title: Sintered silica colloidal crystals with fully hydroxylated surfaces.
abstract: Silica colloidal crystals require multiple processing steps before they are useful materials in analytical applications, such as chemical separations, microarrays, sensors, and total internal reflection microscopy. These chemical processing steps include calcination, sintering, surface rehydroxylation, and chemical modification, but these steps have not been fully characterized for colloidal crystals. Silica particles of nominally 200 nm in diameter were prepared, and FTIR, SEM, UV-visible spectroscopy, and refractive index measurements were used to study the changes in chemical composition, particle size, and particle density throughout the process. The final material is shown to be a durable, crack-free crystal of solid particles bearing a fully hydroxylated surface of silanols, which can then be chemically modified.
authors.affiliation: Department of Chemistry, The University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Thai
authors.initials: T
authors.lastname: Van Le
authors.forename: Eric E
authors.initials: EE
authors.lastname: Ross
authors.forename: Tomika R C
authors.initials: TR
authors.lastname: Velarde
authors.forename: Michael A
authors.initials: MA
authors.lastname: Legg
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Wirth
mesh_terms: D002118:Calcium / Q000737:chemistry*; D003102:Colloids; D003460:Crystallization; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D012821:Silanes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D003102:Colloids; D012821:Silanes; C082343:silanol; D012822:Silicon Dioxide; D002118:Calcium