Elliott Stacey L, Butera Robert J, Hanus Leo H, Wagner Norman J
Center for Molecular & Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, DE 19716, USA.
Faraday Discuss. 2003;123:369-83; discussion 401-21. doi: 10.1039/b204416a.
Fiber-optic quasielastic light scattering and oscillatory shear rheology are employed to monitor the structure formation in concentrated, aqueous dispersions of model, electrostatically stabilized, polymer colloids. A regime of fractal scaling is observed in the vicinity or the gel point, as signified by a power law decay in the autocorrelation function with delay time and a power law dependence of the shear moduli on frequency. The power law exponents and the gel times extracted from the two techniques are compared for the first time on the same dispersion. The details of structure formation and aggregation kinetics in these concentrated dispersions are compared to the universal behavior of DLCA and RLCA aggregation observed at dilute concentrations in these and other dispersions, as well as to polymer gelation.
采用光纤准弹性光散射和振荡剪切流变学来监测模型静电稳定聚合物胶体的浓水分散体中的结构形成。在凝胶点附近观察到分形标度区域，这表现为自相关函数随延迟时间呈幂律衰减，以及剪切模量随频率呈幂律依赖关系。首次在同一分散体上比较了从这两种技术中提取的幂律指数和凝胶时间。将这些浓分散体中结构形成和聚集动力学的细节与在这些及其他分散体稀浓度下观察到的扩散限制凝聚（DLCA）和反应限制凝聚（RLCA）聚集的普遍行为以及聚合物凝胶化进行了比较。
