The atomic force microscope (AFM) was used to study a series of self-assembled systems: alkanethiol self-assembled monolayer (SAM), diblock copolymer thin film, solid supported lipid bilayer membrane, and microgel with double interpenetrating polymer network. In the first system, packing and restructuring of self-assembled monolayers as exhibited by several alkanethiol systems (1-hexanethiol, 1-decanethiol, 11-ferrocenyl-1-undecanethiol) is demonstrated using conducting probe AFM (CP-AFM). Pressure is induced by an AFM tip, and simultaneously, electrical behavior is measured via detection of tunneling currents between metallic tip and substrate. The behavior is fit using a mechanical model that attempts to predict the observed junction resistance as a function of applied force with consideration for mechanical restructuring of the monolayer at higher loads. CP-AFM is also used to study self-assembled thin film of the diblock copolymer polystyrene- block-polyferrocenylsilane (PS-b-PFS) on gold substrate. Simultaneous height and electrical current imaging verify the phase separation of the two blocks of the polymer and additionally, distinguish each block due to differential conductivity. The phase separation of multi-component phospholipid bilayers (phosphatidylcholine/ sphingomyelin/ cholesterol) on supporting substrate into liquid-ordered and liquid-disordered phases is demonstrated using both topographical imaging, and the use of force map analysis through tip indentation and rupture measurements. The segregation and differential mechanical stiffness of the phases help to understand the important role of mechanical stability and rigidity membranes. An automated batch analysis process was implemented to facilitate the procedure. The mechanical properties of microfluidically produced microgels (cross-linked sodium alginate and poly(N-isopropylacrylamide)) are measured using indentation experiments, to evaluate the suitability of these gels as cell-mimics. Nanoscale heterogeneities were avoided by using a tipless cantilever. This body of work shows that the alginate content of these microgels can be varied to tune their mechanical properties and that a platform for mechanical measurement of cell and cell-mimics is possible.

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Increasing energy demand makes the development of higher energy storage batteries, imperative. However, one of the major advantages of fossil fuels as an energy source is they can provide variably large quantities of power when desired. This is where electrochemical capacitors can continue to carve out a niche market supplying moderate energy storage, but with high specific power output. However, current issues with carbon precursors necessitate further development. Further, production requires high temperature, energy intensive carbonization to create the active pore sites and develop the pores. Double-layer capacitive materials researched to replace active carbons generally require properties that include: very high surface area, high pore accessibility and wettability, strong electrical conductivity, structural stability, and optionally reversible functional groups that lend to energy storage through pseudocapacitive mechanisms. In recent years, nanostructured carbon materials which could in future be tailored through bottom up processing have the potential to exhibit favourable properties have also contributed to the growth in this field. This thesis presents research on graphene, an emerging 2-dimensional carbon material. So far, production of graphene in bulk exhibits issues including restacking, structural damage and poor exfoliation. However, the high chemical stability, moderate conductivity and high electroactive behaviour even with moderate exposed surface area makes them an excellent standalone material or a potential support material. Two projects presented focus on enhancing the capacitance through functionality and controlling graphene formation to enhance performance. The first study addresses graphene enhancement possible with heteroatom functionality, produced by a single step low temperature hydrothermal reduction process. The dopant methodology was successful in adding nitrogen functionality to the reduced graphene oxide basal and the effect of nitrogen type was considered. The second study addresses the need for greater control of the rGO structure on the macro-scale. By harnessing the change in interactions between the GO intermediate and final rGO sheets we were able to successfully control the assembly of graphene, creating micro and macro-pore order and high capacitive performance. Further, self assembly directly onto the current collector eliminates process steps involved in the production of EDLC electrodes.

Structures with well-defined architectures and tailored physical properties can be produced by supramolecular self-assembly of stimuli-sensitive polymeric inclusion complexes consisting of cyclodextrins. Recently, there has been significant interest in the use of double hydrophilic block copolymers to design novel supramolecular nanostructures as these polymers micellize under external stimuli, such as temperature, pH, and complexation. Cyclodextrins (CDs) have the ability to spontaneously complex with water-soluble guest molecules. The complexation of the polymer with CD induces self-assembly of the polymers. In this research, two systems were studied, a PEO-b-PNIPAM/α-CD system and a PPO-b-PMAA/β-CD system. First, the block copolymers were synthesized by ATRP to achieve well-defined monodisperse polymers. The chemical composition of the polymer was determined by NMR and gel permeation chromatography. Then, the microstructure and aggregation behaviour in aqueous solutions were studied using a combination of static and dynamic light scattering, and isothermal titration and differential scanning calorimetric techniques.

In recent years there has been much interest in the self-assembly of materials. Much of this research has been focused on the self-assembly of particles in solution (colloids), typically on the order of nanometres or micrometres in size. While it is easy to imagine the self-assembly of either irregularly shaped particles, or particles under an anisotropic potential, a novel class of colloids with engineerable isotropic interactions have achieved this aim. With the use of Self-Consistent Field Theory (SCFT), a mean-field model first developed for polymer melt systems, we develop a model for a system of particles of two species. One species experiences a long-range repulsive and short-range attractive interaction. The other is inert, acting as a solvent in which the former is suspended. Using this method, we calculated the equilibrium morphologies of the system for various parameters including the total volume fraction of one species relative to the other, the strengths and ranges of both the attractive and repulsive components of the interaction, and the relative particle sizes. In this way, we are able to loosely mimic the polymer-coated colloidal systems that are one of the current subjects of self-assembly research. By reducing our model to a simplified, isotropic interaction, we are able to show that the self-assembly of such systems is the result of the nature of the interaction and not any anisotropy within the model. We have also shown that the phase progressions of this system exhibit remarkable agreement with those of diblock copolymer melt systems despite significant differences in the molecules of these two systems.

Multiple ecological factors can simultaneously affect species activity and community structure. The goal of my dissertation was to examine the effects of abiotic factors, biotic factors, and succession on anuran communities. I took a three pronged approach dividing the study into three major chapters. First I focused on abiotic factors that affect anuran breeding activity. I found that weather, rainfall and temperature affect the breeding activity of each species differently, and species in my study area can be placed into 5 different groups based on their association with weather and season: 1) breed within a predictable season (summer) independent of local weather patterns 2) breed opportunistically within a predictable season (summer) dependent on local rainfall 3) breed opportunistically within a predictable season (winter) dependent on local temperature 4) breed opportunistically dependent on local flood level rainfall events and 5) breed opportunistically year round dependent on local temperature in the winter and local rainfall in the summer. In the second part of the study, I created a simulation model of an anuran community using published life history parameters of the anuran species in my study system. Results of the model suggest colonizing ability is important for species with low fecundity and high susceptibility to predation. These early succession species tend to be constrained from later stages of succession by predators. Species that are resistant to predators are generally poor colonizers and tend to arrive late in succession, but once they colonize a pond they tend to persist and recruit successfully. Finally, I explored biotic mechanisms that might be important in structuring anuran communities. I found that with the exception of Rana sphenocephala, anuran species occupying sites with shorter hydroperiods had higher activity rates and were more susceptible to predation. Rana sphenocephala appeared to be better at escaping predation than the other species despite a relatively high activity rate. Examination of published phylogenies indicates R. sphenocephala is derived from a species group that uses permanent water suggesting that R. sphenocephala has retained many anti-predator defenses inherited from its ancestors, even though the species now exploits sites with low predator densities.

Copper oxide with various morphologies, such as nanocubes, nanorods, and nanoribbons was synthesized from the H2O/C2H5OH solution of Cu(OAc)2/NEt3 with or without tetraoctylammonium bromide (TOAB) under mild conditions. In the system of Cu(OAc)2/NEt3 (0.05 mmole : 7.9 mmole) with 0.75 mmole of TOAB in H2O/C2H5OH (10 mL : 40 mL) solution, We found that nanocubes of CuO spontaneously self-assembled into nanorods and then nanosheets with the increasing of reaction time. Structural characterization of the CuO nanorods shows that the rod grows primarily along the [010] direction. Nanorods of CuO were also characterized by TEM, HR-TEM, SAED, and XRD.

Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 2002. / Includes bibliographical references.

Thesis (Ph.D)--Chemistry and Biochemistry, Georgia Institute of Technology, 2009. / Committee Chair: Lyon, Louis; Committee Member: Breedveld, Victor; Committee Member: Bunz, Uwe; Committee Member: Collard, David; Committee Member: Srinivasarao, Mohan. Part of the SMARTech Electronic Thesis and Dissertation Collection.

The Assembly sequencing problem (ASP) is part of the assembly planning process. The ASP is basically a large scale, combinatorial problem which is highly constrianed. The aim of this thesis is to automatically generate assembly sequence(s) for mechanical products. In this thesis, the CAD model of an assembly is represented or modeled as a label-rich graph. The assembly sequences are generated using graph grammar rules that are applied on the graph. The sequences are stored in a search tree and to find an optimal sequence multiple evaluation criteria like time, subassembly stability and accessibility measures are used. This research implements a novel tree search algorithm called "Ordered Depth First Search" (ODFS) to find an optimal assembly sequence in very low processing time. The software has successfully generated an optimized assembly sequence for an assembly with 14 parts. / text