Time-resolved small angle light scattering (SALS) is used to study the ph a
se separation process of water-octane-tetraethylene glycol monodecyl ether
(C10E4) bicontinuous microemulsion. We observe in the structure factor cont
ributions both from macrophase and microphase separation domains characteri
zed by two separate length and time scales. The study of the microphase int
ensity contribution computed according to a random wave model (RWM), eviden
ces, in spite of the respective length scales (that differ by a factor of a
thousand) a morphological similarity with the one corresponding to the sam
e microemulsion in the stable bicontinuous one phase.