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Full-Text Articles in Physics
Synthesis Of Nanocomposites By Laser Ablation, Stephen Mutisya
Synthesis Of Nanocomposites By Laser Ablation, Stephen Mutisya
Theses and Dissertations
Immunoglobulin E (IgE)-conjugated gold nanoparticles were produced via in situ conjugation of gold nanoparticles with immunoglobulin E by laser ablation of Au in a liquid solution. The colloidal stability and the size distribution of the resulting bio-nanoconjugates were examined with UV-Visible spectroscopy (UV-Vis), dynamic light scattering (DLS), and transmission electron microscopy (TEM). These techniques showed that the Au nanoparticles in aqueous solutions were highly monodispersed spherical particles with a very narrow size distribution. The particles net diameter using TEM, was found to be D5 =3.8±0.9nm and D10 =4.7±1.3nm while the hydrodynamic diameter obtained with DLS was found to be h5 …
Aging Effect In The Wettability Of Nickel Nanorod Arrays, Nahla Albarakati
Aging Effect In The Wettability Of Nickel Nanorod Arrays, Nahla Albarakati
Theses and Dissertations
The time-dependent wettability of nickel nanorod arrays was studied by measuring their water contact angles as a function of "aging" time in air. The nickel nanorod arrays were deposited on silicon substrates by DC magnetron sputtering using an oblique angle of 85° with respect to the substrate normal. By changing the deposition time from 10 to 90 min., the diameter, height, and separation of the nanorods were varied. The water contact angles of each sample were then periodically measured from a minimum aging time of 30 min. after deposition and exposure to air, up to a maximum aging time of …
The Effect Of Ambient On Photoluminescence From Gan, Iwona Ruchala
The Effect Of Ambient On Photoluminescence From Gan, Iwona Ruchala
Theses and Dissertations
The effect of ambient on photoluminescence (PL) from GaN was studied. We found that the PL intensity in vacuum was nearly four times higher than in air. The PL intensity also increased after etching the sample in Aqua Regia and BOE to remove the native oxide layer. After etching, the PL intensity was very stable in vacuum, but substantially degraded in air ambient. In HCl vapor (low pH), the PL intensity increased as compared to air ambient, while in NH3 vapor (high pH) it decreased. The quantum efficiency of the exciton and blue luminescence bands increased significantly with increasing excitation …
Stability And Spectroscopic Properties Of Negative Ions, Swayamprabha Behera
Stability And Spectroscopic Properties Of Negative Ions, Swayamprabha Behera
Theses and Dissertations
Negative ions play an important role in chemistry as building blocks of salts and oxidizing agents. Halogen atoms, due to their ability to attract electrons, readily form negative ions. Considerable interest exists in the design and synthesis of new negative ions called superhaogens whose electron affinities are much higher than those of halogen atoms. This thesis deals with the design of such species. Using density functional theory I have studied two classes of superhalogens. First one involves d1 transition metal (Sc, Y, La) atoms surrounded by Cl while the second one involves simple metals (Na, Mg, Al) surrounded by pseudohalogens …
Inducing Active Sites In Clusters: Reactivity Of Al13ix- And Al14iy- (X=0-2, Y=2-4) With Methanol, Christopher Powell
Inducing Active Sites In Clusters: Reactivity Of Al13ix- And Al14iy- (X=0-2, Y=2-4) With Methanol, Christopher Powell
Theses and Dissertations
Size selective reactivity has been observed in pure aluminum cluster anions as a result of Lewis acid and base pairs. Using this a starting point, the goal of this study has been to explore how reactivity is affected with the addition of one or more ligand, which may induce active sites on the surface of the metal clusters. To study this, a theoretical investigation was undertaken on Al13Ix- and Al14Iy- (x=0-2, y=2-4) and their reactivity with methanol. The hypothesis was that iodine can induce a Lewis base site on the opposite side of the cluster, which may enhance reactivity. In …