Asymmetric Fullerene Nanosurfactant: Interface Engineering for Automatic Molecular Alignments

Abstract

Since the molecular self‐assembly of nanomaterials is sensitive to their surface properties, the molecular packing structure on the surface is essential to build the desired chemical and physical properties of nanomaterials. Here, a new nanosurfactant is proposed for the automatic construction of macroscopic surface alignment layer for liquid crystal (LC) molecules. An asymmetric nanosurfactant (C60NS) consisted of mesogenic cyanobiphenyl moieties with flexible alkyl chains and a [60]fullerene nanoatom is newly designed and precisely synthesized. The C60NS directly introduced in the anisotropic LC medium is self‐assembled into the monolayered protrusions on the surface because of its amphiphilic nature originated by asymmetrically programmed structural motif of LC‐favoring moieties and LC‐repelling groups. The monolayered protrusions constructed by the phase‐separation and self‐assembly of asymmetric C60NS nanosurfactant in the anisotropic LC media amplify and transfer the molecular orientational order from surface to bulk, and finally create the automatic vertical molecular alignment on the macroscopic length scale. The asymmetric C60NS nanosurfactant and its self‐assembly described herein can offer the direct guideline of interface engineering for the automatic molecular alignments.

Highly Stable, Pretilted Homeotropic Alignment of Liquid Crystals Enabled by In Situ Self-Assembled, Dual-Wavelength Photoalignment

“…The random distribution of RM aggregates corresponds to the morphological evidence of a factor responsible for homeotropic alignment as it breaks the boundary symmetry conditions of LCs. Morphological observations imply that the nature of alignment formation could be similar to SAMs or nanoparticle doping systems that exert homeotropic alignment of LCs 52,53 . The low RM257 concentration case could not provide much information regarding the anisotropic nature of RM stabilization layer or LC director orientation.…”

Remote-controllable and encryptable smart glasses: a photoresponsive azobenzene molecular commander determines the molecular alignments of liquid crystal soldiers

“…S5 (ESI†), the complete dark state of the orthoscopic POM image and the Maltese cross pattern of the conoscopic POM image indicate that E7 is vertically aligned within the LC command cell. 1 This should be due to the APTMS–ARM ( trans -form of azobenzene) structure positioned perpendicular to the substrate as shown in Fig. 1b.…”

“…Control of the molecular alignment of liquid crystals (LCs) has been widely studied and received significant interest in both academic and engineering fields as an essential research topic in precisely controlling the structural motif and molecular ordering at the nanoscale. [1][2][3][4] In LC applications including displays, light modulators, optical sensors and filters, the control of directional and positional orders of LCs is essential because the performance of such devices strongly depends on the molecular director orientation. 5,6 Recently, more advanced studies have been conducted to selectively modulate LCs to be oriented in the desired direction by applying external stimuli such as light, heat, magnetic fields and electric fields.…”

Light responsive liquid crystal soft matters: structures, properties, and applications

“…The control of molecular alignment is one of the important technologies for high-performance optical devices [49]. Particularly in the LCD industries, the orientation of anisotropic molecules has been achieved by rubbing the polymer-based film [50].…”