Vv. Vasilevskaya et al., Swelling and collapse of physical gels formed by associating telechelic polyelectrolytes, LANGMUIR, 15(23), 1999, pp. 7918-7924
A theory is proposed for the swelling and collapse of physical gels formed
by associating telechelic polyelectrolytes. It is shown that increasing the
of degree of ionization makes the formation of an associative gel less fav
orable and increases the density of the supernatant phase. This leads to th
e contraction of the ee associative gel, in comparison with an analogous ch
emically cross-linked gel. The results of calculation show that the destruc
tion of the associative gel happens monotonically in good solvent, while in
poor solvent it can proceed in a jump-like fashion accompanied by the firs
t-order phase decollapse transition of the associative gel. The addition of
a low molecular weight salt to the solution facilitates the association of
telechelic molecules which produces the associative gel and a further incr
ease of salt concentration leads to the contraction of the associative gel.