Babai Dotan, Pinkas Iddo, Naveh Doron, Tenne Reshef
Faculty of Engineering, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Department of Molecular Chemistry and Materials Science, Weizmann Institute, Rehovot 7600001, Israel.
Nanoscale. 2024 May 23;16(20):9917-9934. doi: 10.1039/d4nr00818a.
Nanocomposite materials, integrating nanoscale additives into a polymer matrix, hold immense promise for their exceptional property amalgamation. This study delves into the fabrication and characterization of polyetherimide (PEI) nanocomposite strings fortified with multiwall WS nanotubes. The manufacturing process capitalizes on the preferential alignment of WS nanotubes along the string axis, corroborated by scanning electron microscopy (SEM). Mechanical measurements unveil a remarkable acceleration of strain hardening in the nanocomposite strings, chiefly attributed to the WS nanotubes. Structural analyses X-ray diffraction (XRD) and wide-angle X-ray scattering (WAXS) reveal intriguing structural alterations during tensile deformation. Notably a semi-crystalline framework ∼100 nm in diameter surrounding the WS nanotubes emerges, which is stabilized by the π-π interactions between the PEI chains. The amorphous majority phase (97% by volume) undergoes also major structural changes upon strain becoming more compact and closing-up of the distance beweeetn the PEI chains. Dynamic mechanical analysis (DMA) demonstrates improved thermal stability of the evolved semi-crystalline π-π oriented PEI molecules, characterized by delayed thermal "structural melting", underscoring the pivotal role of the WS nanotubes in reinforcing the nanocomposite. The insight gained in this study of WS nanotube-reinforced PEI nanocomposite strings, could offer diverse applications for such tailor-made polymeric materials.
纳米复合材料将纳米级添加剂整合到聚合物基体中，因其优异的性能融合而具有巨大的潜力。本研究深入探讨了用多壁WS纳米管增强的聚醚酰亚胺（PEI）纳米复合丝的制备和表征。制造过程利用了WS纳米管沿丝轴的优先排列，扫描电子显微镜（SEM）证实了这一点。力学测量表明，纳米复合丝中的应变硬化显著加速，这主要归因于WS纳米管。结构分析（X射线衍射（XRD）和广角X射线散射（WAXS））揭示了拉伸变形过程中有趣的结构变化。值得注意的是，在WS纳米管周围出现了直径约100 nm的半结晶框架，它通过PEI链之间的π-π相互作用得以稳定。非晶态的主体相（体积占97%）在应变时也会发生重大结构变化，变得更加致密，PEI链之间的距离缩小。动态力学分析（DMA）表明，演化出的半结晶π-π取向的PEI分子的热稳定性得到改善，其特征是热“结构熔化”延迟，这突出了WS纳米管在增强纳米复合材料中的关键作用。本研究中对WS纳米管增强的PEI纳米复合丝的深入了解，可为这种定制聚合物材料提供多种应用。
