Istif Emin, Mantione Daniele, Vallan Lorenzo, Hadziioannou Georges, Brochon Cyril, Cloutet Eric, Pavlopoulou Eleni
Laboratoire de Chimie des Polymères Organiques (LCPO - UMR 5629), Bordeaux INP , Université de Bordeaux, CNRS , 16 Av. Pey-Berland , Pessac 33607 , France.
ACS Appl Mater Interfaces. 2020 Feb 19;12(7):8695-8703. doi: 10.1021/acsami.9b21058. Epub 2020 Feb 7.
The pursuit for novelty in the field of (bio)electronics demands for new and better-performing (semi)conductive materials. Since the discovery of poly(3,4-ethylenedioxythiophene) (PEDOT), the ubiquitous golden standard, many studies have focused on its applications but only few on its structural modification and/or functionalization. This lack of structural variety strongly limits the versatility of PEDOT, thus hampering the development of novel PEDOT-based materials. In this paper, we present a short and simple strategy for introducing an aldehyde functionality in thiophene-based semiconducting polymers. First, through a two-step synthesis, an EDOT-aldehyde derivative was prepared and polymerized, both chemically and electrochemically. Next, to overcome the inability of thiophene-aldehyde to be polymerized by any means, we synthesized a trimer in which thiophene-aldehyde is enclosed between two EDOT groups. The successful chemical and electrochemical polymerization of this new trimer is presented. The polymer suspensions were characterized by ultraviolet-visible-near-infrared spectroscopy, while the corresponding films were characterized by Fourier transform infrared and four-point-probe conductivity measurements. Afterward, insoluble semiconducting films were formed by using ethylenediamine as a cross-linker, demonstrating in this way the suitability of the aldehyde group for the easy chemical modification of our material. The efficient reactivity conferred by aldehyde groups was also exploited for grafting fluorescent polyamine nanoparticles on the film surface, creating a fluorescent semiconducting polymer film. The films prepared by electropolymerization, as shown by means of a sonication test, exhibit strong surface adhesion on pristine indium tin oxide (ITO). This property paves the way for the application of these polymers as conductive electrodes for interfacing with living organisms. Thanks to the high reactivity of the aldehyde group, the aldehyde-bearing thiophene-based polymers prepared herein are extremely valuable for numerous applications requiring the facile incorporation of a functional group on thiophene, such as the functionalization with labile molecules (thermo-, photo-, and electro-labile, pH sensitive, etc.).
（生物）电子领域对新型材料的追求需要性能更优的新型（半）导电材料。自从发现聚（3,4 - 乙撑二氧噻吩）（PEDOT）这一普遍使用的黄金标准材料以来，许多研究都聚焦于其应用，而对其结构修饰和/或功能化的研究却很少。这种结构多样性的缺乏严重限制了PEDOT的通用性，从而阻碍了新型PEDOT基材料的开发。在本文中，我们提出了一种简短而简单的策略，用于在基于噻吩的半导体聚合物中引入醛基官能团。首先，通过两步合成法制备并聚合了一种EDOT - 醛衍生物，包括化学聚合和电化学聚合。接下来，为了克服噻吩醛无法通过任何方法聚合的问题，我们合成了一种三聚体，其中噻吩醛被夹在两个EDOT基团之间。本文展示了这种新型三聚体成功的化学和电化学聚合过程。通过紫外 - 可见 - 近红外光谱对聚合物悬浮液进行了表征，而通过傅里叶变换红外光谱和四点探针电导率测量对相应的薄膜进行了表征。之后，使用乙二胺作为交联剂形成了不溶性半导体薄膜，以此证明醛基对于我们材料的简便化学修饰的适用性。醛基赋予的高效反应活性还被用于在薄膜表面接枝荧光多胺纳米颗粒，从而制备出荧光半导体聚合物薄膜。通过超声测试表明，电聚合制备的薄膜在原始氧化铟锡（ITO）上具有很强的表面附着力。这一特性为这些聚合物作为与生物机体连接的导电电极的应用铺平了道路。由于醛基的高反应活性，本文制备的含醛基噻吩基聚合物对于众多需要在噻吩上轻松引入官能团的应用极为有价值，例如用不稳定分子（热不稳定、光不稳定、电不稳定、pH敏感等）进行功能化。
