Freestanding Fe3O4 / Ti3C2Tx MXene / polyurethane composite film with efficient electromagnetic shielding and ultra-stretchable performance

Electromagnetic pollution seriously affects the human reproductive system, cardiovascular system, people’s visual system, and so on. A novel versatile stretchable and biocompatible electromagnetic interference (EMI) shielding film has been developed, which could effectively attenuate electromagnetic radiation. The EMI shielding film was fabricated with a convenient solution casting and steam annealing with 2D MXene, iron oxide nanoparticles, and soluble polyurethane. The EMI shielding effectiveness is about 30.63 dB at 8.2 GHz, based on its discretized interfacial scattering and high energy conversion efficiency. Meanwhile, the excellent tensile elongation is 30.5%, because of the sliding migration and gradient structure of the nanomaterials doped in a polymer matrix. In addition, the film also demonstrated wonderful biocompatibility and did not cause erythema and discomfort even after being attached to the arm skin over 12 hours, which shows the great potential for attenuation of electromagnetic irradiation and protection of human health.

Theoretical Investigations Of Interfacial Scattering Effects On Thermoelectric Properties Of Bulk Nanostructured PbTe System

ABSTRACTEnhancement of thermoelectric properties at room temperature has been recently demonstrated by spark plasma sintered PbTe nanocubes as compared to other PbTe nanostructures as well as Bulk material. The Seebeck coefficient has been reported to be 400 µV/K which is much higher than the bulk. Moreover, a moderate electrical conductivity ∼ 8000 S/m at room temperature results in considerable higher value of power factor S2σ ∼ 1.28 x 10-3 Wm-1K-2. The enhanced thermoelectric properties have been conjectured to be present due to energy filtering effects at numerous interfaces introduced by nanostructuring. We study how the interfacial scattering affects the power factor by performing theoretical modelling based on Boltzmann Transport Equation (BTE). We also investigate in detail, the role of various electronic parameters such as size, shape, mobility and effective mass etc., on interfacial scattering to optimize its effect on power factor.

Synthesis and EMW absorbing properties of nano SiC modified PDC–SiOC

Nano SiC modified silicon oxycarbide (n-SiC/SiOC) ceramics had special microstructure and phase composition that can lead to electric dipole polarization and interfacial scattering which eventually resulted in the strong absorption capability of n-SiC/SiOC.