- 學位論文
胺化氧化石墨烯材料特性分析與濕度感測器應用
Material Properties Analysis and Application of Humidity Sensor of Amine-functionalized Graphene Oxide.
摘要
本研究使用不同合成方法備製兩種氧化石墨烯，並將其進行胺化，比較不同製程GO胺化改質的成效及濕度感測特性。藉由掃描式電子顯微鏡觀察表面特徵與型態，以X-射線繞射分析、X光能譜分析儀、傅里葉轉換紅外光譜及拉曼光譜儀分析GO之材料特性，證明氧化較高之GO結晶度較佳、缺陷較少，且富含羧基之GO胺化後，材料特性改變更顯著。透過將GO薄膜沉積於石英晶體微天平(QCM)上，測量其在23%~92%相對濕度環境下之諧振頻率變化與阻抗分析，從電導之半高寬換算品質因素來解釋其振盪所造成之能量損失，並輔以Langmuir方程式計算水氣吸附脫/附之動力學參數，證明胺化GO在濕度感測能力上的提升，最後在23%~75%相對濕度環境下反覆測量，結果顯示其在濕度反覆變化下仍可維持正常運作。由於GO之胺化有助於形成更多氫鍵，能捕獲更多水分子，從而提升溼度傳感器之靈敏度，胺化之GO薄膜作為濕敏材料之QCM濕度感測器，具有大範圍的工作溼度、高靈敏性、極短之響應/回復時間與長時間之穩定特性，這些性能證明胺化改質能提升濕度感測性能，令胺化之氧化石墨烯薄膜足以成為未來溼度傳感器之候選材料。
並列摘要
Two types of synthesized graphene oxide (GO) using different fabricated processess were functionalized by amination process. Comparing the effectiveness of amination and humidity sensing characteristics of GO and amine-functionalized GO. Characteristics of synthesized GO, surface morphology and functional groups were investigated by SEM images, EDS, Fourier transform infrared spectra (FTIR) and Raman spectra. The highly oxidized GO has better crystallinity and fewer defects. The material properties of the carboxyl-rich GO were changed more significantly after amination. GO were deposited on quartz crystal microbalance (QCM) device. The moisture sensitivity of GO loaded on QCM sensors ranging from 23% to 92% related humidity were observed by resonant frequency and impedance measurements. The HBW of conductance peak shows the energy loss of QCM sensors. The enzyme parameters of adsorption-desorption at related humidity 23% to 95% were filtered by Langmuir equation. It show that amination improves the humidity sensing capability of GO. Finally, we displays the dynamic response and recovery curves of the GO sensors which undergo the humidity change (low–high–low) for 3 cycles. Since Amine-functionalized GO forms more hydrogen bonds with H2O, it can catch more water molecules and thus increase the sensitivity of the humidity sensor. The humidity sensor that was made of the amine-functionalized graphene oxide film exhibited a wide range of working humidities, a high sensitivity, satisfactory linearity, a small hysteresis, high flexibility, a short response/recovery time and high long-term stability. Amine-functionalized GO help to capture more water molecules that enhance the sensitivity of humidity sensor, thus amine-functionalized GO film can be a candidate for future humidity sensor material.