基于聚丙烯酸二维光子晶体水凝胶的阳离子表面活性剂传感器

Cationic Surfactant Sensor Based on Poly(acrylic acid)Two-dimensional Photonic Crystal Hydrogel

以聚苯乙烯二维光子晶体为模板,丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,2,2-二乙氧基苯乙酮为引发剂,紫外光引发聚合,制备聚丙烯酸二维光子晶体水凝胶(PAA 2D-PCH),利用德拜环法研究了其对阳离子表面活性剂的刺激响应行为.实验结果表明,在pH=7.4的磷酸盐缓冲溶液中,PAA 2D-PCH对阳离子表面活性剂有灵敏的响应,凝胶体积收缩,引起颗粒间距减小,德拜环直径增大,衍射波长蓝移,当氯化十六烷基吡啶(CPC)、溴化十六烷基吡啶(CPB)、十六烷基三甲基溴化铵(CTAB)浓度由0增加到4×10-3 mol/L时,德拜环直径分别增加了5.95、5.50、5.05 cm,颗粒间距分别减小了380、364、341 nm;而在阴离子表面活性剂、非离子表面活性剂和两性离子表面活性剂溶液中,PAA 2D-PCH的德拜环直径基本保持不变,表明其对阴离子型、非离子型和两性离子表面活性剂均无响应.该PAA 2D-PCH制备简单,有望作为传感器用于水体中阳离子表面活性剂的检测,无需复杂的仪器设备,操作方便、可重复利用,兼具可视化的特点.

A polyacrylic acid two-dimensional photonic crystal hydrogel(PAA 2 D-PCH)was prepared with acrylic acid as monomers,ethylene glycol dimethylacrylate as cross-linkers,2,2-diethoxyacetophenone as initiators and polystyrene two-dimensional photonic crystal with bright diffraction under visible light illumination as a template,and its stimulating response properties to cationic surfactants were investigated.The results indicated that the PAA 2 D-PCH had a sensitive response to cationic surfactants,while no response to anion,nonionic and zwitterionic surfactants.When the concentration of CPC,CPB and CTAB was increased from 0 to 4×10-3 mol/L,the diameter of Debye ring increased by 5.95,5.50 and 4.95 cm,respectively,and the particle spacing decreased by 390,364,and 341 nm,respectively.In the anionic surfactant,nonionic surfactant and zwitterionic surfactant solution,the diameter of Debye ring of the PAA 2 D-PCH showed almost no change.The selective recognition of cationic surfactants by PAA 2 D-PCH stemed from the electrostatic interaction between the negatively charged carboxylate ions and the cationic surfactants in the phosphate buffer solution of pH=7.4,causing the PAA 2 D-PCH shrunk,the particle spacing reduced,the diameter of the Debye ring increased,and the diffraction wavelength blue shifted.Study on the response behavior of PAA 2 D-PCH to cationic surfactants by Debye ring method is easy to operate and has the characteristics of reusability and visualization,which is expected to be used for the determination of cationic surfactants in water.