(10n) Advanced Rheological and Neutron Methods for the Rational Design of Soft Materials

Advanced rheological and
neutron methods for the rational design of soft materials

Michelle
Calabrese, University of Delaware

Chemical
& Biomolecular Engineering, 5^th year
PhD candidate

Research Interests: The design of
soft materials with optimal structure and flow properties is critical in
applications ranging from polymer processing to drug delivery, where materials
undergo nonlinear deformations during processing, transport and use.  Unlike standard scattering methods, flow-small
angle neutron scattering (flow-SANS) enables researchers to study the flow-induced
material structure by integrating rheology with time- and spatially-resolved microstructure
measurements. Flow-SANS provides the missing link between the flow behavior and
molecular topology, and can be tailored for complex flows including shear,
extension, and microfluidics. Recent advances in time-resolved data collection
and analysis allow the material structure to be measured continuously in time. As
neutrons are not destructive to samples, flow-SANS is unique and of growing
interest for applications ranging from proteins and biological materials, to
consumer products and oil and energy recovery fluids.

Teaching Interests: My core teaching interests are in the fundamental
fields of fluid mechanics and transport; I am also interested in teaching
applied courses on rheology and materialsÕ characterization.

Successful Proposals &
Grants: NIST
Center for Neutron Research (NCNR, USA) BTAC -  4 of 5 proposals accepted: neutron
spin echo (2015), SANS (2014, 2015), USANS (2014);  Institut Laue-Langevin (ILL, France)-
Visiting scientist grant (2016), 3 of 3 proposals accepted: SANS (2015,
2016)

PhD Dissertation: Structure-property relationships of branched wormlike
micelles via nonlinear rheology and small angle neutron scattering (SANS), Chemical & Biomolecular Engineering, University of Delaware & NCNR,
under the supervision of Norman J. Wagner

Visiting scientist project:
Precise determination of
concentration gradient in shear banding wormlike micelle solutions with Lionel Porcar, ILL

Research Experience: My research thus far has focused around two central
tenants: the characterization of soft materials via non-linear rheology and
neutron techniques, and the development of new neutron techniques and analysis
methods for broader use within the scientific community. The work has been a
collaborative effort with chemical engineers, physicists, chemists and materials
scientists. Specifically, my experimental projects have focused on advanced
rheological techniques and their interpretation (shear startup, large amplitude
oscillatory shear, orthogonal superposition, extensional rheology) and neutron
scattering methods (static SANS, 1-3 plane rheo-SANS, 1-2 plane flow SANS,
neutron spin echo) in various self-assembled surfactant and polymer solutions. While
this work is primarily experimental, an emphasis has been placed on experimentally
validating modeling predictions in regard to flow instabilities. In the instrumentation-based
projects, I have worked closely with beam line scientists at NIST and ILL to improve
SANS capabilities and measurement resolution in space and time; these
developments have been implemented at NIST and the ILL.

Teaching Experience: I have enjoyed many teaching opportunities throughout
my scholastic career. I served as a teaching assistant at both the University
of Delaware and the University of Pennsylvania (undergraduate), where I occasionally
lectured. I held frequent office hours that were well received, as I received a
4.9/5 average in the teaching evaluations from my students.  I was also awarded the Robert L. Pigford Teaching Assistant Award from the CHEG department
at UD. I currently help younger members of my group learn neutron techniques
and design experiments. At Penn, I was a TA, lab instructor and research mentor
for a summer course on biotechnology; I also helped develop material for the
chemical engineering section of the freshman introduction to engineering
course. For several years, I have worked as a tutor and instructor for various afterschool
programs, and continue to do STEM outreach when possible.

Future Direction: As a faculty member,I would continue using a combination of neutron and rheological
techniques to characterize and design materials, while advancing
instrumentation and measurement capabilities for targeted applications. I hope
to extend my current work in surfactants and flow instabilities to biological systems.
Flow-SANS is ideal for studying biological soft materials and artificial
replacements for such materials, as neutrons, unlike x-rays, are not harmful to
the materials. I hope to extend my work surrounding flow instabilities to
optimize the properties of these materials for sensitive applications. Further,
new flow-SANS cells can be easily developed and tailored to approximate
injections or flows in the body, for example. My goal is to reproduce flows
seen in real applications as closely as possible in my experiments, thus I foresee
this work extending into modeling efforts, or collaborating closely with
modeling groups to further our understanding of complex flows.  

My other areas
of interest include developing and optimizing soft materials for energy
applications. I hope to continue a new collaboration with a group at Lawrence
Berkeley National Lab, where weÕve applied flow-SANS methods to study Nafion
solutions for fuel cell applications. Again, these methodologies can be tailored
to approximate the necessary dynamic flow conditions, such as cycling or flow
reversals. Further, recent developments have enabled the simultaneous measurement
of dielectric properties during flow-SANS, which is an area I hope to explore
in these energy-related applications. My overall goal is to apply this
multi-faceted neutron and rheological approach to interesting and relevant soft
materials, using realistic experimental conditions for application-based
projects.

Publications:

1. M.A. Calabrese, S.A. Rogers, L. Porcar & N.J. Wagner. ÒUnderstanding
steady and dynamic shear banding in a branched wormlike micellar solution,Ó Journal
of Rheology (accepted), 2016.

2. M.A. Calabrese, N.J. Wagner and
S.A. Rogers. ÒAn optimized protocol for the analysis of
time-resolved scattering experiments,Ó Soft Matter, 2016.

3. M.A. Calabrese, S.A. Rogers,
R.P. Murphy and N.J. Wagner. ÒThe rheology and microstructure
of branched micelles under shear,Ó Journal of Rheology, 2015, 59(5),
1299-1328.

4. A. Kusoglu, M. Calabrese
and A. Z. Weber. ÒEffect of mechanical compression on
chemical degradation of Nafion membranes,Ó ECS
Electrochemistry Letters, 2014, 3(5), F33-F36.

Reviews, book chapters & other articles:

1. M.A. Calabrese and N.J. Wagner.
ÒNew Insights from Rheo-SANS,Ó chapter in: Wormlike Micelles: Systems, Characterisation, Applications, Royal Society of
Chemistry (2016).

2. M.A. Calabrese, N.J. Wagner,
S.A. Rogers and L. Porcar. ÒEffect
of branching on shear banding in worm-like micelles (WLMs) under large
amplitude oscillatory shear (LAOS),Ó Instrument & Technical Upgrades -
ILL News, Dec. 2015.

3. S.A.
Rogers, M.A. Calabrese, N.J.
Wagner. ÒRheology of branched wormlike micelles,Ó Current Opinion in Colloid
& Interface Science, 2014, 19(6), 530-535.

4. S.A.
Rogers, M.A. Calabrese and
N.J. Wagner. ÒAdvances in Time Resolved Neutron Scattering
from Flowing Complex Fluids,Ó NCNR Annual Report, 2014.