A Model Relating Structure of Colloidal Gels to Their Elastic Properties
A Model Relating Structure of Colloidal Gels to Their Elastic Properties
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DOI：
10.1021/la001121f
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发表时间：
2001-01
期刊：
影响因子：
3.9
通讯作者：
Hua Wu;M. Morbidelli
中科院分区：
文献类型：
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作者：
Hua Wu;M. Morbidelli
提出了胶凝胶微观结构参数与其宏观弹性性能之间的标度模型。该模型允许人们在任何凝胶状态下估计分形维数，纯粹基于流变特性（存储模量和线性极限），而无需诉诸其他类型的测量。特别地，引入了一个适当的有效微观弹性常数来解释连接间和连接内的相互弹性贡献。这就产生了一个新的参数α∈[0,1]，它表明了这两种贡献的相对重要性。这个参数可以从流变学数据中估计出来，它的值决定了主要的凝胶状态。该模型应用于文献报道的12种凝胶体系，并确定了三种凝胶体系：强链接（α = 0），弱链接（α = 1）和过渡（0 < α < 1）。对于前两种情况，新模型正确地再现了Shih等人开发的模型的结果。
A scaling model relating the microscopic structure parameters of colloidal gels to their macroscopic elastic properties is proposed. This model allows one to estimate the fractal dimension in any gelation regime, purely based on rheological properties (storage modulus and limit of linearity), without resorting to other types of measurements. In particular, an appropriate effective microscopic elastic constant is introduced to account for the mutual elastic contributions of both inter- and intrafloc links. This leads to a new parameter, α ∈ [0,1], which indicates the relative importance of these two contributions. This parameter can be estimated from the rheological data, and its value determines the prevailing gel regime. The model is applied to 12 gelation systems reported in the literature and identifies three gelation regimes: strong-link (α = 0), weak-link (α = 1), and transition (0 < α < 1). For the first two regimes, the new model correctly reproduces the results from the model developed by Shih et...