Interaction of supramolecular centers of silica surface with aromatic amino acids

• Published in: Journal of colloid and interface science 2011-10, Vol.362 (1), p.172-179
• Main Authors: Roik, N.V., Belyakova, L.A.
• Format: Article
• Language: English
• Subjects: Adsorption; Amino acids; Amino Acids, Aromatic - chemistry; Aromatic amino acid; beta-Cyclodextrins - chemistry; Chemistry; Exact sciences and technology; General and physical chemistry; Grafting; Imidazoles - chemistry; IR spectroscopy; Mathematical models; Reaction kinetics; Silica; Silicon dioxide; Silicon Dioxide - chemistry; Spectra; Spectroscopy, Fourier Transform Infrared; Surface chemistry; Surface physical chemistry; Surface Properties; UV spectroscopy; β-Cyclodextrin
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2011.05.085

Adsorption of aromatic amino acids onto the surface of silica with chemically attached β-cyclodextrin moieties. [Display omitted] ► β-Cyclodextrin-containing silica preparation under mild conditions. ► Aromatic amino acids adsorption on b-cyclodextrin-containing silica. ► Kinetic adsorption process is described by pseudo-second order kinetic model. Surface grafting of β-cyclodextrin onto aminopropylsilica has been carried out under mild conditions using 1,1′-carbonyldiimidazole as an activator. The obtained β-cyclodextrin-silica has been characterized by means of chemical and IRspectral analysis. Adsorption of para-aminobenzoic and para-aminosalicylic acids onto the surface of hydroxylated silica, aminopropylsilica, and silica with chemically attached β-cyclodextrin moieties has been studied in relation to duration of contact, equilibrium concentration, and solution pH. Chemical immobilization of β-cyclodextrin onto silica surface improves adsorption parameters for aromatic amino acids. The well-known mathematical models for the kinetic and equilibrium adsorption processes have been used, and the main adsorption parameters have been calculated. Kinetic curves of aromatic amino acids adsorption correspond to the model of pseudo-second order reaction. The major contribution to the equilibrium adsorption of para-aminobenzoic and para-aminosalicylic acids onto β-cyclodextrin-containing silica is due to the formation of surface inclusion complexes between grafted oligosaccharide molecules and aromatic amino acids.