Adsorption of phenolic compounds on some hybrid xerogels

作者：Haghbeen K; Legge Raymond L^*

来源：Chemical Engineering Journal, 2009, 150(1): 1-7.

DOI：10.1016/j.cej.2008.11.036

• Adsorption
• Diazo dyes
• Equilibrium isotherms
• Hybrid xerogel
• Phenol

The ability of some hybrid xerogels (HyXs) to adsorb phenolic compounds from aqueous media was studied. it was shown that by incorporating n-alkylormosils (30-50%, v/v) into the composition of the HyXs the ability to adsorb phenolic compounds was improved. Aging of the HyXs was also shown to have an effect on the adsorptive capacity. Sol-gels dried at room temperature had higher adsorptive capacity compared with the analogous gels aged at 4 GC. All HyXs with an ormosil content between 0 and 80% exhibited a base reaction with the phenolic substances. It was also shown that hydrogen bonding appeared to have a negligible effect on the adsorption of the selected phenolic substances for the HyXs studied. It is proposed that adsorption occurs as a result of non-ionic but strong intermolecular Van der Waals interactions and as a consequence is geometry and weight dependant. Considering the molecular weights of the selected phenolic compounds for this study, it is proposed that phenolic substances with a pK(a) < 7 and MW > 180 will be adsorbed by the HyXs selected. In addition, the non-ionic-based adsorption of the phenolic compounds did not follow the Langmuir monolayer adsorption model.

• 出版日期2009-7-15