Molecular organization of hydrophobic molecules and co-adsorbed water in SBA-15 ordered mesoporous silica material

• Published in: Physical chemistry chemical physics : PCCP Vol. 13; no. 7; pp. 2706 - 2713
• Main Authors: MELLAERTS, Randy, ROEFFAERS, Maarten B. J, HOUTHOOFD, Kristof, VAN SPEYBROECK, Michiel, DE CREMER, Gert, JAMMAER, Jasper A. G, VAN DEN MOOTER, Guy, AUGUSTIJNS, Patrick, HOFKENS, Johan, MARTENS, Johan A
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.01.2011
• Subjects: Adsorption; Agglomeration; Chemistry; Colloidal state and disperse state; Confocal; Drugs; Exact sciences and technology; Fluorescence; General and physical chemistry; Hydrophobic and Hydrophilic Interactions; Itraconazole - chemistry; Magnetic Resonance Spectroscopy; Migration; Organizations; Oxazines - chemistry; Porosity; Porous materials; Silicon dioxide; Silicon Dioxide - chemistry; Spectroscopy, Fourier Transform Infrared; Surface physical chemistry; Water - chemistry; Water; Binary compound; Fourier transform spectroscopy; Organization; In situ; Migration; Adsorption isotherm; Confocal microscopy; NMR spectrometry; Hydrophobicity; Porous material; Silica; Aggregation; Infrared spectrum; Release; Drug; Fluid; Desorption; Mesoporosity; Infrared spectrometry; Water soluble compound; Adsorption; Pore; Distribution; Kinetics; Fluorescence microscopy
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c0cp01640c

The purpose of this study was to improve our understanding of the molecular organization of hydrophobic guest molecules in the presence of co-adsorbed water inside SBA-15 ordered mesoporous silica material. Understanding this adsorption competition is essential in the development of applications of controlled adsorption and desorption. The poorly water soluble drug compound itraconazole and the fluorescent probe Nile red were selected for the study. The interaction between itraconazole and SBA-15 was investigated using FT-IR, (1)H MAS NMR and (29)Si MAS NMR spectroscopy, by determination of adsorption isotherms and release kinetics in simulated gastric fluid. The distribution and migration of the hydrophobic fluorescent probe Nile red was visualized in situ using confocal fluorescence microscopy. For both molecules, there was a pronounced influence of the co-adsorbed water on adsorption, hydrophobic aggregation and migration in SBA-15 pores. These insights contribute to the development of practical methods for loading ordered mesoporous silica materials with hydrophobic molecules.