2010 Volume 35 Issue 2 Pages 335-338
Monolayer behavior on the water surface and mesoscopic morphological formation on solid of mixed organized moelcuar films of organo-modified montmorillonite and poly-(L-lactide) (abbrev. PLLA) were investigated by surface pressure-area (π-A) isotherm and atomic force microscopy (AFM). From the results of π-A isotherm of neat PLLA monolayer, clearly phase transition behavior from monolayer to crystal was confirmed with plateau at low surface pressure region. Straight chain-type polymer may form the lamellae like three-dimensional structure at transition point although this type transition behavior generally corresponds to a collapse of monolayer and formation of piled up film. In the case of mixed monolayer with organo-modified montmorillonite, this transition point is independent on the mixed ratio, and indicates almost constant value in their isotherms. That is to say, this is immiscible system. From the result of AFM observation, phase separated structure was confirmed in mesoscopic scales. This phase separated morphology remarkably varied with mixed ratio.
