DEPARTMENTAL SEMINAR
DEPARTMENT OF CHEMICAL AND BIOMOLECULAR
ENGINEERING
FACULTY OF ENGINEERING
National University of Singapore
4 Engineering Drive 4 Singapore 117576
Tel: (65) 6516 2186
Fax: (65) 6779 1936
TOPIC/TITLE
Functional Nanofiber Network Composites (FNNC) for
Targeted Membrane Separations
SPEAKER
Prof Maria Coleman
HOST
Professor Chung Tai-Shung, Neal
DATE
8 June 2010, Tuesday
TIME
10.30 a.m.
VENUE
E5-02-32
SYNOPSIS
Polymers, both elastomers and glassy polymers, have received a lot attention for
membrane based separations because of their tuneable transport properties,
processibility and inherent mechanical stability. A number of alternatives materials
including mixed matrix membranes, ceramics and metal matrix membranes have
been investigated. However, these materials are often limited to separating based
on differences in size and/or inherent condensibility. Interpenetrating polymer
network (IPN) typically consist of a connected phase of a polymer which provides
selective transport within a continous phase of a matrix polymer which provide
mechanical stability are attractive potential membrane materials. While these
materials have potential for providing highly selective transport properties, they are
limited by the ability of the two phases to form two continuous phases. Therefore,
our group has been investigating functional nanocomposite network composites
(FNNC) as tunable alternatives to IPNs.
FNNC consist of a continuous network of high aspect ratio nanofillers, such as
nanofibers, nanotubes or nanowhiskers, with covalently bound functional polymers
that provide a pathway for highly selective transport and/or enhance compatibility
with the matrix polymer. The components of the composite networks can be
designed to allow control of material properties including thermal-mechanical
stability, highly selective analyte transport and processibility. The ability to tune
transport properties through selection of surface bound functional groups allows for a
broad array of potential separations.
This talk will focus on recent efforts in our group to form FNN including surface
functionalization of nanofillers and membrane formation. Specifically, the nanofillers
were functionalized with several functional groups and incorporated within a model
elastomer at loadings up to 40 wt%. The impact of nanofiller loading, surface
functional group and operating conditions on the resulting transport properties for two
model separations will be discussed.
BIOGRAPHY
Maria Coleman received her B.S. in Chemical Engineering from Louisiana Tech.
University and Ph.D. in Chemical Engineering from the University of Texas at Austin
in 1992 under guidance of William Koros. Her project focused on impact of
backbone structure on the gas transport properties of polyimides.
She joined the faculty at the University of Arkansas where her research efforts
focused on polymer synthesis and investigation of post-synthesis membrane
modification. She received an National Science Foundation Presidential Faculty
Fellowship.
She is currently a full professor at the University of Toledo with research focus on
development of novel membrane materials. In addition, her group has worked
extensively with design, synthesis and formation of polymer nanocomposites. She
was recently named the Director of the Institute for Sustainable Engineering
Materials at the University of Toledo.
Please visit our website for more details, http://www.chbe.nus.edu.sg/