β Scribed by Shigehiro Yamaguchi
No coin nor oath required. For personal study only.
We studied the three-phase behavior and dissolution behavior of propanol (C 3 OH) in a water/C 12 EO 8 /C 3 OH/cyclohexane (c-C 6 )/ heptane (C 7 ) system at 35 and 45Β°C. Without C 12 EO 8 , a threephase region (IIIa) consisting of C 3 OH, aqueous (W), and oleic (O) phases exists between R oil (c-C 6 /c-C 6 Ψ C 7 ) β«Ψβ¬ 0.2 and 0.3 (w/w) above 35 wt% C 3 OH. The C 3 OH phase originates from the W phase and becomes identical to the O phase with increasing R oil . In the presence of C 12 EO 8 , the three-phase region expands below 20 wt% C 3 OH. The surfactant phase behaves in two ways according to the role of C 3 OH. When R oil < 0.2, the D p phase forms a closed-loop miscibility gap with a W phase. The added C 3 OH acts as a lipophilic cosurfactant and a water-soluble cosolvent. When R oil > 0.3, a microemulsion (D) phase changes from water-rich to oil-rich in a chiral three-phase body. Most C 3 OH added acts as a lipophilic cosurfactant at R oil β«Ψβ¬ 1. The two types of three-phase behavior are transformed into each other via region IIIa. C 3 OH cooperatively acts with C 12 EO 8 and a higher-order phase is formed.
π SIMILAR VOLUMES
A phase diagram of poly(methyl methacrylate) in mixtures of water and 2-propanol, individually nonsolvents for the polymer, was studied at 25 Β°C. For this system, there were two liquid-liquid demixing regions separated by a miscible region. This cosolvent phenomenon was thought to be a joint effect