Mandal Samir, Samanta Ketaki, Manna Kunal, Kumar Subodh, Bose Suryasarathi
Department of Materials Engineering, Indian Institute of Science, Bangalore, 560012 India.
Nanoscale. 2024 Apr 4;16(14):6984-6998. doi: 10.1039/d3nr06047k.
Carbon fiber-reinforced epoxy (CFRE) laminates have attracted significant attention as a structural material specifically in the aerospace industry. In recent times, various strategies have been developed to modify the carbon fiber (CF) surface as the interface between the epoxy matrix and CFs plays a pivotal role in determining the overall performance of CFRE laminates. In the present work, graphene oxide (GO) was used to tag a polyetherimide (PEI, termed BA) containing exchangeable bonds and was employed as a sizing agent to improve the interfacial adhesion between CFs and epoxy. This unique GO-tagged-BA sizing agent termed BAGO significantly enhanced the mechanical properties of CFRE laminates by promoting stronger interactions between CFs and the epoxy matrix. The successful synthesis of BAGO was verified by Fourier-transform infrared spectroscopy. Additionally, the partial reduction of GO owing to this tagging with BA was further confirmed by X-ray diffraction and Raman spectroscopy, and the thermal stability of this unique sizing agent was evaluated using thermogravimetric analysis. The amount of GO in BAGO was optimized as 0.25 wt% of BA termed 0.25-BAGO. The 0.25-BAGO sizing agent resulted in a significant increase in surface roughness, from 15 nm to 140 nm, and surface energy, from 13.2 to 34.7 mN m of CF. The laminates prepared from 0.25-BAGO exhibited a remarkable 40% increase in flexural strength (FS) and a 35% increase in interlaminar shear strength (ILSS) due to interfacial strengthening between epoxy and CFs. In addition, these laminates exhibited a self-healing efficiency of 51% in ILSS due to the presence of dynamic disulfide bonds in BAGO. Interestingly, the laminates with 0.25-BAGO exhibited enhanced Joule heating and enhanced deicing, though the EMI shielding efficiency slightly declined.
碳纤维增强环氧树脂（CFRE）层压板作为一种结构材料，尤其在航空航天工业中受到了广泛关注。近年来，人们开发了各种策略来改性碳纤维（CF）表面，因为环氧树脂基体与CF之间的界面在决定CFRE层压板的整体性能方面起着关键作用。在本工作中，氧化石墨烯（GO）被用于标记含有可交换键的聚醚酰亚胺（PEI，称为BA），并用作上浆剂以改善CF与环氧树脂之间的界面粘附力。这种独特的GO标记BA上浆剂（称为BAGO）通过促进CF与环氧树脂基体之间更强的相互作用，显著提高了CFRE层压板的机械性能。通过傅里叶变换红外光谱验证了BAGO的成功合成。此外，通过X射线衍射和拉曼光谱进一步证实了由于BA标记导致的GO的部分还原，并使用热重分析评估了这种独特上浆剂的热稳定性。BAGO中GO的含量优化为BA的0.25 wt%，称为0.25 - BAGO。0.25 - BAGO上浆剂使CF的表面粗糙度从15 nm显著增加到140 nm，表面能从13.2增加到34.7 mN/m。由0.25 - BAGO制备的层压板由于环氧树脂与CF之间的界面强化，弯曲强度（FS）显著提高了40%，层间剪切强度（ILSS）提高了35%。此外，由于BAGO中存在动态二硫键，这些层压板在ILSS方面表现出51%的自修复效率。有趣的是，含有0.25 - BAGO的层压板虽然电磁干扰屏蔽效率略有下降，但焦耳热增强且除冰性能增强。
