Formation of interfacial layer between liquid crystal and polymer alignment sublayer

The viscoelastic properties of a liquid crystal (LC) on a polymer sublayer were investigated using a quartz crystal microbalance (QCM). The time-evolution curves of the resonant frequency shift and resonant resistance shift of the QCM for an LC on polystyrene (PS) and hydroxypropyl cellulose (HPC) surfaces show five different stages. Mutual diffusion of polymer chains and liquid crystal molecules proceeded in the third stage, suggesting the formation of a viscoelastic interfacial layer. The thickness of the resultant interfacial layer was estimated to be 240nm on PS and 20nm on HPC, depending on the miscibility of the LC and the polymer.