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Full-Text Articles in Physical Sciences and Mathematics

Development Of An F-Element Separation Chemistry Using Solid Electrolytes, Kristian Guy Myhre Dec 2016

Development Of An F-Element Separation Chemistry Using Solid Electrolytes, Kristian Guy Myhre

Doctoral Dissertations

The f‒elements (lanthanides and actinides) have numerous applications and are critically important to many industries, including the energy, security, and medical industries. One of the barriers to increased use and availability of the f‒elements is the difficulty in separating them from each other due to their similar chemistries. This is especially true of the trivalent f‒elements (lanthanides and minor actinides). The development of separation techniques that maximize the differences in the physicochemical properties of the f‒elements is therefore an important area of research. For these reasons, an effort was undertaken to explore the use of solid …


Evaporation Induced Self-Assembly And Characterization Of Nanoparticulate Films: A New Route To Bulk Heterojunctions, Yipeng Yang Nov 2016

Evaporation Induced Self-Assembly And Characterization Of Nanoparticulate Films: A New Route To Bulk Heterojunctions, Yipeng Yang

Doctoral Dissertations

Polymer-based semiconducting materials are promising candidates for large-scale, low-cost photovoltaic devices. To date, the efficiency of these devices has been low in part because of the challenge of optimizing molecular packing while also obtaining a bicontinuous structure with a characteristic length comparable to the exciton diffusion length of 10 to 20 nm. In this dissertation we developed an innovative evaporation-induced nanoparticle self-assembly technique, which could be an effective approach to fabricate uniform, densely packed, smooth thin films with cm-scale area from home-made P3HT nanoparticles. Unlike the previous reports of nanoparticle-based film formation, we use a mixture of two solvents so …


Cell Modulation Using Functionalized Nanoparticles, Rui Tang Nov 2016

Cell Modulation Using Functionalized Nanoparticles, Rui Tang

Doctoral Dissertations

Monolayer functionalized ultra-small gold nanoparticles (AuNPs) provide a versatile platform for applications in cell research. Through rational design of surface ligands, the chemistry of AuNPs are precisely regulated at atomic level. In this dissertation, applications of AuNPs in cell modulation are discussed. The topics are split into two categories. In the first category, functionalized AuNPs are harnessed to generate a robust monolayer on cell culture surface for cell modulation. The proliferation and behavior of different types of cancer cells and normal cells are modulated by tuning the surface ligands of AuNPs. Fate decision of mesenchymal stem cells are also modulated …


Engineering The Nano-Bio Interface Of Gold Nanoparticles For Biomedical Applications, Ying Jiang Nov 2016

Engineering The Nano-Bio Interface Of Gold Nanoparticles For Biomedical Applications, Ying Jiang

Doctoral Dissertations

Gold nanoparticles (AuNPs) have emerged as a promising platform for a myriad of biomedical applications, including sensing, drug delivery, and antibiotics. In this thesis, I have studied and engineered the interface of AuNPs with different biological systems, demonstrating a large variety of biomedical applications by modulation of these interfaces. My research was initially focused on systematically tuning the physicochemical properties of nanoparticles to understand nano-bio interactions at the cellular level. The results demonstrate that size and surface charge of AuNP interact in an interrelated fashion to modulate nanoparticle internalization by cells, providing an engineering strategy for designing nanomaterials for drug …


Synthesis And Characterization Of Polymeric Anion Exchange Membranes, Wenxu Zhang Jul 2016

Synthesis And Characterization Of Polymeric Anion Exchange Membranes, Wenxu Zhang

Doctoral Dissertations

As alkaline anion exchange membrane fuel cells (AAEMFC) are regarded as promising and important energy devices, the development of high performance anion exchange membranes are in urgent need, as well as fundamental investigation on the structure-property relationship, which are the motivation of this dissertation. Three different polymer systems are presented and focused on polymer synthesis, material morphology, and ion transport phenomena. Crosslinked membranes are promising as practical materials, however, the understanding and further improvement of its performance is hindered by the lack of an ordered morphology or well-defined chemical structure. In Chapter 2, a series of crosslinked membranes were design …


Magnetic Doping Of Semiconductor Molecular Models And Colloidal Nanocrystals, Swamy Pittala Jul 2016

Magnetic Doping Of Semiconductor Molecular Models And Colloidal Nanocrystals, Swamy Pittala

Doctoral Dissertations

Spin-based electronics use the spins of electrons in addition to their charges and have potential applications to create a next generation of quantum computers, capable of storing vast amounts of data in an energy-efficient way. Diluted magnetic semiconductor quantum dots (DMS-QDs) have shown great promise as ideal materials for application in spin-based electronics. However, doping impurities into quantum confined colloidal nanocrystals (NCs) has been a great challenge due to the lack of control over the dopant reactivity during the specific stages of nucleation and growth. The mechanism of dopant incorporation into nanocrystals is complex and well-defined and atomically precise molecular …


Design, Synthesis, And Applications Of Nano-Assemblies Based On Amphiphilic Macromolecules, Hui Wang Jul 2016

Design, Synthesis, And Applications Of Nano-Assemblies Based On Amphiphilic Macromolecules, Hui Wang

Doctoral Dissertations

Recent progress in nanotechnology has been significantly impacting a variety of areas such as utilization in microelectronics, multiphase catalysis, sensing and therapeutics. Our interests are to develop new nanomaterials to understand their structure-property relationships and to utilize them for various applications. In this thesis, we discuss our findings on the design, synthesis and applications of nanomaterials formed by self-assembly of amphiphilic molecules. Micelles are self-assembled nanostructures formed by amphiphilic molecules. They are capable of sequestering hydrophobic guest molecules in an aqueous environment. Other than surfactants, micelles can also be formed by amphiphilic polymers or dendrimers, which are macromolecular surfactants in …


Refractive Index Engineering And Optical Properties Enhancement By Polymer Nanocomposites, Cheng Li Mar 2016

Refractive Index Engineering And Optical Properties Enhancement By Polymer Nanocomposites, Cheng Li

Doctoral Dissertations

The major part of this dissertation discusses the engineering of the refractive index of materials using solution-processable polymer nanocomposites and their applications in building optical components and devices. Three particular polymer nanocomposites have been introduced to achieve materials with tunable refractive indices and enhanced optical properties, which can be used to manipulate the behavior of light or electromagnetic radiations. In the first system, polyhedral oligomeric silsesquioxane (POSS)/polymer nanocomposites are developed. Thin films with tunable, low refractive indicies were fabricated from the composites. The mechanical strength of these films was characterized, and their application in antireflective coatings is discussed. In the …


Supramolecular Strategies For The Generation Of Nanoparticle Assemblies And Biomolecular Thin Films, Bradley P. Duncan Mar 2016

Supramolecular Strategies For The Generation Of Nanoparticle Assemblies And Biomolecular Thin Films, Bradley P. Duncan

Doctoral Dissertations

The conceptual framework of supramolecular chemistry elucidates a powerful set of strategies for chemists to generate functional nanomaterials based on intermolecular forces. My research focused on tuning the molecular interactions of nanoscale components to create larger structures with enhanced properties. In one approach, I developed and optimized an additive-free, nanoimprint lithography-based methodology to generate stable thin films from a variety of proteins. The generalized process retains intrinsic properties of the protein as demonstrated by selective cellular adhesion. The heat and pressure of the nanoimprinting process induces slight structural reorganization of the peptide side chains to yield highly stable films held …