| The main aim in facilitated transport research is to develop selectivity permeable, high-flux membranes with long-term durability, A major impediment to the industrial exploitation of this technology is the problem of membrane unstability.In general, lack of stability is a common limitation of the liquid membrane method and much effort has been devoted to improve its performance.In this thesis, firstly, the synthesis and characterization of a poly(methylsiloxane) containting 4-(-undecan-l-yl-oxy)-4'-(4'-carboxy benzo-15-crown-5) biphenyl side groups, PSC-11, is described. PSC-11 displays a nematic and two smectic enantiotropic mesophases, which are of interest for application in thermal controlling devices that might be turned on and off by external electric or magnetic regulation.Secondly, the solution of PSC-11 in o-nitrophenyl n-octyl ehter (NPOE) were immobilized in a porous polymeric membrane (Celgard 2400) to prepare the supported liquid membranes. The experiments show the stability of the membrane is enhanced in comparison with Benzo-15-crown-5, because of the high partition coefficent (logKc = 22) of PSC-11. These system have been tested for the transport of K+ and Na+. The results were evaluated with transport model for 1:1 carrier cation complex.Lastly, the fixed-site carrier membranes are prepared. That is to say the solution of PSC-11 in chloroform were immobilized in Celgard 2400, then chloroform had been evaporated in vacuum. The transport flux of K+ and Na+ have been measured by those systems. In those systems the transport flux of K+ and Na+ is higher than in supported liquid membrane systems, because of "jumping" transport model in fixed-site carrier membrane. In addition, polymer inclusion membranes(CTA-PIM) is tested. The liquid crystalline function of PSC-11 is explained by external thermal regulation. |
PDF Full Text Request