Comparative study of phenol compounds adsorption on mesoporous sieves with different degrees of modification

Mesoporous sieves MCM-41 modified by trimethylchlorosilane and methyltrimethoxysilane were prepared by postsynthesis grafting (PSG) process and further characterized by thermogravimetric (TG) analysis, FTIR spectroscopy, and nitrogen sorption experiments. Adsorption experiments of phenol and hydroquinone in solutions were carried out. The surface properties of silica were found to be the key factors for the phenol compound adsorption in low concentration solutions. Results showed that the modification of alkyl groups did enhance the loading amount of phenol by employing both the van der Waals force and hydrogen bonds, but it also reduced the adsorption amount of hydroquinone by covering oxygen atoms and hydroxyl groups on the surface when hydrogen bond was a dominant factor due to the specific structure of hydroquinone.

Figure optionsDownload as PowerPoint slideResearch highlights▶ MCM-41 is modified by desired organic groups with different coverages. ▶ Surface properties play the dominant role at low concentration. ▶ Both surface modification and adsorbate structure exert influence to adsorption. ▶ Concentration of solution is the key factor at high concentration.