Abstract The surface properties of nanofillers and surface/interfacial interactions between fillers and matrix play crucial roles in the control of the properties of composites, especially considering hybrid materials used in biomedical, electronic and energy applications. In the present work, we investigate the surface properties of mono-filler and bi-filler composites of poly (lactic acid) (PLA) with graphene nanoplatelets (GNP) and multi-walled carbon nanotubes (MWCNTs) prepared by melt extrusion method. Zeta potential, contact angle (surface energy), Raman spectroscopy, and atomic force microscopy were used to evaluate the interaction between PLA matrix, GNP and MWCNTs particles, and also to characterize filler-polymer composite properties at the surfaces of the film. The effect of filler loading in the GNP/PLA and GNP/MWCNT/PLA composite films surface properties was investigated using surface Zeta potential by streaming and Contact angle measurements. The results suggest that the surface characteristics of the composite film may be synergistically tuned by incorporation of GNPs and MWCNTs with controlling the filler contents and filler combinations.

中文翻译：

---

聚乳酸/石墨烯/碳纳米管复合材料表面特性的组成依赖性

摘要 纳米填料的表面特性以及填料与基体之间的表面/界面相互作用在控制复合材料的性能方面起着至关重要的作用，特别是考虑到用于生物医学、电子和能源应用的混合材料。在目前的工作中，我们研究了聚乳酸 (PLA) 与石墨烯纳米片 (GNP) 和多壁碳纳米管 (MWCNT) 的单填料和双填料复合材料的表面性质，这些复合材料是通过熔融挤出方法制备的。Zeta 电位、接触角（表面能）、拉曼光谱和原子力显微镜用于评估 PLA 基质、GNP 和 MWCNTs 颗粒之间的相互作用，并表征薄膜表面的填料-聚合物复合材料特性。通过流动和接触角测量，使用表面 Zeta 电位研究了填料对 GNP/PLA 和 GNP/MWCNT/PLA 复合膜表面特性的影响。结果表明，复合薄膜的表面特性可以通过加入 GNPs 和 MWCNTs 并控制填料含量和填料组合来协同调节。