Sorption characteristics of CTMA-bentonite complexes as controlled by surfactant packing density

作者：Zhu Runliang; Zhu Lizhong^*; Xu Liheng

来源：Colloids and Surfaces A: Physicochemical and Engineering Aspects , 2007, 294(1-3): 221-227.

DOI：10.1016/j.colsurfa.2006.08.016

• sorption
• organic clay
• surfactant
• hydrophobic organic compounds
• partition phase
• layer charge

This work was to examine the relationship between the configuration and sorption characteristics of surfactant-clay complexes. Various amounts of cetyltrimethylammonium bromide (CTMAB) were intercalated into the bentonite matrixes with different layer charges. Packing densities of the adsorbed surfactants and sorption characteristics of the obtained CTMA-bentonite complexes towards phenol and naphthalene were examined. Experimental results indicated that packing density of the adsorbed surfactant was proportional to the surfactant loading amount and layer charge of the bentonite, and sorption capacities of these complexes had a close relationship with the surfactant packing density. That was, with the increase of surfactant packing density, the organic-carbon normalized sorption coefficient (K-oc) first rose till the maximum, and then began to decrease as the packing density further increased. This could be interpreted that increase of surfactant packing density would render the surfactant phases more hydrophobic environment, and the hydrophobic affinity of the surfactant phases towards the solutes thus increased accordingly. However, in the high surfactant packing density region, the densely packed surfactants reduced the available free space for the solutes, resulting in decrease of sorption capacity for these complexes. Hence, with the increase of surfactant packing density, the adsorbed surfactants would form a series of partition phases showing different affinity to the solutes.

• 出版日期2007-2-15
• 单位浙江大学