POS4-0985
Design of Self-Assembly in Bottlebrush Random Copolymers by Controlling Grafting Density
Topic
S4. Colloids, Interfaces, and Molecular Assemblies for Functional Soft Materials
When and Where
Oct 1, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Jinkee HONG
Ki Su KIM
Presenter(s)
Hey Shin (Soongsil University)
Co-Author(s)
Abstract
Various parameters, including the volume fraction, chain length, and interfacial environment of copolymers have been investigated as design variables for controlling self-assembly. Among them, bottlebrush polymers have enabled the use of grafting density as a new and unique parameter for controlling self-assembly, in addition to the aforementioned factors. Although the control of grafting density and its influence on self-assembly have been extensively investigated in bottlebrush homopolymer and block copolymer systems, its role in bottlebrush random copolymer (BRCP) systems remains largely unexplored. In this study, we synthesized BRCPs composed of poly(styrene) and poly(dimethylsiloxane) with systematically varied grafting densities via using cis-norbornene-2,3-exo-dicarboxylic diethyl ester. Across a wide grafting density range from 1.0 to 0.1, BRCPs exhibited a morphology transition from lamellae to cylinders at approximately z = 0.3. Notably, this morphological transition proceeded without disordering, while the domain spacing gradually increased with decreasing grafting density. Notably, this morphological transition proceeded without disordering. The domain spacing remained nearly constant at approximately 17 nm from z = 1.0 to z = 0.4, but began to increase at z = 0.3 and reached approximately 20 nm at z = 0.1. The same trend was also confirmed in the series with a controlled volume fraction of fPS = 0.6. These results demonstrate that grafting density serves as a distinct design parameter for controlling self-assembly in BRCPs, operating in a manner different from that in bottlebrush homopolymer and bottlebrush block copolymer systems.
