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Full-Text Articles in Nanoscience and Nanotechnology

Solution And Surface Properties Of Architecturally- And Compositionally-Complex Block Copolymers And Their Binary Mixtures, Jesse Lawrence Davis Dec 2015

Solution And Surface Properties Of Architecturally- And Compositionally-Complex Block Copolymers And Their Binary Mixtures, Jesse Lawrence Davis

Doctoral Dissertations

The spontaneous generation of complex structures from polymeric building blocks provides a simple yet effective route to create useful soft matter structures having potential application in a variety of nanotechnologies. The topology, chemical structure, block composition, and sequence of the constituent building blocks of polymers are tunable through synthetic chemistry. This tunability offers attractive opportunities to generate complex, yet well-defined structures with control over the geometry, packing symmetry, and microdomain structure. This thesis work involves the study of the self-assembly behaviors of architecturally complex amphiphilic block copolymers (ABCs). ABCs are composed of two or more chemically distinct blocks that are ...


Field Scale Application Of Nanoscale Zero Valent Iron: Mobility, Contaminant Degradation, And Impact On Microbial Communities, Chris M.D. Kocur Aug 2015

Field Scale Application Of Nanoscale Zero Valent Iron: Mobility, Contaminant Degradation, And Impact On Microbial Communities, Chris M.D. Kocur

Electronic Thesis and Dissertation Repository

This thesis began by verifying that nanoscale zero valent iron (nZVI) synthesis methods could be scaled up and implemented at the field scale in a safe manner. This led to successful demonstration of nZVI injection and mobility under constant head gravity injection into a contaminated utility corridor in Sarnia, Ontario. Where field studies have fallen short in the past was linking the somewhat qualitative field geochemical parameters to other evidence of nZVI transport. Definitive nZVI detection was elusive in previous field studies due to the highly reactive nature of the particles caused by their high surface area. nZVI was detected ...


Surface Modification Of Noble Metal Nanostructures Toward Biomedical Applications, Samir V. Jenkins Jul 2015

Surface Modification Of Noble Metal Nanostructures Toward Biomedical Applications, Samir V. Jenkins

Theses and Dissertations

Noble metal nanostructures have seen a steady increase in biomedical application over the last several decades; new diagnostic and therapeutic modalities are under intense investigation. Many of these applications are possible because of post-synthetic modifications to the particle surface. These modifications take a variety of forms and can significantly affect the pharmacokinetics of these particles. In this work, various surface modifications were investigated. Particle agglomeration, which occurs when particle surfaces remain in contact, can significantly affect the toxicity and efficacy of a nanomedicine. Darkfield microscopy and single-particle ICP-MS were developed as complementary methods to detect agglomeration in blood, with the ...


Synthesis Of Palladium And Palladium-Copper Nanostructures As Electrocatalysts, Haibin Wu Jul 2015

Synthesis Of Palladium And Palladium-Copper Nanostructures As Electrocatalysts, Haibin Wu

Theses and Dissertations

Pd and its alloys are alternatives of Pt as promising catalysts and electrocatalysts for many reactions. Size controlled synthesis of nanoparticles remains a major research subject, since smaller size particles show better catalytic performance. In this work, we developed a modified chemical wet method to prepare Pd and Pd-Cu nanostructures with uniform small size. Different sizes and shapes of Pd nanostructures were successfully synthesized by using the two reducing agents (i.e., L-ascorbyl-6-palmitate or phenylphosphinic acid). The reducing agents play a role to control the final morphologies and sizes of particles. The use of L-ascorbyl-6-palmitate favors to form irregular branch ...


Inertial Force-Driven Synthesis Of Near-Infrared Plasmonic Nanosphere Composites: Physicochemical Characterizations, Joseph Noel Batta-Mpouma May 2015

Inertial Force-Driven Synthesis Of Near-Infrared Plasmonic Nanosphere Composites: Physicochemical Characterizations, Joseph Noel Batta-Mpouma

Theses and Dissertations

Near-infrared (NIR) responsive nanoparticles (NPs) like gold nanorods (GNRs) are important in biomedical fields because of their transparency for biological tissues. Although GNRs are sought after as contrast agents for theranostics in cancer studies, capping ligands like cetyltrimethylammonium bromide (CTAB) for the GNR synthesis are toxic for biological tissues. The need for an alternative to toxic GNRs is of interest to alleviate the problem.

This work aimed to optimize the synthesis of NIR responsive nanosphere composites (NSCs) by inertial force (g-force) using colloidal gold NPs as model, elucidate the mechanism for the NSC formation, and study their detailed physicochemical characteristics ...


Biomolecule Mediating Synthesis Of Inorganic Nanoparticles And Their Applications, Zengyan Wei Feb 2015

Biomolecule Mediating Synthesis Of Inorganic Nanoparticles And Their Applications, Zengyan Wei

All Dissertations, Theses, and Capstone Projects

Project 1.

The conventional phage display technique focuses on screening peptide sequences that can bind on target substrates, however the selected peptides are not necessary to nucleate and mediate the growth of the target inorganic crystals, and in many cases they only show moderate affinity to the targets. Here we report a novel phage display approach that can directly screen peptides catalytically growing inorganic nanoparticles in aqueous solution at room temperature. In this study, the phage library is incubated with zinc precursor at room temperature. Among random peptide sequences displayed on phages, those phages that can grow zinc oxide (ZnO ...


Label-Free Detection Of Cancer Cells With Polysilicon Sensor Chips And Biomolecule-Assisted Synthesis Of Shape-Controlled Nanoparticles, Menglu Shi Feb 2015

Label-Free Detection Of Cancer Cells With Polysilicon Sensor Chips And Biomolecule-Assisted Synthesis Of Shape-Controlled Nanoparticles, Menglu Shi

All Dissertations, Theses, and Capstone Projects

Constant effort has been made for the detection of cancer cells. Recently, ovarian and kidney cancer cell lines have been shown to have higher cellular elasticity as compared to normal cells assessed by monitoring the degree of deformation under hyposmotic pressure. This method has been modified and applied to various cases. In cancer cells, the oncogenic mutant p53 (mtp53) protein is present at high levels and contributes to tumor growth and metastasis. Herein the influence of mtp53 on the mechanical property of breast cancer cells was assessed by monitoring the swelling ratio of cells with time using the impedance measurements ...


Highly-Selective Chemiresistive Sensing And Analysis Of Vapors Using Functionalized Nanotubes, Deon Hines Feb 2015

Highly-Selective Chemiresistive Sensing And Analysis Of Vapors Using Functionalized Nanotubes, Deon Hines

All Dissertations, Theses, and Capstone Projects

Specifically, the project involves the development of a diversified array of nanostructured gas-sensors comprised of selectively, novel surface-functionalized carbon nanotubes (for analyte selectivity by virtue of functionality). Harnessing carbon nanotubes with various electron withdrawing and donating groups help in determining their affinity toward certain prognostic gaseous markers thus increasing specificity of such created sensors. We have devised synthetic routes that have led to the facile production of covalently polyfunctionalized nanotubes in high yield. Seven carbon nanotube analogues were systematically considered and then chemically synthesized, from pristine single-walled nanotubes (SWNT's), for use as the main component of sensory units that ...


The Synthesis And Characterization Of Water-Reducible Nanoscale Colloidal Unimolecular Polymer (Cup) Particles, Cynthia J. Riddles Jan 2015

The Synthesis And Characterization Of Water-Reducible Nanoscale Colloidal Unimolecular Polymer (Cup) Particles, Cynthia J. Riddles

Doctoral Dissertations

"The coatings industry has adapted to more stringent guidelines in paint formulations. Current VOC (volatile organic compound) limits placed by the federal government have pushed the industry toward the development of paint formulations which have very little to no VOC's. The development of Colloidal Unimolecular Polymer (CUP) particles is a step in the direction of providing a resin system which exists in zero VOC aqueous dispersion.

The CUP particles are a part of the polymer field of Single Chain Nano Particles (SCNP) and ranged in diameters of 3-9 nm. The research presented in this dissertation describes the synthesis and ...


Simulation Studies Of Diblock-Copolymer Grafted Nanoparticle Assembly In Solvent And Polymer Matrix, Carla E. Estridge Jan 2015

Simulation Studies Of Diblock-Copolymer Grafted Nanoparticle Assembly In Solvent And Polymer Matrix, Carla E. Estridge

Chemistry & Biochemistry Graduate Theses & Dissertations (1986-2018)

Macroscopic properties of polymer nanocomposites are fundamentally linked to the morphology (or assembled structure) of its constituents. In order to design composites to have specific macroscopic properties it is important to be able to control the assembly of the constituents in the composite. In this thesis we use molecular simulations to study the molecular-level interactions and assembly of one class of polymer nanocomposites, namely diblock-copolymer grafted nanoparticles in solvent and in polymer matrix.

First, we study how the molecular features of the diblock-copolymer grafts affect the assembly of grafted nanoparticles in a (implicit) small molecule solvent. Using coarse-grained molecular dynamics ...


Charge Transfer Dynamics In Complexes Of Light-Absorbing Cds Nanorods And Redox Catalysts, Molly Bea Wilker Jan 2015

Charge Transfer Dynamics In Complexes Of Light-Absorbing Cds Nanorods And Redox Catalysts, Molly Bea Wilker

Chemistry & Biochemistry Graduate Theses & Dissertations (1986-2018)

The use of photoexcited electrons and holes in semiconductor nanocrystals as reduction and oxidation reagents is an intriguing way of harvesting photon energy to drive chemical reactions. This dissertation describes research efforts to understand the photoexcited charge transfer kinetics in complexes of colloidal CdS nanorods coupled with either a water oxidation or reduction catalyst. The first project focuses on the charge transfer interactions between photoexcited CdS nanorods and a mononuclear water oxidation catalyst derived from the [Ru(bpy)(tpy)Cl]+ parent structure. Upon excitation, hole transfer from CdS oxidizes the catalyst (Ru2+→Ru3+) on a 100 ps – 1 ...


The Optoelectronic Properties Of Surface-Modified Semiconductor Nanocrystal Solids, Earl D. Goodwin Jan 2015

The Optoelectronic Properties Of Surface-Modified Semiconductor Nanocrystal Solids, Earl D. Goodwin

Publicly Accessible Penn Dissertations

Colloidal semiconductor nanocrystals have emerged as fascinating new materials and gained interest in the last 30 years because of their size, shape, and compositionally tunable electronic and optical properties as well as their potential to serve as artificial atoms. Challenges and opportunities have arisen when assembling nanocrystals into nanocrystal solids for electronic and optoelectronic applications, largely because of the significant influence of nanocrystal surface chemistry on the electronic, optical, and structural properties of nanocrystal solids. In order to assemble nanocrystal solids for high performance devices, we must understand and be able to control the effects of nanocrystal surface organic capping ...


Functional Nanostructures From Nanoparticle Building Blocks, Jimmy Lawrence Jan 2015

Functional Nanostructures From Nanoparticle Building Blocks, Jimmy Lawrence

Doctoral Dissertations

Advances in the synthetic strategies of engineered nanomaterials, multifunctional molecules and polymers have opened pathways for the development of functional nanomaterials having unique optoelectronic, mechanical, and biological properties. By designing the chemistry of surface ligands, the organic interface of nanoparticles, one can further the versatility and utilization of engineered nanomaterials, opening pathways for breakthroughs in sensing, catalysis, and delivery using nanomaterials.

This thesis describes the synthesis and characterization of small molecule and polymer ligand functionalized inorganic nanoparticles (e.g., metal, semiconducting). Embedding specific chemical functionality into the ligand periphery of nanoparticles enables the resulting functional nanoparticles to react selectively with ...


Understanding The Reactivity Of Molecular Precursors To Colloidal Nanocrystals, Samuel Ralph Alvarado Jan 2015

Understanding The Reactivity Of Molecular Precursors To Colloidal Nanocrystals, Samuel Ralph Alvarado

Graduate Theses and Dissertations

Colloidal semiconductor nanocrystals are materials with intriguing properties that make them useful for a diverse array of applications such as photocatalysts, light-absorbing materials in solar cells, light emitting diodes and luminescent biological tags, to name only a few. Performance of nanomaterials in these applications is directly related to the size, shape and stoichiometry of the nanocrystals. Strategies exist to control these characteristics during colloidal synthesis, but they tend to rely on certain surfactants, additives, or multi-step procedures to achieve desirable properties. This thesis describes new directions in the synthesis of colloidal nanomaterials that use computational chemistry as a guide. Using ...


Functional Silica-Encapsulated Photoactive Nanocrystals, Chia-Cheng Lin Jan 2015

Functional Silica-Encapsulated Photoactive Nanocrystals, Chia-Cheng Lin

Graduate Theses and Dissertations

Silica-based nanocomposites with core/shell configurations have diverse functionalities and applications. We present the preparation and characterization of Co3O4/porous-SiO2 nanocomposites with the examination of their catalytic activity in the dye sensitized water oxidation reaction; a generalized methodology to prepare metal chalcogenides/pnictides with one-pot and one-step manner; the synthesis of Au/Ag/SiO2 multishell nanorods and their application as imaging probes in single particle tracking experiments.

Silica supported Co3O4 nanocomposites have recently drawn much attention due to their high catalytic ability in the water oxidation reaction. We have synthesized several Co3O4/porous silica nanocomposites to study the synergetic effects ...


Tunable Photonic Multilayers From Stimulus-Responsive, Photo-Crosslinkable Polymers, Maria C. Chiappelli Jan 2015

Tunable Photonic Multilayers From Stimulus-Responsive, Photo-Crosslinkable Polymers, Maria C. Chiappelli

Doctoral Dissertations

This dissertation describes the synthesis of photo-crosslinkable copolymers and their utilization for the fabrication and testing of tunable and responsive one-dimensional (1D) photonic multilayers. Photonic multilayers exhibit structural color due to the interference of incident light at layer interfaces, providing a convenient route towards optically responsive materials that do not rely on potentially light- or oxygen-sensitive chromophore-containing pigments and dyes. A fabrication technique based on sequential spin-coating and crosslinking of photo-crosslinkable polymers is used to assemble tunable and responsive photonic multilayers.

Chapter One introduces the fundamental underlying principles of 1D photonic structures and explores their importance in a variety of ...