Implications from Broadband Microwave Absorption of Metal-Modified SiC Fiber Mats.

Understanding the physical requirements for a broad bandwidth is vital for the design of high-efficiency microwave absorber. Our recent works on silicon carbide (SiC) fiber mats-based absorbers imply that metal modification (e.g.

Flexible FeSi/SiC ultrathin hybrid fiber mats with designable microwave absorption performance.

Flexible FeSi/SiC ultrathin fiber mats have been fabricated by electrospinning and high temperature treatment (1400 °C) using polycarbosilane (PCS) and ferric acetylacetonate (Fe(acac)) as precursors. The crystallization degree, flexibility, electrical conductivity, dielectric loss and microwave absorption properties of the hybrid fibers have been dramatically enhanced by the introduction of Fe. FeSi nanoparticles with a diameter around 500 nm are embedded in SiC fibers.

Enhanced Flexibility and Microwave Absorption Properties of HfC/SiC Nanofiber Mats.

Hafnium carbide (HfC) phase, with a high melting point, excellent strength, and high electrical conductivity, could be a suitable addition to enhance the microwave absorption properties of one-dimensional silicon carbide (SiC) nanomaterials without sacrificing its high-temperature thermal stability. In the present work, HfC/SiC hybrid nanofiber mats with different HfC loading contents are fabricated by electrospinning and high-temperature pyrolysis. HfC hybrids with sizes of 5-10 nm are embedded in the SiC nanofibers.

Self-Powered Microfluidic Transport System Based on Triboelectric Nanogenerator and Electrowetting Technique.

Electrowetting technique is an actuation method for manipulating position and velocity of fluids in the microchannels. By combining electrowetting technique and a freestanding mode triboelectric nanogenerator (TENG), we have designed a self-powered microfluidic transport system. In this system, a mini vehicle is fabricated by using four droplets to carry a pallet (6 mm × 8 mm), and it can transport some tiny object on the track electrodes under the drive of TENG.

SiC Nanofiber Mat: A Broad-Band Microwave Absorber, and the Alignment Effect.

Fiber alignment is a key factor that determines the physical properties of nanofiber mats. In this work, SiC nanofiber mats with or without fiber alignment are fabricated via electrospinning and the microwave electromagnetic properties of their silicone resin composites (5 wt %) are investigated in 2-18 GHz. By comparing with the composite containing SiC whisker, it is found that the nanofiber mats show superior dielectric loss and a minimal reflection loss (RL) of around -49 dB at 8.

Electrospinning of Fe/SiC Hybrid Fibers for Highly Efficient Microwave Absorption.

Fe/SiC hybrid fibers have been fabricated by electrospinning and subsequent high-temperature (1300 °C) pyrolysis in Ar atmosphere using polycarbosilane (PCS) and FeO precursors. It is found that the introduction of Fe has had a dramatic impact on the morphology, crystallization temperature, and microwave electromagnetic properties of the hybrid fibers. In addition, the Fe particles have acted as catalyst sites to facilitate the growth of SiCO nanowires on the surface of the hybrid fibers.