Distinctive Optical Properties of Hierarchically Ordered Nanostructures Self-Assembled from Multiblock Copolymer/Nanoparticle Mixtures

Hierarchically Chiral Nanostructures Self-Assembled from Nanoparticle Tethered Block Copolymers

Chiral nanostructures of nanoparticle assemblies have attracted tremendous interest for their fascinating functional properties. Herein, through theoretical simulations, we show that nanoparticle tethered block copolymers can self-assemble into hierarchically chiral nanostructures. Two-fold helices are formed in the hierarchically chiral nanostructures: the diblock copolymers form helical supercylinders while the nanoparticles arrange into chiral assemblies wrapped around the helical supercylinders. The hierarchically chiral nanostructures can be formed in a large parameter window. Circular dichroism calculations demonstrate that the coexistence of polymeric helices and chiral nanoparticle assemblies improves the chiroptical activity. These findings can provide guidelines for designing hierarchically ordered chiral nanostructures with advanced functional properties. This article is protected by copyright. All rights reserved.

Enlarged Phase Regions of Multi-Continuous 3D Network Nanostructures in ABC Triblock Copolymers

Aiming to increase the stability region of three-dimensional (3D) multi-continuous morphologies due to great potential application in smart sensors, gas separation membranes, and photonic materials, in this paper, we control the block ratio of different channels of an ABC triblock copolymer according to the curvature of these multi-continuous nanostructures. In the small A volume fraction region, the multi-continuous gyroid nanostructure is stable when f_B/f_C equals 1/3, while two-domain lamellae (L_B/C) and three-layer lamellae (L₃) are obtained when B and C blocks have comparable volume fractions, suggesting that changing the f_B/f_C ratio is an effective way of forming multi-continuous polymer network nanostructures. Interestingly, a large phase region of the core-shell gyroid and O⁷⁰ are found under the condition of f_B/f_C = 4. The mechanism of changing the ratio to enlarge the phase regimes of multi-continuous nanostructures can be ascribed to the existence of curvature in gyroid and O⁷⁰ nanostructures. Therefore, the formed thin layer must be consistent with these curvatures, which can be tuned by the adjustment of the block ratio. The proposed mechanism and the calculated phase diagram can effectively guide the experimental observation of these multi-continuous nanostructures.

Distinctive Dielectric Permittivity of Hierarchical Nanostructures with Ordered Nanoparticle Networks Self-Assembled from AB-g-NP/AC Block Copolymer Mixtures

Directing nanoparticles into ordered organization in polymer matrix to improve macroscopic properties of nanocomposites remains a challenge. Herein, by means of theoretical simulations, we show the high permittivity of hybrid nanostructures designed with mixtures of AB block copolymer-grafted nanoparticles and lamella-forming AC diblock copolymers. The grafted nanoparticles self-assemble into parallel stripes or highly ordered networks in the lamellae of the AC diblock copolymers. The ordered nanoparticle networks, including honeycomb-like and kagomé networks, provide bending and conductive pathways for concentrating electric fields, which results in the improvement of the permittivity. We envisage that this strategy will open a gateway to prepare hierarchically ordered functional nanocomposites with distinctive dielectric properties.