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Physical Sciences and Mathematics Commons

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Chemistry

Selected Works

Rosalynn Quiñones-Fernández

Selected Works

2015

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Polystyrene Formation On Monolayer-Modified Nitinol Effectively Controls Corrosion, Rosalynn Quiñones-Fernández, Ellen Gawalt Sep 2015

Polystyrene Formation On Monolayer-Modified Nitinol Effectively Controls Corrosion, Rosalynn Quiñones-Fernández, Ellen Gawalt

Rosalynn Quiñones-Fernández

A surface-initiated polymerization of styrene on carboxylic acid terminated phosphonic monolayers was utilized to increase the corrosion resistance of nitinol and nickel oxide surfaces. Alkyl chain ordering, organic reactions, wettability, and film quality of the monolayers and polymers were determined by infrared spectroscopy, atomic force microscopy, matrix-assisted laser desorption ionization spectrometry, and water contact angles. The polystyrene film proved to be a better corrosion barrier than phosphonic acid monolayers by analysis with cyclic voltammetry and electrochemical impedance spectroscopy. The protection efficiency of the polystyrene film on nitinol was 99.4% and the monolayer was 42%.


Structural And Physicochemical Aspects Of Dasatinib Hydrate And Anhydrate Phases, Saikat Roy, Rosalynn Quiñones Sep 2015

Structural And Physicochemical Aspects Of Dasatinib Hydrate And Anhydrate Phases, Saikat Roy, Rosalynn Quiñones

Rosalynn Quiñones-Fernández

Crystal structures for the commercial monohydrate form and an anhydrate form of dasatinib, an oral anti-cancer agent, are presented along with characterization by Raman spectroscopy, powder X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. Solubility measurements conducted in water reveal the anhydrate has dramatically improved solubility compared to the commercial hydrate form. Finally, dasatinib is a rare example of a promiscuous solvate former and the basis for this behavior can now be understood by examining the poor packing efficiency in the unsolvated form.


Understanding Organic Film Behavior On Alloy And Metal Oxides, Aparna Raman, Rosalynn Quiñones, Lisa Barriger, Rachel Eastman, Arash Parsi, Ellen Gawalt Jul 2015

Understanding Organic Film Behavior On Alloy And Metal Oxides, Aparna Raman, Rosalynn Quiñones, Lisa Barriger, Rachel Eastman, Arash Parsi, Ellen Gawalt

Rosalynn Quiñones-Fernández

Native oxide surfaces of stainless steel 316L and Nitinol alloys and their constituent metal oxides, namely nickel, chromium, molybdenum, manganese, iron, and titanium, were modified with long chain organic acids to better understand organic film formation. The adhesion and stability of films of octadecylphosphonic acid, octadecylhydroxamic acid, octadecylcarboxylic acid, and octadecylsulfonic acid on these substrates were examined in this study. The films formed on these surfaces were analyzed by diffuse reflectance infrared Fourier transform spectroscopy, contact angle goniometry, atomic force microscopy, and matrix-assisted laser desorption ionization mass spectrometry. The effect of the acidity of the organic moiety and substrate composition …