Branched Copolymers with Tunable Clusteroluminescence in High Quantum Yield

Abstract

A novel type of fluorescence without large conjugated structures called clusteroluminescence (CL) has attracted a great deal of attention in recent years. Despite its many advantages, the emerging CL still encounters difficulties of low quantum yield (QY) and preliminary mechanisms. In this work, the branched structure was introduced into poly(maleic anhydride-alt-vinyl acetate) by chain transfer monomer. The emission wavelength of the branched copolymers is red-shifted with the increase of branching degree, and the absolute QY of solids can reach up to 29.87%. Further characterizations reveal that the branched structure can improve the flexibility of polymer chains, thereby promoting the intrachain interactions of subgroups. Furthermore, in the case of branched anhydride copolymers, the equilibrium between intrachain interactions and nonradiative transitions holds a crucial significance in determining the QY. This endeavor not only offers new insights into the mechanism of CL but also presents a novel approach to surmount the low QY of anhydride copolymers, thus broadening the horizons of CLgens to unexplored domains.

Hyperbranched Poly(vinyl ether ester)s with Structure-Dependent Intrinsic Fluorescence: Synthesis, Properties, and Applications

“…The construction of functional polymers with regular structures, exceptional performance, and broad applicability holds considerable academic and industrial value. As a vital category of advanced functional materials, fluorescent polymers have garnered increasing interest over decades owing to their distinctive optical properties and considerable potential in applications such as sensors, cell imaging, and drug delivery. − In particular, fluorescent polymers with highly branched structures are the focus of growing attention. − On the one hand, hyperbranched fluorescent polymers showed higher fluorescence quantum yields than linear analogous polymers because these polymers, with their three-dimensional globular architectures, mitigate self-quenching and enhance the fluorescence quantum yield by reducing interchain interactions and π–π stacking. , On the other hand, hyperbranched fluorescent polymers have attractive features such as highly branched topology, numerous terminal functional groups, adjustable chemical structures, and convenient synthetic procedures, which make them applicable in various fields. − Over the past two decades, various fluorescent hyperbranched polymers have been developed, including conjugated, dye-modified, AIEgen-derived, and nonconjugated − fluorescent polymers.…”