Abstract
In this study, a polymerized twisted nematic (TN) network was used as an extrinsic chiral platform to overcome the heterogeneity during spontaneous symmetry breaking in a mixed system comprising an achiral bent-core molecule and rod-like mesogen. The TN platform was prepared by photopolymerizing a reactive mesogen dispersed in a low molecular weight liquid crystal with TN orientation. The use of TN orientation to correct the degeneracy in bent-core molecular systems has been previously reported; however, to the best of our knowledge, this is the first study that uses an extrinsic chiral platform of a polymerized TN network. The heterogeneity in the nano-segregated phase of the achiral mixture was suppressed using the extrinsic TN platform with a twisted angle θ of ≥ |±30°|. When an achiral mixture doped with a luminescent guest molecule was refilled into the extrinsic chiral platform, preferential deracemization with one-handedness occurred, corresponding to the handedness of the TN platform. Therefore, circularly polarized luminescence with a preferential handedness can be achieved using this extrinsic chiral platform.
Highlights
Liquid crystal (LC) phases formed from achiral bent-core (BC) molecules differ from the conventional phases of rod-like mesogens [1,2]
For the cell with a twisted angle θ = +70◦, one chiral domain was observed across the entire area under survey. This is because the extrinsic twisted nematic (TN) platform biased the formation of a particular chiral arrangement of the helical nanofilaments (HNFs)
For the cell with a twisted angle θ = +70°, one chiral domain was observed across the entire area under survey
Summary
Liquid crystal (LC) phases formed from achiral bent-core (BC) molecules differ from the conventional phases of rod-like mesogens [1,2]. In mixed systems comprising BC molecules and rod-like mesogens, the nano-sized phase segregation occurs between the helical nanofilaments (HNFs), originating from the BC molecules and calamitic LC phases originating from the rod-like mesogens [3,4,5]. A rod-like mesogen doped with the dye and segregated from the HNFs forms a chiral superstructure; CPL originating from the dye molecules doped in the rod-like mesogen can be observed [11] This approach enables a simple molecular design to fabricate materials that show CPL from mixed systems consisting of only chemically achiral molecules, because chirality at the molecular level is not necessary. The use of TN orientation to eliminate the degeneracy of BC molecular systems has been reported previously [13,14]; to the best of our knowledge, this is the first study that uses an extrinsic chiral platform derived from a polymerized TN network
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have