Rational design of surface-confined nanostructured self-assemblies based on functional comb-shaped copolymers for tunable molecular orientation

• Published in: Reactive & functional polymers 2021-11, Vol.168, p.105042, Article 105042
• Main Authors: Choi, Jin-Wook, An, Jongil, Son, Seung-Rak, Kim, Soyern, Park, Jisung, Park, Chan Beom, Lee, Jun Hyup
• Format: Article
• Language: English
• Subjects: Acrylic resins; Assemblies; Biosensors; Carboxylic acids; Comb-shaped amphiphilic copolymer; Copolymers; Crystal structure; Fabricability; Hydrophilicity; Indium tin oxides; Liquid crystal; Liquid crystals; Molecular orientation; Nanoelectronics; Nanostructure; Nanostructured materials; Nanostructured self-assemblies; Optical switching; Polyacrylic acid; Segments; Self-assembly; Substrates; Surface-confinement; Vertical orientation
• ISSN: 1381-5148; 1873-166X
• DOI: 10.1016/j.reactfunctpolym.2021.105042

Functional ultrathin nanoarchitectures are commonly based on hierarchical molecular self-assemblies that are structurally tunable and facilely fabricable, and have found a broad range of potential applications from nanoelectronics to biosensors. Here, we demonstrate a simple and elegant approach for the rational design of ultrathin molecular nanoarchitectures for tunable interfacial orientation of liquid crystals (LCs) using the surface-confinement of functional amphiphilic copolymers. The surface-confined nanostructured self-assemblies are simply prepared by introducing common functional polymers into amphiphilic systems. The surface-confined copolymeric nanoalignment layer, which is constructed from the simple doping and molecular self-assembly of comb-shaped amphiphilic copolymers in a confined LC medium, comprises a hydrophobic polyacrylate segment with a long side chain moiety capable of uniformly controlling the LC alignment and a hydrophilic polyacrylic acid segment with a carboxylic acid group confined to the hydrophilic surface of indium tin oxide substrate. The combination of structural variations on amphiphilic copolymer system and tunability of molecular orientation makes the surface-confined copolymeric nano-assemblies highly attractive ultrathin nanoarchitectures. The resulting nanostructured self-assemblies exhibit a spontaneous and uniform vertical orientation of LC molecules, simultaneously providing the LC device with a superfast electro-optical switching time and a strong surface anchoring control. [Display omitted] •A facile and rational strategy to design surface-confined ultrathin nano-assemblies has been presented.•The structural variations on functionalized comb-shaped copolymer offered a tunable molecular orientation for LCs.•A highly hydrophobic surface of dense side-chain arrays afforded a powerful surface anchoring controllability.•An ultrafast electro-optical switching performance of the device was achieved.