POLYION COMPLEX LANGMUIR-BLODGETT LAYERS CONTAINING AN IONIC WATER-SOLUBLE POLYSILANE

Monolayers of anionic amphiphiles, arachidic acid (C19COOH) and a doub le long chain sulfonic acid derivative (2C(12)SO(3)Na), were spread on the water subphase containing an ammonium-containing polysilane (APS) , and Langmuir-Blodgett (LB) films from these polyion complex monolaye rs were prepared. Single layer deposition of these polyion complex mon olayers was successfully achieved onto a hydrophilic substrate under a ll conditions examined, but multilayers could be prepared under limite d conditions in the Z-type mode. The UV absorption spectra of the tran sferred C19COO(H)/APS monolayers indicated that the conformational sta te of APS in the films are dependent on the subphase pH. The absorbanc e of the transferred LB films confirmed that the APS is incorporated m onomolecularly on the lifting process. Polarized UV absorption spectra revealed no preferential orientation of the APS backbone in the LB fi lms. The multilayers formed in the Z-type deposition were eventually i nverted to stacked bilayer structure (Y-type layers) after aging and s uccessive annealing, as proven by the small angle X-ray reflectometry. LB films composed of 2C(12)SO(3)(-)/APS possessed a more refined laye r structure with a more smooth surface than those of C19COO(H)/APS, pr obably due to a better dimensional matching of the APS unit and the cr oss section of the amphiphile. Finally, structural features of the C19 COO(H)/APS polyion complex LB film were discussed in comparison with t hose of a homologous amphiphilic material reported previously (Seki et al. Macromolecules 1995, 28, 5609).