製備摻雜羧基化富勒烯之二氧化鈦奈米材料及其自由基清除特性之研究

Preparation of carboxyfullerene-modified titanium dioxide nanomaterials in radical scavenging activity

楊楷証(Kai-Cheng Yang)

指導教授 ： 陳彥伶

共同指導教授 ： 李昆展(Kuen-Chan Lee)

高雄醫學大學/藥學院/香粧品學系碩士班/碩士(2016年)

摘要

二氧化鈦奈米材料可以保護人類皮膚對抗紫外線，而根據文獻指出二氧化鈦奈米級材料可能會出現細胞毒性以及照光下產生活性氧自由基，而羧基化富勒烯的表面富有π電子形成芳香環結構可以有效地清除大量自由基。因此，使用羧基化富勒烯當作自由基清除者以解決原始富勒烯難溶於水的問題。本研究將以羧基化富勒烯利用酯化的方式修飾在兩種二氧化鈦奈米材料(TNR和P25)表面並觀察照射紫外光下清除自由基的能力。X光繞射圖譜(XRD)顯示水熱法合成的二氧化鈦為金紅石晶型。掃描式電子顯微鏡圖(SEM)可看出二氧化鈦的P25系列複合物為奈米顆粒型材料，而TNR系列複合物主要為奈米棒狀混雜少量奈米顆粒型態。EDS圖譜可發現摻雜C70-COOH樣品之C含量有提高。穿透式電子顯微鏡圖(TEM)顯示二氧化鈦表面附著一層C70-COOH。傅立葉轉換紅外線光譜(FTIR)的結果可看出在1720 cm-1附近有C70-COOH的C=O伸縮震動。為了探討二氧化鈦複合物的清除自由基能力，利用維他命B6(Vit. B6)、對苯二甲酸(TA)、四氮唑藍(NBT)分別針對單線態氧分子、羥基自由基、過氧陰離子自由基進行反應。結果顯示兩種二氧化鈦複合物都能減少環境中的單線態氧分子，但只有P25/C70-COOH擁有清除羥基自由基跟過氧陰離子自由基的能力。

關鍵字

二氧化鈦奈米材料 ； 羧基化富勒烯 ； 自由基清除作用

並列摘要

Titanium dioxide nanomaterials offer superior protection for human skin against ultraviolet light. However, some literature reviews indicated that it might be associated with adverse effects such as cytotoxicity or reactive oxygen species (ROS) under UV-irradiation due to their nanoscale. The surface of carboxyfullerene is covered with π electrons constituting aromatic structures, which can effectively scavenge large amounts of radicals. Here, we used carboxyfullerene as radical scavenger for covering poor solubility of pristine fullerene. The aim of this study is to decorate fullerene - C70-carboxylic acid (C70-COOH) on the surface of titanium dioxide nanorods (TNR) and nanoparticles (P25) for the purpose of scavenging ROS during the UV-irradiation. The modified TiO2 composites were prepared through the esterification of C70-COOH with TNR (TNR/C70-COOH) and P25 (P25/C70-COOH). X-ray diffraction (XRD) pattern revealed that the synthesized TiO2 were rutile phase by hydrothermal process. Scanning electron microscope (SEM) patterns revealed that TiO2 of P25 composites are nanoparticles and TNR composites are major in nanorod with minor nanoparticles. EDS patterns showed that samples mixed with C70-COOH increase the ration of element C. Transmission electron microscope (TEM) patterns revealed that the surface of TiO2 coated with a layer of C70-COOH. Fourier transform infrared (FTIR) showed that the absorbance intensity around 1720 cm-1 is assigned to C=O stretching of C70-COOH. Thermogravimetric Analysis (TGA) patterns showed that the weight losses of TiO2/C70-COOH composites were correspond to the ratio of C70-COOH from 500-700 °C. In order to investigate scavenging radical ability of TiO2 composites, pyridoxine (Vit.B6), terephthalic acid (TA) and nitro blue tetrazolium (NBT) were chosen to react with singlet oxygen, hydroxyl radicals and superoxide ions, respectively. The results showed that both two types of TiO2 composites could reduce the singlet oxygen under the environment but only P25/C70-COOH revealed hydroxyl radicals and superoxide ions scavenging ability.

並列關鍵字

TiO2 nanomaterials ； Carboxyfullerenes ； Radical scavenging activity

參考文獻

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