@article{abbott_maity_burkey_gorga_bochinski_clarke_2014, title={Blending with Non-responsive Polymers to Incorporate Nanoparticles into Shape-Memory Materials and Enable Photothermal Heating: The Effects of Heterogeneous Temperature Distribution}, volume={215}, ISSN={["1521-3935"]}, DOI={10.1002/macp.201400386}, abstractNote={Blending a shape‐memory polymer (SMP) (e.g., thermoplastic polyurethane) with an immiscible carrier polymer (e.g., poly(ethylene oxide) (PEO) or poly(vinyl alcohol) (PVA)) containing dispersed metal nanoparticles (AuNPs) is a simple approach to enable actuation via photothermal heating. For blends containing up to 90% carrier polymer, the shape‐memory capability can be thermally triggered either conventionally or utilizing internal heating via application of light that is resonant with the particle's surface plasmon resonance. When incorporating nanoparticles in this manner, neither chemical modification of the shape‐memory moiety nor solvation of the SMP is necessary. Actuation times are determined by the particular heterogeneous temperature distribution, which generally occurs under both conventional and photothermal heating methods, but with different spatial patterns. Blending an SMP with PEO containing AuNPs imposes a higher transition temperature (the melting point of PEO), enabling heat generated within the nanoparticle‐containing regions to equilibrate throughout the sample, resulting in performance under photothermal conditions comparable with that achieved in a conventional heating approach. SMP:PVA blends actuate at the SMP transition temperature and the response depends on the size of phase segregation between the PVA and SMP; when decreasing the characteristic size of the segregated regions, heat is efficiently transferred and optimal photothermal performance is observed.
image}, number={23}, journal={MACROMOLECULAR CHEMISTRY AND PHYSICS}, author={Abbott, David B. and Maity, Somsubhra and Burkey, Mary T. and Gorga, Russell E. and Bochinski, Jason R. and Clarke, Laura I.}, year={2014}, month={Dec}, pages={2345–2356} }
 @article{burkey_reynolds_borkowski_blondin_2013, title={X-RAY EMISSION FROM STRONGLY ASYMMETRIC CIRCUMSTELLAR MATERIAL IN THE REMNANT OF KEPLER'S SUPERNOVA}, volume={764}, ISSN={0004-637X 1538-4357}, url={http://dx.doi.org/10.1088/0004-637X/764/1/63}, DOI={10.1088/0004-637x/764/1/63}, abstractNote={Kepler's supernova remnant resulted from a thermonuclear explosion, but is interacting with circumstellar material (CSM) lost from the progenitor system. We describe a statistical technique for isolating X-ray emission due to CSM from that due to shocked ejecta. Shocked CSM coincides well in position with 24 μm emission seen by Spitzer. We find most CSM to be distributed along the bright north rim, but substantial concentrations are also found projected against the center of the remnant, roughly along a diameter with position angle ∼100°. We interpret this as evidence for a disk distribution of CSM before the supernova, with the line of sight to the observer roughly in the disk plane. We present two-dimensional hydrodynamic simulations of this scenario in qualitative agreement with the observed CSM morphology. Our observations require Kepler to have originated in a close binary system with an asymptotic giant branch star companion.}, number={1}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Burkey, Mary T. and Reynolds, Stephen P. and Borkowski, Kazimierz J. and Blondin, John M.}, year={2013}, month={Jan}, pages={63} }