Natural Fiber-Anchored Few-Layer Graphene Oxide Nanosheets for Ultrastrong Interfaces in Poly(lactic acid)

The development of high-performance graphene oxide (GO) nanocomposites is challenged by the lack of a feasible and effective route to disperse and exfoliate GO nanosheets, as well as technical gaps in providing precision control over the interfacial interactions. Here we disclose an all-aqueous processing method to immobilize few-layer extended GO nanosheets at ramie fiber driven by hydrogen bonding. The reinforcing efficacy of GO-functionalized ramie (GOFR) was examined in a poly(lactic acid) (PLA) matrix, wherein the GOFR provided large active surfaces to induce chain ordering and lamellar organization. It permitted the preferable formation of well-organized PLA transcrystallinity at GOFR, in contrast to calabash-like and less-ordered transcrystallinity induced by pristine ramie due to the inferior nucleation activity. The transcrystallization kinetics and lamellar orientation degree were significantly facilitated by the addition of chain mobility accelerator in PLA, permitting the formation of prevailing transcrystallinity with large sizes at GOFR The profound control of interphase morphology conferred remarkable improvements in interfacial properties with weak relation to crystallization temperature, as indicated by an over 3-fold increase in interfacial shear strength between GOFR and PLA matrix compared to the counterparts incorporated with pristine ramie. The effort reveals the appealing application of natural fibers as an ideal template to extend GO nanosheets, potentially motivating further efforts toward revolutionary advancements occurring in many fields of materials science and nanotechnology.