Quantitatively monitoring polymer chain growth and topology formation based on monodisperse polymers
Quantitatively monitoring polymer chain growth and topology formation based on monodisperse polymers
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基于单分散聚合物定量监测聚合物链增长和拓扑形成
DOI：
10.1039/c7py00322f
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发表时间：
2017-04
影响因子：
4.6
通讯作者：
Zhang Zhengbiao
中科院分区：
文献类型：
--
作者：
Wang Zimu;Huang Zhihao;Zhou Nianchen;Dong Xue-Hui;Zhu Xiulin;Zhang Zhengbiao
在这项工作中，第一次，聚合物链的生长和拓扑结构的形成进行了监测和定量评估，使用基于马来酰亚胺的荧光探针的基础上的光诱导电子转移（PET）机制。合理设计了一种末端带有马来酰亚胺和巯基官能团的含芴单体。模型反应证明了芴的荧光被相邻的马来酰亚胺基团有效地猝灭。首先，分子量和荧光强度之间的相关性被建立作为校准曲线，使用精确合成的单分散聚合物与不同数量的重复单元通过迭代指数增长策略。其次，逐步增长聚合的马来酰亚胺-芴-硫醇单体逐步消耗马来酰亚胺基团在聚合物链增长，并导致荧光逐渐增加。这提供了一种定量和稳健的方法来监测聚合过程中原位。此外，通过分子内硫醇-马来酰亚胺迈克尔加成在线性前体的高度稀释的溶液中产生环状低聚物，并且由于马来酰亚胺基团的消除，环化过程导致荧光强度逐渐增强。因此，可以基于荧光发射定量计算在确定时间的环状低聚物含量，从而实现用于监测/监视环化过程的实时方法。我们进一步应用这种荧光探针方法来定量监测具有更复杂拓扑结构的聚合物的形成，例如“环状刷状”大分子。这项工作展示了一个简单，强大，通用的平台，用于监测聚合过程中原位，这可能会激发和促进不同的分子设计和制备领域的精密聚合物合成。
In this work, for the first time, polymer chain growth and topology formation was monitored and quantitatively evaluated using a maleimide-based fluorogenic probe based on a photo-induced electron transfer (PET) mechanism. A fluorene-containing monomer bearing terminal maleimide and thiol functional groups was rationally designed. The fluorescence of fluorene was effectively quenched by the adjacent maleimide group, which was proved by model reactions. Firstly, the correlation between molecular weight and fluorescence intensity was established as a calibration curve using precisely synthesized monodisperse polymers with varying numbers of repeating units via an iterative exponential growth strategy. Secondly, step-growth polymerization of the maleimide–fluorene–thiol monomer progressively consumed the maleimide group during polymer chain propagation and led to a gradual increase of fluorescence. This provides a quantitative and robust approach to monitor polymerization processes in situ. Moreover, cyclic oligomers were produced via intramolecular thiol–maleimide Michael addition in highly diluted solutions of linear precursors, and the cyclization process resulted in gradual enhancements of fluorescence intensity due to the elimination of maleimide groups. The cyclic oligomer content at a determined time can thus be quantitatively calculated based on fluorescence emission, enabling a real-time approach for monitoring/surveilling the cyclization process. We further applied this fluorogenic probe method to quantitatively monitor the formation of polymers with more complicated topologies, such as “cyclic-brush-like” macromolecules. This work demonstrates a facile, robust, and versatile platform for monitoring polymerization processes in situ, which may inspire and facilitate diverse molecular design and preparation in the field of precision polymer synthesis.
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影响因子：
4.6
作者：
M. S. Frahn;L. H. Luthjens;J. Warman
通讯作者：
M. S. Frahn;L. H. Luthjens;J. Warman
影响因子：
4.6
作者：
Ö. Pekcan;Y. Yılmaz;O. Okay
通讯作者：
Ö. Pekcan;Y. Yılmaz;O. Okay
影响因子：
3
作者：
R. A. M. Vieira;C. Sayer;E. Lima;J. Pinto
通讯作者：
R. A. M. Vieira;C. Sayer;E. Lima;J. Pinto
影响因子：
15
作者：
Killops, Kato L.;Campos, Luis M.;Hawker, Craig J.
通讯作者：
Hawker, Craig J.
DOI：
10.1021/j100205a001
发表时间：
1992-12
期刊：
The Journal of Physical Chemistry
影响因子：
--
作者：
S. R. Bigham;J. Coffer
通讯作者：
S. R. Bigham;J. Coffer