In this work, polyethylene (PE)/silica microsphere composite melt is used to penetrate the ethylene-α-octene block copolymer (OBC) melt in multi-melt multi-injection molding (M³IM) process. Due to the viscosity difference between PE/silica composite melt and OBC melt, a disturbed flow interface of these two melts formed. Thanks to the “shear-induced migration” theory in suspended balance model (SB model) and the unique flow field in M³IM, silica microspheres can be designed to migrate from high shear rate layer to low shear rate layer in PE/silica core melt, further to intaglio micro-pits on the interface of PE/silica core and OBC skin melt. As a result, the migrated silica microspheres can be intuitively observed by peeling off the OBC layer, as well as a “lotus seedpod”-like structure consisting of quantity-adjustable asperities and micro-pits can be constructed on the peeled surface of OBC layer. This work sheds lights to rapidly fabricate multi-tier structures by polymer melt processing strategies, aiming to manufacture functional devices on a large scale.

在这项工作中，聚乙烯（PE）/二氧化硅微球复合熔体用于在多熔体多次注塑（M ³ IM）工艺中渗透乙烯-α-辛烯嵌段共聚物（OBC）熔体。由于PE /二氧化硅复合熔体和OBC熔体之间的粘度差异，这两种熔体的流动界面形成紊乱。得益于悬浮平衡模型（SB模型）中的“剪切诱导迁移”理论和M ^3中独特的流场IM，二氧化硅微球可以被设计成从PE /二氧化硅芯熔体中的高剪切速率层迁移至低剪切速率层，进一步向PE /二氧化硅芯与OBC表皮熔体的界面上的凹版微坑迁移。结果，通过剥离OBC层可以直观地观察到迁移的二氧化硅微球，并且可以在OBC层的剥离表面上构建一个由“数量可调节的凹凸”组成的“莲子荚”状结构，并形成微坑。这项工作为通过聚合物熔体加工策略快速制造多层结构提供了希望，旨在大规模生产功能器件。