本實驗係研究以預混甲烷火焰,燃燒合成TiO2、Al2O3以及TiO2˙Al2O3陶瓷粉末。利用0.32%之鈦前置物TTIP,調整不同的氧氮比,實驗結果顯示,當氧氮體積比4:6時,TiO2之Anatase晶相可占總重量的97.7%;相反地,當降低氧含量時,Anatase晶相則逐漸轉換成Rutile。同時也證實了在燃燒合成TiO2的過程中,除了溫度之影響外,氧氣之含量也可控制晶相的轉換。 以相同之方法,使用鋁前置物AIP=1.22%,由實驗結果獲得氧化鋁亦有晶相之變化﹙Al2O3-γ→δ→θ→ㄐ~。一般而言,以TTIP =0.175%和AIP=0.76%分別通入燃燒器中燃燒,可得到均勻的複合材料TiO2˙Al2O3,這也改善了傳統複合材料混合不均之缺點。 在粒徑分析方面,於多氧的條件下,會使火焰溫度上升,溫度上升的結果將導致產物粒子碰撞機會增加,因此產物之粒徑相對的較大。而以本文所使用之設備可產出粒徑300~500nm的TiO2粉體以及粒徑100~200nm的Al2O3粉體,相較之下,Al2O3粒徑較TiO2小,且也可發現本實驗所製作的兩種粉體,當降低收集高度時,粒晶皆有縮小的趨勢。
Titania/alumina ceramic powders (TiO2/ Al2O3/ TiO2˙Al2O3) was studied by combustion synthesis as volatilized precursors in premixed CH4+O2+N2 flame. The experiment was used 0.32% titanium precursor (TTIP) under different oxidizer composition conditions. When the molar ratio of oxygen to nitrogen (O2/N2) was 40/60, the result showed that the anatase content was 97.7 wt%. Oppositely, the anatase phase transform to the rutile phase gradually when the molar ratio of oxygen to nitrogen was reducing. Beside the effect of the temperature, the results also showed that oxygen content was the key to control crystalline phase changes. In similar way, the crystalline phase changes were found in the order of Al2O3-γ→δ→θ→