Transient Pyrolysis of PSZ Precursors to Prepare SiCN with Effective Microwave Absorption Properties in High Temperatures Using RF Thermal Plasma

ACS Applied Engineering Materials, Год журнала: 2025, Номер unknown

Опубликована: Апрель 17, 2025

Язык: Английский

Microwave absorption ceramics pyrolyzed from poly(dimethylsilylene)diacetylene‐modified hyperbranched polyborosilazane

Journal of the American Ceramic Society, Год журнала: 2025, Номер unknown

Опубликована: Апрель 27, 2025

Abstract Polymer‐derived ceramics (PDCs) are typically prepared as ceramic‐based microwave absorption materials by doping with high‐dielectric or transition metals, which may lead to the issue of uneven mixing. This study achieves uniform blending at molecular level using poly(dimethylsilylene)diacetylenes (PDSDA) modify hyperbranched polyborosilazane (PBSZ). The alkynyl group and Si−H bonds crosslink form a ceramic precursor, is then pyrolyzed prepare SiBCN excellent performance high temperature stability. introduction PDSDA significantly improved yield, resulting in situ formation more ordered carbon, SiC nanocrystals, nanowires within ceramics. These nanophases uniformly dispersed throughout matrix, enhancing ceramic's dielectric loss properties. After 1400°C, derived from precursor PBSZ:PDSDA mass ratio 10:1 exhibits electromagnetic wave properties, minimum reflection −50.11 dB maximum effective bandwidth 3.11 GHz. Moreover, maintain stability 1500°C both argon air environments. fully exploits designability molecules, providing new approach for preparation PDCs route.

Язык: Английский

Highly Thermally Conductive Flexible Films with Excellent Energy Harvesting and Electromagnetic Shielding Properties

Small, Год журнала: 2025, Номер unknown

Опубликована: Май 22, 2025

Abstract The continuous advancement and miniaturization of modern electronics have increased challenges related to electromagnetic interference (EMI) thermal management. Polymer materials are commonly used for regulation EMI shielding because their low weight, cost‐effectiveness, ease processing. However, achieving both high effectiveness (SE) superior conductivity (TC) in polymeric systems remains a major scientific challenge. In this study, lightweight flexible amino‐functionalized multiwalled carbon nanotube‐graphene nanoplatelet/poly(p‐phenylene benzodioxazole)/poly(ether‐ether‐ketone) composite film (NH 2 ‐MWCNTs&GnPs@PBO/PEEK, NH ‐MGPP) is fabricated using vacuum‐assisted filtration. As result, the ‐MGPP (0.05 mm thick) exhibited exceptional performance (71.47 dB) in‐plane (36.78 W m −1 K ). also demonstrated rapid Joule heating kinetics an efficient photothermal response, enabling effective management energy harvesting capabilities. When integrated into solar‐thermoelectric generator, produced output voltage 1004.9 mV under 5 kW −2 simulated sunlight irradiation, confirming its photo‐thermal‐electrical conversion efficiency. This study presents innovative approach designing developing films with excellent properties heat dissipation Additionally, it introduces new method utilization renewable energy.

Язык: Английский