Journal article
Supercritical carbon dioxide swelling of fluorinated and hydrocarbon surfactant templates in mesoporous silica thin films
Journal of colloid and interface science, Vol.367(1), pp.183-192
02/01/2012
DOI: 10.1016/j.jcis.2011.10.051
PMID: 22137851
Abstract
[Display omitted]
► CO2 penetration in surfactant mesophase evaluated from CO2 based pore expansion of templated film. ► The structure of the fluorocarbon/hydrocarbon surfactant tail determines the pore expansion. ► Preferential CO2 solvation in fluorocarbon segments of the surfactant template is demonstrated. ► Dip-coating of thin films demonstrated on low energy fluorinated-modified substrate.
The penetration of compressed CO2 in hydrocarbon and fluorocarbon regions of concentrated surfactant mesophases are interpreted from differences in the CO2-processed pore expansion of mesoporous silica thin films templated by three surfactants containing varying degrees of hydrocarbon and fluorocarbon functionality. Ordered silica thin films are synthesized for the first time using the 16-carbon (C16) partly fluorinated surfactant, 11,11,12,12,13,13,14,14,15,15,16,16,16-tridecafluorocetyl pyridinium bromide (HFCPB), as a templating agent. Silica films templated with surfactants containing a 8-carbon (C8) fluorocarbon tail (3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl pyridinium chloride (HFOPC)) and a 16-carbon (C16) hydrocarbon tail (cetyl pyridinium bromide (CPB)) and HFCPB (C16) are processed in compressed CO2 (69–172bar, 25°C and 45°C) during synthesis. CO2 processing results in significant pore expansion for films templated with both fluorinated surfactants, while pore expansion is negligible for the hydrocarbon templated material suggesting that preferential CO2 penetration occurs in the ‘CO2-philic’ fluorocarbon segments of the surfactant template. The effect of substrate surface energy on the final uniformity of the dip-coated films is studied by varying the substrate from unmodified glass to a fluorocarbon-capped substrate. The ability to create dip-coated thin films on low surface energy substrates through favorable interaction of surfactant template tail with the substrate surface functional groups is demonstrated.
Details
- Title: Subtitle
- Supercritical carbon dioxide swelling of fluorinated and hydrocarbon surfactant templates in mesoporous silica thin films
- Creators
- Kaustav Ghosh - Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506-0046, United StatesHans-Joachim Lehmler - Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA 52242-5000, United StatesStephen E Rankin - Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506-0046, United StatesBarbara L Knutson - Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506-0046, United States
- Resource Type
- Journal article
- Publication Details
- Journal of colloid and interface science, Vol.367(1), pp.183-192
- DOI
- 10.1016/j.jcis.2011.10.051
- PMID
- 22137851
- NLM abbreviation
- J Colloid Interface Sci
- ISSN
- 0021-9797
- eISSN
- 1095-7103
- Publisher
- Elsevier Inc
- Grant note
- DOI: 10.13039/100000001, name: National Science Foundation NIRT, award: DMR-0210517; DOI: 10.13039/100013735, name: Kentucky Science and Engineering Foundation, award: KSEF-159-RDE-001
- Language
- English
- Date published
- 02/01/2012
- Academic Unit
- Occupational and Environmental Health; Iowa Neuroscience Institute
- Record Identifier
- 9984001082902771
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