POLYMER-DISPERSED LIQUID-CRYSTAL MONOLAYERS

The first examples of two-dimensional polymer-dispersed liquid crystal s (PDLCs) have been prepared via the Langmuir-Blodgett technique and a nalyzed using tapping mode atomic force microscopy (TiMAFM). Character ization of the thermodynamics, polymerization kinetics, and topology o f mixtures of 2-pentadecylaniline (2PDA) and a ferroelectric liquid cr ystal termed 10PPB2 was investigated. Systematic pressure versus area isotherms indicate that the mixed monomer/liquid crystal exists as a p hase-separated monolayer after the evaporation of the spreading solven t, typical of a solution-induced phase separation (SIPS). Interfacial polymerization of the monomer in the presence of the liquid crystal ha s been accomplished. Langmuir-Blodgett-Kuhn (LBK) films obtained by tr ansferring the polymer/liquid crystal system on freshly cleaved mica s urfaces revealed a polymer-dispersed liquid crystalline system with ci rcular liquid crystalline domains trapped within a poly(alkylaniline) matrix. Statistical characterization of domain parameters (i.e. domain density, mean diameter, and polydispersity) was performed, and the ef fect of monolayer and polymerization conditions on these parameters wa s investigated. From these studies it was found that domain morphology could be controlled by the manipulation of monolayer spreading and co mpression rates. The high anisotropy and controlled symmetry of these monolayer liquid crystal domains make them attractive models of bulk P DLCs.