Structural variations in mesoporous materials with cubic Pm(3)over-barn symmetry
2010 (English)In: Microporous and Mesoporous Materials, ISSN 1387-1811, Vol. 133, no 1-3, 27-35 p.Article in journal (Refereed) Published
The fine structural details of mesoporous materials possessing Pmn symmetry prepared with varying amphiphilic surfactants under acid and alkaline conditions are investigated using electron crystallography and sorption studies. The structural data derived is used to understand the parameters that govern the formation of cavity–windows and to propose synthetic strategies in order to control independently the size of the cavities and cavity–windows. Results support that whilst attainment of Pmn cubic packing is due to the overall surfactant geometry, the formation of cavity–windows is associated with the hydration layer formed at the interphase between the surfactant and the silica wall. The charge density at the micelle surface may be tailored using two strategies: (i) using dicationic gemini surfactants at low pHs resulting in an increase in the hydration layer; or (ii) by using co-structure directing agents such as organoalkoxysilanes which reduce the hydration layer surrounding the micelles. The latter leads to the formation of higher cavity sizes and may be useful for tuning fine structural details of mesoporous materials when considering their use in important applications such as gas separation.
Place, publisher, year, edition, pages
2010. Vol. 133, no 1-3, 27-35 p.
Amphiphilic surfactants; Mesoporous materials; Electron microscopy; Structural solutions; Gas separation
IdentifiersURN: urn:nbn:se:su:diva-43090DOI: 10.1016/j.micromeso.2010.04.007ISI: 000279061000004OAI: oai:DiVA.org:su-43090DiVA: diva2:353537