초록 |
We used the organic solvents arranged by solvent group according to Snyder in which solvents are placed in groups of similar selectivity. The fully water-soluble solvents used by us as an additive are ethyl alcohol, isopropyl alcohol, methanol, and n-propyl alcohol which belong to the solvent group 2, n,n-dimethylformamide, 2-methoxyethanol, pyridine, tetrahydrofuran which belong to the solvent group 3, and aceton, acetonitrile, 1,4-dioxane which belong to the solvent group 6. The cloud-point measurements were used to investigate phase behavior of W/C (water in CO2) microemulsion formed by using the sodium salt of bis(2,2,3,3,4,4,5,5-octafluoro-1-pentyl)-2-sulfosuccinate (di-HCF4) as a surfactant with adding fully water-soluble organic solvents. The cloud points were measured every 10oC at temperature ranging 40-100oC with a constant CO2 concentration and constant W0 (water to surfactant molar ratio). The plots of the cloud points were described by temperature vs. pressure. In this work, the best additive among the solvents was isopropyl alcohol and the worst additive was n,n-dimethylformide. |