The Formation of Supramolecular Rigid Glass Based on Transparent Deep Eutectic
Xi Hou, Jianqiang Meng, Tianqiang Yin, Xin Tan, Juan Li, Gai Zhao, Shengyi Dong
Abstract
The development of transparent materials with mechanical rigidity and hardness via the non-covalent bonding of low-molecular-weight building blocks is a major challenge. Although various strategies have been developed to improve the mechanical performance of supramolecular materials, they are frequently accompanied by complex designs and tedious syntheses. Therefore, it is urgent to develop perspectives that are fundamentally distinguished from previous strategies. In this study, a new design solution that involves with non-covalent molecular recognition, deep eutectic solvent formation, and solvent-free photopolymerization is conceived and validated. Metal coordination and hydrogen bonding between zinc tetrafluoroborate hydrate (ZTH) and acrylamide (AM) facilitated the formation of ZTH-AM, which can be recognized as the analogue of the glass liquid in the preparation of inorganic glass. ZTH-AM significantly suppressed the nucleation and crystallization of ZTH and AM. Subsequently, it is used to fabricate transparent poly[ZTH-AM] glass in bulk using photopolymerization. The obtained supramolecular glass is rigid, exhibiting high tensile strength (93.50 MPa), Young's modulus (1.12 GPa), and hardness (92.1 HD).