[Nano Research] Janus (BNNS/ANF)-(AgNWs/ANF) thermal conductivity composite films with superior electromagnetic interference shielding and Joule heat performances
作者：?Yixin Han, Kunpeng Ruan and Junwei Gu*
關鍵字：Thermally conductive composites
論文來源：期刊
具體來源：Nano Research
發表時間：2022年
Highly thermal conductivity materials with excellent electromagnetic interference shielding and Joule heating performances are ideal for thermal management in the next generation of communication industry, artificial intelligence and wearable electronics. In this work, thermal conductivity silver nanowires (AgNWs) are prepared by polyol thermal method using silver nitrate as the silver source and ethylene glycol as the solvent and reducing agent, and boron nitride (BN) is taken as raw material to prepare thermal conductivity and insulating boron nitride nanosheets (BNNS) with the help of isopropyl alcohol (IPA) and ultrasonication-assisted peeling method, which are compounded with aramid nanofibers (ANF) prepared by chemical dissociation, respectively, and the (BNNS/ANF)-(AgNWs/ANF) thermal conductivity and electromagnetic interference shielding composite films with Janus structure are prepared by the “vacuum-assisted filtration and hot pressing” method. The results show that Janus (BNNS/ANF)-(AgNWs/ANF) thermal conductivity and electromagnetic interference shielding composite films exhibit “one side insulating, one side conducting” properties, the surface resistivity of the BNNS/ANF surface is 4.7×1013 Ω, while the conductivity of the AgNWs/ANF surface is 5275 S/cm. The (BNNS/ANF)-(AgNWs/ANF) thermal conductivity and electromagnetic interference shielding composite film with thickness of 95 μm has a high in-plane thermal conductivity coefficient of 8.12 W/(m·K) and excellent electromagnetic interference shielding performance of 70 dB. The composite film also has excellent mechanical properties (tensile strength and tensile modulus of 122.9 MPa and 2.7 GPa, respectively). It also has good temperature-voltage response characteristics (high Joule heating temperature at low supply voltage (5 V, 215.0oC), fast response time (10 s)), excellent electrical stability and reliability (stable and constant real-time relative resistance under up to 300 cycles and 1500 s of tensile-bending fatigue work tests).
兼具優異電磁屏蔽性能和焦耳熱性能的高導熱材料是下一代通訊工業、人工智能和可穿戴電子產品領域中理想的熱管理材料。本文以硝酸銀為銀源、乙二醇為溶劑和還原劑，采用多元醇熱法制備導熱導電銀納米線（AgNWs），并以氮化硼（BN）為原料，借助異丙醇（IPA）及超聲輔助剝離法制備導熱絕緣氮化硼納米片（BNNS），分別與化學解離制備的芳綸納米纖維（ANF）復合，經“真空輔助抽濾-熱壓”法制備具有Janus結構的(BNNS/ANF)-(AgNWs/ANF)導熱屏蔽復合膜。結果表明，Janus (BNNS/ANF)-(AgNWs/ANF)導熱屏蔽復合膜展現出“一面絕緣、一面導電”特性，BNNS/ANF面表面電阻率為4.7×1013 Ω，而AgNWs/ANF面電導率為5275 S/cm。95 μm厚的(BNNS/ANF)-(AgNWs/ANF)導熱屏蔽復合膜具有8.12 W/(m·K)的高面內熱導率和70 dB的卓越電磁屏蔽效能。該復合膜還具有優異的力學性能（拉伸強度和拉伸模量分別為122.9 MPa和2.7 GPa），良好的溫度-電壓響應特性（如低供電電壓下的高焦耳加熱溫度（5 V、215.0oC）、快速響應時間（10 s）），優異的電穩定性和可靠性（長達300次、1500 s的拉伸-彎曲疲勞工作試驗下表現出穩定和恒定的實時相對電阻）。