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You searched for +publisher:"Georgia Tech" +contributor:("Angus Wilkinson"). Showing records 1 – 3 of 3 total matches.

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1. Rolle, Clarence J. Selective aerobic oxidations catalyzed by manganese(III) complexes using redox-active ligands.

Degree: PhD, Chemistry and Biochemistry, 2011, Georgia Tech

URL: http://hdl.handle.net/1853/42827 

Selective oxidations are important for the functionalization of compounds in organic synthesis and chemical industry. Using O2 as a terminal e- acceptor would be ideal because it is cheap and environmentally friendly, but aerobic oxidations are often prone to unselective free radical autoxidation. Recently developed palladium catalysts use O2 as a selective multi-electron oxidant for various organic transformations. Although these methods are powerful and sophisticated, the lower cost of base metals makes them attractive as potential alternatives. The challenge is to develop methods for effecting multi-electron transformations at metals that typically prefer one electron changes. To this end, the development of manganese(III) complexes containing redox-active ligands as catalysts for selective oxidase-type oxidation of organic substrates was pursued. Bis(tetrabromocatecholato) manganese(III) complexes were shown to aerobically oxidize catechols to form quinones and H2O2. This reactivity was extended to other alcohol and amine substrates. In these reactions, the non-innocent tetrabromocatecholate ligands may impart a multi-electron character to the metal. To directly probe the intermediacy of ligand-centered radicals in catalytic turnover, a series of structurally similar manganese(III) complexes with aminophenol-derived ligands were prepared and characterized. The capacity of these ligands to undergo low-energy redox changes, allowed for isolation of an electron transfer series spanning two redox states without a change in oxidation state at the metal center. The ligand-centered redox events were a key feature in aerobic homocoupling of Grignard reagents. Advisors/Committee Members: Jake Soper (Committee Chair), Angus Wilkinson (Committee Member), Christoph Fahrni (Committee Member), Christopher Jones (Committee Member), Kent Barefield (Committee Member).

Subjects/Keywords: Oxidation chemistry; Metal catalysts; Metalloenzymes; Manganese; Manganese catalysts; Oxidases; Oxidation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Rolle, C. J. (2011). Selective aerobic oxidations catalyzed by manganese(III) complexes using redox-active ligands. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/42827

Chicago Manual of Style (16th Edition):

Rolle, Clarence J. “Selective aerobic oxidations catalyzed by manganese(III) complexes using redox-active ligands.” 2011. Doctoral Dissertation, Georgia Tech. Accessed January 20, 2021. http://hdl.handle.net/1853/42827.

MLA Handbook (7th Edition):

Rolle, Clarence J. “Selective aerobic oxidations catalyzed by manganese(III) complexes using redox-active ligands.” 2011. Web. 20 Jan 2021.

Vancouver:

Rolle CJ. Selective aerobic oxidations catalyzed by manganese(III) complexes using redox-active ligands. [Internet] [Doctoral dissertation]. Georgia Tech; 2011. [cited 2021 Jan 20]. Available from: http://hdl.handle.net/1853/42827.

Council of Science Editors:

Rolle CJ. Selective aerobic oxidations catalyzed by manganese(III) complexes using redox-active ligands. [Doctoral Dissertation]. Georgia Tech; 2011. Available from: http://hdl.handle.net/1853/42827

2. Cates, Ezra Lucas Hoyt. Development of visible-to-ultraviolet upconversion phosphors for light-activated antimicrobial surfaces.

Degree: PhD, Civil and Environmental Engineering, 2013, Georgia Tech

URL: http://hdl.handle.net/1853/47619 

A new form of antimicrobial surface was developed, which relies on an optical mechanism rather than chemical inactivation of microorganisms. Through the photoluminescence process of upconversion, low energy photons can be amplified into higher energy photons, and in this case, phosphors capable of converting visible light into germicidal UVC radiation were synthesized. Host crystals were doped with a praseodymium activator ion and shown to emit UVC photons upon excitation by blue or violet light. Surface coatings were prepared and proof-of-concept experiments demonstrated that, under exposure to a household fluorescent lamp, sufficient UVC radiation was emitted from the surfaces to achieve observable inactivation of surface bacterial spores and inhibition of biofilm growth. Material engineering was conducted to achieve higher optical conversion efficiency, wherein lithium codoping and development of alternative oxyfluoride host crystals were found to significantly improve upconversion emission. Implications of polychromatic excitation were investigated by conducting photoluminescence spectroscopy under combined laser beam excitation, while the effects of other application parameters are also discussed. These findings show that upconversion-based antimicrobial materials have strong potential for offering sustainable and effective technology for the prevention of diseases. Advisors/Committee Members: Jaehong Kim (Committee Chair), Angus Wilkinson (Committee Member), Ching-hua Huang (Committee Member), John Crittenden (Committee Member), Seung Soon Jang (Committee Member).

Subjects/Keywords: Photoluminescence; Disinfection; Upconversion; Antimicrobial; Anti-infective agents; Phosphors

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Cates, E. L. H. (2013). Development of visible-to-ultraviolet upconversion phosphors for light-activated antimicrobial surfaces. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/47619

Chicago Manual of Style (16th Edition):

Cates, Ezra Lucas Hoyt. “Development of visible-to-ultraviolet upconversion phosphors for light-activated antimicrobial surfaces.” 2013. Doctoral Dissertation, Georgia Tech. Accessed January 20, 2021. http://hdl.handle.net/1853/47619.

MLA Handbook (7th Edition):

Cates, Ezra Lucas Hoyt. “Development of visible-to-ultraviolet upconversion phosphors for light-activated antimicrobial surfaces.” 2013. Web. 20 Jan 2021.

Vancouver:

Cates ELH. Development of visible-to-ultraviolet upconversion phosphors for light-activated antimicrobial surfaces. [Internet] [Doctoral dissertation]. Georgia Tech; 2013. [cited 2021 Jan 20]. Available from: http://hdl.handle.net/1853/47619.

Council of Science Editors:

Cates ELH. Development of visible-to-ultraviolet upconversion phosphors for light-activated antimicrobial surfaces. [Doctoral Dissertation]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/47619


Georgia Tech

3. Han, Man Huon. Development of synthesis method for spinel ferrite magnetic nanoparticle and its superparamagnetic properties.

Degree: PhD, Chemistry and Biochemistry, 2008, Georgia Tech

URL: http://hdl.handle.net/1853/26465 

The magnetic spinel ferrite nanoparticle is exceptionally intriguing nanocrystal system due to the industrial importance of various technical applications and the scientific significance of studying the quantum origin of magnetism. Studies of quantum influences upon magnetic properties have revealed that the spin-orbit coupling and the net magnetization greatly affect the net magnetic properties of each spinel ferrite system differently. In case of cobalt ferrite where spin-orbit coupling is relatively large, increasing Cr3+ doping concentration, which has smaller magnetic moment and zero angular moment, decreases blocking temperature, saturation magnetization, remnant magnetization and coercivity. However, in case of manganese ferrite where spin-orbit coupling is relatively small, increasing Cr3+ doping concentration, reduces all the magnetic parameters except coercivity. The coercivity increases due to smaller magnetocrystalline anisotropy energy constant which forces the coercivity to increase as saturation magnetization decreases in accordance with Stoner-Wohlfarth theory. In order to improve product quality and quantity, synthesis routes in hot oleylamine and aminolytic reaction were developed. Both methods were proven to be extremely effective, environmental friendly, inexpensive, and simple routes in the synthesis of a variety of spinel ferrite systems including CoFe2O4, MnFe2O4, NiFe2O4, and ZnFe2O4 from a single source metal precursor. Advisors/Committee Members: Z. John Zhang (Committee Chair), Angus Wilkinson (Committee Member), C P Wong (Committee Member), E. Kent Barefield (Committee Member), Mostafa El-Sayed (Committee Member).

Subjects/Keywords: Nanotechnology; Magnetism; Nanoparticle; Ferrites (Magnetic materials); Nanoparticles Magnetic properties; Spinel

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Han, M. H. (2008). Development of synthesis method for spinel ferrite magnetic nanoparticle and its superparamagnetic properties. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/26465

Chicago Manual of Style (16th Edition):

Han, Man Huon. “Development of synthesis method for spinel ferrite magnetic nanoparticle and its superparamagnetic properties.” 2008. Doctoral Dissertation, Georgia Tech. Accessed January 20, 2021. http://hdl.handle.net/1853/26465.

MLA Handbook (7th Edition):

Han, Man Huon. “Development of synthesis method for spinel ferrite magnetic nanoparticle and its superparamagnetic properties.” 2008. Web. 20 Jan 2021.

Vancouver:

Han MH. Development of synthesis method for spinel ferrite magnetic nanoparticle and its superparamagnetic properties. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Jan 20]. Available from: http://hdl.handle.net/1853/26465.

Council of Science Editors:

Han MH. Development of synthesis method for spinel ferrite magnetic nanoparticle and its superparamagnetic properties. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/26465

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