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Near-infrared (NIR) thermally activated delayed fluorescence (TADF) materials have shown great application potential in organic light-emitting diodes, photovoltaics, sensors, and biomedicine. However, their fluorescence efficiency (ΦF) is still highly inferior to those of conventional NIR fluorescent dyes, seriously hindering their applications. This study aims to provide theoretical guidance and experimental verification for highly efficient NIR-TADF molecular design. First, the light-emitting mechanism of two deep-red TADF molecules is revealed using first-principles calculation and the thermal vibration correlation function (TVCF) method. Then several acceptors are theoretically designed by changing the position of the cyano group or by introducing the phenanthroline into CNBPz, and 44 molecules are designed and studied theoretically. The photophysical properties of DA-3 in toluene and the amorphous state are simulated using a multiscale method combined with the TVCF method. The NIR-TADF property for DA-3 is predicted both in toluene and in the amorphous state. Experimental measurement further confirms that the TADF emission wavelength of DA-3 is 730 nm and ΦF is as high as 20%. It is the highest fluorescence efficiency reported for TADF molecules with emission wavelengths larger than 700 nm in toluene. Our work provides an effective molecular design strategy, and a good candidate for highly efficient NIR-TADF emitters is also predicted.

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For flexible strain sensors, the optimization between sensitivity and working range is a significant challenge due to the fact that high sensitivity and high working range are usually difficult to obtain at the same time. Herein, a breathable flexible strain sensor with a double-layered conductive network structure was designed and developed, which consists of a thermoplastic polyurethane (TPU)/carbon nanotube (CNT) layer (as a substrate layer) and a Ag nanowire (AgNW) layer. The TPU/CNT layer is made of electrospinning TPU with CNTs deposited onto the surface of TPU fibers, and the flexible TPU/CNT mat guarantees the integrity of the conductive path under a large strain. The AgNW layer was prepared by depositing different amounts of AgNWs on the surface of the TPU/CNT layer, and the high-conductivity AgNWs offer a low initial resistance. Benefitting from the synergistic two-layer structure, the as-obtained flexible strain sensor exhibits a very high sensitivity (up to 1477.7) and a very wide working range (up to 150%). Besides, the fabricated sensor exhibits fast response (88 ms), excellent dynamical stability (7000 cycles), and excellent breathability. The working mechanism of the strain sensor was further investigated using various techniques (microscopy, equivalent circuit, and thermal effects of current). Furthermore, the as-fabricated flexible strain sensors accurately detect the omnidirectional human motions, including subtle and large human motions. This work provides an efficient approach to achieve the optimization between high sensitivity and large working range of strain sensors, which may have great potential applications in health monitoring, body motion detection, and human–machine interactions.

Faced with the presence of radiation sources in many different areas, researchers are beginning to focus on the development of personal protective equipment. The design and manufacture of lightweight, lead‐free, and flexible X‐ray shielding materials have recently become a challenge in materials science, whereas, high‐Z materials, which are essential raw materials for high‐performance X‐ray protective fillers, are non‐renewable, and their exploitation and utilization usually require long‐term planning. In this study, a new route is demonstrated to the preparation of multifunctional polymer/high‐Z material nanofibrous membrane through electrospinning and subsequent solvothermal processes. The resultant Bi2WO6/WO3/polyacrylonitrile hybrid nanofibrous membrane possesses a remarkable X‐ray attenuating property with an attenuation rate of 90.10% at 30 keV and a mass attenuation coefficient of 2.97 cm2 g−1 at 83 keV. In addition, the freestanding hybrid nanofibrous membrane also possesses excellent photocatalytic activities for the degrading of cationic water pollutants, showing promising potential in industrial wastewater treatment, and providing a new strategy for the design and applications of multifunctional and recyclable shielding materials.

Through space charge transfer (TSCT) based thermally activated delayed fluorescence (TADF) molecules with sky-blue emission have drawn great attentions in recent studies. Corresponding theoretical investigations to reveal the inner mechanisms...

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Superhydrophobic electromagnetic interference (EMI) materials are becoming increasingly important to the longterm service of outdoor all-weather electrical equipment. It is an urgent need to prepare flexible and robust high-performance EMI shielding materials to work in harsh environments. To this end, we demonstrate a delicate structure design of superhydrophobic EMI shielding material that possesses desired properties via chemical deposition of silver nanocluster on electrospun polymer nanofibers followed by stearic acid (SA) modification. The porous electrospun hybrid membrane with a spatially distributed silver coating enabled excellent electrical conductivity up to 57 319 S cm −1 . Notably, superior EMI shielding effectiveness (SE) of 90.14 dB in an ultrabroadband frequency range is achieved in conjugation with the specific shielding effectiveness (SSE/t) of 14 253 dB cm 2 g −1 , owing to the combined effects of favorable porous structure and interfacial polarization. The thin coating of the SA layer endowed the film with superhydrophobicity (water contact angle up to 156.7°) and superior corrosion resistance with only 6.56% loss in EMI SE after 40 days incubation in the salt spray tank. The integrated functionalities being achieved in the hybrid membrane, such as high resistance to mechanical deformation (3.55% loss in EMI SE after 2000 times of bending), self-cleaning property, long-term (12 months) performance stability under high mechanical and chemical tolerance, offer great promise for outdoor all-weather electronic equipment under harsh environments.