基于静电作用选择性吸附染料的超分子凝胶剂

Supramolecular gelators for selective adsorption of dyes based on electrostatic interaction

设计、合成了一系列季铵盐型凝胶剂,仅通过调控季铵盐烷基侧链的长度,可得到两种自组装模式不同的凝胶剂。通过FTIR、XRD研究了甲苯干凝胶的自组装模式。结果表明,这两种干凝胶具有相反的表面Zeta电位,通过静电作用实现了对阴阳离子染料的选择吸附。在二元阴阳离子混合染料水溶液中,表面带有负电荷的干凝胶可优先捕获阳离子染料,而表面带有正电荷的干凝胶可捕获阴离子染料。特别是表面带有负电荷的干凝胶对龙胆紫表现出优异的吸附性能,在60 min左右的平衡吸附量高达1313.16 mg/g。将凝胶剂负载于三聚氰胺海绵骨架表面,得到的改性三聚氰胺海绵吸附染料种类与对其改性的干凝胶保持一致,且对染料的吸附量均明显高于干凝胶的吸附量,尤其是对龙胆紫的吸附量提升至2488.22 mg/g。

A series of quaternary ammonium salt-type gelators were designed and synthesized,and two types of gelator with different self-assembly modes could be obtained only by quaternary alkyl side chain length modulation.The self-assembly patterns of toluene xerogels were then investigated by FTIR and XRD.The results showed that two xerogels synthesized had opposite surface Zeta potentials and achieved selective adsorption of anionic and cationic dyes through electrostatic interaction.In binary anionic-cationic mixed dye aqueous solutions,the xerogel with negative surface charges preferentially captured cationic dyes,while that with positive surface charges preferred anionic dyes.Furthermore,the negatively charged xerogel exhibited excellent adsorption activity for crystal violet,with an equilibrium adsorption capacity up to 1313.16 mg/g in~60 min.The dye selectivity of modified melamine sponge,synthesized via loading the gelators on the surface of melamine sponge skeleton,was consistent with that of the xerogel used for modification.Moreover,the dye adsorption capacities of the modified melamine sponge were all significantly improved in comparison to those of the xerogels,especially that for crystal violet reached up to 2488.22 mg/g.