Room-Temperature High-Efficiency Solid-State Triplet-Triplet Annihilation Up-Conversion in Amorphous Poly(olefin sulfone)s.
Room-Temperature High-Efficiency Solid-State Triplet-Triplet Annihilation Up-Conversion in Amorphous Poly(olefin sulfone)s.
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DOI：
10.1021/acsami.6b12625
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发表时间：
2017-02
影响因子：
9.5
通讯作者：
A. Turshatov;D. Busko;N. Kiseleva;S. Grage;I. Howard;B. Richards
中科院分区：
文献类型：
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作者：
A. Turshatov;D. Busko;N. Kiseleva;S. Grage;I. Howard;B. Richards
三重态-三重态湮灭上转换（TTA-UC）是一种能够在太阳光下实现光谱转换的新兴技术。先前，发现对于高于聚合物的玻璃化转变温度（T > Tg），可以在聚合物主体中实现有效的TTA-UC。相比之下，TTA-UC具有高的量子产率的温度低于Tg很少报道。在这篇文章中，我们报告了新的聚合物主机，其中有效的TTA-UC观察到远低于Tg，当聚合物是在一个完全的固体状态。用上转换染料负载四种聚（烯烃砜）主体，并测量TTA-UC的绝对量子产率（ηTTA-UC）。对于聚（1-十二碳烯砜）测得ηTTA-UC = 2.1%的最高值。重要的是，该值在真空和环境条件下相同，表明主体材料具有良好的氧气屏障作用。我们进行了时间分辨发光实验，以阐明TTA-UC的基本步骤的影响。除了光学表征，我们使用魔角旋转固态NMR实验来估计T2横向弛豫时间。相对较长的T2时间测量的聚（烯烃砜）的研究（共）聚合物，这出乎意料地与宏观上的刚性共存的纳米级流动性的增强。这可以解释客体分子之间特殊的三重态能量转移，尽管宏观刚性。
Triplet-triplet annihilation up-conversion (TTA-UC) is a developing technology that can enable spectral conversion under sunlight. Previously, it was found that efficient TTA-UC can be realized in polymer hosts for temperatures above the polymer's glass transition (T > Tg). In contrast, TTA-UC with high quantum yield for temperatures below Tg is rarely reported. In this article, we report new polymer hosts in which efficient TTA-UC is observed well below Tg, when the polymer is in a fully solid state. The four poly(olefin sulfone) hosts were loaded with upconversion dyes, and absolute quantum yields of TTA-UC (ηTTA-UC) were measured. The highest value of ηTTA-UC = 2.1% was measured for poly(1-dodecene sulfone). Importantly, this value was the same in vacuum and at ambient conditions, indicating that the host material acts as a good oxygen barrier. We performed time-resolved luminescence experiments in order to elucidate the impact of elementary steps of TTA-UC. In addition to optical characterization, we used magic angle spinning solid-state NMR experiments to estimate the T2 transverse relaxation time. Relatively long T2 times measured for poly(olefin sulfone)s indicate an enhanced nanoscale fluidity in the studied (co)polymers, which unexpectedly coexists with a rigidity on the macroscale. This would explain the exceptional triplet energy transfer between the guest molecules, despite the macroscopic rigidity.