摘要
随着无线通信技术的发展,电磁辐射污染日益严重,开发超轻、超薄、柔性、高机械性能的电磁屏蔽材料以保护精密电子器件免受电磁辐射干扰十分必要。以纤维素纳米纤维(CNFs)为基质,银纳米线(Ag NWs)和氧化石墨烯(GO)为导电填料,通过交替真空抽滤CNFs和具有不同比例的Ag NWs/GO混合液的方法构建了一种超薄柔性电磁屏蔽复合纸(厚度为34μm)。研究了复合薄膜的润湿性、力学性能以及电磁屏蔽性能,揭示了复合纸微观结构及组成对其润湿性、力学性能以及电磁屏蔽性能的影响。SEM测试结果表明,该复合纸具有多层结构。导电性测试结果表明,3个导电层导电性呈梯度变化。接触角测试的结果表明,形成多层梯度结构后,复合纸的接触角为115°,表现出了一定的疏水性。万能力学试验机的结果表明,多层梯度结构复合纸的应力和应变分别为26.7 MPa和2.16%,相比混合非梯度复合纸有了一定的提升。矢量网络分析仪的测试结果表明,具有梯度结构的复合纸在8.2 GHz时,电磁屏蔽效能为24 dB,高于混合非梯度结构复合纸的效能(19 dB),并以吸收损耗为主。因此,通过构建分层梯度结构可以显著提升复合纸的力学性能以及电磁屏蔽性能。
With the development of wireless communication technology,electromagnetic radiation pollution is becoming more and more serious.It is necessary to develop ultra-light,ultra-thin,flexible,and great mechanical properties electromagnetic shielding materials to protect precision electronic devices from electromagnetic radiation interference.Silver nanowires are often used as fillers to prepare two-dimensional composite papers and films or three-dimensional sponges and aerogels due to their excellent electrical conductivity,high aspect ratio and good mechanical flexibility.Cellulose nanofibers(CNFs)are abundant,low cost,biodegradable and have high crystallinity,excellent mechanical properties,and good biocompatibility.At the same time,CNFs with abundant active groups can bond with different conductive fillers,and then construct composite materials with enhanced structure through self-assembly.Therefore,using cellulose nanofibers and Ag NWs as substrates and fillers,it is expected to develop ultra-thin,flexible and high mechanical properties electromagnetic shielding materials.In this study,using cellulose nanofibers(CNFs)as matrix,silver nanowires(Ag NWs)and graphene oxide(GO)as conductive fillers,the ultra-thin and flexible electromagnetic shielding composite paper with gradient structure(with a thickness of 34μm)was constructed by an alternate vacuum filtration of CNFs and Ag NWs/GO mixtures with different proportions.The wettability,mechanical properties and electromagnetic shielding properties of the composite film were studied,and the influence of the microstructure and composition of the composite paper on its wettability,mechanical properties and electromagnetic shielding properties were investigated.SEM results showed that the composite paper had a layered structure.The electrical conductivity test results showed that the conductivity of the three conductive layers varied in gradient.The results of the contact angle test showed that the contact angle of the composite paper was 115°after the formation of the
作者
张建成
郭伟佳
沈顺禹
张倩
李彩彩
ZHANG Jiancheng;GUO Weijia;SHEN Shunyu;ZHANG Qian;LI Caicai(School of Chemistry and Materials Engineering,Zhejiang A&F University,Hangzhou 311300,China)
出处
《林业工程学报》
CSCD
北大核心
2024年第4期63-71,共9页
Journal of Forestry Engineering
基金
浙江省自然科学基金(LQ20C160004)
浙江农林大学校科研发展基金(2019FR009)。
关键词
纤维素纳米纤维
银纳米线
氧化石墨烯
梯度结构
电磁屏蔽
cellulose nanofiber
silver nanowire
reduced graphene oxide
gradient structure
electromagnetic shielding
