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Magnetic Studies Of Iron Oxide Nanoparticles Coated With Oleic Acid And Pluronic® Block Copolymer, Marco Morales Torres, Tapan Kumar Jain, V. Labhasetwar, Diandra Leslie-Pelecky
Magnetic Studies Of Iron Oxide Nanoparticles Coated With Oleic Acid And Pluronic® Block Copolymer, Marco Morales Torres, Tapan Kumar Jain, V. Labhasetwar, Diandra Leslie-Pelecky
Diandra Leslie-Pelecky Publications
We have prepared and studied iron-oxide nanoparticles coated with oleic acid (OA) and Pluronic® polymer. The mean diameter of the iron-oxide nanoparticles was 9.3(±)0.8 nm. Saturation magnetization values measured at 10 K varied from 66.1(±0.7) emu/g to 98.7(±0.5) emu/g. At 300 K the loops showed negligible coercive field. The peaks in zero-field-cooled susceptibility decreased from 280 to 168 K with increasing OA concentration up to 10.6 wt %, and remained nearly constant for higher concentrations. This suggests that incomplete coverage of the OA allows small, interacting agglomerates to form.
Spin Glass Or Random Anisotropy?: The Origin Of Magnetically Glassy Behavior In Nanostructured Gdal2, P. M. Shand, C. C. Stark, D. Williams, Marco Morales Torres, T. M. Pekarek, Diandra Leslie-Pelecky
Spin Glass Or Random Anisotropy?: The Origin Of Magnetically Glassy Behavior In Nanostructured Gdal2, P. M. Shand, C. C. Stark, D. Williams, Marco Morales Torres, T. M. Pekarek, Diandra Leslie-Pelecky
Diandra Leslie-Pelecky Publications
Initially crystalline GdAl2 was mechanically milled for long times to produce a highly chemically disordered phase with approximately 8-nm grains. Analysis of dc magnetization measurements using an Arrott plot and the approach to saturation suggest the presence of significant random anisotropy. ac susceptibility measurements showed that the shift in the peak temperature with frequency usually seen in magnetically glassy and superparamagnetic systems was virtually undetectable in the 10–1000-Hz frequency range. Based on these results, we believe that this material represents an interacting system with random anisotropy, where the anisotropy is the result of surface and interface asymmetries. ©2005 American …
Iron Oxide Nanoparticles For Sustained Delivery Of Anticancer Agents, Tapan K. Jain, Marco Morales Torres, Sanjeeb K. Sahoo, Diandra Leslie-Pelecky, Vinod Labhasetwar
Iron Oxide Nanoparticles For Sustained Delivery Of Anticancer Agents, Tapan K. Jain, Marco Morales Torres, Sanjeeb K. Sahoo, Diandra Leslie-Pelecky, Vinod Labhasetwar
Diandra Leslie-Pelecky Publications
We have developed a novel water-dispersible oleic acid (OA)-Pluronic-coated iron oxide magnetic nanoparticle formulation that can be loaded easily with high doses of water-insoluble anticancer agents. Drug partitions into the OA shell surrounding iron oxide nanoparticles, and the Pluronic that anchors at the OA-water interface confers aqueous dispersity to the formulation. Neither the formulation components nor the drug loading affected the magnetic properties of the core iron oxide nanoparticles. Sustained release of the incorporated drug is observed over 2 weeks under in vitro conditions. The nanoparticles further demonstrated sustained intracellular drug retention relative to drug in solution and a dose-dependent …
The Stability And Oxidation Resistance Of Iron- And Cobalt-Based Magnetic Nanoparticle Fluids Fabricated By Inert-Gas Condensation, Nguyen H. Hai, Raymond Lemoine, Shaina Remboldt, Michelle A. Strand, Steve Wignall, Jeffrey E. Shield, Diandra Leslie-Pelecky
The Stability And Oxidation Resistance Of Iron- And Cobalt-Based Magnetic Nanoparticle Fluids Fabricated By Inert-Gas Condensation, Nguyen H. Hai, Raymond Lemoine, Shaina Remboldt, Michelle A. Strand, Steve Wignall, Jeffrey E. Shield, Diandra Leslie-Pelecky
Diandra Leslie-Pelecky Publications
Magnetic nanoparticle fluids have numerous biomedical applications, including magnetic imaging, drug delivery, and hyperthemia treatment for cancer. Ideal magnetic nanoparticle fluids have well-separated, biocompatible nanoparticles with a small size distribution that form a stable colloid. We have combined inert-gas condensation, which produces nanoparticles with low polydispersity, with deposition directly into a surfactant-laden fluid to prevent agglomeration. Iron, cobalt, and iron-nitride nanoparticle fluids fabricated using inert-gas condensation have with mean particle sizes from 5-50 nm and remain stable over long periods of time. Iron and cobalt nanoparticles oxidize on exposure to air, with oxidation rates dependent on surfactant type and concentration. …
Broadening Middle-School Students’ Images Of Science And Scientists, Diandra Leslie-Pelecky, Gayle A. Buck, Angela Zabawa
Broadening Middle-School Students’ Images Of Science And Scientists, Diandra Leslie-Pelecky, Gayle A. Buck, Angela Zabawa
Diandra Leslie-Pelecky Publications
The ‘mad scientist’ stereotype is alive and well – and not an image most K-12 students can (or want to) embrace. Project Fulcrum, a National Science Foundation-funded GK-12 program, partners math, science and engineering graduate students with elementary and middle-level teachers. One project goal – broadening student images of science and scientists –is addressed by projects developed by the teacher/scientist teams that are focused on the specific needs of their students. The projects developed focus on scientists, the use of science in different types of jobs, and developing scientific skills. Pre-project research, in which teachers probe the motivation behind their …