Dispersing carbon nanomaterials in solvents is effective in transferring their significant mechanical and functional properties to polymers and nanocomposites. However, poor dispersion of carbon nanomaterials impedes exploiting their full potential in nanocomposites. Cellulose nanocrystals (CNCs) are promising for dispersing and stabilizing pristine carbon nanotubes (pCNTs) and graphene nanoplatelets (pGnP) in protic media without functionalization. Here, the underlying mechanisms at the molecular level are investigated between CNC and pCNT/pGnP that stabilize their dispersion in polar solvents. Based on the spectroscopy and microscopy characterization of CNCpCNT/pGnP and density functional theory (DFT) calculations, an additional intermolecular mechanism is proposed between CNC and pCNT/pGnP that forms carbonoxygen covalent bonds between hydroxyl end groups of CNCs and the defected sites of pCNTs/pGnPs preventing re-agglomeration in polar solvents. This work's findings indicate that the CNC-assisted process enables new capabilities in harnessing nanostructures at the molecular level and tailoring the performance of nanocomposites at higher length scales.

中文翻译：

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碳纳米材料与纤维素纳米晶体的水分散体：分子相互作用的研究

将碳纳米材料分散在溶剂中可有效地将其显着的机械和功能特性转移到聚合物和纳米复合材料中。然而，碳纳米材料的差分散性阻碍了它们在纳米复合材料中的全部潜力。纤维素纳米晶体 (CNC) 有望在没有功能化的质子介质中分散和稳定原始碳纳米管 (pCNT) 和石墨烯纳米片 (pGnP)。在这里，研究了 CNC 和 pCNT/pGnP 之间分子水平的潜在机制，以稳定它们在极性溶剂中的分散。基于CNC的光谱和显微镜表征pCNT/pGnP 和密度泛函理论 (DFT) 计算，在 CNC 和 pCNT/pGnP 之间提出了一种额外的分子间机制，它在 CNCs 的羟基端基和 pCNTs/pGnPs 的缺陷位点之间形成碳-氧共价键，防止在极性溶剂。这项工作的结果表明，CNC 辅助工艺能够在分子水平上利用纳米结构并在更高长度尺度上调整纳米复合材料的性能。