- 學位論文
溶膠凝膠法製備具中孔洞結構釔安定氧化鋯之製程與性質探討
Characteristics and Synthesis of Mesoporous YSZ by Sol Gel Method
摘要
本研究利用溶膠-凝膠法(sol-gel)合成出具規則性排列之中孔洞(mesoporous)結構釔安定氧化鋯，實驗探討改變界面活性劑含量對於微胞形成之影響，熟化環境變化、不同界面活性劑攪拌時間及熱處理溫度對於孔洞型態之影響。 實驗結果顯示，以非離子三區塊共聚物界面活性劑(P123)做為模板，於溫度40℃相對溼度40% 環境合成下經700℃熱處理可產出具中孔洞結構釔安定氧化鋯，由小角度x-ray繞射發現2θ = 0.24 有一明顯繞射峰出現，亦即表示材料內部具有有序排列的中孔洞結構。經氮氣等溫吸/脫附儀量測並配合BET與BJH理論，顯示材料平均孔徑分佈約6.74 nm，由吸/脫附曲線能夠看出材料孔洞結構屬於長柱狀結構，BET比表面積值約94.24 m2/g。此外，其他結果，如界面活性劑添加量多寡，可清楚顯示微胞形成的影響機制；大氣熟化條件下，BET比表面積及平均孔徑皆有明顯的增加；界面活性劑攪拌時間增加及熱處理溫度增加時BET比表面積下降，平均孔徑增加。穿透式電子顯微鏡影像的顯微結構觀察，本研究所製備的中孔洞結構釔安定氧化鋯其孔洞型態為六角堆積排列的長柱狀孔洞。
並列摘要
The purpose of this study is to synthesize the yttrium stabilized zirconia with ordered mesoporous structure by the sol-gel method. The effect of surfactant concentration, aged environment, surfactant mixing time and thermal treatment temperature on the pore formation is studied. The experimental results show that when taking non-ionic tri-block copolymer surfactant (P123) as template, porous structure of yttrium stabilized zirconia can be synthesized under 40℃ and 40% relative humidity environment followed by a 700℃ heat treatment. The diffraction peak at 2θ = 0.24 observed by small angle x-ray diffraction method indicates the existence of ordered internal pore structure arrangement. Based on the results of nitrogen isotherm adsorption-desorption measurements and Barrett-Emmett-Teller (BET) and Barrett-Joyner-Halanda (BJH) theories, the mesoporous structure with average pore size of 6.74 nm can be estimated. The absorption-desorption curves suggest that the material pore structure is channel structure with approximate BET surface area value of 94.24 m2/g. Other results such as the effect of amounts of surfactant on the micelle formation mechanism is clearly observed; Both BET surface area and average pore diameter markedly increase under atmospheric curing conditions; The average pore size increases with increasing surfactant mixing time and heat treatment temperature while the BET surface area decreases. After TEM observation, the morphology of yttrium stabilized zirconia porous structure prepared in this study is channel structure.