Dependence of Alloy Composition in Color Change of Brass Foil by Oxide Thin Layer Formation
It is known that copper foil undergoes a color change in heating by oxide thin layer formation. Therefore, we focused on the color change by the oxidation of brass foil. Brass foil (Akaguchi (Cu87%Zn13% alloy) and Aoguchi (Cu85%Zn15% alloy)) also undergoes color change by oxidation, and it shows heating time and temperature dependence. Brass foil need longer heating time to appear color change than copper foil, and we can visually confirm that the brass has corrosion resistant. In addition, color change of brass foil depends on the percentage of copper in the brass, and Aoguchi shows rapidly color change in same heating condition. We show that brass has different physical properties than copper, even with a high percentage of copper in brass, and this was verified through comparison using diffusion length and RGB data in Aoguchi and Akaguchi. We demonstrate these colored brass foils are used as art materials, and our results expanded material using possibility of brass foil.
Rhodium-Catalyzed Enantioselective 1,2-Addition of ArylboronicReagents to α-Ketoesters using Chiral Diene Ligands
本研究是以「tert-butyl 2-oxo-2-phenylacetate 進行 1,2-不對稱加成製備成 tert-butyl 2-hydroxy-2,2-diphenylacetate之最適化實驗」做為實驗目標,在起始物的苯環上添加不同的取代基進行反應,以探討不同的 tert-butyl 2-oxo-2-phenylacetate 衍生物產率及鏡像超越值的差異。研究結果顯示,在以取代基位置為操作變因的實驗中,間位、對位擁有 48% 及 43% 的產率,鄰位產率則僅有 12% ,但鏡像超越值皆能達 >90% ee。由此可推論鄰位因有較大的立體阻礙,使得反應不易發生;間位雖比對位有較高的立體阻礙,但因與反應處相距較遠,故影響較小;而鏡像選擇性不受立體阻礙影響。為了使間位和對位反應的差異更為明顯,故決定在間位及對位以不同電子效應的基團做為取代基進行反應。研究結果也顯示,當間位具有一個拉電子特性的 CF3取代基,能使 α–ketoester 之加成產物產率>99%。未來若能進一步以更多不同的推拉電子基做為取代基,則可望使立體阻礙大小與推拉電子效應被量化,進而預測產率,協助進行最適化製備的研究過程中,更有效率的找到最適化條件。
Synthesis of Macro Porous Activated Carbon from Waste Polyethylene Terephthalate (PET) Bottles and Investigation of Usability in Dye Removal from Water Sources
Colorants are used in many industries, especially in the textile industry. These substances both cause visual pollution and create an anaerobic environment for aquatic creatures. In this study, it is aimed to examine the usability of activated carbon synthesized from waste polyethylene terephthalate (PET) bottles, which is an important environmental problem, in removing the pollution caused by the colorants caused by industrial activities in water resources.