本研究是利用一鍋化溶液混合法(one-pot solution-mixing)來製備還原氧化石墨烯(RGO)和聚二甲基二烯丙基氯化銨(PDDA)(RGO/PDDA)奈米複合材料薄膜並應用於阻抗型濕度感測器。利用原子力顯微鏡(AFM)、傅立葉轉換紅外光譜儀(FTIR)以及拉曼光譜儀來分析RGO/PDDA 奈米複合材料薄膜之表面特徵及其材料結構特徵。並利用量測RGO/PDDA 奈米複合材料薄膜之相對濕度對電性的函數，進一步探討RGO 添加量的多寡對於RGO/PDDA 奈米複合材料薄膜之電性和濕度感測特性，以證明RGO在RGO/PDDA奈米複合材料中的濕度感測之角色。以RGO/PDDA 奈米複合材料薄膜所製成的阻抗型濕度感測器具有耐高濕(97%RH)和化學環境(20% 乙醇蒸氣)的良好材料特性、長的工作濕度範圍、高感度、良好的線性、濕滯現象小、反應及回覆時間短、低溫度依賴性以
及長期穩定度高。另外利用頻譜阻抗來探討RGO/PDDA 奈米複合材料薄膜之濕度感應機制。
Novel impedance-type humidity sensors based on reduced graphene oxide and poly (diallyldimethylammonium chloride) (RGO/PDDA) nanocomposite film were fabricated by the one-pot solution-mixing route. The effects of the amount of added RGO on the electrical and humidity-sensing properties of the RGO/PDDA nanocomposite film were investigated. The RGO/PDDA nanocomposite film was characterized by atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) and Raman. The electrical and humidity-sensing properties of the RGO/PDDA nanocomposite film to which various amounts of RGO were added were measured in detail as a function of relative humidity, to elucidate the contribution of RGO to the humidity-sensing capacity. The impedance-type humidity sensor that was made of the RGO/PDDA nanocomposite film exhibited satisfactory resistance to high humidity atmosphere (97% RH) and chemical environment (20% C2H5OH vapor), a wide range of working humidities, a high sensitivity, good linearity, a small hysteresis, a short response/recovery time, a weak dependence on temperature and high long-term stability. The sensing mechanism of the RGO/PDDA nanocomposite film was explained with reference to impedance plots.
