沉淀聚合制备荧光聚脲微球及Fe3+检测

以异氟尔酮二异氰酸酯为单体, 以氨基功能化的1.8-萘二甲酰亚胺(AABD)为荧光基团, 在水/丙酮质量比为3/7的混合溶剂中, 通过沉淀聚合制备了表面洁净的高度单分散荧光聚脲微球(FPU). 通过FTIR及¹H NMR对AABD及FPU的化学结构进行了表征; 通过UV-Vis光谱确定FPU中嵌入的AABD荧光单元的含量; 通过荧光光谱研究了FPU固体粉末分散在水中及溶解在N-甲基吡咯烷酮中的荧光特性以及FPU分散在不同Fe³⁺浓度水溶液中的荧光变化. 结果表明, FPU的平均粒径(D_n)为5.24 μm, 粒径分布(D_w/D_n)为1.004, 具有强烈的绿色荧光(激发波长为420 nm, 最大发射波长为522 nm); FPU分散在水中不发生荧光自猝灭, 其荧光强度随着Fe³⁺浓度的增加(10^-4 ~10^-3 mol/L)呈线性降低.

Preparation of Fluorescence Polyurea Microspheres Through Precipitation Polymerization and Their Use for Fe3+ Determination†

Uniform and fluorescent polyurea microspheres(FPU) were synthesized via precipitation polymerization of isophorone diisocyanate in water/acetone mixture, bonding different amount amino-functionalized 1,8-naphthalimide(AABD) as fluorescent chromorephore. The chemical structure of AABD was confirmed by ¹H NMR and FTIR spectra. The AABD content in FPU was investigated by UV-Vis spectroscopy, and the enhanced properties of FPU was characterized by fluorescent spectroscopy. The results showed that, the uniform FPU microspheres of about 5 μm in diameter exhibited considerable green fluorescence emission at 522 nm when they were excited at 420 nm, and the fluorescence intensity was significant enhacced in comparsion with pure AABD in water or FPU dissolved in N-methyl pyrrolidone at the same concentration of AABD units. A linear decrease in fluorescence intensity of FPU was observed with increased Fe³⁺ concentration changed from 10^-4 mol/L to 10^-3 mol/L. This provides a potential application for AABD-containing FPU for Fe³⁺ determination in aqueous systems.