WorldCat Identities

Nuzzo, Ralph G.

Overview
Works: 49 works in 50 publications in 1 language and 61 library holdings
Roles: Author
Publication Timeline
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Most widely held works by Ralph G Nuzzo
The phase dynamic of nanoscale materials by Ralph G Nuzzo( Visual )

2 editions published in 2000 in English and held by 3 WorldCat member libraries worldwide

Oxygen reduction electrocatalysis by Matthew S Thorum( )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

This dissertation is focused on the investigation of the oxygen reduction reaction (ORR) utilizing both existing and newly discovered electrocatalysts. Interest in the ORR is motivated by its application in the cathodes of most fuel cells. The slow kinetics of the ORR are a major barrier to the widespread usage of fuel cells, thus motivating research aimed at increasing understanding of existing electrocatalysts and driving demand for the development of improved electrocatalysts for the ORR. The first section focuses on laccase, a multicopper oxidase that catalyzes the four-electron reduction of oxygen to water. Upon adsorption to an electrode surface, laccase is known to reduce oxygen at overpotentials lower than the best noble metal electrocatalysts usually employed. Whereas the electrocatalytic activity of laccase is well established on carbon electrodes, laccase does not typically adsorb to better defined noble metal surfaces in an orientation that allows for efficient electrocatalysis. In this work, anthracene-2-methanethiol (AMT) was employed to modify the surface of Au electrodes and the electrocatalytic activity of adsorbed laccase was examined. AMT facilitated the adsorption of laccase, and the onset of electrocatalytic oxygen reduction was observed as high as 1.13 VRHE. Linear Tafel behavior was observed with a 144 mV/dec slope, consistent with an outer-sphere single-electron transfer from the electrode to a Cu site in the enzyme as the rate-determining step of the oxygen reduction mechanism. Inspired by the multicopper active site of laccase, the second section focuses on the precipitation of an insoluble complex of copper(II) with 3,5-diamino-1,2,4-triazole onto a carbon black support that leads to the formation of an efficient catalyst for the ORR referred to as CuDAT. The oxygen-reduction activity is reported over a wide pH range from 1 to 13 and the onset of the ORR occurs at potentials as high as 0.86⁰́⁹VRHE, making CuDAT the most active synthetic copper-based electrocatalyst for the ORR reported to date. For the first time, ex situ magnetic susceptibility measurements were used to demonstrate the presence of multicopper sites on the electrode. The final section addresses the question of whether or not the active sites for the ORR in electrocatalysts based on carbon-supported transition-metal complexes are metal-centered as this has become controversial, especially for heat-treated materials. Some have proposed that the transition metal only serves to form highly active sites based on nitrogen and carbon. Here, we examine the oxygen reduction activity of carbon-supported iron(II) phthalocyanine (FePc) before and after pyrolysis at 800 °C and CuDAT in the presence of several anions and small-molecule poisons, including fluoride, azide, thiocyanate, ethanethiol, and cyanide. CuDAT is poisoned in a manner consistent with a copper-based active site. Although FePc and pyrolyzed FePc are remarkably resilient to most poisons they are poisoned by cyanide indicative of iron-based active sites
Unconventional structured semiconductors and their applications in optoelectronics and photovoltaics by Xiaoying Guo( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

Microfluidic assembly and packing dynamics of colloidal granules by Robert F Shepherd( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

Granular materials composed of primary colloidal particles are of both scientific and technological importance. The creation of granular systems for fundamental studies of their packing dynamics as well as applications ranging from ceramics processing to low-cost MEMS devices requires the ability to precisely control the granule size, size distribution, shape, and composition. Many methods exist for producing colloidal granules, including fluidized granulation, high shear mixer granulation, and spray drying. However, none of these methods provide adequate control over these important parameters. In this thesis, we use microfluidic-based assembly methods to control granular size, shape, and chemical heterogeneity. We then investigate the packing dynamics of non-spherical granular media using X-ray micro-computed tomography. Monodisperse spheroidal granules composed of colloid-filled hydrogels are created in a sheath-flow microfluidic device. By exploiting the physics of laminar flow in microchannels, drops composed of silica microspheres suspended in an aqueous acrylamide monomer solution are created within a continuous oil phase. The interfacial tension between these two immiscible fluids drives a Rayleigh-mode instability that promotes drop formation. Next, the drops undergo photopolymerization to create an acrylamide hydrogel that freezes in the desired morphology and composition during assembly. To demonstrate the flexibility of this new granulation technique, we assemble both dense homogenous and Janus granules in both spherical and discoid geometries. To produce non-spherical granular media, a lithographic-based microfluidic technique known as stop-flow-lithography is employed. Specifically, colloidal granules and microcomponents in the form of microgear, triangular, discoid, cuboid, and rectangular shapes are produced by this approach. In addition, pathways are demonstrated that allow these building blocks to be transformed into both porous and dense oxide and non-oxide structures. Finally, large quantities of non-spherical colloidal granules of controlled surface roughness are created via stop-flow lithography in cube and rectangular prism geometries of varying polydispersity. Their packing behavior under static and dynamic conditions is investigated by X-ray micro-computed tomography. Their voronoi volume distribution is quantified as a function of granule shape and agitation time using image analysis techniques. These data are then fit to a probabilistic k-Gamma analytical function, which allows one to quantify an order parameter, k, for the jamming condition of low dispersity cube, rectangular prism and bimodal cube granules. We find a steadily decreasing k-value for monodisperse cubes, suggesting local cube rearrangement during consolidation; while monodisperse rectangular granules and a bimodal distribution of cube granules demonstrate a relatively consistent k-value during consolidation, suggesting the local granule configuration remains similar. In each case, the data collapse onto a single master curve, suggesting a qualitatively similar jamming condition during compaction
Functional nanostructured plasmonic materials: fabrication, simulation, imaging and sensing applications by Jimin Yao( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

Surface plasmons, due to their extreme sensitivity to changes in refractive index occurring at a metal/dielectric interface and their ability to significantly enhance electromagnetic fields near a metal, offer exciting opportunities for real-time, fully label free forms of chemical/biological detection and field-enhanced applications including surface enhanced Raman scattering (SERS), and photovoltaics. Novel classes of plasmonic crystals fabricated with precisely controlled arrays of subwavelength metal nanostructures provide a promising platform for the sensing and imaging of surface binding events with micrometer spatial resolution over large areas. Soft lithography, one family of unconventional nanofabrication methods, provides a robust, cost-effective route for generating highly uniform, functional nanostructures over large areas with molecular scale resolution. This dissertation describes the development and utility of several classes of functional, nanostructured plasmonic materials with predictable optical properties. A novel, low-cost optical sensor with atomic scale sensitivity at visible wavelength range was developed by tuning the optical response of a plasmonic crystal to visible wavelengths through optimization of the distribution and thickness of the thin metal film. Sensing and imaging of various surface binding events were studied to demonstrate their utility for label-free detection. Finite-Difference Time-Domain (FDTD) calculations were carried out to model the optical response of the system and gain insight into the physics of the system. New classes of plasmonic crystals were developed using new materials and fabrication methods, in concert with rational design of the device form factor guided by both experiment and computational electrodynamics simulations
Development of soft lithography based non-planar and 3-D photo-patterning techniques by Audrey M Bowen( )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

The fusion of soft lithography fabrication processes and optical lithography has been demonstrated in the literature. The focus of this thesis is on the adaptation of soft lithography protocols and further understanding of the materials chemistry of PDMS that allows for fabrication of soft optical lithography masks. A collection of new methods for fabrication of photolithography masks that are used in new forms of 3D patterning, such as patterning on non-planar (3D) surfaces and fabricating multi-height (3D) photoresist structures, is presented. The mask fabrication processes utilize novel approaches to soft lithography that allow for desired optical properties to be easily programmed into the masks. This body of work progresses from the simplest optics, binary modulation of intensity through optically dense mask elements, to grayscale mask elements that vary in optical density and thus allow for single step multi-intensity exposures, and finally to a stamp fabrication approach that results in features with triangular cross-sections that are then used to transfer the patterns into application enabling materials for use in a number of systems that require careful manipulation of light-matter interactions. By harnessing both the benefits of soft lithography and optical lithography, these new patterning protocols provide more efficient, lower cost, methods for achieving novel patterning in forms that prove to be extremely challenging with traditional lithographic processes
Direct-write assembly of 3D microperiodic scaffolds for tissue engineering applications by Sara T Parker( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

Soft lithography - materials and applications to plasmonic sensing and surface-enhanced raman scattering by Tu T Truong( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

The interest of unconventional techniques for nanofabrication has grown exponentially in recent years due to demanding equirements in micro/nanoscale structures for photonics, microfluidics, biotechnology, and flexible electronics. Soft lithographic methods use elastomeric stamps, molds and conformable photomasks as patterning elements to provide capabilities that are unavailable with conventional techniques: patterning at molecular scale resolution (~1 nm); ability to form three-dimensional (3D) structure directly, in a single step; experimental simplicity and applicability to large areas. This dissertation explores new materials for the soft molds in order to enhance the resolution and application of soft lithographic methods. A commercially available perfluoropolyethylene (a-PFPE) and a synthesized material based on poly[(3-mercaptopropyl) methylsiloxane] (PMMS) are used in a variety of soft lithographic techniques for high fidelity and high resolution patterning. As an application example, I describe a class of quasi-3D plasmonic crystals for biosensing as well as surface-enhanced Raman scattering, with the connection to theoretical results obtained from rigorous electrodynamics simulations
Conjugated carbon monolayer membranes - synthesis and integration techniques by Sakulsuk Unarunoatai( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

The existence of graphene, a single sheet of graphite and the simplest class of conjugated carbon monolayer, discovered in 2004, has attracted immensely interests from scientific community. The research in this area has grown exponentially attributed to its exceptionally high electron mobility, high elastic moduli, and observations of unconventional phenomena in physics. Unfortunately, the original technique for producing graphene sheet on insulating substrates, i.e. by mechanical exfoliation from a piece of graphite, is not scalable. Hence, it is utmost important to find approaches for producing large area graphene or improving film transfer quality. It is also interesting to explore other types of related two-dimensional materials. The first part of this dissertation describes a strategy for the synthesis of a class of conjugated carbon monolayer membranes. The process starts with the formation of self-assembled monolayer of alkyne-containing monomers on flat or structured solid support such as silicon oxide and silicon nitride followed by chemical crosslinking within monolayer. Once linked, the membranes are robust enough to be released from the support and transferred to other surfaces. Likewise, three-dimensional objects, such as balloons and cylinders, with monolayer thickness can be generated with similar method. The second part focuses on graphene layer which is epitaxially grown on SiC wafer. This growth technique has been known for producing large-area graphene films, but the graphene film is required to be exploited on the growth substrate due to unavailability of transfer procedure. I adopted and improved the techniques, used for transferring carbon nanotube, to transfer graphene films from SiC substrates to arbitrary substrates. The technique utilized a bilayer film of either gold/polyimide or palladium/polyimide as a transfer element. The properties of transferred film were characterized by different techniques including Raman spectroscopy, SEM, AFM and STM. I finally fabricated simple devices on this transferred graphene sheet to measure electrical properties of the film
Manipulating soft materials to direct cell growth in multiple dimensions by Jennifer N Shepherd( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

Creating in vitro microenvironments for the study of important biological processes, examples of which include chemotaxis, haptotaxis, axonal guidance and angiogenesis, has been a relevant research focus for many years. Microfabrication techniques involving soft lithography, microfluidic devices and direct-write assembly can be used to create such microenvironments. Soft lithography techniques, which typically include microcontact printing and decal transfer, rely on elastomeric molds, stamps or flexible photomasks to create patterns on or transfer patterns to, an underlying surface; these molds or stamps themselves have also been used for study. In microfluidic devices, small fluid volumes are transported through microchannels via gravity or pressure-driven methods. Biological studies are either conducted within the gradients maintained by laminar flow through the microchannels, or on the residually patterned underlying rigid surface, created via physi-adsorption or through chemical interactions with the surface. Both soft lithography and residual substrate microfluidic patterning approaches yield planar patterned substrates. In contrast, fluidic gradients maintained in microchannels are three-dimensional in nature, but are only used for specific applications⁰́₄e.g. the study of non adherent cell types such as white blood cells. Recent studies, however, have shown that different cell types present important biological differences, in their differentiation, proliferation rates, migration and cell signaling, in two- versus three-dimensional culture systems. Thus, there has been increased interest in the development of three-dimensional fabrication techniques to create microenvironments that can better mimic those found in vivo. Direct-write assembly is an example of a three-dimensional fabrication method that enables the creation of micro-periodic structures with well defined features and an interconnected porous network, 1-100℗æm in size. Other 3D fabrication techniques include electrospinning, solvent/particulate leaching and freeze drying, however they usually yield random three-dimensional structures with an unpredictable porous structure. This thesis describes three different in vitro systems generated using three distinct microfabrication techniques, including a modified decal transfer lithography, a combination of microfluidic assembly and microcontact printing, as well as direct-write assembly, for the study of primary mammalian hippocampal neuron development, one of the most well characterized in vitro models of neurite development currently available
Structural and chemical characterization of complex nanomaterials at atomic resolution by Sergio I Sanchez( )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

Bioanalytical applications of microfluidic devices by Huaibin Zhang( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

The first part of the thesis describes a new patterning technique--microfluidic contact printing--that combines several of the desirable aspects of microcontact printing and microfluidic patterning and addresses some of their important limitations through the integration of a track-etched polycarbonate (PCTE) membrane. Using this technique, biomolecules (e.g., peptides, polysaccharides, and proteins) were printed in high fidelity on a receptor modified polyacrylamide hydrogel substrate. The patterns obtained can be controlled through modifications of channel design and secondary programming via selective membrane wetting. The protocols support the printing of multiple reagents without registration steps and fast recycle times. The second part describes a non-enzymatic, isothermal method to discriminate single nucleotide polymorphisms (SNPs). SNP discrimination using alkaline dehybridization has long been neglected because the pH range in which thermodynamic discrimination can be done is quite narrow. We found, however, that SNPs can be discriminated by the kinetic differences exhibited in the dehybridization of PM and MM DNA duplexes in an alkaline solution using fluorescence microscopy. We combined this method with multifunctional encoded hydrogel particle array (fabricated by stop-flow lithography) to achieve fast kinetics and high versatility. This approach may serve as an effective alternative to temperature-based method for analyzing unamplified genomic DNA in point-of-care diagnostic
Monolayer Films Prepared by the Spontaneous Self-Assembly of Symmetrical and Unsymmetrical Dialkyl Sulfides from Solution Onto Gold Substrates: Structure, Properties, and Reactivity of Constituent Functional Groups( Book )

1 edition published in 1987 in English and held by 1 WorldCat member library worldwide

Exposure of evaporated gold films supported on silicon wafers to solutions of dialkyl sulfides (R(CH2)m-S-(CH2)n-R'; R and R'=CH3 or CO2H) or alkyl thiols (R(CH2)nSH, R=CO2H or CH3) in methanol or ethanol results in rapid formation of a monolayer of the organosulfer compound adsorbed onto the gold. The resulting films have been characterized using a number of techniques, including X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IRS), ellipsometry, and wetting. These self-assembled, supported organic monolayer films are systems that can be used to study problems in the physical-organic chemistry and materials science of organic surfaces, especially the relation between the molecular-level structure of the film constituents and the macroscopic properties of the assembled monolayers. Keywords: Thin film, Monolayer, Surface spectroscopy, electronic materials
Materials and design strategies for solar microcells by Christopher Corcoran( )

1 edition published in 2014 in English and held by 1 WorldCat member library worldwide

The stress and strain behavior of materials for energy storage and production by Michael Cason( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

Directed lithium transport in high capacity lithium-ion battery electrodes by Jay Goldman( )

1 edition published in 2014 in English and held by 1 WorldCat member library worldwide

Linear allylic C-H oxidation: methods and utility by Nicolaas Vermeulen( )

1 edition published in 2012 in English and held by 1 WorldCat member library worldwide

Fabrication and transfer assembly of microscale, solid-state light emitting diodes and solar cells for transparent and flexible electronics applications by Eric Brueckner( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

Materials and design strategies for flexible electronics by Hoon-sik Kim( )

1 edition published in 2012 in English and held by 1 WorldCat member library worldwide

Design and characterization of advanced battery technologies and mechanistic studies of the oxygen reduction reaction for fuel cells by Christopher J Barile( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

 
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English (21)