芳香基表面修飾之奈米金粒子與其在氣體感測器之應用

Abstract

本篇論文主要藉由兩種不同反應條件的兩相合成法，將不同碳鏈 的芳香基重氮鹽修飾至奈米金粒子表面，得到四個不同的新型材料， 分別為New 6C-Au、New 8C-Au、New 10C-Au、Old 10C-Au，藉由 1H-NMR、FT-IR、UV-Vis、TEM、Raman、XRD、EDS 儀器和技術， 鑑定及分析材料的結構及組成，證實製程成功將芳香基重氮鹽修飾至 奈米金粒子表面。 將製備完成的材料應用於有機氣體感測器，利用質量式(QCM)及 阻抗式(CR)兩種氣體感測器，進行有機氣體感測器應用，可以有效的 應用於n-Butyl acetate、n-Butanol、n-Octane、Toluene 氣體感測。由 QCM 的感測結果得知，材料對有機氣體的選擇性為BA  Octane  Toluene  Butanol，而CR 感測結果顯示，材料的選擇性則為: 極性氣 體分子 非極性氣體分子，本論文由材料結構的差異探討氣體選擇性 的影響。In this thesis, 4-alkylaryl layers were modified onto the gold nanoparticles via reduction of their diazonium salts. Two types of modified gold nanoparticles were obtained with different reaction conditions in the two-phase synthesis. As a results, there were four types of gold nanoparticles (i.e. New 6C-Au, New 8C-Au, New 10C-Au and Old 10C-Au) modified with 4-alkylaryls which were different in the alkyl chain length and reaction conditions. The composition of reaction precursors and gold nanoparticles were characterized with various techniques, e.g. 1H-NMR, FT-IR, UV-Vis, TEM, Raman, XRD and EDS. The resulting gold nanoparticles coated with 4-alkylaryl layers were utilized in application of sensing organic gas compounds. Materials coated onto both chemiresistor (CR) and quartz crystal microbalance (QCM) transducers as chemical sensors for the detection of airborne volatile organic compounds (VOCs). The VOCs studied in the work were n-butyl acetate, n-butanol, n-octane and toluene. The sequence of QCM selectivity for these gold nanopartilces are BA Octane Toluene Butanol. Nevertheless, the CR sensor is more selective to polar gas than nonpolar gas. Our results indicate that the sensitivity of gas compound is strongly related to the chemical structures of coated molecules.