The Department of Chemical Engineering is part of the Engineering Experiment Station and is in the School of Chemical Sciences in the College of Liberal Arts and Sciences. Special research facilities available to the department include a time-shared digital computer for computer control of experiments, extensive shop facilities, including machine shop, glass shop, and electronics shop, modern spectroscopy laboratories for NMR, IR, UV, EPR, Raman, and mass spectroscopy, a microanalytical laboratory, and radiochemistry and radio isotope facilities.
Control of Biomaterial Interactions with Proteins through Tailored
Manipulation of Molecular Surface Properties
D. Leckband,* S. R. Sheth
Whitaker Foundation
Biomaterial rejection is linked to the initial protein adsorption
upon contact with foreign materials with body fluids. Our objective is
to minimize or control protein and biological interactions with new
materials through the tailored manipulation of the molecular forces
controlling the outcomes of encounters between foreign materials and
biological fluids. Using a combination of direct force measurements,
biochemical methods, and molecular modeling, we are quantifying the
relationship between molecular surface structure and composition,
surface forces, and protein adsorption. These data are intended to
guide the design of new, effective biocompatible materials.
Molecular Forces Determining the Strength of Receptor-mediated Cell
Adhesion
D. Leckband,* T. Calvert
National Science Foundation, BES-9503045
Cell adhesion is mediated and modulated through contacts between
chemical moieties on cell surfaces. In particular, the enhanced
expression of certain glycolipids on cancer cells may determine their
metastatic potential. The significance of specific glycolipid
interactions, however, is linked directly to the strengths of the
molecular forces governing the resulting adhesion. We are using direct
force measurements, fluorescence microscopy, and light scattering to
quantify the magnitudes and ranges of glycolipid-mediated adhesive
forces and to determine the impact of those forces on the strengths of
glycolipid-mediated membrane attachments. We are testing directly the
role of membrane surface components in cell adhesion and the potential
utility of therapeutics designed to block their interactions.
Biosensor Design and Performance -- The Role of Transducer Surface
Composition
D. Leckband,* R. Vijayendran, N. Lavrik
U.S. Office of Naval Research, N00014-96-1-339
Many biosensor designs are based on the selective binding of soluble
analyte to immobilized receptors. The surface microenvironment can,
however, significantly affect sensor performance. We are currently
quantifying changes in protein-binding strengths in response to
interfacial perturbations. Furthermore, kinetic modeling of site-
selective adsorption data have demonstrated that subtle interfacial
perturbations impact sensor performance. Our objective is to determine
the molecular basis of altered protein function by the surface
microenvironment and to optimize sensor performance through the
tailored manipulation of the transducer surface properties.
Protein Structure and Molecular Recognition
D. Leckband,* T. Calvert, S. Sivasankar, C. Yeung
National Institutes of Health, 1R29GM51338-02
Protein surface topology plays a major role in modulating the rates
of protein-binding events. We are using direct force measurements to
probe the impact of local protein structural motifs on the forces that
control the rates of protein collisions. In particular, we are
investigating the impact of surface charge distributions and protein
orientation on protein electrostatic surface properties and the
resulting protein interactions. Use of both wild type and engineered
proteins permits precise control of the surface region probed.
Measurements are compared with theoretical calculations. The
functional implications of these findings are being investigated by
Brownian dynamics simulations and kinetic measurements.
Surface Display of Antibodies in Yeast for Affinity Maturation
K. D. Wittrup,* E. T. Boder, J. V. Antwerp
Whitaker Foundation
A novel system has been developed to engineer proteins to have
desirable binding properties. Genetic fusions to a cell wall protein
allow the protein of interest to be tethered to the cell surface and
probed for binding to fluorescently labeled targets. Introduction of
diversity into a population by mutagenesis is followed by isolation of
desirable mutations by flow cytometry and sorting.
Engineering Disulfide Formation Kinetics to Enhance Heterologous
Secretion in Saccharomyces cerevisiae
K. D. Wittrup,* R. Raines, E. V. Shusta, W. S. Kwon
National Science Foundation, BES 95-31407
The purpose of this work is to measure and manipulate the redox
regulation of yeast's secretory pathway in order to improve production
yields of pharmaceutical proteins. Genetic, biochemical, and fermentor
operation strategies will be implemented to alter the cellular
processing of disulfides, covalent crosslinks which stabilize the
folded structure of a protein.
Protein-folding Kinetics in the Endoplasmic Reticulum
K. D. Wittrup,* J. M. Kowalski, S. J. Bannister
National Institutes of Health, GM50673
The goal of this project is to examine the kinetics of protein
processing in the secretory pathway in order to identify the
mechanistic steps which limit the yield and rate of protein secretion.
The ultimate goal is to use this information to rationally design
improved production systems for phamaceutical proteins.
Supercomputer Studies of Turbulent Transport
T. J. Hanratty,* D. Papavassiliou, Y. Na, I. Iliopoulos
National Science Foundation, CTS 92-09877
We are exploring new methods of interpreting turbulent transport of
molecular species or particles that describe the field as resulting
from a distribution of sources and sinks. These studies are carried
out with a supercomputer simulation of turbulent flow in a channel and
are made possible by the development of particle-tracking routines. Of
particular interest is the effect of molecular transport on turbulent
mixing, the effect of gravity on particle transport in dispersed
flows, and aerosol impaction on walls. Direct numerical simulations of
turbulent heat transfer in a channel have been carried out from Prandt
number varying between 0.05 and 10.
Strategies for Using Advanced Computer Architectures in Chemical
Process Engineering
M. A. Stadtherr,* K. Camarda, J. Hua
National Science Foundation, DMI 93-22682
The modeling, simulation, design, and optimization of complex
chemical processes, steady- or unsteady-state, can be done much more
effectively using advanced computer architectures, especially those
using some form of parallel processing. However, since current methods
for solving such problems were developed for use on conventional
serial computers, they usually cannot take much advantage of the power
of parallel computing. Thus, solution strategies must be completely
rethought. The goal of this project is to develop and apply new
strategies for exploiting the power of parallel computing in process
engineer-ing. Some of the techniques developed are already inuse in
supercomputer versions of commercial simulation programs. Advances
have been made in problem-solving speed through the development of
improved sparse matrix techniques and in problem-solving reliability
through the use of interval mathematics.
Spectral Boundary Element Methods
J. J. L. Higdon,* P. Dimitrakopoulos
National Science Foundation, DMS 93-12308
The goal of the proposed research is to develop robust spectral
boundary integral algorithms for three-dimensional transport problems
in realistic geometries. The spectral boundary elements combine the
high-order convergence associated with spectral methods and the
versatility of boundary element methods. To realize the potential of
this method, each of the four major components must be optimized: (1)
formulation of the integral equation, (2) discretization, (3)
numerical integration, and (4) solution of the algebraic linear
systems.
Control-relevant Identification of Sheet and Film Processes
R. D. Braatz*
E. I. du Pont de Nemours & Co.
Sheet and film processes, which include coating, papermaking, and
polymer film extrusion processes, are of worldwide industrial
importance. Existing identification and estimation techniques require
much more input-output data than are usually available for poorly
conditioned large-scale sheet and film processes. The objective of
this project is to exploit the inherent structure of these processes
to improve numerical conditioning and the robustness of model and
state estimates. This is leading to the development of an automatic
identification procedure, where the model and an estimate of its
accuracy are iteratively improved as opportunities for increased
input-output testing become available.
Analysis and Control of Large-Scale Dynamic Neural Network Systems
R. D. Braatz,* E. Rios-Patron
Fulbright Program
Although neural networks have been heavily applied in the process
industries, there have existed no general techniques for analyzing the
stability and performance of these systems. Polynomial-time computable
analysis tools are being developed that are applicable to dynamic
neural network systems with arbitrary interconnections. The
application of these tools for optimization-based nonlinear control is
under investigation.
Analysis of Systems with Process Constraints and Time Delay
Uncertainties
R. D. Braatz,* E. L. Russell, E. Rios-Patron
Fulbright Program
Process constraints, time delays, and model uncertainties are
prevalent in large-scale industrial processes. Existing algorithms for
computing robustness margins do not adequately address the effect of
time delay uncertainties and process constraints on the overall closed
loop stability and performance. An algorithm is being developed for
mapping time delay uncertainties to equivalent finite-dimensional real
parametric variations that can be analyzed using available techniques.
The effect of process constraints on closed loop stability and
performance is addressed using improved Lyaponov function techniques.
Pattern Recognition Approaches for Fault Detection and Diagnosis
R. D. Braatz,* E. L. Russell, L. H. Chiang
International Paper Co.
Pattern recognition techniques are being developed for the on-line
detection and isolation of faults in large-scale industrial plants.
These algorithms notify the process operator when abnormal process
behavior has occurred and its likely cause, based on past data
histories for which similar behavior has occurred. Subspace
identification and operator-theoretic statistical methods are being
investigated for improving the dynamic behavior of the developed
techniques.
Reconciliation of Robust Control Theories
R. D. Braatz,* J. G. VanAntwerp
E. I. du Pont de Neumours & Co.
Numerous researchers over the last few decades have proposed
techniques to rigorously address model inaccuracies in multivariable
systems. The purpose of this project is to draw theoretical
connections between various branches of robust control theory. This is
leading to relationships between modern and classical control methods,
theoretical justifications of ad hoc methods for the synthesis of
robust controllers, and to the removal of computational limitations
posed by these methods for the analysis of robust controllers.
Globally Optimal Robust Reliable Control of Large-Scale Sheet and Film
Processes
R. D. Braatz,* N. V. Sahinidis, J. G. VanAntwerp
E. I. du Pont de Neumours & Co.
We are developing computational approaches for designing globally
optimal controllers for large-scale sheet and film processes. The
resulting controllers are robust to inaccuracies in physical
properties of the sheet or film and to faults and/or failures in
measured and manipulated variables. One of the key ideas in these
approaches is to exploit nonlocalized structural characteristics of
the sheet or film.
Modeling and Fault Detection for Large-Scale Nonlinear Dynamic
Processes
R. D. Braatz,* E. Rios-Patron
Fulbright Program
The objective of this research is to develop approaches for the black
and grey box modeling of large-scale nonlinear dynamic processes.
These techniques, which involve time-scale, chemometric, and
decomposition data reduction methods, incorporate a priori known
causality information and are applicable also to the detection and
isolation of process faults.
Modeling and Control of Industrial Crystallizers
R. D. Braatz,* D. L. Ma, T. Togkalidou
Merck
Crystallization from solution is an industrially important unit
operation because of its ability to provide high-purity separations.
For efficient downstream operations (such as filtration or washing),
control of the mean particle size, shape, purity, and the crystal size
distribution can be critically important. This project focuses on the
development of models for large-scale crystallizers, which incorporate
fundamental physics of particle nucleation and growth as well as heat
transfer and mixing. Techniques are being developed for crystallizer
design and control that involve parameter estimation, optimal
statistical design to characterize the crystallization system, and
multivariable nonlinear optimal control schemes for ensuring product
quality is maintained.
Effect of Pipe Size in Two-Phase Flow
T. J. Hanratty,* B. Woods, L. Pan, E. Hurlburt
U.S. Department of Energy, DE-FG02-86ER13556
The influence of pipe diameter on flow regime transitions and on the
modeling of stratified, slug, and annular flows is being studied. Two
flow facilities are available. One has horizontal pipes with diameters
of 1 in., 2 in., and 4 in. The other is a vertical system with pipes
of 3/8 in., 3/4 in., and 1 1/2 in. Accomplishments include the
development of a theory to predict the transition from stratified to
slug flow, the development of an interpretation of entrainment
measurements for annular flow in terms of the fundamental rate
processes, the development of an understanding of the wave patterns in
stratified flow, and the use of photographic methods to determine drop
size in annular flow.
Laboratory and supercomputer experiments are being used to understand
the structure of turbulence close to a wall. Highly organized flows
are being identified that are responsible for the sustaining of wall
turbulence. The effect of external influences, such as pressure
gradients, drag-reducing agents, micelles, and imposed flow
oscillations, on these structures is being studied. New photographic
techniques (PIV) are being exploited to obtain simultaneous
measurements at as many as 12,000 points.
Turbulent Flow Over Wavy Surfaces
T. J. Hanratty,* M. Warholic, Y. Na, D. Heist
National Science Foundation, CTS 92-00936
Turbulent flow over wavy surfaces is being studied both in the
laboratory and by a direct numerical simulation. A particular emphasis
during the year is the separated region that exists for large-
amplitude waves. This well-defined separation bubble is being studied
to provide the physical understanding needed to compute and control
separated flows. The flow in the separated region is highly three-
dimensional and seldom resembles the pattern indicated by the time-
averaged streamlines.
Mass Transfer at Gas-Liquid Interfaces
T. J. Hanratty,* S. Duke
University of Illinois
Gas absorption at an interface is of considerable interest in
environmental and processing problems. It is controlled by flow
fluctuations in the liquid in a region of about 200 microns thickness
close to the interface. These fluctuations are greatly enhanced when
waves are present. Experiments are being conducted to understand this
process. A technique involving oxygen quenching of fluorescence is
used to study the concentration field close to the interface. Optical
methods are being developed to map out the instantaneous spatial
variation of wave slope.
Mechanics of Suspensions
J. J. L. Higdon,* E. Guckel
American Chemical Society Petroleum Research Fund
Concentrated suspensions of microscopic particles are encountered
throughout the chemical process industry. The goal of this project is
to characterize the rheology and sedimentation behavior of these
systems, with special attention given to suspensions with
nonhydrodynamic interparticle forces and particles of nonspherical
shape, e.g., fibers and platelets. We are developing novel
computational algorithms for large-scale many-body simulations to
investigate these systems. Our methods follow the basic approach of
the well-known Stokesian dynamics algorithm, but yield an operational
count O( 3) effort of the traditional approach.
Inertial, Viscous, and Acoustic Effects on Drop Displacement Processes
J. J. L. Higdon,* P. Dimitrakopoulos, D. Graham
National Science Foundation, CTS 95-22724
The displacement of a fluid bubble or droplet from a solid substrate
is an important phenomenon in a variety of processes ranging from
enhanced oil recovery to precision coating operations. In this
project, we are investigating the yield conditions for droplet
displacement in both the viscous and inertial regimes. Additional
studies are being conducted to assess the effect of fluctuating
pressure fields associated with acoustic waves. Numerical computations
are performed using finite-element and spectral boundary element
techniques.
Rheology and Structure of Liquid Foams
J. J. L. Higdon,* E. Metsi
Mobil Corp.
Liquid-liquid or liquid-gas foams exhibit an interesting range of
rheological behavior including yield stresses, wall slip, and stress
discontinuities. In addition, the structure and length scales of a
foam undergo continuous evolution under the action of shear. The goal
of this project is to develop efficient algorithms for the simulation
of foam rheology. These algorithms require detailed resolution of the
microscopic fluid flows within a large-scale system which captures the
disorder and range of length scales present in realistic foam flows.
Order/Disorder Transitions in Colloidal Dispersions under Shear
W. R. Schowalter,* D. Dratler
University of Illinois; Monsanto Co.
Stokesian dynamics is being used to show the perturbations possible
when a colloidal dispersion contains a few particles with a radius
different from an otherwise monodisperse system. From the results we
hope to explain the well known order/disorder transitions that occur
when nominally monodisperse systems are subjected to increasing shear
rates.
Rheology in a Potential Vortex
W. R. Schowalter,* K. Sarkar
University of Illinois; Monsanto Co.
Vortex flows offer a special flow history for viscoelastic materials
because of the revolution of principal axes of strain rate without a
corresponding rotation of the fluid. We are studying the consequences
of these kinematics for rheologically complex materials.
Solvation Forces in Protein Crystallization
C. F. Zukoski,* D. Rosenbaum, M. Farnum, E. Kokkoli
National Aeronautics and Space Administration, NAG 8-976
Manipulating the tertiary structures of proteins is crucial to many
biological technologies. X-ray diffraction is the technique of choice
to gain such insight. However, proteins are notoriously difficult to
crystallize and, as a result, data on tertiary structures remain
limited. In this study, we investigate protein/protein interactions
mediated by the solvent to learn better how to induce crystallization.
Our work focuses on using continuous phase chemical potential as a
variable in controlling the ordering process.
The materials investigated in this study are those metals and alloys
which tend spontaneously to form protective surface layers and become
thereby susceptible to localized corrosion when the protective layers
are disturbed. Special attention is given to transport-controlled flow
of current between local anodic and cathodic regions on the corroding
surface. Topics under current study include passivity breakdown in
pits, crevices, and cracks.
A group project explores fundamental surface processes involved in
electrochemical deposition of copper films, with specific emphasis on
the role adsorbates play in mediating the film growth. The program
involves comprehensive studies of the solid-liquid interface in
conjunction with analytical modeling of the growth processes.
Experimental techniques of study include atomic force microscopy of
electrode surfaces, in situ IR spectroscopy of adsorbed organic
additives, and confocal fluorescent microscopy.
The basic thesis of our research is that high pressure is an
essential tool for understanding electronic phenomena in condensed
systems. With increasing compression there is increased overlap among
electronic orbitals. Different types of orbitals are perturbed to
different degrees. A study of these perturbations permits one to
characterize electronic states and excitations, to test theories, and,
under some circumstances, to induce electronic transitions to new
ground states. Our current work involves: (1) The tuning of triplet
energy levels in molecules containing N or O atoms in rigid polymeric
media. The stabilization of antibonding orbitals with respect to
nonbonding orbitals brings about dramatic changes in physical and
chemical properties important for applications in molecular electronic
devices. (2) A comparison of the emission properties of molecules
dissolved in polymers with those attached to a polymer chain. (3)
Nonlinear optical phenomena.
Photochromic Self-assembled Surfaces Formed Using Polypeptides
V. K. Gupta*
University of Illinois
This research explores molecular-level principles for photocontrol of
the optical and the interfacial properties of self-assembled
monolayers. Towards the goal of enhancing the photostimulated response
we are exploring the use of photoresponsive polymers such as a-helical
polypeptides because these biological macromolecules are structurally
anisotropic and possess macrodipoles. By establishing principles based
on which structure and organization of surfaces can be engineered for
optimal control of physico-chemical properties, the proposed research
will permit light-assisted manipulation of adsorption-desorption of
biomolecules on surfaces, wetting-dewetting of polar or nonpolar
fluids, and optical anisotropy such as birefringence or dichroism in
thin films.
Chemical Selectivity of Organized Assemblies of Macrocycles on Solid
Substrates
V. K. Gupta*
University of Illinois
Chemically selective surfaces are essential to chemical and
biochemical sensing as well as in new processes for chemical
purification/separation. This research centers on surfaces that
contain immobilized macrocycles as model receptor molecules with a
potential for complexing with organic adsobates in solution via guest-
host interactions. The proposed research addresses the need for
understanding how characteristics such as surface density of receptor
molecules, steric barriers to binding or molecular flexibility of
receptor chains can be manipulated to enhance the guest-host binding.
Optimization of the guest-host complexation properties will facilitate
new analytical/diagnostic procedures and applications where catalytic
activity can be confined to an interface through guest-host
complexation.
Ion- and Photon-enhanced Surface Diffusion
E. G. Seebauer,* R. Ditchfield
National Science Foundation, CTS 95-06419
Our recent measurements of surface diffusion on Si have demonstrated
that both photon illumination and low-energy ion bombardment can
significantly alter surface diffusion on Group IV semiconductors.
Neither effect has ever been observed directly before. Photon-induced
modifications seem to be mediated electronically, as substrate doping
affects the results. Ion-induced modifications clearly involve some
sort of momentum transfer. Both effects can have direct implications
for semiconductor processing.
Surface diffusion on semiconductors is important in several aspects
of microelectronic device fabrication. We are making measurements of
surface diffusion under real processing temperatures and pressures
using our recently developed laser technique of second harmonic
microscopy. Under such conditions, we find that the diffusion
mechanism changes from simple site hopping to a previously unknown
vacancy-mediated form. We are probing surface diffusion in a variety
of adsorption systems to determine the precise nature of this
mechanism.
Simulations of Surface Diffusion by Molecular Dynamics
E. G. Seebauer,* R. Ditchfield
National Science Foundation, CTS 95-06419
We are performing computer simulations of surface diffusion on
silicon and germanium by molecular dynamics. This approach uses
selected interatomic potentials and integrates the equations of motion
for an ensemble of surface atoms. We have shown good correspondence
between the simulational results and experiments for Ge on Si. We are
now examining the effects of low-energy ion bombardment.
Chemical Vapor Deposition of Titanium Silicide
E. G. Seebauer*
Sematech
Chemical vapor deposition of titanium silicide is being investigated
for metallizing future generations of integrated circuits. Based on
ultrahigh-vacuum kinetic studies, we have developed a quantitative
predictive model for growth, and have confirmed potential growth
conditions in real deposition experiments. This work represents the
first such optimization performed based on fundamental kinetic surface
studies in any adsorption system of practical interest. Work now
focuses on bringing the process into suitable form for large-scale
production.
In this investigation we examine the flow properties of weakly
flocculated suspensions. A model system has been chosen in which, by
solution pH, the suspension can be reversibly gelled. By mapping out a
phase boundary in pH/volume fraction space, we are able to explore the
relationship between flocculation in colloidal suspensions and sol-gel
transitions observed in molecular systems. The mechanical properties
of the gelled samples are of importance in determining porosity and
suspension processibility. We are currently seeking general
descriptions of yielding and flow in terms of the depth of the
interparticle attractive potential.
The short-range interactions between colloidal particles become
increasingly important as the suspension volume fraction is raised and
the particle size shrinks. In this project we investigate the role of
hydration forces that act between particles spaced on the order of
several solvent diameters in controlling the processability of
nanophase ceramic precursor powders. By varying the interaction
potential through control of pH, ionic strength, and chemical
potential of the continuous phase, dense suspensions of particles with
diameters of 1 to 10 nm are prepared. The driving forces for
densification, rheology of the suspensions, and properties of the
fired ceramics are studied.
The structure and flow of dense suspensions of uniform particles is
investigated with particular attention paid to how materials flow at
high-volume fraction. Methods of achieving flowable suspensions at
volume fractions above 0.6 are sought through the use of bimodel
mixtures of particles. Effects of particle size ratio and number ratio
are studied. Small-angle neutron scattering studies are used to
characterize microstructures at rest and under shear flow.
Platelet Orientation in the Flow of Dense Suspensions
C. F. Zukoski,* S. Jogun
U.S. Department of Energy, DE-FG02-96ER4539
The orientation of clay particles has been investigated as a funtion
of shear rate and packing fraction using wide-angle x-ray scattering
and conductivity. These results are used to confirm predictions
developed for dilute suspensions. The influence of particle
orientation on the flow of dense suspensions has been subject to
theoretical or experimental investigation. Our studies demonstrate a
limited volume fraction sensitivity of the fractional degree of
orientation at a given shear rate.
Halogen-Free Methods for Catalyst Regeneration
R. I. Masel,* R. Steger, L. Nigg
National Science Foundation, CTS 95-02141; Exxon Corp.
The current methods for catalyst regeneration produce small amounts
of dioxin. The objective of this project is to see if we can develop a
method to regenerate catalysts using a chelation scheme. Results so
far indicate that we can etch metal particles using a variety of
chelating agents and then convert and redeposit the metal to produce a
redispersed catalyst. Current research considers how the nature of the
chelating affects the binding process and the rate of catalyst
redispersion.
Intrinsic Barriers as a Guide to Mechanisms of Reactions on Solid
Surfaces
R. I. Masel,* N. Chen, P. Blowers, L. Farmer
National Science Foundation, CTS 96-10115
The objective of this project is to see if one can use simple design
rules based on something called an intrinsic barrier to predict the
mechanisms of reactions on metal catalysts. Ab initio calculations are
being used to develop correlations for barriers to reactions. The
correlations are then used to predict reaction mechanisms and rates.
So far we have found that we can correlate the decomposition chemistry
for a wide number of dehydrogenation reactions using the method.
Current work attempts to extend the method to isomerization reactions.
Brownian Dynamics of Semiflexible Chains
A. J. McHugh,* N. C. Andrews
American Chemical Society Petroleum Research Fund
Analyses of the conformational dynamics and rheo-optical behavior of
semiflexible macromolecules are investigated using Brownian dynamics
and configuration-biased Monte Carlo methods. Calculations are based
on a discrete version of the wormlike chain model, extended to include
torsional degrees of freedom and hydrodynamic flow. Calculations for
rheological (stresses, viscometric functions) and optical quantities
(birefringence, dichroism, light scattering) are done for steady and
transient shear and extensional flows. The role of flexibility in the
transient overshoot and relaxation behavior is emphasized.
Semiflexible Macromolecules in Shear Flow
A. J. McHugh,* A. Immaneni, A. Lee
American Chemical Society Petroleum Research Fund
The effects of shear flow, temperature, and pH on secondary
structure, conformational states, and phase stability of
macromolecules in the solution state are investigated using modulated
polarimetry and laser Raman spectroscopy. Molecules include those with
charged side groups, of which poly-L-lysine (PLL) is a model, and
those with uncharged side groups, of which poly-g-benzyl-L-glutamate
(PBLG), poly-e-CBZ-L-lysine (PCBL), and hydroxypropyl cellulose (HPC)
are examples. Flow birefringence and optical rotatory power are used
to probe molecular rigidity changes when conditions of temperature and
solvent environment are varied.
Continuum Modeling of Flow-induced Crystallization
A. J. McHugh,* A. Doufas
University of Illinois
Models of flow-induced crystallization are developed based on
theories of nucleation-controlled and strain-induced crystallization,
coupled with the irreversible thermodynamic formalism of the continuum
Hamiltonian brackets. Model analyses include the effects of
relaxational and orientational processes as well as simultaneous
deformation histories on the crystallization kinetics in terms of
molecular relaxation times, a crystallization parameter, and the melt
molecular weight. Calculations of the crystallization rate, chain
elongation, stress, and birefringence are done for a variety of flow
kinematic histories, including transient flow. Results are compared to
experimentally observed trends reported in the literature.
Dynamics of Phase Inversion
A. J. McHugh,* P. Graham, B. A. Barton, K. Brodbeck
National Science Foundation, CTS 94-21580; Alza Corp.
We are developing quantitative models to describe the mechanisms
involved in membrane structure formation by phase inversion of polymer
solutions. Experiment and theory are being pursued for both the
nonsolvent and thermal quench processes. The former involves optical
techniques we developed for the measurement of mass transfer and
gelation rates and comparison to models based on ternary diffusion
formalisms. The latter involves measurements of small-angle scattering
behavior in thermally quenched films and comparison to models for
phase transformation by spinodal decomposition and nucleation and
growth. Both experiments also involve analyses of film morphologies by
scanning electron microscopy.
Processing of Reactive Cement-Based Composites
A. J. McHugh,* A. Walberer
NSF Center for Advanced Cement-Based Materials
The rheological and processing behavior of reactive, cement-based
pastes are studied. Rheological studies focus on measurements of the
extensional viscosity and nonlinear relaxation behavior in equibiaxial
flows. Processing of phenol resin/cement pastes is being carried out
in a Banbury-type mixer. The objective is to quantify the relationship
between paste chemistry, mixing history, and final composite
properties.
Rapid thermal processing (RTP) constitutes an increasingly common
method for oxidation, silicidation, and related steps in integrated
circuit fabrication. Kinetic analysis of RTP often remains relatively
crude and employs the concept of ``thermal budget.'' We are showing on
experimental and theoretical grounds that this concept often yields
incorrect predictions for heating programs. Instead, we are developing
an alternate approach based on chemical rate selectivity.
Removal of NOx from Combustion Flues
E. G. Seebauer,* E. Blomiley
Electric Power Research Institute
We are looking at inexpensive metal oxides like Fe2O3 as candidates
for photoadsorption of NOx from combustion flue gases. Photoadsorption
is a novel alternative to conventional selective catalytic reduction
in that no separate injection of reductant is needed. Also, the flue
gas needs no reheating. Several halogen-treated oxide surfaces have
shown promise.
Compressive Properties of Cementitious Systems
C. F. Zukoski,* G. Channell
National Science Foundation, CTS 95-31959
The compaction of cementitious systems controls weeping phenomena,
aggregate settling, and formation of uniform coatings in spin casting
of cementitious pipe linings. In this project, we investigate
compressive properties of cements and other weakly flocculated
suspensions. Links are sought between compressive and shear yield
stresses. In addition, the influence of vibrations in aiding
compaction is under study.
Richard C. Alkire
Member, National Academy of Engineering
Fellow, American Association for the Advancement of Science
Fellow, Honorary Member, and Past President, The Electrochemical Society
Teaching Excellence Award, School of Chemical Sciences, UIUC, 1982
Research Award, Electrochemical Division, The Electrochemical Society, 1983
Professional Progress Award, American Institute of Chemical Engineers, 1985
Carl Wagner Memorial Award, The Electrochemical Society, 1985
G. W. Kidd Outstanding Alumnus Award, Lafayette College, 1988
Director, American Institute of Chemical Engineers, 1988-91
E. V. Murphree Award, American Chemical Society, 1991
Technical Achievement Award, National Association of Corrosion Engineers, 1992
Edward Goodrich Acheson Medal, The Electrochemical Society, 1996
Richard D. Braatz
Hertz Fellow, 1991
Hertz Foundation Doctoral Thesis Prize, 1993
Du Pont Young Faculty Award, 1995
Teaching Excellence Award, School of Chemical Sciences, UIUC, 1997
Harry G. Drickamer, Emeritus
Member, National Academy of Engineering
Member, National Academy of Sciences
Member, Center for Advanced Study, UIUC
Member, American Philosophical Society
Doctor of Chemical Science Honoris Causa, Russian Academy of Science
Fellow, American Academy of Arts and Sciences
Fellow, American Institute of Chemical Engineers
Fellow, American Physical Society
Allan P. Colburn Award, American Institute of Chemical Engineers, 1947
Ipatieff Prize, American Chemical Society, 1956
Alpha Chi Sigma Award, American Institute of Chemical Engineers, 1967
Buckley Prize for Solid State Physics, American Physical Society, 1967
Bendix Research Award, American Society for Engineering Education, 1968
William H. Walker Award, American Institute of Chemical Engineers, 1972
Irving Langmuir Award in Chemical Physics, American Physical Society, 1974
P. W. Bridgman Medal, International Association for High Pressure Science and Technology, 1977
Michelson/Morley Award, 1978
Chemical Pioneers Award, American Institute of Chemists, 1983
John Scott Award, City of Philadelphia, 1984
Warren K. Lewis Award, American Institute of Chemical Engineers, 1986
Senior U.S. Scientist Award, Alexander von Humboldt Foundation, Germany, 1986
Peter Debye Award in Physical Chemistry, American Chemical Society, 1987
Welch Award, R. A. Welch Foundation, 1987
Distinguished Alumni Achievement Award, University of Michigan, 1987
Elliott Cresson Medal, The Franklin Institute, 1988
Outstanding Materials Chemistry Award, U.S. Department of Energy, 1989
National Medal of Science, 1989
Director's Distinguished Lectureship, Lawrence Livermore Laboratory, 1991
Gold Medal, American Institute of Chemists, 1996
Thomas J. Hanratty, Emeritus
Member, National Academy of Engineering
Fellow, American Academy of Arts and Sciences
Fellow, American Physical Society
Fellow, American Institute of Mechanics
Honorary Doctorate, Villannova University
Allan P. Colburn Award, American Institute of Chemical Engineers, 1957
Curtis W. McGraw Award, American Society for Engineering Education, 1963
William H. Walker Award, American Institute of Chemical Engineers, 1964
Professional Progress Award, American Institute of Chemical Engineers, 1967
Senior Research Award, American Society for Engineering Education, 1979
Shell Distinguished Chair in Chemical Engineering, UIUC, 1981-90
Ernest Thiele Award, Chicago Section, American Institute of Chemical Engineers, 1986
University Scholar, UIUC, 1987
J. W. Westwater Professorship, UIUC, 1989-97
Lamme Medal, Ohio State University, 1997
Jonathan J. L. Higdon
NSF Presidential Young Investigator Award, 1984
Teaching Excellence Award, College of Liberal Arts and Sciences, UIUC, 1988
Teaching Excellence Award, School of Chemical Sciences, UIUC, 1990, 1994
Stanley Corrsin Lectureship in Fluid Mechanics, Johns Hopkins University, 1993
Deborah E. Leckband
National Institutes of Health FIRST Award, 1993
National Science Foundation Career Award, 1995
Richard I. Masel
Exxon Faculty Fellowship in Solid-State Chemistry, American Chemical Society, 1982
NSF Presidential Young Investigator Award, 1984
Walter G. May, Emeritus
Member, National Academy of Engineering
Fellow, American Institute of Chemical Engineers
Tau Beta Pi Eminent Engineer, 1988
Award in Chemical Engineering Practice, American Institute of Chemical Engineers, 1989
Teaching Excellence Award, School of Chemical Sciences, UIUC, 1989, 1991
Anthony J. McHugh
Senior U.S. Scientist Award, Alexander von Humboldt Foundation, Germany, 1988
Alumni Professorship, Department of Chemical Engineering, UIUC, 1989
School of Chemical Sciences Teaching Award, UIUC, 1990, 1995
Lycan Professorship, School of Chemical Sciences, UIUC, 1995
William R. Schowalter
Member, National Academy of Engineering
Fellow, American Academy of Arts and Sciences
Doctorat Honoris Causa, Institut National Polytechnique de Lorraine, France
William H. Walker Award, American Institute of Chemical Engineers, 1982
J. S. Guggenheim Foundation Fellow, 1987-88
E. C. Bingham Medal, Society of Rheology, 1988
Edmund G. Seebauer
NSF Presidential Young Investigator Award, 1988
Dow Teaching Excellence Award, 1988
Du Pont Young Faculty Award, 1989
Observer for U.S. Delegation, International Union of Pure and Applied Chemistry General Assemblies, 1989, 1991
Alfred P. Sloan Foundation Fellow, 1994-96
Inventor Recognition Award, Semiconductor Research Corp., 1995
School of Chemical Sciences Teaching Award, UIUC, 1996
Mark A. Stadtherr
Excellence in Teaching Award, School of Chemical Sciences, UIUC, 1978
Xerox Award for Faculty Research, College of Engineering, UIUC, 1982
GTE Emerging Scholar Lectureship, University of Notre Dame, 1986
James W. Westwater, Emeritus
Member, National Academy of Engineering
Fellow, American Institute of Chemical Engineers
William H. Walker Award, American Institute of Chemical Engineers, 1966
Max Jacob Award, American Institute of Chemical Engineers, 1972
Bendix Award, American Society for Engineering Education, 1974
Founders' Award, American Institute of Chemical Engineers, 1984
Heat Transfer and Energy Conversion Award, American Institute of Chemical Engineers, 1989
Ernest W. Thiele Award, Chicago Section, American Institute of Chemical Engineers, 1994
K. Dane Wittrup
NSF Presidential Young Investigator Award, 1990
Andersen Consulting Award for Excellence in Advising, College of Engineering, UIUC, 1991, 1993
Dow Chemical Company Excellence in Teaching Award, 1989-90
School of Chemical Sciences Award for Teaching Excellence, UIUC, 1993
Charles F. Zukoski
NSF Presidential Young Investigator Award, 1987
Everitt Award for Teaching Excellence, College of Engineering, UIUC, 1992
Fulbright Teaching/Scholar Fellowship to visit the University of Melbourne, 1992
University Scholar, UIUC, 1994-97
Plenary Lecture: 13th Symposium on Industrial Crystallization, Toulouse, France, September 1996
Moulton Medal, Institute of Chemical Engineers, 1997
Publication Award, Society of Rheology, 1997
Ralph K. Iler Award, American Chemical Society, 1997