Postsynthesis stabilization of free-standing mesoporous silica films.
Mixed ammonia-water vapor postsynthesis treatment provides a simple and convenient method for stabilizing mesostructured silica films. X-ray diffraction, transmission electron microscopy, nitrogen adsorption/desorption, and solid-state NMR (13C, 29Si) were applied to study the effects of mixed ammonia-water vapor at 90 degrees C on the mesostructure of the films. An increased cross-linking of the silica network was observed. Subsequent calcination of the silica films was seen to cause a bimodal pore-size distribution, with an accompanying increase in the volume and surface area ratios of the primary (d = 3 nm) to secondary (d = 5-30 nm) pores. Additionally, mixed ammonia-water treatment was observed to cause a narrowing of the primary pore-size distribution. These findings have implications for thin film based applications and devices, such as sensors, membranes, or surfaces for heterogeneous catalysis.
Vogel
R
R
Department of Chemistry & Centre for Nanotechnology and Biomaterials, The University of Queensland, Qld 4072, Australia.
Dobe
C
C
Whittaker
A
A
Edwards
G
G
Riches
J D
JD
Harvey
M
M
Trau
M
M
Meredith
P
P
D000327:Adsorption; D000641:Ammonia / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission / Q000379:methods; D009584:Nitrogen / Q000737:chemistry; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
D014867:Water; D012822:Silicon Dioxide; D000641:Ammonia; D009584:Nitrogen