Yongqiang Guo, Hua Qiu*, Kunpeng Ruan, Yali Zhang and Junwei Gu*. Hierarchically multifunctional polyimide composite films with strongly enhanced thermal conductivity. Nano-Micro Letters, 2021, 10.1007/s40820-021-00767-4. 2020IF=16.419.（1區材料科學Top期刊）
https://doi.org/10.1007/s40820-021-00767-4
Abstract
The development of lightweight and integration for electronics requires flexible films with high thermal conductivity and electromagnetic interference (EMI) shielding to overcome heat accumulation and electromagnetic radiation pollution. Herein, the hierarchical design and assembly strategy was adopted to fabricate hierarchically multifunctional polyimide composite films, with graphene oxide/expanded graphite (GO/EG) as the top thermally conductive and EMI shielding layer, Fe3O4/polyimide (Fe3O4/PI) as the middle EMI shielding enhancement layer and electrospun PI fibers as the substrate layer for mechanical improvement. PI composite films with 61.0 wt% of GO/EG and 23.8 wt% of Fe3O4/PI exhibits high in-plane thermal conductivity coefficient (95.40 W/(m·K)), excellent EMI shielding effectiveness (34.0 dB), good tensile strength (93.6 MPa), and fast electric-heating response (5 s). The test in the central processing unit verifies PI composite films present broad application prospects in electronics fields.
電子產品的輕薄化和高集成化發展亟需具有優異導熱和電磁屏蔽性能的柔性薄膜材料來解決其快速熱積聚和內在的電磁干擾問題。本文通過分層設計再組裝策略制備了上層為氧化石墨烯/膨脹石墨（GO/EG）、中間層為四氧化三鐵/聚酰亞胺（Fe3O4/PI）、下層為PI纖維的多層級多功能PI基復合薄膜。當GO/EG和Fe3O4/PI的用量分別為61.0 wt%和23.8 wt%時，HMPM兼具最佳的面內導熱系數（95.40 W/(m·K)）、電磁屏蔽效能（34.0 dB），優異的拉伸強度（93.6 MPa）和快速的電熱響應性（5 s）。以電腦CPU為實際散熱場景驗證了PI復合薄膜在輕薄化、小型化的電子設備領域具有廣闊應用前景的可能性。
論文創新點
1. 通過分層設計再組裝策略制備了多層級多功能聚酰亞胺基柔性復合薄膜。
2. 通過向膨脹石墨中添加少量氧化石墨烯解決了膨脹石墨無法成膜的問題。