2010/01/25 by A. Shahin, Yogesh M. Joshi
Chemistry · Materials Science · Physics and Astronomy · #Aqueous solution #Chemical engineering #Chemical physics #Chemistry #Clay minerals and soil interactions #Composite material #Electrostatics and Colloid Interactions #Material Dynamics and Properties #Materials science #Physical chemistry #Rheology #Salt (chemistry) #cond-mat.soft
paper · pdf · doi:10.1021/la9032749
27 pages, 8 figures. Langmuir, in press
openalex publication_date 2010/01/25 · arxiv created 2010/01/26 · arxiv updated 2010/02/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the aging behavior of aqueous suspension of Laponite having 2.8 wt % concentration using rheological tools. At various salt concentration all the samples demonstrate orientational order when observed using crossed polarizers. In rheological experiments we observe inherent irreversibility in the aging dynamics which forces the system not to rejuvenate to the same state in the shear melting experiment carried out at a later date since preparation. The extensive rheological experiments carried out as a function of time elapsed since preparation demonstrate the self-similar trend in the aging behavior irrespective of the concentration of salt. We observe that the exploration of the low-energy states as a function of aging time is only kinetically affected by the presence of salt. We estimate that the energy barrier to attain the low-energy states decreases linearly with increase in the concentration of salt. The observed superposition of all the elapsed time and the salt-concentration-dependent data suggests that the aging that occurs in low salt concentration systems over a very long period is qualitatively similar to the aging behavior observed in systems with high salt concentration over a shorter period.