分子印迹聚合反应中功能单体与模板分子间作用力的光谱分析

要获得吸附性能良好的非共价型分子印迹聚合物,聚合前模板分子与功能单体的结合程度至关重要。而相关研究报道较少。文章采用紫外光谱并结合红外光谱分析法,研究了模板分子穿心莲内酯与功能单体丙烯酰胺(AM)在3种溶剂乙腈、四氢呋喃和乙酸乙酯中相互作用力的大小。实验结果发现,穿心莲内酯与AM在乙腈溶剂中,224nm处的紫外吸收峰发生蓝移,蓝移5nm,且吸收峰增强,红外光谱中O—H伸缩振动峰发生蓝移,蓝移近8cm-1,N—H伸缩振动峰蓝移近6cm-1,表明两者之间发生较强的蓝移氢键作用力;而它们在另两种溶剂中作用力很微弱。因此,加入功能单体后光谱改变越大分子间作用力越强,识别点的选择性越好,由此制备的分子印迹聚合物吸附性能越好。

The spectroscopy analysis of intermolecular interaction between the template molecule and functional monomer before polymerization

To prepare the non-covalent molecularly imprinted polymers (MIPs) with good adsorption properties,the degree of interaction is important factor between the template molecule and functional monomer before polymerization. The correlative research has been reported less. In the present paper, UV combined with infrared spectra was applied to study intermolecular interaction of the template molecule and functional monomer. andrographolide was used as the template molecule, acrylamide (AM) as the functional monomer in the three kinds of solvents, namely acetonitrile, tetrahydrofuran and ethyl acetate. The experimental results showed that the UV absorption peaks at 224 nm exhibited blue-shift of 5 nm, and the absorption peak increased for andrographolide and AM in acetonitrile solvent. In IR spectra, the O--H stretching vibration was also blue-shifted by nearly 8 cm(-1), while the N--H stretching vibration of blue shift was about 6 cm(-1). The data showed that the strong interaction of blue-shifted hydrogen bonds generated between the molecules of andrographolide and AM. And intermolecular interaction was very weak in other two solvents. It is obvious that the stronger the intermolecular interaction, the greater the spectroscopy changes, the better the selectivity of identification points, and thus the better the adsorption properties of MIPs are.