Herein, we report negative anomalous electrical tunability of the nanocomposite chitosan and graphene oxide (CS–GO) films based upon the dependence of dielectric constant and resistivity on DC bias. The origin of such anomalous tunability can be traceable to the reversible transformation of GO to reduced graphene oxide. In this transformation, H+ ions are released from water or GO side groups and those of $${\text{NH}}_{3}^{ + }$$ from CS; both ions participate in the reversible reduction process. Here, the capacitance exhibits negative tunability such that the dielectric constant increases and the resistivity decreases with increasing of DC bias. To probe this new phenomenon, we studied GO concentrations from 0 to 15 wt.% and water contents from 0 to 25 wt.%. Our results suggest that chitosan–GO nanocomposites can be readily prepared for the development of novel devices required in flexible organic electronics.

中文翻译：

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壳聚糖-氧化石墨烯纳米复合材料的负电可调性

在此，我们报告了基于介电常数和电阻率对 DC 偏压的依赖性的纳米复合壳聚糖和氧化石墨烯（CS-GO）薄膜的负异常电可调性。这种异常可调性的起源可以追溯到 GO 向还原氧化石墨烯的可逆转变。在这个转换中，H+ 离子从水或 GO 侧基中释放出来，而 $${\text{NH}}_{3}^{ + }$$ 则从 CS 中释放出来；两种离子都参与可逆还原过程。这里，电容表现出负可调性，使得介电常数增加，电阻率随着直流偏置的增加而降低。为了探索这种新现象，我们研究了 0 到 15 wt.% 的 GO 浓度和 0 到 25 wt.% 的水含量。