Oligomerization-Induced Supramolecular Glass with Superior Processability and Optical Functions

Abstract

The fabrication of glasses, including silicate glasses, polymers, and amorphous metals, typically relies on the melting-quenching technique. However, this approach faces significant challenges when applied to recently emerging molecular glasses due to the inherent thermal instability of small molecules. Herein, the discovery of a new supramolecular glass (BGG) is presented, formed by a unique melting-quenching method that leverages unusual chemistry pathways. By manipulating the heating of a small molecule (benzoguanamine, BG), catalyst-free self-condensation reactions occur and produce multiple oligomers in a liquid state. The resulting high compositional and conformational entropy suppresses crystallization, allowing solidification into a rigid supramolecular glass under robust conditions. Despite being composed of low-weight molecules, the extensive intermolecular interactions endow BGG with distinct aggregation-induced emission (AIE, quantum yield up to 60%), polymer-like Young's modulus (7.95 GPa), and superior glass transition temperature (100.1 °C). BGG's excellent processability is exemplified by the fabrication of thin films and fibers, showcasing potential applications in photovoltaics and photonic waveguides. BGG also serves as a platform for synthesizing diverse donor-acceptor hybrids with > 95% energy transfer efficiency, enabling the creation of advanced materials with customizable functionalities.