Abstract Combining neutron and X-ray scattering (SANS, SAXS, and WAXD) as the contrast matching probes, the hierarchical structures of the multi-wall carbon nanotubes/high density polyethylene (MWCNTs/HDPE) composites (0.1–2.0 wt%) have been studied. SANS measurement avoided the correlation peak associated to the semicrystalline nature of HDPE from SAXS, and the passible scattering from the stretch induced voids. Benefitting from SANS data, the power law (α) taking the flexible cylinder suggested that whole MWCNTs in the unstretched composites follow a self-avoiding random walk (α ≈ 1.67). SANS data suggest a hollow flexible cylinder structure with outer and inner diameters (core-shell-like cross section) of the scatterers as ca. 12.6 nm and 4.1 nm, while the Kuhn length is about 43.0 nm. Tensile test displayed improved mechanical properties. Interestingly, the Hermans orientation parameter (f) of HDPE crystals (fc) in the stretched composites are around a plateau ca. 0.96 initially, while decreased remarkably to 0.776 when the fraction is further increased to 2.0 wt%. f obtained by SANS showed a similar tendency (decreased from 0.756 to 0.572). Combining all the results along with differential scanning calorimetry (DSC) measurement, a mechanism of adhered crystals on the surface of MWCNTs and a reinforcement model are proposed.

中文翻译：

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MWCNT 增强半晶 HDPE 复合材料的层次结构：通过中子和 X 射线散射的对比匹配研究

摘要 结合中子和 X 射线散射（SANS、SAXS 和 WAXD）作为对比匹配探针，多壁碳纳米管/高密度聚乙烯（MWCNTs/HDPE）复合材料（0.1-2.0 wt%）的分级结构具有被研究过。SANS 测量避免了与来自 SAXS 的 HDPE 的半结晶性质相关的相关峰，以及来自拉伸引起的空隙的可透过散射。受益于 SANS 数据，采用柔性圆柱体的幂律 (α) 表明未拉伸复合材料中的整个 MWCNT 遵循自避免随机游走 (α ≈ 1.67)。SANS 数据表明，散射体的外径和内径（核壳状横截面）为中空的柔性圆柱体结构。12.6 nm 和 4.1 nm，而 Kuhn 长度约为 43.0 nm。拉伸试验显示出改善的机械性能。有趣的是，拉伸复合材料中 HDPE 晶体 (fc) 的 Hermans 取向参数 (f) 大约在一个平台附近。最初为 0.96，而当分数进一步增加到 2.0 wt% 时，显着下降到 0.776。SANS 获得的 f 显示出类似的趋势（从 0.756 下降到 0.572）。将所有结果与差示扫描量热法 (DSC) 测量相结合，提出了多壁碳纳米管表面粘附晶体的机制和增强模型。