对负离子对氧化石墨烯/聚苯胺电磁性能的影响

Effect of counter anions on the electromagnetic properties of graphene oxide/polyaniline

摘要:

以过硫酸铵为引发剂，控制掺杂质子浓度为1 mol/L，分别以Cl-、CSA-（樟脑磺酸根）和SO42-为对负离子，通过原位化学氧化聚合法制备得到掺杂态氧化石墨烯/聚苯胺复合材料。采用SEM、FTIR和XRD对复合材料进行形貌和结构表征，采用四探针法、矢量网络分析仪分别测试复合材料的电磁参数，并计算材料的阻抗和反射损耗（RL）。结果表明，3种复合材料均呈现聚苯胺纳米椎体包覆氧化石墨烯片层的三明治形貌。对负离子为SO42-时，复合物的电导率最高为5.500 S/cm，同时介电损耗能力最强。而樟脑磺酸掺杂复合物的驻波比在14.2 GHz处可达到1.1，更接近行波状态，具有最佳阻抗匹配性能。其最佳反射损耗为-30 dB（9.925 GHz，2.75 mm），有效吸波频宽（RL小于–10 dB的频率范围）最高可至4.845 GHz（12.305~17.15 GHz，2 mm）。

Abstract:

The graphene oxide/polyaniline composites were synthesized by in-situ chemical oxidation polymerization using Cl-, CSA- (camphor sulfonic anion group) and SO42- as counter anions, with 1 mol/L proton concentration and ammonium persulfate as initiator. SEM, FTIR and XRD analyses were conducted to characterize the morphologies and structures, four-probe method and vector network analyzer were employed to determine the electromagnetic parameters. The impedance and reflection loss (RL) were calculated. The results indicated that the three types of composites appear to be sandwich-like structure with graphene oxide layer coated by polyaniline nanocones. The electronic conductivity reaches 5.500 S/cm portending higher dielectric loss capacity, when the para-anion is SO42-. While the standing-wave ratio of CSA doping composite is up to 1.1 at 14.2 GHz and much closer to a traveling wave state suggesting the best impedance matching, whose minimum RL reaches -30 dB (9.925 GHz, 2.75 mm) and effective absorbing bandwidth (RL<-10 dB) reaches 4.845 GHz (12.305~17.15 GHz, 2 mm).