Mixed films of poly(n-hexyl isocyanate) and poly (vinyl acetate) at the air-water interface

We study interfacial properties of rigid-rod-like poly(n-hexyl isocyanate) (PHIC). flexible poly(vinyl acetate) (PVAc), and mixed films of PHIC and PVAc spread at the air-water interface as a function of the molar fraction of PHIC by surface pressure measurements and fluorescence microscopy. From the plots of the experimental mean area of the mixed polymer film,, at a constant surface pressure as a function of the molar fraction of PHIC in the mixed films, the binary mixtures of PHIC/PVAc were concluded to be Compatible at the airwater interface. This means that the hydrophobic hexyl group of PHIC takes a horizontal orientation to (lie air-water interface rather than a perpendicular one, leading to PHIC and PVAc having the same interfacial orientation. Compatibility of the binary mixtures of PHIC/PVAc at the air-water interface is also confirmed by their fluorescence microscopic images. since PIIIC proves to he inhomogenous and PVAc is homogeneous with the aid of a fluorescence probe. respectively. (c) 2005 Elsevier Inc. All rights reserved.