Rich polymorphism of a rod-like liquid crystal (8CB) confined in two types of unidirectional nanopores

Abstract

We present a neutron and X-rays scattering study of the phase transitions of 4-n-octyl-4'-cyanobiphenyl (8CB) confined in unidirectional nanopores of porous alumina and porous silicon (PSi) membranes with an average diameter of 30 nm. Spatial confinement reveals a rich polymorphism, with at least four different low temperature phases in addition to the smectic A phase. The structural study as a function of thermal treatments and conditions of spatial confinement allows us to get insights into the formation of these phases and their relative stability. It gives the first description of the complete phase behavior of 8CB confined in PSi and provides a direct comparison with results obtained in bulk conditions and in similar geometric conditions of confinement but with reduced quenched disorder effects using alumina anopore membranes

Accepted in EPJ E - Soft Matter

References in corpus (4)

• Molecular dynamics of a short range ordered smectic phase nanoconfined into porous silicon
• Smectic Liquid Crystals in an Anisotropic Random Environment
• Structure and relaxation processes of an anisotropic molecular fluid confined into 1D nanochannels
• Dynamics of 8CB confined into porous silicon probed by incoherent neutron backscattering experiments

Cited by in corpus (3)

• Soft matter in hard confinement: phase transition thermodynamics, structure, texture, diffusion and flow in nanoporous media - topical review
• Continuous Paranematic-to-Nematic Ordering Transitions of Liquid Crystals in Tubular Silica Nanochannels
• Criticality of an isotropic-to-smectic transition induced by anisotropic quenched disorder