Age dependent hydration, heterogeneity and network rigidity of aqueous Laponite dispersions in their sol, gel and glass phases have been studied systematically in the clay concentration range c = 0.3–3.5 % (w/v) which revealed the following interesting features: (i) both in the sol and gel regime (c < 1.8% (w/v)), the intensity of light scattered I(q,c) scaled with concentration c as, I(q,c) ∼ cα with α = 0.95 at t = 0, and 0.63 after t = 6 months implying that this temporal growth resulted from the formation of a colloidal gel; (ii) in the glass phase (c ≥ 2% (w/v)), scattered intensity from samples remained constant (α = 0), meaning that there was disorder in the system at higher solid contents, and the clay particles were randomly arranged, and this intensity profile did not change with the aging; (iii) the dynamic structure factor data showed low concentration dispersions (gels) having a single mode relaxation time (fast mode) which shifted to longer relaxation time with aging. In the glass phase, in addition to the fast mode that remained invariant of aging, a slow mode which shifted to longer relaxation time with aging was noticed; (iv) rigidity modulus (G′) and yield stress (σ) measurements showed that there are two universal power-law relations governing their behavior as a function of clay concentration; G′, σ ∼ cδ with δ = 2.3 for gels and 2.8 for glass. Both these parameters revealed similar logarithmic time dependence with aging as σ, G′ = βln(tw/tm), where β is a constant and tm is the characteristic time scale for the development of micro structures; (v)
