Neutron Sciences Directorate

Shull Fellow Oct. 2015 – present
Biology & Soft Matter Division, Oak Ridge National Laboratory 
Developing a science program to investigate curvature-mediated membrane phenomena in topologically nanostructured lipid membranes. The project utilizes the tunability of nanopatterned thermoresponsive polymer scaffolds to generate controllable 2D architectures in supported lipid membranes. The premise of this system is that it enables real-time realization of lateral membrane reorganization and peripheral protein binding in response to local membrane curvature, thus providing insights into critical membrane functions such as signal transduction, cell trafficking, and host-pathogen interactions. In addition, this tunability of membrane topography is envisioned to open new avenues to thermally switchable membrane-based biosensors.

Postdoctoral Scholar Oct. 2012 – Sept. 2015 
NIST Center for Neutron Research & University of Maryland at College Park

• Performed high-resolution characterization of structural and dynamical hierarchy in polymer nanocomposites, both of which are critical for material design and application
• Explored the local ordering of concentrated carbon nanotube suspensions in supersolvents for scalable fluid-phase processing of carbon coatings and composites.
• Examined dispersion and interfacial wetting in composites with dissimilar brush and matrix polymer using scattering, precise modeling and entropy/enthalpy balance.
• Investigated nanoscale structure and dynamics of lipid bilayers and their response to membrane composition and protein insertion, a key factor for effective drug delivery.
• Employed colloidal patterning of modulated substrates using controlled meniscus drag for facile head-to-tail assembly of long gold-nanorod chains with easy transfer to polymer films for use in enhanced plasmonic devices and multistructured electronics.

Research Assistant Sept. 2008 – Sept. 2012 
Indiana University Center for Exploration of Energy and Matter (Prof. Roger Pynn)

• Contributed to the design and applications of the novel neutron spin-echo small angle measurement technique, aimed at real-space realization of density autocorrelations.
• Developed a new scattering approach to characterize matter in nanoconfinement.
• Implemented the new approach to study the assembly of colloidal nanosuspensions in submicron confinement and the conformity of thermoresponsive polymer films to underlying surface nanomodulations.
• Developed and designed code for the analysis of dynamical scattering from periodic nanostructures. Unlike previous dynamical theory codes that report instabilities beyond few diffraction orders, this code is stable up to hundreds of orders and thus constitutes an exact model for dynamical scattering. It also allows 3D observation of the x-ray or neutron wavefunction which is essential for understanding and utilizing beam optics, e.g. tunneling effects, standing wave patterns, and waveguide behavior.
• Developed codes based on different approximate scattering theories (Born, Distorted-Wave Born and Phase-Object approximations) to interpret weak scattering effects.
• Designed sample cells for scattering studies on confined fluids and liquid interfaces. 

Research Assistant Aug. 2007 – Aug. 2008 
Indiana University Experimental Nuclear Physics Group (Dr. Edward Stephenson)

• Built the magnetic flux return setup for the aCORN apparatus designed for neutron beta decay measurements.
• Performed detailed magnetic field mapping to detect inhomogeneities that are detrimental for neutron decay measurements.
• Ran Monte Carlo simulations to optimize the experimental settings for data collection

Research Assistant Nov. 2006 – July 2007
American University of Beirut, Pulsed Laser Deposition Lab (Prof. Malek Tabbal)

• Studied the optimization of growth conditions of chromium and carbon thin films using short-pulse laser in different gas environments.
• Conducted AFM on the films to test their growth rate and lateral homogeneity