Dumbravă Oana, Popovici Dumitru, Vasincu Decebal, Popa Ovidiu, Ochiuz Lăcrămioara, Irimiciuc Ștefan-Andrei, Agop Maricel, Negură Anca
"Petru Poni" Institute of Macromolecular Chemistry, Gr. Ghica Voda Alley, 41A, 700487 Iasi, Romania.
Department of Biophysics and Medical Physics, Faculty of Dental Medicine, "Grigore T. Popa" University of Medicine and Pharmacy, 16 University Str., 700115 Iasi, Romania.
Polymers (Basel). 2022 Apr 6;14(7):1487. doi: 10.3390/polym14071487.
Organic semiconductors are an attractive class of materials with large application in various fields, from optoelectronics to biomedicine. Usually, organic semiconductors have low electrical conductivity, and different routes towards improving said conductivity are being investigated. One such method is to increase their ordering degree, which not only improves electrical conduction but promotes cell growth, adhesion, and proliferation at the polymer-tissue interface. The current paper proposes a mathematical model for understanding the influence of the ordering state on the electrical properties of the organic semiconductors. To this end, a series of aromatic poly(azomethine)s were prepared as thin films in both amorphous and ordered states, and their supramolecular and electrical properties were analyzed by polarized light microscopy and surface type cells, respectively. Furthermore, the film surface characteristics were investigated by atomic force microscopy. It was established that the manufacture of thin films from mesophase state induced an electrical conductivity improvement of one order of magnitude. A mathematical model was developed in the framework of a multifractal theory of motion in its Schrodinger representation. The model used the order degree of the thin films as a fractality measure of the physical system's representation in the multifractal space. It proposed two types of conductivity, which manifest at different ranges of fractalization degrees. The mathematical predictions were found to be in line with the empirical data.
有机半导体是一类极具吸引力的材料，在从光电子学到生物医学等各个领域都有广泛应用。通常，有机半导体的电导率较低，目前正在研究各种提高其电导率的方法。其中一种方法是提高它们的有序度，这不仅能改善导电性能，还能促进聚合物 - 组织界面处的细胞生长、黏附及增殖。本文提出了一个数学模型，用于理解有序状态对有机半导体电学性质的影响。为此，制备了一系列处于非晶态和有序态的芳香族聚（偶氮甲碱）薄膜，并分别通过偏光显微镜和表面型电池对其超分子和电学性质进行了分析。此外，还通过原子力显微镜研究了薄膜的表面特性。结果表明，由中间相态制备薄膜可使电导率提高一个数量级。在薛定谔表象的多分形运动理论框架内建立了一个数学模型。该模型将薄膜的有序度用作多分形空间中物理系统表征的分形性度量。它提出了两种类型的电导率，分别在不同的分形化程度范围内表现出来。研究发现数学预测与实验数据相符。
