本文選題：羥基氧化鋁 + 凝膠　； 參考：《吉林大學》2015年碩士論文

【摘要】：本論文中所述的羥基氧化鋁納米膠體是指鋁的氫氧化物、羥基氧化物及其各級脫水產(chǎn)物所形成的納米膠體的統(tǒng)稱,由于產(chǎn)物所含的Al、0、0H的比例不同,因而具有不同的結(jié)構(gòu)和性質(zhì)。這些膠體由于微觀形貌可控,被廣泛的用于結(jié)構(gòu)陶瓷、催化劑、吸附劑以及微電子功能材料等,已成為當今材料科學領(lǐng)域的前沿研究課題之一。 在已有的制備方法中,大多數(shù)方法傾向于運用活性劑、沉淀劑、解膠劑等制備羥基氧化鋁、氫氧化鋁膠體。在實驗過程中,還要控制pH值,反應(yīng)時間也較長,反應(yīng)步驟復雜,限制了這些膠體的生產(chǎn)與應(yīng)用。因此,探究一種簡單易行的方法具有十分重要的意義。本論文用溶劑熱醇解法制備了不同形貌的羥基氧化鋁膠體,主要研究內(nèi)容和結(jié)果如下： (1)以無水氯化鋁為鋁源,分別與無水甲醇、無水乙醇、正丙醇在不同條件下進行反應(yīng),生成氫氧化鋁納米薄片。當反應(yīng)溫度降低到160℃時,無樣品生成。說明無水氯化鋁與醇類反應(yīng),生成羥基氧化鋁膠體的下臨界溫度為160℃。 (2)通過X射線衍射、掃描電子顯微鏡和透射電子顯微鏡等技術(shù)對制備的樣品進行表征,發(fā)現(xiàn)產(chǎn)物均為納米片狀結(jié)構(gòu),其結(jié)晶度隨時間的延長和溫度的升高而提高。 (3)以無水氯化鋁為鋁源,以甲醇為前驅(qū)物時,產(chǎn)物以氫氧化鋁Al(OH)3為主；以乙醇、正丙醇為前驅(qū)物時,產(chǎn)物以氫氧化鋁的各級脫水產(chǎn)物為主,并隨溫度升高和時間延長,最終轉(zhuǎn)化為羥基氧化鋁A1OOH。 (4)通過對觀測到的現(xiàn)象進行系統(tǒng)分析,推演其反應(yīng)機理,認為反應(yīng)通過如下路徑進行：AlCl3+3ROH→Al(OR)3+3HCl Al(OR)3+3ROH→Al(OH)+3ROR Al(OH)3→AlOOH+H2O 進而推演出片狀納米結(jié)構(gòu)的生長機制：在溫度較低、反應(yīng)時間較短時，均生成塊狀Al(OH)3膠體，隨著反應(yīng)時間的延長，反應(yīng)溫度的升高，，發(fā)生不同級次的脫水，向AlOOH轉(zhuǎn)化；由于AlOOH具有層狀結(jié)構(gòu)，在(010)表面羥基的作用下，塊狀Al(OH)3膠體最終分裂成片狀納米結(jié)構(gòu)，溫度越高，時間越長，納米片越��；由于表面羥基和范德華力的影響，這些納米片在高溫下發(fā)生彎曲，甚至包裹成球狀。
[Abstract]:The hydroxyl alumina colloids in this thesis refer to the hydroxides of aluminum, hydroxyl oxides and the colloids formed by their dehydration products. The products have different structures and properties because of the different proportion of Al _ 2O _ 0 O _ (0) H in the products. These colloids have been widely used in structural ceramics, catalysts, adsorbents and microelectronic functional materials because of their controllable morphology, and have become one of the leading research topics in the field of material science. In the existing preparation methods, most of the methods tend to use active agents, precipitators and colloids to prepare hydroxyl alumina and aluminum hydroxide colloids. In the process of experiment, pH value should be controlled, the reaction time is longer and the reaction steps are complicated, which limits the production and application of these colloids. Therefore, it is of great significance to explore a simple and easy method. In this thesis, hydroxyl alumina colloids with different morphologies were prepared by solvothermal alcoholysis. The main contents and results are as follows: Using anhydrous aluminum chloride as aluminum source, anhydrous methanol, anhydrous ethanol and n-propanol were reacts under different conditions to produce aluminum hydroxide nanocrystals. When the reaction temperature was reduced to 160 鈩

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