POS3-0450
Overcoming the High-χ Mixing Dilemma: High-Entropy-Inspired Quaternary Systems for Ordered Block Copolymer Monoliths
When and Where
Nov 30, -0001
12:00am - 12:00am
Presenter(s)
WonJune Yeo (KAIST)
Co-Author(s)
Abstract
Achieving thermodynamic miscibility in multicomponent polymer systems is a fundamental challenge, as the large degree of polymerization (N) drastically suppresses mixing entropy and drives macroscopic phase separation. This limitation sharply restricts the synthesis of high-interfacial-segregation block copolymers (BCPs), which are highly desirable for advanced lithography and membrane fabrications. To resolve this central dilemma between high-χ systems and homogeneous mixing, we report a solvent-free, high-entropy-inspired quaternary approach that expands the miscibility window during polymerization-induced microphase separation (PIMS). By co-formulating a quaternary mixture comprising a high-χ monomer, a low-χ solubilizing component, a cross-linker, and a macro-chain transfer agent, we suppress unfavorable solvent–antisolvent interactions and maintain an initially homogeneous state even under large high-χ monomer loadings. Furthermore, we implement a targeted high-β strategy by incorporating sterically bulky pendant groups to selectively elevate the temperature-independent entropic contribution, accelerating access to the order–disorder transition (ODT). Unlike conventional low-χ PIMS systems that typically yield kinetically arrested, disordered morphologies, our dual thermodynamic-kinetic control allows the evolving network to safely bypass the macroscopic immiscibility gap, organizing into highly periodic nanostructures prior to kinetic arrest by cross-linking. This strategy yields mechanically robust BCP monoliths that serve as scalable precursors for complex pore architectures, including monolithic gyroids, establishing a powerful new paradigm for advanced polymer processing and nanostructure fabrication.
