Physical Sciences and Mathematics Commons^™

Gas-Surface Interactions: Reactive And Non-Reactive Scattering, Azar Farjamnia

Doctoral Dissertations

The adsorption and dissociation of small molecules on metal surfaces are key steps in many industrial reactions. A detailed understanding of the dynamics of these reactions provides us with the ability to control the outcome and efficacy of the reactions. The molecule-metal interactions will lead to reorientation, energy redistribution, or bond dissociation in the molecule. The process is strongly depending upon the initial conditions, i. e. the incident energy and vibrational state of the molecule, and the surface temperature. We use a fully quantum approach to compute the dissociative sticking probability of the molecules at zero overage, on the surface …

Deconvoluting The Effects Of Surface Chemistry And Nanoscale Topography: Pseudomonas Aeruginosa Biofilm Nucleation On Si-Based Substrates, Zhang Zhang, Jingling Huang, Carmen Say, Robert L. Dorit, Kate Queeney

Chemistry: Faculty Publications

Hypothesis

The nucleation of biofilms is known to be affected by both the chemistry and topography of the underlying substrate, particularly when topography includes nanoscale (nm) features. However, determining the role of topography vs. chemistry is complicated by concomitant variation in both as a result of typical surface modification techniques. Analyzing the behavior of biofilm-forming bacteria exposed to surfaces with systematic, independent variation of both topography and surface chemistry should allow differentiation of the two effects.

Experiments

Silicon surfaces with reproducible nanotopography were created by anisotropic etching in deoxygenated water. Surface chemistry was varied independently to create hydrophilic (OH- terminated) …

Evaluating Differences In The Active-Site Electronics Of Supported Au Nanoparticle Catalysts Using Hammett And Dft Studies, G. Kumar, Luke Tibbitts, Jaclyn Newell, Basu Panthi, Ahana Mukhopadhyay, Robert M. Rioux, Christopher J. Pursell, M. Janik, Bert D. Chandler

Chemistry Faculty Research

Supported metal catalysts, which are composed of metal nanoparticles dispersed on metal oxides or other high-surface-area materials, are ubiquitous in industrially catalysed reactions. Identifying and characterizing the catalytic active sites on these materials still remains a substantial challenge, even though it is required to guide rational design of practical heterogeneous catalysts. Metal-support interactions have an enormous impact on the chemistry of the catalytic active site and can determine the optimum support for a reaction; however, few direct probes of these interactions are available. Here we show how benzyl alcohol oxidation Hammett studies can be used to characterize differences in the …

Surface Oxygenation Of Biochar Through Ozonization For Dramatically Enhancing Cation Exchange Capacity, Matthew D. Huff, Sarah Marshall, Haitham A. Saeed, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

Background

Biochar cation exchange capacity (CEC) is a key property that is central to biochar environmental applications including the retention of soil nutrients in soil amendment and removal of certain pollutants in water-filtration applications.

Results

This study reports an innovative biochar-ozonization process that dramatically increases the CEC value of biochars by a factor of 2. The ozonized biochars also show great improvement on adsorption of methylene blue by as much as a factor of about 5. In this study, biochar samples treated with and without ozone were analyzed by means of pH and CEC assays, water field capacity measurement, elemental …