Graphene products have been used as conductor filler in polymers matrix, resulting in a conductive composite for optoelectronic applications. In this work, the effect of oxygen content of reduced graphene oxide (rGO) products on its dispersion in poly(3-hexylthiophene) (P3HT) and the electrical properties of the P3HT-rGO composites is studied. Graphene oxides (GOs) with different concentrations of oxygen species were first prepared by a modified Tour method. Each GO product was reduced with the same amount of L-ascorbic acid to obtain the corresponding rGO. By using X-Ray Photoelectron Spectroscopy (XPS) and Raman spectroscopy, oxygen-related species and their concentration in GO and rGO products have been identified. The sizes of graphene sheets in those two carbon products are estimated by Dynamic Light Scattering (DLS) method. We find that the dispersion degree of the rGO product in a hydrophobic P3HT matrix depends on content of carboxyl (–COOH) and epoxy (C–O–C) groups on GO as well as on the graphene sheet size. At the same time, the most reduced and conductive rGO product (rGO-4) comes from a GO with the lowest oxygen content and lowest concentration of –COOH species, giving the largest graphene sheet sizes and spacing between the sheets. The homogeneous P3HT-rGO-4 composite material shows a micrometer sized laminated structure and a percolation threshold point around 20 wt%. The electrical conductivity of the composite is close to 10^–1 S m⁻¹, two orders of magnitude larger than the pristine P3HT. It is concluded that the electrical properties of rGO products can be improved by tailoring the type and concentration of oxygen species in GO.

石墨烯产品已用作聚合物基体中的导体填料，从而形成了用于光电应用的导电复合材料。在这项工作中，研究了还原的氧化石墨烯（rGO）产物的氧含量对其在聚（3-己基噻吩）（P3HT）中的分散性和P3HT-rGO复合材料的电学性能的影响。首先通过改进的Tour方法制备具有不同氧物种浓度的氧化石墨烯（GOs）。用相同量的L-抗坏血酸还原每种GO产物，以获得相应的rGO。通过使用X射线光电子能谱（XPS）和拉曼光谱，已经确定了与氧气有关的物种及其在GO和rGO产品中的浓度。这两种碳产品中石墨烯片的尺寸通过动态光散射（DLS）方法估算。我们发现，rGO产物在疏水性P3HT基质中的分散程度取决于GO上羧基（–COOH）和环氧基（C–OC–C）的含量以及石墨烯片的尺寸。同时，还原性和导电性最高的rGO产品（rGO-4）来自具有最低氧含量和–COOH物种浓度最低的GO，从而提供了最大的石墨烯片尺寸和片间距。均质的P3HT-rGO-4复合材料显示出微米级的层压结构，其渗透阈值约为20 wt％。复合材料的电导率接近10 还原性和导电性最高的rGO产品（rGO-4）来自具有最低氧含量和–COOH种类最低浓度的GO，从而提供了最大的石墨烯片尺寸和片间距。均质的P3HT-rGO-4复合材料显示出微米级的层压结构，其渗透阈值约为20 wt％。复合材料的电导率接近10 还原性和导电性最高的rGO产品（rGO-4）来自具有最低氧含量和–COOH种类最低浓度的GO，从而提供了最大的石墨烯片尺寸和片间距。均质的P3HT-rGO-4复合材料显示出微米级的层压结构，其渗透阈值约为20 wt％。复合材料的电导率接近10^–1 S m ^-1，比原始的P3HT大两个数量级。结论是，可以通过调整GO中的氧种类和浓度来改善rGO产品的电性能。