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Full-Text Articles in Physical Sciences and Mathematics

Kinetics Of Photochemical And Mechanochemical Organic Reactions On Surface, Yerzhan Zholdassov Sep 2023

Kinetics Of Photochemical And Mechanochemical Organic Reactions On Surface, Yerzhan Zholdassov

Dissertations, Theses, and Capstone Projects

Solvents used in traditional chemical processes account for a large percentage of reaction mass and waste and can pose significant environmental and health risks. The environmentally friendly nature of mechanochemistry, in addition to other benefits, makes it a promising approach for sustainable chemistry over traditional solvent-based methods. However, it is still not a widely adopted method for performing chemical reactions on an industrial scale. This is partially due to the significant challenge associated with understanding the reaction kinetics under mechanochemical conditions. Many variations of scanning probe lithography (SPL) techniques are able to manipulate the organic molecules with precise control over …


Tools And Strategies For The Patterning Of Bioactive Molecules And Macromolecules, Daniel J. Valles Sep 2021

Tools And Strategies For The Patterning Of Bioactive Molecules And Macromolecules, Daniel J. Valles

Dissertations, Theses, and Capstone Projects

Hypersurface Photolithography (HP) is a printing method for fabricating structures and patterns composed of soft materials bound to solid surfaces and with ~1 micrometer resolution in the x, y, and z dimensions. This platform leverages benign, low intensity light to perform photochemical surface reactions with spatial and temporal control of irradiation, and, as a result, is particularly useful for patterning delicate organic and biological material. In particular, surface- initiated controlled radical polymerizations can be leveraged to create arbitrary polymer and block- copolymer brush patterns. Chapter 1 will review the advances in instrumentation architectures from our group that have made these …


Toxic Gas Sensing On Nanoporous Carbons, Nikolina-Eleni Travlou Sep 2017

Toxic Gas Sensing On Nanoporous Carbons, Nikolina-Eleni Travlou

Dissertations, Theses, and Capstone Projects

Activated carbons, either synthetic, developed in our laboratory, or commercial, were prepared or further modified, in order to introduce specific heteroatoms such as oxygen, nitrogen and sulfur to their matrices. Chips coated with thin layers of the carbon samples were used for the sensing of gaseous ammonia. They were exposed to continuous cycles of various ammonia concentrations (10-500 ppm), and changes in normalized resistance were analyzed. In all cases linear responses were recorded and the chips reached sensitivities as high as 31%, which are comparable to those of modified graphene-based sensors. The applied specific surface chemical modifications were an effective …


Exploring Sewage Sludge/Fish Waste-Based Materials As Adsorbents Of Pharmaceuticals From Water Phase, Lilja Nielsen Feb 2016

Exploring Sewage Sludge/Fish Waste-Based Materials As Adsorbents Of Pharmaceuticals From Water Phase, Lilja Nielsen

Dissertations, Theses, and Capstone Projects

In an effort to enable wastewater treatment that is more economical and environmentally friendly, alternative adsorbents composed of sewage sludge and fish waste were tested for the removal of pharmaceuticals from aqueous phase. Sewage sludge, fish waste and their homogenized mixtures (90:10, 75:25, 50:50) were carbonized at two temperatures (650 and 950 °C). The obtained materials were extensively characterized in terms of their chemistry and porosity. Adsorption isotherms were used to determine adsorption capacity for 3 model pharmaceuticals: carbamazepine, sulfamethoxazole, and trimethoprim. To simulate the complex environment in the wastewater treatment plant, the adsorption capacity for a multi-component solution, containing …