Jj. Effing et al., ASSOCIATIVE PHASE-SEPARATION OBSERVED IN A HYDROPHOBICALLY-MODIFIED POLY(ACRYLAMIDE) SODIUM DODECYL-SULFATE SYSTEM/, Journal of physical chemistry, 98(10), 1994, pp. 2499-2502
Experimental evidence has been found for associative phase separation
in a mixture of a nonclouding hydrophobically modified poly(acrylamide
) and sodium dodecyl sulfate. The phase separation is strongly depende
nt on the concentration of added Na(2)S0(4). The phase separation regi
on in the presence of salt decreases with increasing temperature. Clea
ring transition temperatures from the two-phase to the one-phase regio
n are reported. Fluorescence measurements using pyrene as the luminesc
ence probe, H-1 NMR spectra, and viscosity measurements show that the
interaction between polymer and surfactant takes place also when no ph
ase separation occurs. In systems with 3% polymer concentration this i
nteraction leads to gel formation (but no phase separation) even in th
e absence of salt.