreement with the latter, the intermediate scattering function, I(Q,t), computed via the inverse Fourier transform, follows timetemperature superposition according to the rheological shift factor. The contribution of the segmental motion to the scattering function I(Q,t) was fitted with a stretched exponential function (or its Fourier transform in the frequency domain). The fitted stretching exponent β for segmental motion is 0.61 in both frequency and time domain, much higher than 0.5 (Rouse model), but in agreement with theoretical results realistically accounting for the chain stiffness. QENS studies of segmental motion in PDMS had indicated that the experimental data followed the Rouse model up to a very large Q, well beyond the validity range of the model. We suggest that the rotational motion of the methyl groups is responsible for this observation.

Metallic‐phase selenide molybdenum (1T‐MoSe2) has become a rising star for sodium storage in comparison with its semiconductor phase (2H‐MoSe2) owing to the intrinsic metallic electronic conductivity and unimpeded Na+ diffusion structure. However, the thermodynamically unstable nature of 1T phase renders it an unprecedented challenge to realize its phase control and stabilization. Herein, a plasma‐assisted P‐doping‐triggered phase‐transition engineering is proposed to synthesize stabilized P‐doped 1T phase MoSe2 nanoflower composites (P‐1T‐MoSe2 NFs). Mechanism analysis reveals significantly decreased phase‐transition energy barriers of the plasma‐induced Se‐vacancy‐rich MoSe2 from 2H to 1T owing to its low crystallinity and reduced structure stability. The vacancy‐rich structure promotes highly concentrated P doping, which manipulates the electronic structure of the MoSe2 and urges its phase transition, acquiring a high transition efficiency of 91% accompanied with ultrahigh phase stability. As a result, the P‐1T‐MoSe2 NFs deliver an exceptional high reversible capacity of 510.8 mAh g−1 at 50 mA g−1 with no capacity fading over 1000 cycles at 5000 mA g−1 for sodium storage. The underlying mechanism of this phase‐transition engineering verified by profound analysis provides informative guide for designing advanced materials for next‐generation energy‐storage systems.