Interaction of sodium dodecyl sulfate and salts of C11-C17 carboxylic acids with poly(diallyldimethylammonium bromide) gel

The effects of both nature and chain length (the number of carbon atoms n is between 11 and 17) of anionic surfactants on surfactant interaction with poly(diallyldimethylammonium bromide) hydrogel were studied. At room temperatures, an increase in n was shown to slow drastically the surfactant-induced gel collapse. The difference decreases as temperature rises due to solubility enhancement in surfactants with higher n. The maximum contraction of the polymer network was detected where the salt of myristic acid (n=13) was used as surfactant. Both an increase and a decrease of n result in higher equilibrium gel volumes