本論文利用FTIR系統,測量紅外光吸收峰值轉換為水分子層數之校正因子,以得到水分子吸附量。並且也在該系統上建立熱脫附系統,進行熱脫附分析,定量熱脫附過程中水分子脫附量,比較二者差異。 在FTIR系統進行偏振調變紅外光反射吸收光譜之量測中,利用殘餘氣體分析儀以及游離式真空計,得到殘餘氣體分析儀水氣信號之電流強度轉換水氣分壓因子為1.1x10^6Pa/A。在冰膜實驗中,利用液態氮冷卻樣品,使凝結係數近似為1,帶入氣體動力公式計算吸附層數,得到轉換光譜吸收峰值對水分子層數校正因子約為7.5±54%。 在熱脫附實驗中,建立了紅外光加熱系統,並且重新設計載具與樣品,使樣品溫度能夠等速率上升至550℃,以便可以同時進行FTIR以及熱脫附分析,當固定升溫速率為0.25˚K/s,可以得到在溫度約342℃與413℃時,存在脫附尖峰,其脫附能為(39.9±5%) kcal/mol以及(46.9±1.5%) kcal/mol。而在溫度377℃時雖有脫附峰值,但此峰值來自載具的脫附影響,無法計算脫附能。由熱脫附譜圖分析,得知0℃以下和0℃以上之熱脫附量,分別為2.9x10^13和8.6x10^17個水分子。然而FTIR分析樣品表面水分子吸附量約為1.3x10^16個水分子。其中加熱之紅外光會影響FTIR之偵檢器的訊號的程度,以及樣品載具熱脫附釋氣的干擾可能是差異的主因。
The FTIR system was used to study the calibration factor of the amount of water adsorption on aluminum surface to the intensity of the IR absorption spectrum. In addition, a TDS system was established at the same vacuum system to measure the amount of water desorption during thermal desorption process. The calibration factor was measured as 7.5±54% layer/absorption in this experiment. For the TDS experiment, an aluminum sample was heated up to 550℃ at a rate of 0.25˚K/s after being exposed to water vapor at 6.5x10^(-7)Pa for 40 mins. The results showed that the desorption peaks appeared at 342℃ and 413℃. The corresponding desorption energy were (39.9±5%) kcal/mol and (46.9±1.5%) kcal/mol. The amounts of water vapor desorbed were 2.9x10^13 and 8.6x10^17 molecules for the heating process under and above 0℃, respectively. These numbers are different from the data of 1.3x10^16 molecules measured by the FTIR analysis. There were two reasons about the difference that the effect of the background from sample holder and the interfered from the scattered heating IR.