New construction strategies of carbon‐based composites for flexible electromagnetic interference shielding films

The repair and regeneration of cartilage is a challenge for scientists and clinical surgery. Achieving cell adhesion and regeneration, anti‐inflammatory, lubrication, targeted drug delivery and controlled release simultaneously in cartilage treatment are the goals of researchers. Polymer composites and hybrids have the potential to realize above functions in cartilage tissue engineering. This review refers to cartilage injuries, current clinical techniques, and their benefits and limitations, focusing on the most relevant and state of art of advanced polymers for cartilage tissue engineering. The frontier applications of multifunctional polymer composites and hybrids in cartilage tissue engineering are discussed in depth, including polymer scaffold, polymer bio‐lubricant, and zwitterionic polymer for drug delivery and sustained drug release. A summary of comprehensive properties of polymers such as processability, mechanical properties, biocompatibility, biodegradability, hydrophilicity, cytotoxicity, etc., and their mechanisms are analyzed. Furthermore, some key challenges and outstanding concerns on polymer‐based materials for cartilage tissue engineering are presented followed by future perspectives.Highlights The state of art of advanced polymers for cartilage tissue engineering. The advanced bionic property and mechanism of polymer composites and hybrids. Polymers for scaffold, biolubricant, drug delivery, sustained drug release. Future perspectives on polymer composites, hybrids‐based cartilage materials.

Advanced polymer composites and polymer hybrids for cartilage tissue engineering

Liu,

Hu,

et al. 2024

Preparation and properties of three‐dimensional hexagonal honeycomb woven composites with superior electromagnetic wave absorbing and load bearing performances

Yao,

Guo,

Zhou

et al. 2024

With the advent of the 5G era, electromagnetic pollution has been increasingly serious. Structural electromagnetic wave (EW) absorbing composites play a key role in both civil and military applications. However, the laminated plate structure and laminated honeycomb structure EW‐absorbing composites were prone to delamination and low EW absorbing performance. To enhance the EW absorption and mechanical properties of composite materials, this study successfully developed a novel three‐dimensional hexagonal honeycomb woven composites (3D‐HHWC). 3D‐HHWC with a three‐dimensional hexagonal honeycomb woven fabric (3D‐HHWF) as the reinforced materials was manufactured by the vacuum‐assisted resin transfer molding (VARTM) process with epoxy resin, carbon black (CB), multi‐walled carbon nanotubes (MWCNTs), and carbonyl iron powder (CIP) as functional materials. The EW absorption performance and bending mechanical properties of 3D‐HHWC with different structural parameters were compared and analyzed. The test results demonstrated that the 3D‐HHWC (H2‐3) achieved a remarkable minimum reflection loss of −38.1 dB with the effective electromagnetic absorption band (EAB) 13.8 GHz. Additionally, CST provided a clear explanation of the electromagnetic field distribution elucidating the mechanism for EW absorption. While the 3D‐HHWC (H2‐3) had a maximum bending load 6603.9 N without obvious delamination phenomenon. Furthermore, finite element simulation clarified internal stress distribution explaining the failure mechanisms. In conclusion, the 3D‐HHWC exhibited outstanding EW absorption and mechanical properties for widespread application in military and aerospace fields.Highlights The 3D‐HHWC was formed by VARTM process with epoxy resin, CB, MWCNTs, and CIP. The 3D‐HHWC had excellent EM performance with RLmin −38.1 dB and EAB 13.8 GHz. CST provided a clear explanation of the electromagnetic field distribution. The 3D‐HHWC had a maximum bending load 6603.9 N without obvious delamination. FEM clarified internal stress distribution to explain the failure mechanisms.

Fe₃O₄‐doped highly electromagnetically shielded PAN‐PVP composite porous carbon films

Yang,

Liao,

et al. 2024

With the wide application of modern electronic devices, the problem of electromagnetic pollution is becoming more and more serious, and the demand for efficient electromagnetic shielding materials is becoming more and more urgent. To address this problem, we homogeneously mixed polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP), and triiron tetraoxide (Fe3O4) nanoparticles by solution blending, and prepared composite precursor membranes by taking advantage of the magnetic properties and good electromagnetic loss characteristics of Fe3O4, as well as the high thermal stability and film‐forming properties of PAN and PVP. Subsequently, carbonized PAN‐PVP/ Fe3O4 composite films with different Fe3O4 contents were successfully prepared by carbonization under high temperature inert atmosphere to convert PAN and PVP into carbon materials. It was found that the PAN‐PVP/ Fe3O4 porous carbon film with 3 wt% Fe3O4 addition had a conductivity of 3.99 S·mm−1 at a thickness of 0.42 mm, and an average EMI SET of 78.9 dB, SEA of 64.8 dB, and SSEt of 1838 dB/(cm2·g−1) in the X‐band, which is a typical wave absorbing material and can meet commercial electromagnetic shielding requirements. This work provides new ideas and methods for the research and development of polymer‐based porous carbonized film as electromagnetic shielding materials.Highlights The carbon films with rich porous structure were prepared. Fe3O4 was successfully embedded into the carbon film. Carbon films have an efficient conducting network. Carbon film has excellent electromagnetic shielding performance. The main shielding mode of carbon film is absorption.