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Full-Text Articles in Physical Sciences and Mathematics
Systematic Approach To Electrostatically Induced 2d Crystallization Of Nanoparticles At Liquid Interfaces, Sumit Kewalramani, Suntao Wang, Yuan Lin, Huong Giang Nguyen, Qian Wang, Masafumi Fukuto, Lin Yang
Systematic Approach To Electrostatically Induced 2d Crystallization Of Nanoparticles At Liquid Interfaces, Sumit Kewalramani, Suntao Wang, Yuan Lin, Huong Giang Nguyen, Qian Wang, Masafumi Fukuto, Lin Yang
Faculty Publications
We report an experimental demonstration of a strategy for inducing two-dimensional (2D)crystallization of charged nanoparticles on oppositely charged fluid interfaces. This strategy aims to maximize the interfacial adsorption of nanoparticles, and hence their lateral packing density, by utilizing a combination of weakly charged particles and a high surface charge density on the planar interface. In order to test this approach, we investigated the assembly of cowpea mosaic virus (CPMV) on positively charged lipid monolayers at the aqueous solution surface, by means of in situX-ray scattering measurements at the liquid–vapor interface. Theassembly was studied as a function of the solution …
Enhanced Electrochemistry Of Nanoparticle-Embedded Polyelectrolyte Films: Interfacial Electronic Coupling And Distance Dependence, Callie E. Dowdy, Michael C. Leopold
Enhanced Electrochemistry Of Nanoparticle-Embedded Polyelectrolyte Films: Interfacial Electronic Coupling And Distance Dependence, Callie E. Dowdy, Michael C. Leopold
Chemistry Faculty Publications
Factors affecting the electronic communication believed to be responsible for the enhanced solution electrochemistry observed at electrodes modified with hybrid polyelectrolyte–nanoparticle (PE–NP) film assemblies were systematically investigated. Specifically, the faradaic current and voltammetric peak splitting recorded for cyclic voltammetry of ferricyanide redox species (Fe(CN)63−/4−) at films constructed with various architectures of citrate-stabilized gold NPs embedded in polyelectrolyte films composed of poly-l-lysine and poly-S-styrene were used to establish the relative importance of both distance and electronic coupling. Layer-by-layer construction of PE–NP films allowed for the position and density of NPs to be varied within the film to assess electronic coupling between …
Synthesis And Characterization Of An Europium-Porphyrin Complex, Alejandro Blinder
Synthesis And Characterization Of An Europium-Porphyrin Complex, Alejandro Blinder
All Capstone Projects
Photodynamic therapy (PDT) is a promising treatment that has continued to improve over the past thirty years when the first commercially approved photosensitizer (PS) was introduced. Although PDT has many successful applications, the terrifying number of new cancer cases reported each year makes scientists focus their efforts towards the development of new efficient PS for PDT. The biggest obstacle that prohibits PDT from becoming a more widely used therapy is the ineffective photosensitizers (PS) that are available on the market today. The purpose of this study was to evaluate the synthesized metal-porphyrin complex as a possible candidate as a PS. …
Phenomena Characterization Of Energy Materials By X-Ray Absorption Spectroscopy, Ming-Yao Cheng, Chun-Jen Pan, Ju-Hsiang Cheng, Bing-Joe Hwang
Phenomena Characterization Of Energy Materials By X-Ray Absorption Spectroscopy, Ming-Yao Cheng, Chun-Jen Pan, Ju-Hsiang Cheng, Bing-Joe Hwang
Journal of Electrochemistry
The aim of this review is to introduce the characterization of energy materials by X-ray absorption spectroscopy (XAS) . This technique allows us to probe changes in the valance state and the local environment of the targeted element in the active material; thereby,leading to a better understanding of its electrochemical behavior,and hopefully showing the way to improved performance. Here,electrocatalysts for fuel cells and active electrode materials for Li-ion batteries are taken as the examples that illustrate the capability of XAS and allow observation and theory to be correlated with electrochemical phenomena.
Core-Shell Nanoparticles: Synthesis, Design, And Characterization, Kyler Carroll
Core-Shell Nanoparticles: Synthesis, Design, And Characterization, Kyler Carroll
Theses and Dissertations
The design of core/shell nanoparticles is of great interest for a wide range of applications. The primary focus of this dissertation is on the design and optimization of two synthetic routes. The first one is an aqueous reduction method using sodium borohydride and sodium citrate. This method was extended to design two types of core/shell nanoparticles, both of which have many applications in bio-sensing, magnetic resonance imaging, and magnetically guided SERS for the identification of environmental threats. The first, Fe/Ag core/shell nanoparticles were designed using a novel one-pot method by varying the AgNO3 addition time in the system. For …
Enhanced Oxygen Activation Over Supported Bimetallic Au-Ni Catalysts, Bert D. Chandler, Cormac G. Long, John D. Gilbertson, Christopher J. Pursell, G. Vijayaraghavan, K. J. Stevenson
Enhanced Oxygen Activation Over Supported Bimetallic Au-Ni Catalysts, Bert D. Chandler, Cormac G. Long, John D. Gilbertson, Christopher J. Pursell, G. Vijayaraghavan, K. J. Stevenson
Chemistry Faculty Research
New bimetallic Ni-Au supported nanoparticle catalysts were prepared by using dendrimer templated nanoparticles. Amine-terminated generation 5 polyamidoamine (PAMAM) dendrimers were anchored to a commercial silica with a siloxane linked anhydride. The dendrimer was then alkylated and used to template Ni-Au nanoparticles, which were subsequently extracted into organic solution as thiol monolayer protected clusters (MPCs). Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) indicated bimetallic nanoparticles of about 2 nm in size. Nanoparticles were deposited onto P-25 TiO2, and the capping thiol ligands were removed under flowing H2. DRIFTS infrared spectra of adsorbed CO showed only Au on the catalyst …
Chemically Directed Immobilization Of Nanoparticles Onto Gold Substrates For Orthogonal Assembly Using Dithiocarbamate Bond Formation, Mh Park, Xx Duan, Y Ofir, B Creran, D Patra, Xy Ling, J Huskens, Vm Rotello
Chemically Directed Immobilization Of Nanoparticles Onto Gold Substrates For Orthogonal Assembly Using Dithiocarbamate Bond Formation, Mh Park, Xx Duan, Y Ofir, B Creran, D Patra, Xy Ling, J Huskens, Vm Rotello
Vincent Rotello
Dithiocarbamate-mediated bond formation combined with soft lithography was used for the selective immobilization of amine-functionalized silica nanoparticles on gold substrates. The available amine groups on the upper surface of the immobilized silica nanoparticles were further utilized for postdeposition of additional materials including particles, dyes, and biomolecules. The robustness of dithiocarbamate-mediated immobilization enables orthogonal assembly on surfaces via selective removal of the masking thiol ligands using iodine vapor etching followed by further functionalization.
Sorption Of Bovine Serum Albumin On Nano And Bulk Oxide Particles, Lei Song
Sorption Of Bovine Serum Albumin On Nano And Bulk Oxide Particles, Lei Song
Masters Theses 1911 - February 2014
Manufactured oxide nanoparticles (NPs) have large production and widespread applications, which will inevitably enter the environment. NPs can interact with proteins in living beings due to the fact that NPs can transport into blood or across cell membranes into cells. Conformational change of protein molecules after sorption on oxide NPs has been reported. Therefore, it is important to understand the adsorption mechanism of protein onto oxide NPs surfaces. Although few works have reported protein adsorption behaviors, a general systematic comparison of the effects of particle size and surface groups on protein adsorption by widely studied NPs still needs to be …
Corrosion Protection Of Aa 2024-T3 Aluminium Alloys Using 3, 4-Diaminobenzoic Acid Chelated Zirconium-Silane Hybrid Sol-Gels, P.C. Rajath Varma, John Colreavy, John Cassidy, Mohamed Oubaha, Colette Mcdonagh, Brendan Duffy
Corrosion Protection Of Aa 2024-T3 Aluminium Alloys Using 3, 4-Diaminobenzoic Acid Chelated Zirconium-Silane Hybrid Sol-Gels, P.C. Rajath Varma, John Colreavy, John Cassidy, Mohamed Oubaha, Colette Mcdonagh, Brendan Duffy
Articles
Organic-inorganic polymers formed by hydrolysis/condensation reactions of alkoxide precursors, such as organically modified silanes (Ormosils) have found applications as electronic, optical and protective coatings. Such coatings possess important characteristics such as chemical stability, physical strength and scratch resistance. Further performance improvement is achieved through the incorporation of zirconium and titanium based nanoparticles, also formed through the sol-gel process. However due to the inherent difference in the reactivity of the precursors, the hydrolysis of each precursor must be carried out separately before being combined for final condensation. Zirconium precursors are commonly chelated using acetic acid or acetyl acetonate prior to hydrolysis, …
Effects Of Silver Nanoparticles On Photochemical Processes Focusing On Luminol Chemiluminescence, Scott Milam
Effects Of Silver Nanoparticles On Photochemical Processes Focusing On Luminol Chemiluminescence, Scott Milam
Master's Theses and Doctoral Dissertations
Silver nanoparticles of varying sizes were synthesized. Their effects on enhancing or quenching the photochemical processes of tryptophan fluorescence, a ruthenium complex decay constant and chemiluminescence of luminol and ferricyanide, were studied. The tryptophan fluorescence was slightly enhanced by smaller nanoparticles and showed slight quenching in the presence of larger nanoparticles. The tris (2,2’-bipyridyl ruthenium (II) chloride) complex was excited using a 532 nm laser, and the decay constant was measured. Neither gold nor silver nanoparticles showed an impact on this process. The luminol chemiluminescence was studied with an emphasis on holding the concentration of nanoparticles, surface area, and silver …