珍珠-链结构型PCN/SiO2复合纳米纤维的构筑及高效电磁波吸收性能研究

Construction of Pearl-Chain Structured PCN/SiO2 Composite Nanofibers and Study of Their Efficient Electromagnetic Wave Absorption Performance

摘要:

PAN基纳米纤维作为一维纳米碳材料，具有高长径比、优异介电性能和低密度等特性，在电磁波（EMW）吸收领域备受关注。然而，PAN纳米纤维的高导电性和单一组分，导致其阻抗不匹配和电磁波衰减能力差，从而限制了其应用。为解决这一问题，通过引入零维的SiO₂纳米球，构建一种独特的一维PCN/SiO₂珍珠-链结构复合纳米纤维。均匀的零维SiO₂纳米球通过静电纺丝锚定在直径均匀的PCN纳米纤维中，形成周期性电磁损耗单元，增加了异质界面的数量，导致极化弛豫作用增强。由于透波材料SiO₂的低介电常数特性，复合材料的阻抗匹配性能得到显著改善。此外，电磁波在PCN/SiO₂复合纳米纤维上的多次反射和散射进一步增加了电磁波能量的损耗。通过调控SiO₂纳米球的含量可调节PCN/SiO₂复合纳米纤维的介电损耗特性，可促进其在低、中、高频段下都发挥出高效的吸波特性。实验结果表明，PCN/SiO₂复合纳米纤维在7.2 GHz频率下，实现了-56.14 dB的反射损耗（R_L），并在2.3 mm的匹配厚度下EAB值达到5.52 GHz，证明该复合纳米纤维具有良好的电磁波吸收性能和相对较宽的有效吸收带宽。PCN/SiO₂复合纳米纤维表现出柔韧、轻质和自支撑特性，是一种潜在的多功能EMW吸收材料。（专精特新·电磁波吸收与屏蔽用新型材料的研究进展专辑十二之九）

Abstract:

PAN-based nanofibers， as one-dimensional carbon materials， have attracted widespread attention in the field of electromagnetic wave （EMW） absorption due to their high aspect ratio， excellent dielectric properties， and low density. However， due to the high conductivity and single component presence of PAN nanofibers， their electromagnetic wave absorption performance is not outstanding. It exhibits impedance mismatch and poor electromagnetic wave attenuation capability. This article introduces zero dimensional SiO₂ nanospheres to construct a unique one-dimensional PCN/SiO₂ pearl chain composite nanofiber， achieving matched impedance characteristics and excellent EMW attenuation capability. Uniform zero dimensional SiO₂ nanospheres are anchored in PCN nanofibers with uniform diameter through electrospinning， forming periodic electromagnetic loss units. This increases the number of heterogeneous interfaces， leading to enhanced polarization relaxation. Due to the presence of SiO₂， a low dielectric constant transparent material， the impedance matching characteristics have been improved. In addition， the incident electromagnetic waves on PCN/SiO₂ composite nanofibers increase the reflection and scattering of the incident electromagnetic waves， promoting the loss of electromagnetic wave energy. It is worth noting that by controlling the content of SiO₂ nanospheres added to regulate their dielectric loss characteristics， PCN/SiO₂ composite nanofibers can be promoted to exhibit efficient absorption properties in low， medium， and high frequency bands. Experimental data shows that PCN/SiO₂ composite nanofibers exhibit an refection loss （R_L） of -56.14 dB at mid to low frequencies of 7.2 GHz， demonstrating excellent electromagnetic wave absorption performance. Moreover， the composite nanofibers also have a relatively wide effective absorption bandwidth （EAB）. At a matching thickness of 2.3 mm， the EAB value reaches 5.52 GHz. PCN/SiO₂ composite nanofibers exhibit flexibility， lightweight， and self-supporting properties， making them a potential multifunctional EMW absorbing material.