PVA/角蛋白复合膜对亚甲基蓝吸附性能的研究

Study on the adsorption performance of PVA/keratin composite membrane for methylene blue

将PVA和牦牛毛提取的角蛋白进行共混,制备了PVA/角蛋白复合膜,探究其对亚甲基蓝的吸附性能,考察吸附时间、角蛋白含量、温度对PVA/角蛋白复合膜吸附性能的影响。结果表明:该复合膜对亚甲基蓝的吸附量随吸附时间先高速升高后趋于平衡,时间趋近于无穷大时,吸附率高达74.33%左右,随角蛋白含量的增大呈增速减缓的上升趋势,随温度升高不断下降,且在各个温度下的吉布斯自由能ΔG都小于0,该吸附反应都能自发正向进行。PVA/角蛋白复合膜对于Langmuir型分子吸附模型、准二级动力学模型的拟合度更高,说明该吸附过程主要由单分子层的化学吸附来完成。

The PVA/keratin composite membrane was prepared by blending PVA and keratin extracted from yak hair,and its adsorption performance for methylene blue was investigated.The effects of adsorption time,keratin content and temperature on the adsorption performance of PVA/keratin composite membrane were studied.The results showed that the adsorption efficiency of the composite membrane for methylene blue increased rapidly at the beginning and then tended to balance with the adsorption time.When the adsorption time approached infinity,the adsorption rate reached about 74.33%.With the increase of keratin content,the adsorption rate showed an increasing trend but the rate of increase slowed down,and continuously decreased with the increase of temperature.The Gibbs free energyΔG at various temperatures was less than 0,and the adsorption reaction could be spontaneous and forward.PVA/keratin composite membrane had a higher fit for Langmuir type molecular adsorption model and quasi-second order kinetic model,indicating that chemical adsorption of single molecular layer governed the adsorption process mainly.