Ubiquitous Chiral Symmetry Breaking of Conjugated Polymers via Liquid-Liquid Phase Separation

Spontaneous chiral symmetry breaking remains a fascination in chemistry, biology, materials science, and even astronomy. Chiral symmetry breaking usually requires intrinsic molecular chirality or extrinsic chiral sources but remains rare in non-chiral systems. Here, we reveal a ubiquitous, entropy-driven chiral symmetry breaking mechanism observed in 22 out of 35 conjugated polymers in the absence of any chiral source – a phenomenon overlooked for decades. Chiral assemblies spontaneously occur through liquid-liquid phase separation (LLPS) of lyotropic mesophases from isotropic solutions upon concentration increase. Machine learning identifies underpinning molecular features validated by further molecular design. The universality of this phenomenon hints at a possible link between LLPS and chiral symmetry breaking in the origin of life while paving the way for an emerging frontier of chiral electronics.