The use of dispersed cross-links with different levels of strength is one of the most successful strategies for toughening a hydrogel. By using a model hydrogel having dispersed association of single-component short alkyl chains, this work demonstrates that the differential modulus–elongation relation derived from tensile curves can reflect the structural evolution of dispersed cross-links at a molecular level. This analysis method allows for decoupling the mechanical contribution of strong and weak hydrophobic clusters, which serve as the minor and major cross-links in our system, respectively. At small deformation, the weak hydrophobic associations majorly determine the stiffness, and their rupture releases folded partial chains to endow deformation capacity. At large deformation, the strength ratio of strong and weak hydrophobic association should be balanced to achieve the optimal strength. Furthermore, the structural parameters of these partial chains, including the Kuhn number, the Kuhn length and the chain conformation, are determined based on scaling theory of extensibility. These results allow for correlating the apparent mechanics to the structural parameters of the dispersed hydrophobic association, paving the way for customized mechanics for specific applications.

中文翻译：

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通过拉伸行为分析了水凝胶中分散的疏水缔合的结构演变。

具有不同强度水平的分散交联的使用是增韧水凝胶的最成功策略之一。通过使用具有单组分短烷基链的分散缔合的模型水凝胶，这项工作表明，由拉伸曲线得出的微分模量-伸长率关系可以在分子水平上反映分散交联的结构演变。这种分析方法可以使强疏水团簇和弱疏水团簇的机械作用解耦，它们分别充当我们系统中的次要和主要交联点。在小的变形中，弱的疏水缔合主要决定了刚度，并且它们的破裂释放折叠的部分链以赋予变形能力。大变形时 为了达到最佳强度，应平衡强疏水缔合和弱疏水缔合的强度比。此外，这些部分链的结构参数，包括库恩数，库恩长度和链构象，是基于可扩展性的缩放理论来确定的。这些结果允许将表观力学与分散的疏水缔合的结构参数相关联，为针对特定应用的定制力学铺平了道路。