| This work will discuss novel aqueous two-phase systems (ATPS) discovered by adding fluoroalcohols, (esp., trifluoroethanol (TFE) and hexafluoroisopropanol (HFIP)) to solutions containing cationic-anionic mixed surfactants ("catanionic surfactants"). Sodium dodecyl sulfate (SDS) is the primary anionic and cetyltrimethylammonium bromide (CTAB) the primary cationic surfactant investigated. However, this research shows that ATPSs can form with other catanionic systems (e.g., SDS:DTAB), as well as nonionic (e.g., Triton X-100) and zwitterionic surfactants (e.g., 3-(N,N-dimethylmyristylammonio) propane sulfonate). The phase separations can occur at wide range of surfactant concentrations (2mM-500mM for SDS:CTAB), and even at mole ratios other than 1:1 when HFIP is used to induce the phase separation.;The composition of each phase of the biphasic system is studied and it is revealed that the surfactant-rich phase (coacervate phase) also contains a large percentage of fluoroalcohol relative to the aqueous phase. The percentage of fluoroalcohol is determined by attenuated total reflectance---Fourier transform infrared spectroscopy (ATR-FTIR) while the percentage of water was determined by Karl Fischer titration. The percentage of water in the coacervate phase increased up to 36% (w/w) for 1:1 SDS:CTAB-HFIP as the total amount of HFIP increased for the system.;Studies were also performed on solutions of SDS:CTAB with fluoroalcohols at compositions that did not induce phase separations. Conductivity was used to determine the effect that the TFE has on SDS micelles, CTAB micelles, and mixed SDS-CTAB micelles. Capillary vesicle electrokinetic chromatography and dynamic light scattering was employed to study the effect that TFE has on SDS-CTAB mixed vesicles. 1:1 SDS:CTAB with TFE was also investigated as a potential dynamic coating that could be used in capillary electrophoresis to reduce the wall interactions with basic compounds. Unfortunately, while the coating proved to be stable, it was not particularly effective in reducing the charge on the wall.;A solvatochromic study was conducted to study the hydrogen bonding and dipolar interactions present within various biphasic systems. Several catanionic solutions of SDS:CTAB with HFIP were analyzed and compared to three Triton X-100 cloud point systems (systems that phase separate upon a change in temperature) and a few more classical water-organic systems (e.g., water-octanol). The catanionic coacervate systems with HFIP proved to be significantly different from both the biphasic water-organic systems as well as the nonionic cloud-point systems. The catanionic coacervate phases were found to be quite similar to each other in terms of their dipolarity and hydrogen bonding abilities and showed that the surfactants had a much smaller effect on the hydrogen bonding and dipolarity than the HFIP.;Finally the extraction capability of the ATPSs of 1:1 SDS:CTAB with either TFE or HFIP was examined. Various dyes, a hormone (estradiol), a homologous series of alkylphenones, and several proteins were extracted and analyzed by several analytical techniques: ultraviolet-visible spectroscopy, micellar electrokinetic chromatography, high performance liquid chromatography, and fluorescence spectroscopy, respectively. As expected, the hydrophobic solutes partition strongly into the coacervate phases. Three proteins were effectively extracted into the coacervate. |
