PEI@PLA气凝胶制备及其染料吸附性能研究

Preparation of PEI@PLA aerogel and its dye adsorption property research

研究聚乳酸接枝聚乙烯亚胺气凝胶(PEI@PLA气凝胶)用于处理染料废水的效果。采用冷冻干燥法制备出具有定向通道形态的PEI@PLA气凝胶,对其外观形貌、化学组成、表面润湿性和压缩性能进行了测试,探讨了PEI@PLA气凝胶在不同温度、pH值和NaCl含量条件下与含染料废水的反应,评估了PEI@PLA气凝胶对染料的吸附效果。结果表明:PEI@PLA气凝胶具有超强的亲水性和在60%恒定应变下优异的压缩性能;PEI@PLA气凝胶对于废水中染料的吸附量随着PEI含量的增加而不断增加,气凝胶中PEI含量为210 mg,其对橙黄G(OYG)和刚果红(CR)染料的吸附能力高达(408.4±14.4)mg/g和(637.5±22.7)mg/g;吸附动力学表明,伪二阶动力学模型更适合分析PEI@PLA-150气凝胶对CR的吸附,同时,CR在气凝胶上的吸附平衡行为更符合朗格缪尔等温线模型。认为:PEI@PLA气凝胶作为染料废水吸附材料展现出优异的吸附性能。

The effect of polylactic acid grafted polyethylenimine aerogel(PEI@PLA aerogel)on the treatment of dye wastewater was studied.Freeze-drying method was adopted to prepare PEI@PLA aerogel with directional channel.Its morphology,chemical composition,surface wettability and compressibility were tested.The reaction of PEI@PLA aerogel with dye-containing wastewater under different temperatures,pH values and NaCl contents were discussed.The adsorption effect of PEI@PLA aerogel on dye was evaluated.Test results showed that PEI@PLA aerogel had excellent hydrophilicity and compressibility under 60%constant strain.The adsorption capacity of PEI@PLA aerogel on dye in wastewater was increased with the increase of PEI content.When the content of PEI in aerogel was 210 mg,its adsorption capacities for orange G(OYG)and congo red(CR)dyes were up to(408.4±14.4)mg/g and(637.5±22.7)mg/g respectively.It was shown from adsorption kinetics,the pseudo-second-order kinetic model was more suitable for analyzing the adsorption of CR on PEI@PLA-150 aerogel.Meanwhile,the adsorption equilibrium behavior of CR on aerogel was more suitable for the Langmuir isotherm model.It is considered that PEI@PLA aerogels exhibit excellent adsorption property as dye wastewater adsorption materials.