Wang Chang, Qu Lunjun, Chen Xiaohong, Zhou Qian, Yang Yan, Zheng Yan, Zheng Xian, Gao Liang, Hao Jinqiu, Zhu Lingyun, Pi Bingxue, Yang Chaolong
School of Materials Science and Engineering, Chongqing University of Technology, Chongqing, 400054, China.
Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China.
Adv Mater. 2022 Aug;34(34):e2204415. doi: 10.1002/adma.202204415. Epub 2022 Jul 22.
Room-temperature phosphorescence (RTP) materials have garnered considerable research attention owing to their excellent luminescence properties and potential application prospects in anti-counterfeiting, information storage, and optoelectronics. However, several RTP systems are extremely sensitive to humidity, and consequently, the realization of long-lived RTP in water remains a formidable challenge. Herein, a feasible and effective strategy is presented to achieve long-lived polymeric RTP systems, even in an aqueous environment, through doping of synthesized polymeric phosphor PBHDB into a poly(methyl methacrylate) (PMMA) matrix. Compared to the precursor polymer PBN and organic molecule HDBP, a more rigid polymer microenvironment and electrostatic interaction are formed between the PMMA matrix and polymer PBHDB, which effectively reduce the nonradiative decay rate of triplet excitons and dramatically increase the phosphorescence intensity. Specifically, the phosphorescence lifetime of the PBHDB@PMMA film (1258.62 ms) is much longer than those of PBN@PMMA (674.20 ms) and HDBP@PMMA (1.06 ms). Most importantly, a bright-green afterglow can be observed after soaking the PBHDB@PMMA film in water for more than a month. The excellent water resistance and reversible response properties endow these systems with promising potential for dynamic information encryption even in water.
室温磷光（RTP）材料因其优异的发光性能以及在防伪、信息存储和光电子学方面的潜在应用前景而受到了广泛的研究关注。然而，一些RTP体系对湿度极其敏感，因此，在水中实现长寿命RTP仍然是一项艰巨的挑战。在此，我们提出了一种可行且有效的策略，通过将合成的聚合物磷光体PBHDB掺杂到聚甲基丙烯酸甲酯（PMMA）基质中，即使在水性环境中也能实现长寿命的聚合物RTP体系。与前体聚合物PBN和有机分子HDBP相比，PMMA基质与聚合物PBHDB之间形成了更刚性的聚合物微环境和静电相互作用，这有效地降低了三重态激子的非辐射衰减速率，并显著提高了磷光强度。具体而言，PBHDB@PMMA薄膜的磷光寿命（1258.62毫秒）比PBN@PMMA（674.20毫秒）和HDBP@PMMA（1.06毫秒）长得多。最重要的是，将PBHDB@PMMA薄膜浸泡在水中一个多月后，可以观察到亮绿色的余辉。优异的耐水性和可逆响应特性使这些体系即使在水中也具有动态信息加密的广阔潜力。
