Design of Nonionic Surfactants for Supercritical Carbon
Dioxide
J. B. McClain,
D. E. Betts,
D. A. Canelas,
E. T. Samulski,
J. M. DeSimone,
*
J. D. Londono,
H. D. Cochran,
G. D. Wignall,
*
D. Chillura-Martino,
R. Triolo
Interfacially active block copolymer amphiphiles have been
synthesized and their self-assembly into micelles in supercritical carbon dioxide (CO2) has been demonstrated with small-angle
neutron scattering (SANS). These materials establish the design
criteria for molecularly engineered surfactants that can stabilize and disperse otherwise insoluble matter into a CO2 continuous
phase. Polystyrene-b-poly(1,1-dihydroperfluorooctyl
acrylate) copolymers self-assembled into polydisperse core-shell-type
micelles as a result of the disparate solubility characteristics of the
different block segments in CO2. These nonionic surfactants
for CO2 were shown by SANS to be capable of emulsifying up
to 20 percent by weight of a CO2-insoluble hydrocarbon into
CO2. This result demonstrates the efficacy of
surfactant-modified CO2 in reducing the large volumes of
organic and halogenated solvent waste streams released into our
environment by solvent-intensive manufacturing and process industries.
J. B. McClain, D. E. Betts, D. A. Canelas, E. T. Samulski, J. M. DeSimone, Department of Chemistry, University of North Carolina, CB
3290, Venable and Kenan Laboratories, Chapel Hill, NC 27599, USA.
J. D. Londono, H. D. Cochran, G. D. Wignall, Oak Ridge National
Laboratory, Oak Ridge, TN 37831, USA.
D. Chillura-Martino and R. Triolo, Departimento di Chimica
Fisica, University of Palermo, 90123 Palermo, Italy.
*
To whom correspondence should be addressed.
