A Study of Fe₃O₄ Magnetic Nanoparticle RF Heating in Gellan Gum Polymer Under Various Experimental Conditions for Potential Application in Drug Delivery

Author

Gabriel Marcus, University of South FloridaFollow

Graduation Year

2014

Document Type

Thesis

Degree

M.S.

Degree Name

Master of Science (M.S.)

Department

Physics

Degree Granting Department

Physics

Major Professor

Pritish Mukherjee, Ph.D.

Co-Major Professor

Sarath Witanachchi, Ph.D.

Committee Member

Hariharan Srikanth, Ph.D.

Committee Member

Manh-Huong Phan, Ph.D.

Keywords

Agar, Linear Response Theory, Magnetite, PNIPAM, Neel relaxation

Abstract

Magnetic nanoparticles (MNPs) have found use in a wide variety of biomedical applications including hyperthermia, imaging and drug delivery. Certain physical properties, such as the ability to generate heat in response to an alternating magnetic field, make these structures ideal for such purposes. This study's objective was to elucidate the mechanisms primarily responsible for RF MNP heating and determine how such processes affect polymer solutions that might be useful in drug delivery. 15-20 nm magnetite (Fe₃O₄) nanoparticles at 0.2% and 0.5% concentrations were heated with RF fields of different strengths (200 Oe, 400 Oe and 600 Oe) in water and in 0.5% gellan gum solution. Mixing and fan cooling were used in an attempt to improve accuracy of data collection. Specific absorption rate (SAR) values were determined experimentally for each combination of solvent, concentration and field strength. Theoretical calculation of SAR was performed using a model based on linear response theory. Mixing yielded greater precision in experimental determination of SAR while the effects of cooling on this parameter were negligible. Solutions with gellan gum displayed smoother heating over time but no significant changes in SAR values. This was attributed to low polymer concentration and lack of structural phase transition. The LRT model was found to be adequate for calculating SAR at low polymer concentration and was useful in identifying Neel relaxation as the dominant heating process. Heating trials with MNPs in 2% agar confirmed Neel relaxation to be primarily responsible for heat generation in the particles studied.

Scholar Commons Citation

Marcus, Gabriel, "A Study of Fe₃O₄ Magnetic Nanoparticle RF Heating in Gellan Gum Polymer Under Various Experimental Conditions for Potential Application in Drug Delivery" (2014). USF Tampa Graduate Theses and Dissertations.
https://digitalcommons.usf.edu/etd/5537