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One-dimensional (1D) elastic conductors are an important component for constructing a wide range of soft electronic devices due to their small footprint, light weight, and integration ability. Here, we report the fabrication of an elastic conductive wire by employing a liquid metal (LM) and a porous thermoplastic elastomer (TPE) as building blocks. Such an LM-TPE composite wire was prepared by electrospinning of TPE microfibers and coating of a liquid metal. An additional layer of electrospun TPE microfibers was deposited on the wire for encapsulation. The porous structure of the TPE substrate that is composed of electrospun fibers can substantially improve the stretchability and electrical stability of the composite LM-TPE wire. Compared with the wire using a nonporous TPE as a substrate, the break strain of the LM-TPE wire was increased by 67% (up to ∼2300% strain). Meanwhile, the resistance increase of the wire during 1900% strain of stretching could be controlled as low as 12 times, which is much more stable than that of other LM-based 1D elastic conductors. We demonstrate that a light-emitting diode and an audio playing setup, which use the LM-TPE wire as an electrical circuit, can work with low-intensity attenuation or waveform deformation during large-strain (1000%) stretching. For a proof-of-concept application, an elastic inductance coil was made using the LM-TPE wire as building blocks, and its potential applications in strain sensing and magnetic field detection were demonstrated.

We report a facile solvothermal synthesis of novel octahedral CoFe2O4–reduced graphene oxide (RGO) hybrid and pure CoFe2O4 that were used as heterogeneous photo-Fenton catalysts for the degradation of organic dyes in water. We investigated the structures, morphologies and catalytic activity of both the CoFe2O4 nanoparticles and CoFe2O4–RGO hybrids. The morphology of CoFe2O4 nanoparticles displays size-dependent shapes changing from granular (or sheet) to octahedral shapes with the introduction of RGO. Compared with bare CoFe2O4, the octahedral CoFe2O4–RGO hybrids serve as novel bifunctional materials displaying higher saturation magnetization values and excellent heterogeneous activation of H2O2 at nearly neutral pH. The high saturation magnetization (41.98 emu g−1) of CoFe2O4–RGO hybrids aids their separation from the reaction mixture. In addition, the remarkable enhancement in the photo-Fenton activity of the CoFe2O4–RGO hybrids under visible light irradiation was attributed to the graphene/CoFe2O4 heterojunction, which aided the separation of excited electrons and holes. Furthermore, the CoFe2O4–RGO hybrids exhibited better removal efficiency for cationic methylene blue (MB) dye than for anionic methyl orange (MO) dye. Meanwhile, the CoFe2O4–RGO hybrids displayed acceptable photocatalytic stability, and we proposed an activation mechanism of H2O2 by the octahedral CoFe2O4–RGO hybrids.

Bi-Doped nitridated germanate glasses covering the whole NIR region from 800–1600 nm have attracted considerable attention due to their potential application in tunable fiber lasers and optical amplifiers. However, it remains challenging to regulate the luminescence behaviour of Bi because of the coexistence of multi-centers in the glasses. Here, we successfully regulated multi Bi NIR centers to obtain a flatter and ultra-broadband emission in nitridated germanate glasses. By varying the alkaline earth metal fluorides from MgF2 to BaF2, the glass structures were gradually depolymerized. A looser glass network, on one hand, promoted Bi in lower valences to be oxidized into Bi2+ and Bi3+, thus reducing the NIR emission intensity at ∼1150 and ∼1260 nm; on the other hand, it also enhanced the energy transfer from Bi+ to Bi0, which resulted in a relatively flatter emission band. In addition, the depolymerised glass structure could facilitate more nitride bonds, which are favorable for dispersing and stabilizing the new Bi NIR active centers related to germanate for ∼930 and ∼1490 nm emission. This investigation offers an efficient way to manipulate the multi-center luminescence behaviour of Bi in nitridated germanate glasses, and is beneficial to understand the mechanism of Bi NIR emission centers in glasses.

Elastic fiber conductors are advantageous for applications in wearable electronics due to their small size, light weight, and excellent integration ability. Here, we report the fabrication of elastic fiber conductors with a three-dimensional (3D) porous structure using electrospun thermoplastic elastomer (TPE) microfibers and silver nanoparticles (AgNPs) as the building blocks. With the 3D porous structure, such a fiber is highly permeable to gases and liquids. As such, the performance of the fiber in many applications of wearable electronics (especially wearable sensors and detectors) can be improved significantly. Benefitting from the excellent processability of TPE and dispersibility of AgNPs, the fiber is highly compatible with thermal and solvent welding. In addition, the fiber also possesses super stretchability, high conductivity, and robust endurance to deformation. As a proof-of-concept application, we demonstrate that a rope-shaped capacitor made by plying one pair of such fibers can detect the volume change of artificial sweat with 17-times higher sensitivity than the capacitor using nonporous fibers as electrodes. We further demonstrate that, by integrating two groups of perpendicularly arranged fibers into a monolithic porous mat, sensitive matrix-addressed monitoring of artificial sweat can be realized.

Paper plays an important role in various aspects of human life. However, most of the paper materials are vulnerable to both flame and water, which seriously restrict their performance in many applications. Here, we report a new kind of flame-retardant paper with high-temperature-resistant hydrophobicity. This kind of paper was fabricated by vacuum filtration of electrospun fluorinated SiO2 fibers and methyl silicon resin. It is mechanically flexible. Its Young’s modulus is 94 MPa, similar to normal printing paper. The optimized paper demonstrated a water contact angle (WCA) of 151°, which can be maintained as high as 126° even after 30 min of annealing at the temperature of 600 °C. Finally, writing with inorganic ink can be performed on this paper with inhibited ink diffusion. The written paper can maintain its integrity after 5 min of firing by alcohol flame. The flame-retardant and hydrophobic paper here may extend the applications of paper in wide range of fields.

Sol-gel derived noble-metal-silica nanocomposites are very useful in many applications. Due to relatively low price, higher conductivity, and higher chemical stability of silver (Ag) compared with copper (Cu), Ag-silica has gained much more research interest. However, it remains a significant challenge to realize high loading of Ag content in sol-gel Ag-silica composite with high structural controllability and nanoparticles’ dispersity. Different from previous works by using multifunctional silicon alkoxide to anchor metal ions, here we report the synthesis of Ag-silica nanocomposite with high loading of Ag nanoparticles by employing acetonitrile bi-functionally as solvent and metal ions stabilizer. The electrical conductivity of the Ag-silica nanocomposite reached higher than 6800 S/cm. In addition, the Ag-silica nanocomposite could simultaneously possess high electrical conductivity and positive conductivity-temperature coefficient by properly controlling the loading content of Ag. Such behavior is potentially advantageous for high-temperature devices (like phosphoric acid fuel cells) and inhibiting the thermal-induced increase of devices’ internal resistance. The strategy proposed here is also compatible with block-copolymer directed self-assembly of mesoporous material, spin-coating of film and electrospinning of nanofiber, making it more charming in various practical applications.