Highly sensitive sensors with extensive applications are extremely desired in the next-generation wearable electronics for human motion monitoring, human-machine interface and intelligent robotics, while single-functional pressure sensors cannot fulfill the growing demands of modern technological advances. Herein, an all-fabric and multilayered piezoresistive sensor based on conductive metal-organic framework/layered double hydroxide (cMOF/LDH) hetero-nanoforest is demonstrated to achieve multiple applications including pulse detection, joint motion detection, sound detection and information transmission. Benefiting from the synergism of cMOF/LDH hetero-nanoforest and multilayered structure, the sensor exhibits a high sensitivity (1.61×10 9 kPa −1 ) over a broad pressure range (0-100 kPa), a fast response/recovery time (71 ms/71 ms) and a low detection limit (18 Pa), as well as reliable dynamic stability (8000 cycles). It is gratifying to note that the introduction of cMOFs endows the sensor with the potential to detect the concentration of NH 3 (1-100 ppm) and sunlight intensity (10-100 mW cm −2 ). This work shows great potential in multifunctional sensing, which enlightens a strategy for advancing the development process of highly sensitive intelligent wearable devices.
Metal–organic frameworks (MOFs) manifest enormous potential in promoting electromagnetic wave (EMW) absorption thanks to the tailored components, topological structure, and high porosity. Herein, rodlike conductive MOFs (cMOFs) composed of adjustable metal ions of Zn, Cu, Co, or Ni and ligands of hexahydroxytriphenylene (HHTP) are prepared to attain tunable dielectric properties for a tailored EMW absorption. Specifically, the influences of the cMOFs’ composition, charge transport characteristic, topological crystalline structure, and anisotropy microstructure on dielectric and EMW absorption performance are ascertained, advancing the understanding of EMW attenuation mechanisms of MOFs. The boosted conductive and polarization losses derived from the conjugation effects and terminal groups, as well as shape anisotropy, lead to a prominent EMW absorption of the cMOFs. The Cu-HHTP confers a minimum reflection loss (RLmin) of −63.55 dB at the thickness of 2.9 mm and a maximum effective absorption bandwidth of 5.2 GHz. Moreover, Zn-HHTP showcases the absorption superiority in the S-band (2–4 GHz) with an RLmin of −62.8 dB at a thickness of 1.9 mm. This work not only hoists the mechanistic understanding of the structure–function relationships for the cMOFs but also offers guidelines for preparing functional MOF materials.
Wang Shuli,Lu Jihan,Yang Yuanyuan,Yao Jing,Li Zhuo
Effectively separating wide types oil-water mixtures from immiscible to emulsions and in-situ recovering viscous crude oil is an urgent issue in alleviating water pollution and recycling oils. We developed a composite sponge of Cu-HHTP/Fe/PDMS@sponge with superhydrophobicity, excellent photothermal conversion ability and stability for multi-type oils separation from water environments. For light oil-water mixtures, the sponge showed super separation efficiency up to 99.95 % and reusability in the long-term; for oil-in-water emulsion, the separation efficiency was as high as 99.49 %; for recovery of viscous crude oil from water, the absorption capacity of the sponge reached 70 g/g and the continuous absorption rate was up to 6.56 g/min. After soaked in harsh chemical solutions and 500-cycle compression, the sponge still exhibited excellent flexibility and recoverability in viscous oil. The excellent performances of the multifunctional sponge were due to the construction of micro/nano-scale hierarchical structures by PDA and Cu-HHTP, protected with PDMS coating to improve both the hydrophobicity and stability. The introduction of Fe 3 O 4 with Cu-HHTP strengthened the photothermal conversion efficiency with the sponge surface temperature rapidly increased from room temperature to 102.4 °C under simulated sunlight exposure (1 kW/m 2 ), and resulted in the sponge can be remote-controlled magnetically. This simultaneous, fast and continuous oil-water separation and adsorption processes can be readily and widely applied for oily water purification and oil-spill cleanup.
危险品化学品经营许可证（带存储）