title: Temperature dependence of aging kinetics of hectorite clay suspensions.
abstract: The aging of salt-free hectorite suspensions with different concentrations (c(L)=2.9, 3.2 and 3.5 wt%) stored for 2 days or 4 days was studied by rheology at different temperatures. The evolution of storage and loss moduli G' and G″ during aging followed aging time-temperature superposition. The temperature dependence of the shift factor a(T), which reflected the aging kinetics, was interpreted by the reaction-limited colloidal aggregation (RLCA) mechanism with counterion condensation in calculating the double-layer interaction of the charged clay particles. Temperature dependence of the plateau modulus and yield stress of the suspension aged for 800 s was modeled with the soft glassy rheology (SGR) theory. The estimated noise temperature x indicated that the sample aged at higher temperature corresponded to a deeper quench in the nonergodic state. Under larger amplitude of oscillatory shear, the suspension exhibited a strain rate-frequency superposition (SRFS). The shearing eliminated the effects of aging and heating.
authors.affiliation: Research Institute of Materials Science and State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China.
authors.forename: Ruiwen
authors.initials: R
authors.lastname: Shu
authors.affiliation: Research Institute of Materials Science and State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China. Electronic address: mswxsun@scut.edu.cn.
authors.forename: Weixiang
authors.initials: W
authors.lastname: Sun
authors.affiliation: Research Institute of Materials Science and State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China.
authors.forename: Xinxing
authors.initials: X
authors.lastname: Liu
authors.affiliation: Research Institute of Materials Science and State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China. Electronic address: mcztong@scut.edu.cn.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Tong
keywords: Aging; Counterion condensation; Hectorite clay suspension; Yielding