Physical Sciences and Mathematics Commons^™

Fabrication Of Gold Nanoraspberry Arrays By Soft Lithography, Christy Yu-Qing Xie

Undergraduate Student Research Internships Conference

Nanostructures and nanoparticles have garnered increasing interest over the past decade due to their unique properties and applications. These properties include localized surface plasmon resonance (LSPR) and allow for surface modification. We can tune these properties depending on the nanoparticle’s size, shape, and geometry.

This work aims to fabricate plasmonic platforms through patterning gold nanoparticles (raspberries) by microcontact printing, a simple and cost-effective soft lithography technique. This is done through large-scale patterning using polydimethylsiloxane (PDMS) stamps to pattern an adhesion template and spatially guide the adsorption of gold nanoparticles (AuNPs).

Genotoxicity And Inflammatory Potential Of Stainless Steel Welding Fume Particles: An In Vitro Study On Standard Vs Cr(Vi)-Reduced Flux-Cored Wires And The Role Of Released Metals., Sarah Mccarrick, Valentin Romanovski, Zheng Wei, Elin M Westin, Kjell-Arne Persson, Klara Trydell, Richard Wagner, Inger Odnevall, Yolanda S Hedberg, Hanna L Karlsson

Chemistry Publications

Welders are daily exposed to various levels of welding fumes containing several metals. This exposure can lead to an increased risk for different health effects which serves as a driving force to develop new methods that generate less toxic fumes. The aim of this study was to explore the role of released metals for welding particle-induced toxicity and to test the hypothesis that a reduction of Cr(VI) in welding fumes results in less toxicity by comparing the welding fume particles of optimized Cr(VI)-reduced flux-cored wires (FCWs) to standard FCWs. The welding particles were thoroughly characterized, and toxicity (cell viability, DNA …

New Weldable 316l Stainless Flux-Cored Wires With Reduced Cr(Vi) Fume Emissions Part 1 – Health Aspects Of Particle Composition And Release Of Metals, Yolanda Hedberg

Chemistry Publications

Welding fumes have been found to be carcinogenic and stainless steel welders may be at higher risk due to increased formation of hexavalent chromium (Cr(VI)). The slag-shielded methods, identified to generate most airborne particles and Cr(VI), would potentially be most harmful. With ever-stricter limits set to protect workers, measures to minimize human exposure become crucial. Austenitic stainless steel flux-cored wires of 316L type have been developed with the aim to reduce the toxicity of the welding fume without compromised usability. Collected particles were compared with fumes formed using solid, metal-cored and standard flux-cored wires. The size, morphology and composition were …

Zinc–Phosphorus Clusters For Solution Synthesis Of Zinc Phosphide Nanoparticles, Kyungseop Lee

Electronic Thesis and Dissertation Repository

Synthesis of zinc phosphide (Zn₃P₂) nanoparticles is an emerging topic of investigation as Zn₃P₂ is a candidate material for the next generation solar cells. Despite the early discovery of its favorable electronic properties that are well-suited for photovoltaic applications, a major focus of synthetic strategy was with vapor/chemical deposition methods. Solution methods with greater control over size, crystal structure and composition at a lower production cost, has been underdeveloped in comparison. In this context, this thesis describes the synthesis, characterization and reactivity of zinc phosphido clusters: [Zn₂(μ-PPh₂)₂(PPh …

Poly(Ester Amide)S With Pendant Azobenzenes: Multi-Responsive Self-Immolative Moieties For Modulating Polymer Assemblies, Andrew D. Wong, Alex Prinzen, Elizabeth Gillies

Chemistry Publications

Azobenzenes are well-known for their trans–cis photoisomerization, but it was recently demonstrated that azobenzene derivatives could also undergo reduction to trigger a 1,6-elimination and initiate de- polymerization of a self-immolative polymer. Herein we explore the optimization of azobenzenes as reduction-sensitive moieties, and their incorporation into functional materials. A library of azobenzenes with electron-withdrawing groups was synthesized, and their rates of reduction by hydrazine were deter- mined. Unexpectedly, a 2-Cl substituent increased the rate of reduction more than other electronegative or sterically-demanding substituents. Next, a new diester monomer containing the 2-Cl-azobenzene was synthesized and incorporated into a poly(ester amide) (PEA) backbone, …

Poly(Ester Amide) And Poly(Ethyl Glyoxylate) Nanoparticles For Controlled Drug Release, Amira Mohamed Moustafa

Electronic Thesis and Dissertation Repository

The objective of this research was to develop polymeric nanoparticles (NPs) having improved drug release properties for drug delivery. Poly(ester amide)s (PEAs) are promising biodegradable polymers. PEA NPs were prepared via emulsification-evaporation and salting-out methods and optimized through by varying different processing parameters. Polymer-model drug conjugates based on PEAs containing L-aspartic acid and rhodamine B were synthesized and used for NP preparation. Release behavior was studied and compared to a control system with physically encapsulated rhodamine B. It was shown that the release of rhodamine B from the covalent system did not show the burst effect and exhibited a slower …

Photochromic Molecular Materials For The Controlled Organization Of Nanoparticles, Kristen Elise Snell

Electronic Thesis and Dissertation Repository

The displacement of polystyrene nanoparticles promoted by bulk azo mass transfer using interferential light illumination will be discussed. For this a variety of different push pull small azo molecules were synthesis and characterized, changing the polarity, hydrophobicity and bulky groups around the azo moiety. These small dyes appear to orientate quicker than similarly report azo polymers, of entanglement of the azobenzene group in the polymeric backbone. These dyes were used to form surface relief grating on the thin films due to the bulk mass transfer. This mass transfer was exploited to align polystyrene nanoparticles in the crests and troughs of …

Surface Functionalization And Bioconjugation Of Nanoparticles For Biomedical Applications, Longyan Chen

Electronic Thesis and Dissertation Repository

Colloidal inorganic nanoparticles (NPs) have been attracting considerable interest in biomedicine, from drug and gene delivery to imaging, sensing and diagnostics. It is essential to modify the surface of nanoparticles to have enhanced biocompatibility and functionality for the in vitro and in vivo applications, especially in delivering locally and recognizing biomolecules. Herein, the goal of this research work is to develop advanced NPs with well-tailored surface functionalities and/or bio-functionality for the applications in cell tracking and analytes detection.

In the first project, quantum dots incorporating with gelatin nanoparticles (QDs-GNPs) have been developed for bioimaging applications. Two different approaches have been …

Electrochemiluminescence Of Thienyltriazoles, Iridium Complexes, Au25 Clusters And Pbs Nanoparticles, Kalen N. Swanick

Electronic Thesis and Dissertation Repository

Electrogenerated chemiluminescence or electrochemiluminescence (ECL), produces light in the vicinity of a working electrode by the excited species of a luminophore formed via electron transfer between radical cations and anions, which are electrogenerated. In order for the ECL system to be efficient, the radicals must be stable in solution. This can be enhanced by adding co-reactants such as benzoyl peroxide (BPO) and tri-n-propylamine (TPrA) that produce strong oxidizing or reducing radicals upon redox reactions. ECL pairs electrochemical and spectroscopic methods and is a powerful analytical technique that is highly sensitive and selective.

A comprehensive, mechanistic study of ECL …

Micro- And Nanoparticles In Uv-Cured Thin Films, T. Christopher Corkery, Joseph Chan, Mike J. Idacavage, Elizabeth R. Gillies, Paul J. Ragogna

Chemistry Presentations

No abstract provided.