Physical Sciences and Mathematics Commons^™

Chitosan Graphene Composite Fabrication And Characterization For Treatment Of Harmful Algal Blooms And Toxins, Sarah Zetterholm

Master's Theses

Chitosan graphene composites were fabricated and characterized as a management strategy for harmful algal blooms (HABs) caused by various species of cyanobacteria. These chitosan graphene materials were compared to previously studied chitosan graphene-oxide composites in both material properties and HAB treatment. In previous studies, adsorption of the cyanobacteria onto the surface of the composite materials has been observed. Investigations of the pure materials for these composites are also included in this study to determine whether removal is a result of charge interactions with the composite, or as an inherent property of the graphene or graphene oxide. Initial results suggest that …

Peo-Ppo-Peo Surfactant Mixtures As Templates For Silicas With Very Large Cylindrical Mesopores At Ambient Temperature And With Helical Mesopores At Sub-Ambient Temperature, Laurance Beaton

Dissertations, Theses, and Capstone Projects

The original research described herein concerns the synthesis of mesoporous silicas through a surfactant-templating method. The approach taken involved the use of a mixed surfactant system of two poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) surfactants, with one of the copolymers containing a much larger percentage of hydrophobic (PPO) blocks than the employed co-surfactant. Systematic adjustments of experimental parameters initially enabled the preparation of 2-D hexagonally ordered mesoporous silicas (SBA-15) of uncommonly large pore diameter at ambient temperature. Comparable silica was synthesized with and without temperature control. Additional adjustments to experimental parameters, including reduction of the relative amount of framework precursor used in …

Pressure Driven Desalination Utilizing Nanomaterials, Fangyou Xie

Master's Theses

Nanomaterials such as graphene oxide and carbon nanotubes, have demonstrated excellent properties for membrane desalination, including decrease of maintenance, increase of flux rate, simple solution casting, and impressive chemical inertness. Here, two projects are studied to investigate nanocarbon based membrane desalination. The first project is to prepare hybrid membranes with amyloid fibrils intercalated with graphene oxide sheets. The addition of protein amyloid fibrils expands the interlayer spacing between graphene oxide nanosheets and introduces additional functional groups in the diffusion pathways, resulting in increase of flux rate and rejection rate for the organic dyes. Amyloid fibrils also provide structural assistance to …

Modification Of 2d Materials Utilizing Functional Polymer Interfacial Layers, Ryan Selhorst

Doctoral Dissertations

This dissertation describes the modification of 2D transition metal dichalcogenides (TMDCs). These materials exhibit unique electronic properties, ranging from metallic to insulating, and can transport either electrons (n-type) or holes (p-type). Polymers containing electronically-active moieties offer a path to control the electronic properties of a 2D material without altering the inherent structure of the semiconductor. This dissertation focuses on the synthesis of polymers bearing chalcogen-rich or zwitterionic moieties to alter the electronic and solution properties of 2D materials. Chapter 2 describes polymers containing sulfur-rich tetrathiafulvalene (TTF) and their effects as electroactive coatings on the TMDC molybdenum disulfide (MoS₂). …

Nanomaterials For Double-Stranded Rna Delivery, Stuart Lichtenberg

Theses and Dissertations--Plant and Soil Sciences

RNA interference has enormous potential as a potent, specific, and environmentally friendly alternative to small molecule pesticides for crop protection. The use of exogenous double-stranded RNA offers flexibility in targeting and use in crops in which transgenic manipulation is not an option. The combination of RNAi with nanotechnology offers further advantages that are not available with dsRNA alone. In this work, I have evaluated several different combinations of nanomaterials and polymers for use in RNAi-based pest control systems. First, I have characterized the use of chitosan/dsRNA polyplex nanoparticles for gene knockdown using the model nematode Caenorhabditis elegans. Though chitosan/dsRNA …

Flexible And Versatile Soft Templates For Mesoporous Silicas And Organosilicas Based On Pluronic Block Copolymer Surfactants And Their Mixtures, George Farid

Dissertations, Theses, and Capstone Projects

In this dissertation, the work will be discussed that was focused on the synthesis of consolidated periodic mesoporous materials such as 2-D hexgonal ordered mesoporous silicas (SBA-15) as well as single-micelle-templated silica and organosilica nanotubes and nanospheres using triblock copolymer surfactants and their mixtures in the presence of a swelling agent. The introductory section, Chapter 1, will address the current state of the tunability of single-micelle-templated silica and organosilica nanotubes and will compare it with the work presented in this dissertation on the use of a dual-surfactant templating systems. Chapter 2 of the dissertation discusses transmission electron microscopy characterization of …

Synthesis Of Metal-Containing Phosphines And Their Use In Coordination, Polymer, And Materials Chemistry, Amir Rabiee Kenaree

Electronic Thesis and Dissertation Repository

This thesis describes the investigation of a novel strategy for the synthesis of metal-containing small molecules, polymers, and nanomaterials. In this context, a new family of air-stable, homo- and heterometallic primary, secondary, and tertiary phosphines were prepared via the radical-initiated hydrophosphination reaction of PH₃ with vinylferrocene and/or vinylruthenocene. The full characterization of the phosphines confirmed their targeted structures and proved that the properties of the starting metallocenes are reflected in those of the resulting phosphines.

To study the coordination behavior of this family of phosphines, primary, secondary, and tertiary ethylferrocene phosphines were reacted with Group 6 metal carbonyl adducts …

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 …

Nanomaterials From Biologically Active Molecules: Self-Assembly And Molecular Recognition, Min Yu

Dissertations

This dissertation describes the development of molecular assemblies and molecular recognition of phospholipids (PLs) that exhibit potential applications in emerging nanotechnologies. It consists of two parts: (1) structural features of PLs responsible for recognition of synthetic copolymers, and (2) design, synthesis and analysis of magnetic nanotubes obtained from PLs with a common theme of colloidal synthesis served as a platform for film formation and nano-assemblies of nanotubes. Poly(methyl methacrylate/n-butyl acrylate) (p-MMA/nBA) colloidal particles that were stabilized by 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) PLs were synthesized, and upon the particle coalescence, PL stratification resulted in the formation of surface localized ionic clusters (SLICs). These …