Multicomponent bilayers of double-chain (fluorocarbon, 2F; hydrocarbon, 2H; mixed chain, 1F1H) ammonium amphiphiles were immobilized on Millipore membranes as composite films with poly(vinyl alcohol). Differential scanning calorimetry and ESCA indicated that the hydrocarbon and fluorocarbon components form separated domains and that the fluorocarbon component is concentrated near the film surface. Permeation of 02 and N2 through these films was examined by the high-vacuum method. The separation factor (Po2/PN2 = 2.0–2.8) was apparently determined by the surface monolayer formed from the fluorocarbon (2F) amphiphile, without regard to the hydrocarbon (2H) content. The permeability coefficient (P) was enhanced by the presence of the fluid domain of the liquid-crystalline hydrocarbon (2H) bilayer, and a 100 times jump in P was observed for a composite film of 2F/2H/1F1H (1:7:1) and PVA near the phase transition temperature of the hydrocarbon bilayer.
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry