title: Surface-modified mesoporous silicas as recyclable adsorbents of an endocrine disrupter, bisphenol A.
abstract: Surface-modified mesoporous silicas (MSs) were investigated for recyclable adsorption of an endocrine disrupter, bisphenol A (BPA). Surface-modified MSs were prepared by (i) post-synthesis surface modification of MSs using surface hydroxyl groups and organosilanes (m-MS) and by (ii) co-condensation of tetraethoxysilane and the corresponding organosilanes (d-MS). Infrared measurements indicated that organic groups mainly existed on the surface of m-MS, which resulted in a surface characterized by high hydrophobicity. Both organic groups and isolated hydroxyl groups existed on the surface of d-MS, resulting in both hydrophobicity and hydrophilicity on the surface. The amount of BPA adsorbed on surface-modified MSs per organic group was similar for m-MS and d-MS, however, the d-MS established equilibrium for BPA adsorption faster than m-MS, as measured by UV-vis spectra. A larger amount of BPA per surface area could be adsorbed on carbon materials than on the surface-modified MSs, however, the regeneration of carbon materials by washing could not be done easily. The surface-modified MSs retain adsorption capacity for BPA after several regeneration cycles, demonstrating that the surface-modified MSs are effective recyclable adsorbents of the endocrine disrupter, bisphenol A.
authors.affiliation: Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan.
authors.forename: Aritomo
authors.initials: A
authors.lastname: Yamaguchi
authors.forename: Terumasa
authors.initials: T
authors.lastname: Awano
authors.forename: Kenichi
authors.initials: K
authors.lastname: Oyaizu
authors.forename: Makoto
authors.initials: M
authors.lastname: Yuasa
mesh_terms: D000327:Adsorption; D001559:Benzhydryl Compounds; D002244:Carbon / Q000737:chemistry; D052244:Endocrine Disruptors / Q000737:chemistry / Q000302:isolation & purification*; D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D036103:Nanotechnology / Q000379:methods*; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification*; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014961:X-Ray Diffraction; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D002244:Carbon; D052244:Endocrine Disruptors; D010636:Phenols; D012822:Silicon Dioxide; C006780:bisphenol A; D000098826:Bisphenol A Compounds