冷冻交联制备ZM-CSt-PVA复合凝胶及吸附Cu2+ 性能

Preparation of ZM-CSt-PVA composite gel though freezing cross-linking method and adsorption performance of Cu2+

摘要:

以两性离子单体(ZM)、木薯淀粉(CSt)和聚乙烯醇(PVA )为主要原料，采用一锅法，通过冷冻交联制备ZM接枝共聚CSt-PVA互穿网络复合凝胶(ZPG2)。使用红外光谱仪(FTIR)、热重分析仪(TGA)、偏光显微镜(POM)、扫描电镜-能谱仪(SEM-EDS)对ZPG2进行表征，评价了ZPG2对Cu2+的静态吸附效果。结果表明：300 ℃以下，ZPG2的热稳定性良好；ZM的存在可产生反聚电解质效应和化学配位效应，显著提高凝胶吸附能力；在吸附温度25 ℃、ZPG2用量0.1g、Cu2+ 质量浓度[已按审稿意见2.3，全文统一修改为质量浓度]2×103 mg/L、溶液体积100mL时，饱和吸附量为199 mg/g；吸附过程符合Langmuir等温吸附模型和准二级动力学模型。

Abstract:

Using zwitterionic monomer (ZM), cassava starch (CSt) and polyvinyl alcohol (PVA) as main raw materials,a ZM graft copolymerized CSt-PVA interpenetrating network composite gel (ZPG2) was prepared through a freezing cross-linking method with a one-pot process. ZPG2 was characterized by Fourier infrared spectrometer(FTIR), Thermogravimetric analyzer(TGA), Polarized light microscopy (POM), Scanning electron microscope and Energy dispersive spectrometer (SEM-EDS). Static adsorption effects of ZPG2 on Cu2+ was evaluated. The results showed that ZPG2 had good thermal stability below 300 ℃. The presence of ZM produced an anti-polyelectrolyte effect and a chemical coordination effect, which could increase gel adsorption capacity significantly. Saturated adsorption amount could be as much as 199 mg/g when adsorption temperature was 25℃, ZPG2 dosage was 0.1g, Cu2+ concentration was 2×103 mg/L, and the solution volume was 100mL. The data of adsorption was in accord with Langmuir isotherm adsorption model and pseudo-second-order kinetic model.