臺灣博碩士論文加值系統

本研究以Pickering emulsion法製備二氧化鈦/鎳巨孔複合材。經有機界面活性劑分子的選擇吸附，具有部分疏水表面的二氧化鈦微粒能穩定停駐於泡沫的氣-液界面，阻止鄰近氣泡間之合併及破裂。接著再加入帶有親水性表面的鎳粉，藉由機械球磨帶動而存在水相中，經乾燥、燒結即可得到複合多孔體。
首先，選取數種界面活性劑對二氧化鈦進行表面改質，由接觸角量測結果可知，陽離子型界面活性劑皆可將接觸角提高至50°以上，其中氯化苯銨松寧(Benzethonium chloride,BZT)的改質效果最為卓越，接觸角提高至90°。調整BZT濃度，接觸角隨濃度上升而提高，藉由熱重與熱差分析儀(TG/DTA)，可知此吸附為單層吸附且尚未達到飽和。調整BZT濃度製作二氧化鈦多孔體，並以電子顯微鏡(SEM)觀察微結構發現，孔徑大多分布於5~400 µm，且BZT濃度在臨界微胞濃度(cmc)為0.1時，粉體間未有團聚現象發生，在0.25 cmc以上則皆有團聚粒子不均勻散佈於結構中。以壓汞測孔儀(Mercury Intrusion Porosimetry)分析多孔體孔隙率以及孔徑分布，發現二氧化鈦多孔體的平均孔徑大於1 µm，孔隙率皆在90%以上，其中以BZT濃度0.25 與0.5 cmc製備的多孔體之泡沫穩定性較高。
後續加入鎳粉於二氧化鈦漿料中，並以瓊脂(Agar)快速固化乳膠微泡，藉由調整鎳粉比例，觀察複合多孔體之微結構變化，接著再調變總固含量，由微結構觀測隨固含量上升，複合多孔體之壁厚有增加的趨勢，再以壓汞測孔儀分析孔徑分布及孔隙率，孔徑大多分布於5~400 µm，平均孔隙皆在1 µm以上，複合多孔體之孔隙率則介於62~82%間，吾人並以電子微探儀(EPMA)分析多孔結構中，壁厚截面的微區元素分布，最後再量測多孔體機械性質以及導電性。

This research aims to prepare TiO2/Ni macroporous composite foams via Pickering Emulsion route. By selective adsorption of surfactants, the TiO2 particles with a partially hydrophobic surface could reside at the air-water interface, preventing coalescence and disproportionation to occur between neighboring bubbles. Subsequent addition of Ni particles with a hydrophilic surface into the TiO2 suspension would favor the Ni particles to stay in the water phase so that macroporous composite foams was obtained after balling mixing followed then by drying and sintering.
Different surfactants were selected for the surface modification of the TiO2 particles in water. Contact-angle measurement revealed that cationic surfactants successfully increase contact angle to more than 50°. Benzethonium chloride (BZT) in particular showed a pronounced increase in the contact angle above 90°. By tailoring the BZT concentration, contact angle of the TiO2 particles could be fine tuned. The BZT adsorption on the TiO2 surface followed the Langmuir adsorption. The BZT concentration was then varied to produce TiO2 porous foams and their microstructure characterized by SEM. When the BZT concentration was more than 0.25 cmc, agglomeration of the TiO2 particles randomly dispersed in the foam structure became apparent. Porosity and pore-size distribution of the composite foams were characterized by mercury intrusion porosimetry. The average pore size of the foams was all above 1 µm, porosity all above 90%, especially for those prepared by using BZT concentration of 0.25 and 0.5 cmc. Their lower average pore diameter revealed that the foams were stable during the foaming stage.
Finally, Ni particles were added into the TiO2 suspension together with addition of agar as the fast-setting agent to consolidate emulsions. By tailoring TiO2/Ni ratio, microstructure of the composite foams was examined. The suspensions with a higher solids content were found to result in a foam with a thicker cell wall. From the mercury porosimetry, the composite foams with a porosity ranging from 62 to 82 %, an average pore size all above 1 µm were obtained. EPMA was also used to characterize elemental distribution across the cell wall, together with measurement of electrical conductivity and bending strength of the porous composites.

摘要 I
Abstract II
目錄 III
表目錄 VI
圖目錄 VII
第一章緒論 1
1-1前言 1
1-2研究動機 1
第二章文獻回顧 3
2-1乳膠泡沫 3
2-1-1 Pickering emulsion 3
2-1-2泡沫穩定性 5
2-2製備多孔陶瓷 6
2-2-1複製法 7
2-2-2犧牲模板法 8
2-2-3直接泡沫成形法 9
2-2-4二氧化鈦多孔體製備 10
2-2-5二氧化鈦-鎳複合多孔材製備 15
2-3 Gelcasting 17
第三章實驗流程與分析儀器介紹 22
3-1實驗藥品 22
3-2製程設備 23
3-3製備二氧化鈦多孔體 24
3-3-1選取界面活性劑增進二氧化鈦表面疏水性 24
3-3-2由BZT濃度變化調整二氧化鈦疏水性 25
3-3-3調整二氧化鈦固含量製備二氧化鈦多孔體之實驗流程 26
3-3-4調整BZT濃度製備二氧化鈦多孔體 26
3-3-5加入瓊脂快速固化二氧化鈦多孔體實驗流程 27
3-4製備二氧化鈦-鎳複合多孔體 28
3-4-1改變二氧化鈦:鎳體積比對瓊脂快速固化多孔體之實驗流程 28
3-4-2改變複合二氧化鈦-鎳多孔體總固含量之實驗流程 29
3-5多孔體機械強度量測 30
3-6多孔體電性量測 30
3-7分析儀器 31
第四章結果與討論 33
4-1二氧化鈦粉體分析 33
4-1-1二氧化鈦之微觀形貌以及元素成分分析 33
4-1-2二氧化鈦之XRD結構分析 34
4-1-3二氧化鈦在不同pH值的zeta potential 35
4-1-4二氧化鈦表面親疏水性 35
4-2奈米鎳粉材料分析 36
4-2-1鎳之微觀形貌以及元素成分分析 36
4-2-2鎳之XRD結構分析 39
4-2-3鎳在不同pH值的zeta potential 39
4-2-4鎳表面親疏水性 40
4-3製備二氧化鈦多孔體 41
4-3-1選取界面活性劑調整二氧化鈦疏水性 41
4-3-2改變BZT濃度調整二氧化鈦接觸角以及吸附行為 41
4-3-3增加二氧化鈦固含量調整微結構 42
4-3-4調整BZT濃度製備二氧化鈦多孔體 43
4-3-5二氧化鈦多孔體機械強度測試 46
4-3-6加入瓊脂快速固化二氧化鈦多孔體 46
4-4製備二氧化鈦-鎳複合多孔體 48
4-4-1調整鎳含量製備二氧化鈦-鎳複合多孔體 48
4-4-2增加固含量對二氧化鈦-鎳複合多孔體微結構之影響 51
4-4-3二氧化鈦-鎳複合多孔體XRD結構分析 55
4-4-4二氧化鈦-鎳複合多孔體機械強度測試 56
4-4-5二氧化鈦-鎳複合多孔體電性量測 57
第五章結論 58
參考文獻 60

如左格所示(由於此格有字數限制，無法全部貼上，因此置於右格，請見諒!!)