多壁碳纳米管与活性炭吸附中分子毒素的比较

Comparison Study on Adsorption of Middle Molecular Substances with Multiwalled Carbon Nanotubes and Activated Carbon

近年出现的多壁碳纳米管(MWCTs),因其有多空隙结构,高比表面积,高比表面能,高反应活性等决定其优异的吸附性能,非常有利于中分子毒物的吸附。本文的目的是研究MWCTs对中分子物质的吸附能力。我们选取维生素B12(VB12)作为中分子毒素的模拟物,分别利用扫描电子显微镜(SEM)和透射电子显微镜(TEM)观察MWCTs和商业用"炭肾"中活性炭的微观形貌,用紫外可见吸收光谱对比二者对VB12的吸附性能。实验中观察到MWCTs能形成发达的空隙结构,孔径多在"中孔"范围内。与活性炭相比,MWCTs的中孔孔隙结构远比活性炭发达,具有比活性炭更大的比表面积。通过Langmuir方程和Freundlich方程的拟合分析,VB12在MWCTs上的吸附为多分子层吸附,而在活性炭上的吸附类型更倾向于Langmuir模型对应的单分子层的吸附。MWCTs较活性碳有更快的吸附速率、更大的吸附量,可望成为新型的灌流器吸附剂。

In recent years,multi-walled carbon nanotubes（MWCTs） are very favorable to the adsorption of middle molecular substances in the hemoperfusion because of their multiporous structure,large surface area and high reactivity,which are beneficial to the excellent absorption properties.The purpose of this study was to study the MWCTs on the adsorption capacity of the middle molecular substances.Vitamin B12（VB12） was selected as a model of the middle molecular substances.The morphologies of MWCTs and activated carbon from commercial ＂carbon kidney＂ were observed with scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.The adsorption behavior of VB12 was comapred to each other with UV-visible absorption spectra.The MWCTs formed a sophistaicate gap structure,and compared to the activated carbon,MWCTs had a larger surface area.By Langmuir equation and Freundlich equation fitting analysis,VB12 adsorption on MWCTs is fit for multi-molecular layer adsorption,and the adsorption type of activated carbon is more inclined to the model corresponding to Langmuir monolayer adsorption.The adsorption rate of MWCTs is faster than that of the activated carbon and the adsorption capacity is greater,which could be expected to become the new adsorbent in the hemoperfusion.