Effect of DMSO\nAddition on the Hexagonal Phase of\nthe System Triton X/Water

This research studied the role of DMSO in a binary system\nof Triton\nX and water in the hexagonal mesophase. One effect of DMSO addition,\ndetermined using polarized optical microscopy and small-angle X-ray\nscattering measurements, is to promote a decrease in the hexagonal\nto isotropic phase transition temperature, <i>T</i><sub>H‑ISO</sub>, decreasing the range of temperatures of the hexagonal\nphase until the hexagonal phase completely disappears when DMSO is\nadded up to 5.0 mol %. The periodicity and the lattice parameter of\nthe hexagonal arrangement, calculated as a function of DMSO concentration,\nslight increased due to the insertion of DMSO molecules in the water\nregion, causing a greater distance between the cylindrical micelles,\nwhile the radius of the apolar domains kept constant at 22 (1) Å.