高吸附與辨識能力之有機無機複合拓印高分子製備與鑑定

Abstract

本研究利用有機物聚合法及溶膠-凝膠法製備以雙酚A為模板的有機無機複合拓印高分子，藉由無機物的剛性結構提高對模板分子的拓印程度，並以有機物的膨潤性增進標的物於高分子內的傳輸效能，以達到高吸附量與辨識能力的目的。研究顯示當交聯劑四乙氧基矽烷(Tetraethyl orthosilicate)與3-(甲基丙烯醯氧)丙基三甲氧基矽烷(3-(Methacryloyloxy)propyl trimethoxysilane) 莫耳比例為15：10時拓印高分子有最佳質地及吸附量。TGA分析指出材料中有機物與無機物間的重量比例為1：1，模板分子萃取率近100%。等溫吸附數據及Langmuir模式模擬結果得出拓印高分子最大吸附量可高達65.8 mg/g。由29Si及13C NMR圖譜分析可知雙酚A模板於合成過程中以Si-O-C共價鍵結方式拓印於高分子內，完整的孔洞結構大幅提升高分子對雙酚A的吸附量，使拓印因子(α)有2.5優異表現，此外拓印高分子對結構類似物質Phenol、Bis(2-hydroxyphenyl)methane、4-tert-butylphenol及17β- Estradiol的選擇性因子(β)為78.2、11.5、2.3和趨近於無限大，在HPLC層析實驗中對phenol及4-tert-butylphenol得到分離因子為31.8及3.9，重複實驗證實拓印高分子的無機孔洞擁有良好的穩定性，在5次的吸附及萃取循環中相對標準偏差為3.9%。整體結果顯示有機無機複合拓印高分子對雙酚A具高吸附量與選擇性，可作為分離、層析或感測元件的先進材料。

Abstract In this study, a BPA-imprinted organic-inorganic hybrid, which exhibits high adsorption and recognition capability, was successfully fabricated by using polymerization and sol-gel processes. Rigidity of inorganic framework improves imprinting extend. In addition, flexible organic moiety allows high mass transfer in the imprinted polymer. Tetraethyl orthosilicate (TEOS) and 3-(methacryloyloxy)propyl trimethoxysilane (MEMO) were used as the inorganic and organic cross linkers, respectively, and an optimal TEOS-to-MEMO molar ratio for the highest adsorption capacity was 15:10. TGA analysis indicates that the imprinted polymer contains equal mass in the organic and inorganic components. Almost 100% imprinted molecules were extracted from the imprinted matrix to leave a high quantity of available sites (1.881020 /g) for rebinding the target. The maximum binding capacity, which was calculated from Langmuir model, was 65.8 mg/g. The 29Si and 13C NMR spectra reveal that the BPA molecules were imprinted into the cavities in terms of formation of Si-O-C covalent bonding. A high level of imprinting led to a imprinting factor (α) of 2.5, and resulted in the selectivity factor (β) of 78.2, 11.5, 2.3 and infinity for Phenol, Bis(2-hydroxyphenyl)methane (2HDPM), 4-tert-butylphenol (4TBP) and 17β- Estradiol (E2) analogues, respectively. Moreover, the separation factor (s) for phenol and 4TBP was 31.8 and 3.9, respectively, in the HPLC column test. Recoverability of the hybrid shows a small relative standard deviation of 3.9% reveling a high stability of imprinted cavities. These results in this study clearly indicate that the hybrid exhibits outstanding adsorption and recognition performance, which is highly promising for the applications in separation, chromatography and sensing.