properties and structure. Analytical Supercritical Fluid Extraction
[http://www.gatech.edu/textileIfaculty/ Supercritical fluid extraction is an emerging analytical tech-
carr/carr.html] nique that has the potential to both reduce extraction times of
Haskell Beckham: See page 5 textile substrates by a factor of 5-10 and to drastically reduce
the amount of solvent required for analysis of extractables.
Arthur J. Ragauskas, an Assistant
Professor of Wood Chemistry at the
Our work in this area is now
Institute of Paper Science and Tech- We are researching primarily focused on gaining a
nology since 1989, earned a Ph.D. in deeper fundamental under-
organic chemistry from the Univ. of supercritical fluids standing of the solubility and
Western Ontario in 1985. After post- used 60th as
dots at Univ. of Alberta and Colorado
transport aspects of supercriti-
State, Art was a research associate processing fluids
with the National Research Council of
Canada. His research interests in-
clude bleaching kraft pulps. cal fluid extraction. . . . and for
Since temperature and analytical applications
Steven B. Warner: See page 4 pressure have a defini- such as extraction.
William J. Wepfer, a Professor of Me- tive effect on the quan-
chanical Engineering and Director of tity and composition of
Graduate Studies at Georgia Tech, the extracts (See polypropylene staple fiber example in fig-
joined the faculty in 1980. He earned ure), we will have to develop an experimental method to moni-
a Ph.D. in mechanical engineering in
1979 from Wisconsin. Bill’s research tor extractions in real time. Initially we are studying the
interests include thermodynamics, dynamics of supercritical fluid extraction of butyl stearate us-
thermal systems, heat transfer, in- ing 100% CO, and CO, with 5 mole percent methanol added.
strumentation and the experimental We have recently found that with supercritical fluid extrac-
tions of fiber finishes, gravimetric analysis may be avoided,
.+..*. .l . . .**. .*..*.
leading to a fully automated process. With extractions of car-
An Investigation Into the Use of pets and carpet backings, potential volatile organic emissions
can be measured.
Supercritical Fluid Technology for
We are now studying the roles of the various chemical and
Analytical, Process and Environmental physical processes which occur during supercritical CO, expo-
Applications in Textiles sure. We will be attempting to characterize the behavior of fi-
Michael J. Drews ( C l e m s o n ) bers and films in supercritical fluids in terms of their
temperature/pressure/concentration phase behavior and com-
We are investigating the use of supercritical fluid technology
pare the results to those predicted on the basis of polymer so-
for analytical, process and environmental applications in poly-
lution theory using molecular modeling.
mers. fibers and textiles. Our studies range from transport into
the fiber, as in dyeing, to transport out of the fiber, as in Supercritical Fluid Dyeing Studies
process-scale extractions of the fiber itself. We are also ex- Dyeing with supercritical CO, is totally recyclable, thereby
ploring the theoretical and practical aspects of using fluids generates no waste effluent stream. Water is completely
other than pure CO2 as well as the use of supercritical fluids in avoided, no auxiliary agents are used and residual dyestuff is
other processes. recovered in a reusable form. In addition, less energy is used
to heat the dye liquor and drying is not required after dyeing.
Polypropylene Percent We are fundamentally studying the various chemical and
Weight Loss vs T and P physical processes that occur during supercritical CO, dyeing.
We want to identify the effects of supercritical fluid dyeing on
fiber morphology as well as the effects of morphology on the
dyeing process. Initially, our work centers on
-determining differential partition co-efficients of dyes
having different supercritical CO, solubilities
- learning if dye solubility during supercritical fluid dyeing
can be described with an equation of state
[Other Contributors: Technical Staff: Kim Ivey, Clark Xu;
Graduate students: Pam Wolfe, Jing Bai, Jamie Eggleston, J.
For Further Information, see page 38
20 National Textile Center Research Briefs: December 1995