Date of Award

2022-12-01

Degree Name

Doctor of Philosophy

Department

Environmental Science and Engineering

Advisor(s)

Ahmed A. El Gendy

Abstract

Scrutinizing the remarkable and tunable properties of magnetic materials at a nanoscale size "There's Plenty of Room at the Bottom..." Richard Feynman, this study attempts to find sustainable solutions to some of the deteriorating environmental, health, and energy problems the world is encountering. Due to their simple preparation, surface adaptability, and tunable magnetic and optical properties, magnetic nanoparticles have been extensively investigated in water treatment, cancer therapy, data storage, and more. However, relying on non-reusable and chemical-based treatment agents in water, complex and costly cancer treatment procedures and molecular magnets that operate far below room temperature limited those attempts from feasibility. Thus, green, and sustainable materials and methods have long been in high demand. Here in we developed novel and optimized in organic and organic soft magnets suitable for water treatment, tumor cell obliteration, and room-temperature molecular magnets as energy-efficient data storage and spintronic devices. Green synthesized nanoparticles removed MB and 4-NA above 80% efficiency under a wide range of conditions and 94% under optimum conditions in 2 - 160 minutes. Moreover, nanoparticles were successfully grown on PVA surfaces as alternative recyclability for weakly magnetic materials. We introduced secondary metabolites as a novel platform in magnetic hyperthermia for the first time that showed a temperature in the therapeutic limit, Tmax=45oC, high dT/dt and SAR = 230.61 W/g, and improved dispersion. Different sizes (Ave. DSEM = 64 nm) and magnetic properties (106 emu/g - 241 emu/g) were tuned at various reaction temperatures and concentrations. Ultra-high magnetic saturation (241 emu/g) was observed in response to low reaction temperature. We also discovered graphene-based, stable, and room-temperature molecular magnets (2.9 emu/g at 300K) with magnetocrystalline anisotropy of 8 x105 and 3x 107 J/m3 in aminoferrocene and graphene-based aminoferrocene respectively. These values are comparable and even two orders of magnetiude larger than the pure iron metal under normal conditions.

Language

en

Provenance

Received from ProQuest

File Size

184 p.

File Format

application/pdf

Rights Holder

Yohannes Weldemariam Getahun

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