Ogurtsov Nikolay A, Bliznyuk Valery N, Mamykin Andrii V, Kukla Oleksandr L, Piryatinski Yuri P, Pud Alexander A
Institute of Bioorganic Chemistry and Petrochemistry, NAS of Ukraine, 50 Kharkivske shose, Kyiv, 02160, Ukraine.
Phys Chem Chem Phys. 2018 Feb 28;20(9):6450-6461. doi: 10.1039/c7cp07604e.
We report significant improvements in the structure and electronic properties of a poly(3-alkylthiophene) representative, namely poly(3-methylthiophene) (P3MT), when it is synthesized in the presence of submicron electroactive poly(vinylidene fluoride) (PVDF) particles. The applied template oxidative synthesis leads to the formation of the PVDF/P3MT composite consisting of core-shell particles. The shells are constituted with a monolayer of 20-40 nm nanoparticles of the doped P3MT (P3MT-Cl) precipitated at the surface of the spherical PVDF cores. This morphology differs strongly from the hierarchical one of the neat P3MT synthesized without PVDF particles. In the latter case, 20-60 nm P3MT nanoparticles form ∼200 nm aggregates, which, in turn, are arranged in a few micrometer agglomerates. Furthermore, we demonstrate that compared to the neat polymer, doped P3MT in the shells of the composite is characterized with higher effective conjugation length, regioregularity of the molecular structure, improved intrachain packing order and lower bipolaron/polaron ratio. These features of the PVDF/P3MT composite strongly suggest applicability of this material in various electronic devices. As a proof of concept, we report on an improved sensing performance of the PVDF/P3MT-Cl composite compared with the neat P3MT-Cl in detection of several volatile organic compounds known as markers for some diseases and toxic substances. We have discovered that the maximal improvement in the sensor response magnitude corresponds to the case when the values of the analyte electronegativity and polythiophene work function are close. We associate this behavior with a higher surface dipole component of the work function of the PVDF/P3MT-Cl composite compared to that of the neat conducting polymer.
我们报道了一种聚（3-烷基噻吩）代表物，即聚（3-甲基噻吩）（P3MT），在亚微米级电活性聚偏二氟乙烯（PVDF）颗粒存在下合成时，其结构和电子性能有显著改善。所采用的模板氧化合成法导致形成了由核壳颗粒组成的PVDF/P3MT复合材料。壳层由沉淀在球形PVDF核表面的单层20 - 40 nm掺杂P3MT（P3MT-Cl）纳米颗粒构成。这种形态与在没有PVDF颗粒的情况下合成的纯P3MT的分层形态有很大不同。在后一种情况下，20 - 60 nm的P3MT纳米颗粒形成约200 nm的聚集体，这些聚集体又排列成几微米的团聚体。此外，我们证明，与纯聚合物相比，复合材料壳层中的掺杂P3MT具有更高的有效共轭长度、分子结构的区域规整性、改善的链内堆积顺序和更低的双极化子/极化子比率。PVDF/P3MT复合材料的这些特性强烈表明这种材料在各种电子器件中的适用性。作为概念验证，我们报道了与纯P3MT-Cl相比，PVDF/P3MT-Cl复合材料在检测几种作为某些疾病和有毒物质标志物的挥发性有机化合物时具有更好的传感性能。我们发现，传感器响应幅度的最大改善对应于分析物电负性和聚噻吩功函数值接近的情况。我们将这种行为与PVDF/P3MT-Cl复合材料相比纯导电聚合物具有更高的功函数表面偶极子分量联系起来。
