Swelling behavior of lamellar phases with calcium dodecyl sulfate, heptanol or octanol, and water

The swelling behavior of calcium dodecyl sulfate (CDS)/water with heptanol and octanol was investigated at 25 degrees C. Both systems form a condensed lamellar phase at a high content of surfactant and cosurfactant and a high ly swollen lamellar phase at a low surfactant content. There is no single-p hase channel between both lamellar regions. A dilute L-3 phase exists in th e heptanol system as well as in the octanol system. This LQ phase is water- like transparent and shows no streaming birefringence. On dilution of sampl es with an appropriate composition of water, iridescent phases can be obtai ned which display bright blue to green colors. In contrast to CDS with pent anol or hexanol, the lamellar region is broken into a dilute phase and a co ndensed phase because of decreasing undulation forces of systems containing longer chain alcohols.