Chapter 13
Downloaded by UNIV OF CALIFORNIA SAN DIEGO on December 8, 2015 | http://pubs.acs.org Publication Date: January 6, 2009 | doi: 10.1021/bk-2009-1006.ch013
Emulsion-Templated Porous Materials Using Concentrated Carbon Dioxide-in-Water Emulsions and Inexpensive Hydrocarbon Surfactants Colin D. Wood, Bien Tan, Jun-Young Lee, and Andrew I. Cooper* Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 3BX, United Kingdom *Corresponding author: email:
[email protected] Supercritical carbon dioxide is the most extensively studied supercritical fluid (SCF) medium for polymerization reactions and organic transformations. This can be attributed to a list of advantages ranging from solvent properties to practical environmental as well as economic considerations. In addition, when CO is used for the synthesis and processing of porous materials additional advantages are also realized. The subject of this review will be the synthesis of porous materials and in particular emulsion-templated polymers. The development of inexpensive hydrocarbon surfactants will also be discussed. 2
© 2009 American Chemical Society
In Gas-Expanded Liquids and Near-Critical Media; Hutchenson, K., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2009.
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244 Introduction Supercritical C 0 (scC0 ) is a sustainable solvent because it is nontoxic, nonflammable, and readily available in high purity from a number of sources. (7,/ C 0 has been shown to be a versatile solvent for polymer synthesis and processing/2-5j and it has been exploited quite widely for the preparation of porous materials:^ for example, scC0 has been used for the production of microcellular polymer foams,(7,$ biodegradable composite materials/Pj macroporous polyacrylates/Zfl-/.?,) and fluorinated microcellular materials.(14) A significant technical barrier with using C 0 is that it is a relatively weak solvent: important classes of materials which tend to exhibit low solubility in scC0 include polar biomolecules, pharmaceutical actives, and high-molecular weight polymers.(7,2,tf,/5-/#) Until recently, the only polymers found to have significant solubility in C 0 under moderate conditions (
