Université Lille Nord de France, Lille, France.
J Colloid Interface Sci. 2012 Apr 1;371(1):89-100. doi: 10.1016/j.jcis.2011.11.083. Epub 2012 Jan 17.
We have investigated the adsorption equilibrium of selected cyclodextrins onto activated carbons. A number of parameters were examined including the type of carbon material, the size of macrocyclic cavity, and the chemical nature of the oligosaccharide (e.g., neutral, anionic, or cationic cyclodextrin). Adsorption isotherm studies revealed that the maximum amount of cyclodextrin immobilized on the carbon surface is obtained for the native β-CD, while the adsorption capacity of the ionic cyclodextrins derivatives strongly depends on the net surface charge of the activated carbon. The affinity of cyclodextrins for activated carbons was further utilized to prepare modified activated carbons containing controlled amounts of cyclodextrins through an adsorption process. The resulting materials were characterized by N(2) adsorption-desorption volumetric measurements, FTIR and Raman spectroscopy, while the quantitative determination of the oligosaccharide content on activated carbons was performed by gravimetric measurements. On the basis of the Turbiscan results, it was found that the chemical structure of cyclodextrins, which are incorporated in the carbon framework, had significant influence on the dispersibility and stabilization of the solid particles in water. Agglomeration and precipitation of the carbon particles were markedly suppressed with substituted cyclodextrins whose hydroxyl groups were partially substituted by methyl or alkylammonium groups.
我们研究了选定的环糊精在活性炭上的吸附平衡。考察了许多参数，包括碳材料的类型、大环腔的大小以及寡糖的化学性质（例如中性、阴离子或阳离子环糊精）。吸附等温线研究表明，在碳表面固定的最大环糊精量是天然 β-CD，而离子型环糊精衍生物的吸附容量强烈依赖于活性炭的净表面电荷。环糊精对活性炭的亲和力进一步用于通过吸附过程制备含有受控量环糊精的改性活性炭。通过氮气吸附-解吸体积测量、FTIR 和拉曼光谱对所得材料进行了表征，而通过重量法对活性炭中环糊精含量进行了定量测定。根据 Turbiscan 的结果，发现环糊精的化学结构，其被纳入碳骨架，对固体颗粒在水中的分散性和稳定性有显著影响。用部分羟基被甲基或烷基铵取代的取代环糊精显著抑制了碳颗粒的团聚和沉淀。
