A one-step melt mixing strategy based on the synergism of steam explosion and alternating convergent-divergent flow, is innovatively developed to fabricate high-performance high-density polyethylene (HDPE)/expanded graphite (EG) nanocomposites within 4 min, without any chemical reagents or complex pretreatments. A successful synergy of the external forces from surrounding elongational melts and the internal forces from steam explosion results in EG rapidly exfoliating into few-layer graphene and simultaneously dispersing in HDPE evenly. The thinnest exfoliated EG reaches two-layer graphene (1.4 nm). Benefit from excellent exfoliation and dispersion effect, the nanocomposites feature low melt resistance and relaxation time, good ductility. Furthermore, the nanocomposites obtain a greater increment of dielectric constant as more EG adding, but always maintain an extremely low dielectric loss (<0.01), exhibiting a potential for 5G communication materials. This strategy provides a promising pathway for industrially producing functional nanocomposites with high-content fillers and manufacturing nanosheets via melt-exfoliating 2D layered materials.

创新地开发了一种基于蒸汽爆炸和交替的收敛-发散流协同作用的一步熔融混合策略，可在4分钟内无需任何化学处理即可制备高性能高密度聚乙烯（HDPE）/膨胀石墨（EG）纳米复合材料试剂或复杂的预处理。来自周围的延伸熔体的外力和来自蒸汽爆炸的内力的成功协同作用导致EG快速剥落成几层石墨烯，同时均匀地分散在HDPE中。剥落最薄的EG到达两层石墨烯（1.4 nm）。得益于出色的剥离和分散效果，纳米复合材料具有较低的抗熔性和松弛时间，良好的延展性。此外，随着更多EG的添加，纳米复合材料的介电常数增加更大，但始终保持极低的介电损耗（<0.01），显示出5G通信材料的潜力。该策略为工业生产具有高含量填料的功能性纳米复合材料以及通过熔融剥落2D层状材料制造纳米片提供了一条有希望的途径。