磷酸基團於牙科材料與稀土金屬離子回收之應用

Abstract

本論文包括兩部分。第一部分為磷酸鹽基團於牙科材料之應用。 第二部分為磷酸鹽基團於吸附劑之應用。 在第一部分，磷酸鹽基團為牙齒中的主要成分之一。因此，在現代牙科中磷酸鹽基團之衍生物被使用於樹脂黏合劑與黏著改善劑用於增強其鍵結強度。然而，仍有許多問題存在於牙科材料中，例如聚合過程中材料的收縮與未聚合的單體。為了恢復牙齒良好的美觀及功能，玻璃纖維根柱(fiber post)在臨床的使用日益頻繁，然而玻璃纖維根柱的黏著強度仍有改善的空間。有鑒於玻璃纖維根柱的失敗常起因於與牙本質的黏著力不佳，本研究以研發新型牙本質黏著劑(bonding agent)，提升樹脂黏著劑與牙本質的結合強度為主要目的。 在本論文中，使用bis[2-(methacryloyloxy)-ethyl] phosphate (2MP)製成bonding agent，並以isobornyl acrylate (IBOA) 及ethylhexylacrylate (EHA)為樹脂黏著劑之原料，透過微拉伸試驗(microtensile test)、推離鍵結試驗(push-out test)及破裂韌性試驗(fracture toughness test)測試含不同比例2MP (30%, 35%, 40%)的bonding agent，和市售樹脂黏著劑(NX3, Variolink II, RelyXUnicem, Panavia F 2.0)所表現之黏著強度，並以長時間恆溫水浴(37℃, 5 months)測試各組別長時間的黏著強度變化。此外利用表面化學分析電子光譜儀觀測出氫鍵存在於牙本質黏著劑與膠原蛋白間，牙本質黏著劑中的磷酸基團與膠原蛋白內的氨基酸基團於界面上產生大量的氫鍵來增強牙本質黏著劑黏著強度，並於黏著界面上提出存在於牙本質黏著劑與膠原蛋白間遷移的機制。 在第二部分，金屬離子汙染是會影響到生物的健康。普遍來說，吸附法為處理金屬離子廢水最合適也最具經濟價值的方法。然而，處理稀土金屬離子上具有高吸附量的吸附劑是不易被找到的。為了改善這個吸附量，藉由氧化石墨烯與磷酸基團來合成出一種奈米複合吸附劑(GO-Zr-P)。其結果發現此奈米複合吸附劑在廣泛的氫離子濃度指數下對於銪離子、鑭離子和鈰離子仍有好的吸附效果。並且其吸附量會受到氫離子濃度指數的影響。對於銪離子而言其在氫離子濃度指數等於7時，最大吸附量為242.42 毫克/克，對於鑭離子而言其在氫離子濃度指數等於7時，最大吸附量為174.22 毫克/克。對於鈰離子而言其在氫離子濃度指數等於5時，最大吸附量為156.9 毫克/克。由此奈米複合吸收劑(GO-Zr-P)的特殊性質，其具有應用於工業上的水處理。

The thesis includes two parts. Part Ⅰ is the application of phosphate group of dental materials. Part Ⅱ is the application of phosphate group of the adsorbents. In part Ⅰ, One of the major components of the tooth is the phosphate group. Consequently, the derivatives of phosphate groups are used in the resin composites and bonding systems to increase the bond strength in modern density. However, there are several problems in the dental materials such as the shrinkage and unpolymerized monomer in the polymerization process. In order to improve dental restoration to achieve better aesthetic outcomes, fiber posts have been used more frequently. However, the loss of adhesion or detachment of fiber posts from root canals is usually happened.in this thesis, a novel resin cement and bonding agents were developed to increase the bond strength between the bonding agent and collagen. Three concentrations (30, 35, and 40 wt%) of bis[2-(methacryloyloxy)-ethyl] phosphate (2MP) were prepared as key dentin bonding agent components and isobornyl acrylate (IBOA) and ethylhexylacrylate (EHA) were used as key components to fabricate the resin cement. The specimens were tested after cementation 24 hours and storage in distilled water at 37℃ for 5 months to observe long term stability by evaluating the bond strength. Besides, the hydrogen bond is detected by XPS between bonding agents and dentin. The phosphoric acid groups which is in the bonding agent produce a large amount of hydrogen bonds at the interface with the amino acid groups which is in the collagen to enhance the adhesive strength of the dentin adhesive. According the results,the mechanism of migration between dentin adhesives and collagen is proposed on the adhesive interface. In part Ⅱ, the pollutions of metal ions are harmful to health of creatures. In generally speaking, the adsorption has been used as a suitable and economic water treatment process to remove metal ions. However, high adsorption capacity of adsorbents for rare earth metal ions is not easy to find. In order to improve the adsorption capacity, a nanocomposite adsorbent was synthesized by graphite oxide and phosphate group(GO-Zr-P). The results showed the GO-Zr-P nanocomposite also shown a wide range of pH for Eu+3, La+3 and Ce+3. The adsorption capacity was influenced by the pH value. The maximum adsorption capacity of Eu+3 was 242.42 mg/g at pH 7 and the maximum adsorption capacity of La+3 and Ce+3 at pH 5 were 174.2 mg/g and 156.9 mg/g, respectively. The special property of GO-Zr-P nanocomposite had potential application in industrial wastewater treatment.