Enhanced electromagnetic wave absorption properties of Ni magnetic coating-functionalized SiC/C nanofibers synthesized by electrospinning and magnetron sputtering technology

Self-Standing MOF-Derived Co@SiCnw Nanocomposite Aerogel with a Hierarchical Microstructure for Highly Effective and Wideband Electromagnetic Attenuation

To meet the requirements of lightweight and wideband attenuation for advanced electromagnetic (EM) absorption materials, the combination of both MOF composition and hierarchical structural design was applied as the strategy to prepare the MOF-derived Co@SiC nanowire (Co@SiCnw) nanocomposite aerogel. The hierarchical and laminated structures with multiple Co@SiCnw layers were constructed via a mixed growth-assisted freeze-drying and calcination process. The ultralightweight Co@SiCnw presents a low density of 0.11 g/cm3. With abundant second-phase polarization interfaces and enlarged EM wave attenuation channels to enhance dielectric and conductive loss, the optimized Co@SiCnw offers a minimal reflection loss (RLmin) of -61.4 dB at 10.0 GHz (2.64 mm) and an effective absorption bandwidth (EAB) as wide as 7.44 GHz with a sample thickness of only 2.16 mm. Furthermore, multifunctionalities, including low density, thermal insulation, and self-standing, were demonstrated for Co@SiCnw, making it a high-performance and practical microwave absorption material.

Review of Progress in Marine Anti-Fouling Coatings: Manufacturing Techniques and Copper- and Silver-Doped Antifouling Coatings

Marine biofouling presents numerous challenges, including increased drag, reduced efficiency, and ecological imbalance. This review presents an overview of recent advances in antifouling coatings. First, essential preparation techniques such as cold spray, plasma spray, magnetron sputtering, and laser cladding are introduced, including the specific characteristics of each method. Next, the antifouling performance of Cu-doped and Ag-doped coating is analyzed. Emphasis is placed on the differences in coating composition, preparation methods, and their effects on antifouling and anticorrosion properties. The future development of antifouling technologies is also discussed, emphasizing the creation of multifunctional coatings, the optimization of coating microstructures for better performance, and the advancement of sustainable materials to minimize environmental impact.

State-of-the-art in carbides/carbon composites for electromagnetic wave absorption

Electromagnetic wave absorbing materials (EWAMs) have made great progress in the past decades, and are playing an increasingly important role in radiation prevention and antiradar detection due to their essential attenuation toward incident EM wave. With the flourish of nanotechnology, the design of high-performance EWAMs is not just dependent on the intrinsic characteristics of single-component medium, but pays more attention to the synergistic effects from different components to generate rich loss mechanisms. Among various candidates, carbides and carbon materials are usually labeled with the features of chemical stability, low density, tunable dielectric property, and diversified morphology/microstructure, and thus the combination of carbides and carbon materials will be a promising way to acquire new EWAMs with good practical application prospects. In this review, we introduce EM loss mechanisms related to dielectric composites, and then highlight the state-of-the-art progress in carbides/carbon composites as high-performance EWAMs, including silicon carbide/carbon, MXene/carbon, molybdenum carbide/carbon, as well as some uncommon carbides/carbon composites and multicomponent composites. The critical information regarding composition optimization, structural engineering, performance reinforcement, and structure-function relationship are discussed in detail. In addition, some challenges and perspectives for the development of carbides/carbon composites are also proposed after comparing the performance of some representative composites.

Long-Range Uniform SiCxOy Beaded Carbon Fibers for Efficient Microwave Absorption

SiC_xO_y beaded carbon fibers were successfully fabricated for the first time using a facile and stable electrospinning and temperature process. The resulting fibers showcase a unique micro-nanocomposite structure, in which β-SiC beads with a silica-enriched surface are strung together with defect carbon fibers, as confirmed by XRD, XPS, and HRTEM investigation. The SiC_xO_y beaded carbon fibers display efficient microwave absorption performance, with a minimum reflection loss of -58.53 dB and an effective absorption bandwidth of 5.92 GHz. A modified Drude-Lorentz model was developed for SiC_xO_y beaded carbon fibers to reveal the double-peaked feature of the permittivity of these fibers, which is in good agreement with experimental measurements. Moreover, simulations were performed to extract polarized electric fields and microwave energy volume losses within a typical distribution of SiC_xO_y beaded carbon fibers. It is concluded that the dipole relaxation and hopping migration of localized electrons give a superior contribution to the overall decay of the microwave energy. This study indicates that SiC_xO_y beaded carbon fibers with a unique micro-nanocomposite structure hold great promise for microwave absorption applications. Additionally, this fabrication strategy offers a unique approach to producing micro-nanocomposite structures and highlights their potential applications.

Electrospun Nanofiber Composites for Drug Delivery: A Review on Current Progresses

A medication's approximate release profile should be sustained in order to generate the desired therapeutic effect. The drug's release site, duration, and rate must all be adjusted to the drug's therapeutic aim. However, when designing drug delivery systems, this may be a considerable hurdle. Electrospinning is a promising method of creating a nanofibrous membrane since it enables drugs to be placed in the nanofiber composite and released over time. Nanofiber composites designed through electrospinning for drug release purposes are commonly constructed of simple structures. This nanofiber composite produces matrices with nanoscale fiber structure, large surface area to volume ratio, and a high porosity with small pore size. The nanofiber composite's large surface area to volume ratio can aid with cell binding and multiplication, drug loading, and mass transfer processes. The nanofiber composite acts as a container for drugs that can be customized to a wide range of drug release kinetics. Drugs may be electrospun after being dissolved or dispersed in the polymer solution, or they can be physically or chemically bound to the nanofiber surface. The composition and internal structure of the nanofibers are crucial for medicine release patterns.

Electromagnetic Interference Shielding with Electrospun Nanofiber Mats—A Review of Production, Physical Properties and Performance

With a steadily increasing number of machines and devices producing electromagnetic radiation, especially, sensitive instruments as well as humans need to be shielded from electromagnetic interference (EMI). Since ideal shielding materials should be lightweight, flexible, drapable, thin and inexpensive, textile fabrics belong to the often-investigated candidates to meet these expectations. Especially, electrospun nanofiber mats are of significant interest since they can not only be produced relatively easily and cost efficiently, but they also enable the embedding of functional nanoparticles in addition to thermal or chemical post-treatments to reach the desired physical properties. This paper gives an overview of recent advances in nanofiber mats for EMI shielding, discussing their production, physical properties and typical characterization techniques.