2018 AIChE Annual Meeting
(6er) Dynamic Microstructure and Interactions in Complex Fluids Under Flow and Confinement
Author
2nd year NRC Postdoctoral Research Fellow, NIST Center for
Neutron Research
Visiting Scholar, Dept. of
Chemical and Biomolecular Engineering, University of Delaware.
Research Interests:
Gels, slurries, and dispersions
are examples of complex fluids, or liquid mixtures comprised of nanoparticles,
dissolved polymers, and surfactant assemblies. The macroscopic engineering
properties of these materials are determined by the structure and strong
interactions between microscopic constituents in the mixture. Experimental
measurements of colloidal (i.e. electrostatic, Van der Waals, and
polymer-mediated) forces combined with bulk structural and mechanical
characterization methods presents an opportunity to comprehensively interpret
phenomena such as dispersion stability, viscosity, flocculation rates,
gelation, and particle adhesion to substrates. Further, many complex fluids
exhibit properties that depend on the deformation history that the material
experiences during processing or application, which drives their microstructure
out of equilibrium. Examples include confinement of lubricant layers in engine
oil formulations, pumping of electrochemical slurries in grid-scale flow
batteries, and deposition of functional inks and coatings in printed
electronics. Future innovations in formulations and technologies based on
concentrated, multicomponent complex fluid mixtures requires expertise in
characterizing the microstructure and interactions between of complex fluids
when far from equilibrium.
My interest is to link
interfacial structure and colloidal interactions to bulk rheological and
tribological properties in complex fluids undergoing dynamic deformations such
as confinement and shear. The resulting structure-property relationships will
inform the design of soft materials with engineered flow and friction behavior.
Armed with core experimental expertise in surface forces, tribology, rheology,
and in-situ light and neutron scattering, I hope to study a broad range of
fundamental problems in applied colloid science. Early research thrusts would
include multi-component suspension rheology, slurries for energy applications,
and artificial joint lubrication.
Summary of Research
Experience
Postdoctoral Work: Topology
of wormlike micelles under shear flow studied with simultaneous dielectric
spectroscopy and RheoSANS
Supervisors: Paul Butler (NIST
Center for Neutron Research) and Norm Wagner (Chemical and Biomolecular
Engineering, University of Delaware).
Core competencies: Suspension and
surfactant rheology. Small angle neutron scattering. Neutron reflectometry.
Light scattering.
Representative publication: J.K.
Riley, J.J. Richards, N.J. Wagner, P.D. Butler. Branching and alignment
in reverse wormlike micelles studied with simultaneous dielectric spectroscopy
and RheoSANS Soft Matter, 2018, article online. *SELECTED FOR
JOURNAL COVER*.
PhD Dissertation: Friction
control by adsorption of polymer brush nanoparticles
Supervisor: Bob Tilton, Chemical
and Biomedical Engineering, Carnegie Mellon University.
Core competencies: Surface forces
measurements via atomic force microscope. Polymer, surfactant, and nanoparticle
adsorption. Atom transfer radical polymerization. Nanotribology.
Representative publication: J.K.
Riley, K. Matyjaszewski, R.D. Tilton. Friction and adhesion control
between adsorbed layers of polyelectrolyte brush grafted nanoparticles via
pH-triggered bridging interactions Journal of Colloid and Interface
Science, 2018, 526, 114-123
Teaching Interests:
I have BChE and PhD degrees in
Chemical Engineering, and I would be excited to teach any core undergraduate
ChemE course across thermodynamics, transport phenomena (particularly fluid
mechanics), or reaction kinetics. During my undergraduate studies, I benefited
from small class sizes and fantastic instructors, and I hope to propagate the
same dedicated approach to educating the future chemical engineers of the
world. Having also attended two institutions with rich history in training and
educating engineers in colloid science Carnegie Mellon University (PhD) and
the University of Delaware (postdoc) I have a sincere interest in developing
classroom-based courses and laboratory modules related to colloids, polymers,
surfactants, and surfaces.
It is my goal to offer a
comprehensive graduate-level course on Fundamentals of Colloid and Interface
Science and an elective course on Formulation Engineering. The latter would
offer advanced undergraduate students in physics, chemistry, biology, and materials
engineering students a look into the microscopic toolbox of polymers,
surfactants, and nanoparticles and how they are incorporated into everyday
products such as creams, shampoos, inks, and drug delivery technologies. This
course would emphasize experimental techniques and hands-on formulation design
principles useful for careers in pharmaceuticals, biotechnology, personal care,
oil and gas, electronic materials, etc. The hands-on components would be
readily adapted as educational STEM outreach modules suitable at the K-12
level.
Select Teaching Experience:
NIST Center for Neutron
Research Instructor for biannual NIST Summer School on Small Angle
Neutron Scattering. Developed lecture and group-based modules on the design,
execution, and analysis of SANS experiments.
University of Delaware
Guest lecturer for graduate level Colloid Science and Engineering course
taught by Professor Norm Wagner. Developed lectures and accompanying laboratory
modules on surfactants, monolayers, colloidal stability, and light scattering.
Student Mentoring NIST (3 undergraduate summer researchers), UD (1
undergraduate REU and 1 high school student), CMU (3 undergraduate senior
honors projects and 4 masters student projects).