Tonge Christopher M, Paisley Nathan R, Polgar Alexander M, Lix Kelsi, Algar W Russ, Hudson Zachary M
Department of Chemistry , The University of British Columbia , 2036 Main Mall , Vancouver , British Columbia , Canada V6T 1Z1.
ACS Appl Mater Interfaces. 2020 Feb 5;12(5):6525-6535. doi: 10.1021/acsami.9b22464. Epub 2020 Jan 28.
Polymer-based emitters are a promising route to the production of low-cost, scalable solution-processable luminescent materials. Here we describe a series of acrylic oxadiazole-based donor-acceptor monomers with tunable emission from blue to orange, with quantum yields as high as 96%. By introducing structural constraints that limit donor-acceptor orbital overlap, thermally activated delayed fluorescence (TADF) was observed in these materials. Polymerization by Cu(0) reversible deactivation radical polymerization (RDRP) gave high-molecular-weight copolymers ( > 20 kDa) with dispersities ranging from 1.10 to 1.45, using a room-temperature procedure with Cu wire as a catalyst. One of these materials, which had phenothiazine as donor moiety, exhibited conformationally dependent dual emission, giving a mixture of prompt fluorescence and delayed fluorescence peaks, whose relative ratios varied based on the amount of O present during measurement. We demonstrate that this material can combine prompt and delayed fluorescence to act as a single-component, all-organic, ratiometric oxygen sensor without external calibrant. Application to ratiometric oxygen sensing is demonstrated both using a polymer thin film and via incorporation of this material into water-soluble polymer dots (Pdots), with a ratiometric response to O throughout the range of partial pressures relevant to biological environments.
基于聚合物的发光体是生产低成本、可扩展的溶液可加工发光材料的一条有前途的途径。在此，我们描述了一系列基于丙烯酸恶二唑的供体-受体单体，其发射光从蓝色可调至橙色，量子产率高达96%。通过引入限制供体-受体轨道重叠的结构限制，在这些材料中观察到了热激活延迟荧光（TADF）。使用铜丝作为催化剂，通过室温下的铜（0）可逆失活自由基聚合（RDRP）进行聚合，得到了高分子量共聚物（>20 kDa），分散度在1.10至1.45之间。其中一种以吩噻嗪作为供体部分的材料表现出构象依赖性双重发射，产生即时荧光和延迟荧光峰的混合物，其相对比例根据测量过程中存在的氧含量而变化。我们证明，这种材料可以结合即时荧光和延迟荧光，作为一种无需外部校准剂的单组分全有机比率型氧传感器。使用聚合物薄膜以及将这种材料掺入水溶性聚合物点（Pdots）中，都证明了其在比率型氧传感中的应用，在与生物环境相关的整个分压范围内对氧具有比率响应。
