Arrested state of clay-water suspensions: gel or glass?
The aging of a charged colloidal system has been studied by small-angle x-ray scattering, in the exchanged momentum range Q=0.03-5 nm(-1) , and by dynamic light scattering, at different clay concentrations (C(w)=0.6-2.8%) . The static structure factor S(Q) has been determined as a function of both aging time and concentration. This is the direct experimental evidence of the existence and evolution with aging time of two different arrested states in a single system simply obtained only by changing its volume fraction: an inhomogeneous state is reached at low concentrations, while a homogeneous one is found at high concentrations.
Ruzicka
B
B
SOFT INFM-CNR and Dipartimento di Fisica, Università di Roma La Sapienza, Rome, Italy.
Zulian
L
L
Angelini
R
R
Sztucki
M
M
Moussaïd
A
A
Ruocco
G
G