Incorporating π-Conjugated Amino Acids Into Multi-Functional Amorphous Materials.

Abstract

The controlled fabrication of amorphous materials from small organic molecules and their translation into high-performance functional materials remain long-standing challenges. Here, we introduce a multicomponent assembly strategy to developed amorphous materials from π-conjugated amino acids, offering a versatile platform for high-performance adhesive and optical applications. The incorporation of proline-based building blocks into multicomponent networks bypasses the crystallization-induced self-assembly that otherwise dominates in solution, thereby driving liquid-liquid phase separation-like pathways to yield amorphous aggregates. These aggregates exhibit exceptional thermoreversible adhesion to iron-based substrates, with their densely packed architecture facilitating rarely observed excimer emission of fluorene. Furthermore, enhanced charge-transfer interactions with 1,2,4,5-tetracyanobenzene shift the photoluminescence from indigo to green, increase the quantum yield by orders of magnitude, and transition the emission from short-lived prompt fluorescence to long-lived thermally activated delayed fluorescence. Through supercooling, amorphous glasses with high hardness and optical transparency were successfully fabricated, wherein increasing the number of components enables systematic tuning of surface roughness, wettability, quantum yield, emission wavelength, and excited-state lifetime. This work establishes a novel paradigm for synthesizing amorphous materials within multicomponent high-entropy systems, positioning amino acid and short peptide derivatives as a versatile class of biomolecular building blocks for advanced adhesive and photonic applications.