Buckypapers are thin films of nanostructured membranes made from carbon nanotubes (CNTs), which are amazingly strong nanomaterials that measure 1/50,000th the diameter of a human hair. Buckypapers have outstanding thermal, electrical and physical properties that can be used for numerous applications such as de-icing, lightning-strike protection, miniaturization of electrical connections, smart-materials, etc. Buckypaper is a relatively new material that still needs to be produced more efficiently in order to create bulk nanostructured composites with desirable dispersion and in-plane alignment nanotubes. The current batch-production method has its own associated limitations and problems, including overheating suspensions with small volumes, as well as spilling and improper sonication operation. Manufacturing buckypapers through an automated continuous process will significantly increase their quality, success rates, production rates and processing efficiency. More importantly, this type of process will provide the much-needed continuity of buckypapers for use in composite automation production and the enhancement of electrical conducting properties. This thesis developed a continuous suspension production process, examined effective filtering methods and discussed the integration of the two main processes to form a complete continuous and automated manufacturing process. The work also presented quality control methods and procedures developed specifically for continuous buckypaper using UV-vis spectroscopy techniques. This thesis concludes with the characterization of the resultant continuous buckypaper products to examine their nanostructures and properties. The success of developing the prototype of an automated continuous process provides critical techniques for further realizing industrial production of quality nanotube buckypapers for various applications. / A Thesis Submitted to the Department of Industrial and Manufacturing Engineering in Partial Fulfillment of the Requirements for the Degree of Master of Science. / Spring Semester, 2008. / April 9, 2008. / Dispersion, Ultrasonic, Suspension, Buckypaper SWNT, UV-vis, Nanotubes, Quality / Includes bibliographical references. / Zhiyong Liang, Professor Directing Thesis; Ben Wang, Committee Member; Irinel Chiorescu, Committee Member.

Carbon nanotubes (CNTs) demonstrate extraordinary properties and show great promise in enhancing in-plane and out-of-plane properties of traditional polymer/fiber composites and enabling functionality. However, current manufacturing challenges hinder the realization of their potential. In the dissertation research, both experimental and computational efforts have been conducted to investigate effective manufacturing techniques of CNT integrated multiscale composites. The fabricated composites demonstrated significant improvements in physical properties, such as tensile strength, tensile modulus, inter-laminar shear strength, thermal dimension stability and electrical conductivity. Such multiscale composites were truly multifunctional with the addition of CNTs. Furthermore, a novel hierarchical multiscale modeling method was developed in this research. Molecular dynamic (MD) simulation offered reasonable explanation of CNTs dispersion and their motion in polymer solution. Bi-mode finite-extensible-nonlinear-elastic (FENE) dumbbell simulation was used to analyze the influence of CNT length distribution on the stress tensor and shear-rate-dependent viscosity. Based on the simulated viscosity profile and empirical equations from experiments, a macroscale flow simulation model on the finite element method (FEM) method was developed and validated to predict resin flow behavior in the processing of CNT-enhanced multiscale composites. The proposed multiscale modeling method provided a comprehensive understanding of micro/nano flow in both atomistic details and mesoscale. The simulation model can be used to optimize process design and control of the mold-filling process in multiscale composite manufacturing. This research provided systematic investigations into the CNT-based multiscale composites. The results from this study may be used to leverage the benefits of CNTs and open up new application opportunities for high-performance multifunctional multiscale composites. / A Dissertation Submitted to the Department of Industrial and Manufacturing Engineering in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy. / Summer Semester, 2008. / June 17, 2008. / Multifunctional Materials, Multiscale Composites, Carbon Nanotubes / Includes bibliographical references. / Chuck Zhang, Professor Co-Directing Dissertation; Ben Wang, Professor Co-Directing Dissertation; Subramanian Ramakrishnan, Outside Committee Member; Zhiyong Liang, Committee Member; David Jack, Committee Member.

Many researchers proposed the use of carbon nanotubes as an advanced metal catalyst support for electrocatalysis applications. In this research, buckypaper (thin film of preformed nanotube network) electrodes with different weight ratios of carbon nanomaterials, including SWNT, MWNT, CNF, and Vulcan XC-72 (CB), were fabricated and compared by their electrochemical properties using cyclic voltammetry (CV) test. Platinum (Pt) nanoparticles were successfully electrodeposited on the mixed buckypapers in mixed ethylene glycol, H2PtCl6, and H2SO4 aqueous solutions by applying a potential pulse at 0.2 and -0.25 V, forming Pt/mixed buckypaper electrodes. The dispersion and particle size of Pt nanoparticles on the buckypapers were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The average diameter of Pt nanoparticles on the buckypapers was 10 nm. Surface areas of the Pt nanoparticles on the mixed buckypapers were determined by cyclic voltammogram measurements in 0.5 M H2SO4 solution, and electrocatalytic performances of the resultant buckypaper electrodes were observed. Compared to the Pt/CB electrodes, the Pt/SWNT+MWNT buckypaper electrode exhibits higher electrocatalytic performance. The highest electrochemical surface area (ECSA) of Pt/SWNT+MWNT (1:3) electrodes reaches 43.7m2/g and is about 1.6 times higher than that of the Pt/CB electrode. This may be attributed to the small particle size and good dispersion of platinum, high conducting property of carbon nanotubes, special deposition phenomenon, and unique three–dimension electrode structure. The research results suggest that mixed buckypapers are good candidates for catalyst supports in fuel cell applications because of their high electrocatalytic performance. The reduction of the amount of precious metal catalyst (Pt) needed is important for real-world applications. Further research into the optimization of Pt deposition and nanostructure of mixed buckypapers could lead to highly efficient and potentially affordable electrodes for fuel cell applications. / A Thesis submitted to the Department of Industrial and Manufacturing Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Fall Semester, 2007. / November 06, 2007. / Electrode, Buckypaper, PEMFC / Includes bibliographical references. / Zhiyong Liang, Professor Directing Thesis; Jim P. Zheng, Outside Committee Member; Ben Wang, Committee Member; Chuck Zhang, Committee Member.

Polymer composites are in a period of significant growth due to the increased use in the automobile, marine and aerospace application. Some of the advantages of using composites over other materials are weight savings, corrosion resistance and functional integration. However, long cycle times and higher tooling costs of the available manufacturing processes make it difficult to mass-produce composite products. Resin infusion double flexible tooling (RIDFT) is a novel process developed by the Florida Advanced Center for Composite Technologies (FAC2T) at FAMU-FSU College of Engineering aimed at tackling some of the above-mentioned problems. The use of one-sided mold provides a huge cost advantage over Resin Transfer Molding (RTM). However, using cost effective materials can reduce the cost further. In this thesis research, the various steps involved in the manufacture of the RIDFT mold were identified. The seven steps to manufacture a RIDFT mold are, Initial Graphics Exchange Standard (IGES) file tooling import/repair, mold design, material selection and preparation, NC programming, machine setup, machining and finishing and polishing. The problems at each of these stages were identified. The solutions to some of the problems, which might result in decrease in the tool manufacturing time, were found. To tackle with IGES file import problems some guidelines are presented. The various steps involved in the mold design stage are: compensation of permeable layer thickness, compensation of silicone layer thickness compensation of thickness of part and addition of draft surface. The tooling parameters compensation part of the mold design process was implemented by using both offset and scaling methods using C programming. The materials used for tooling until now are reviewed for pros and cons. Some of the tooling materials, that can be used in future, are also suggested. In order to help the mold manufacturer with the selection of machining parameters a macro was written in Microsoft Excel. Three cases were studied to show how the objectives of thesis are met. / A Thesis submitted to the Department of Industrial Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Fall Semester, 2003. / November 11, 2003. / CAD Errors, RIDFT, NURBS, Mold Design / Includes bibliographical references. / Chuck Zhang, Professor Directing Thesis; Okenwa Okoli, Committee Member; Zhiyong Liang, Committee Member.

Nanomaterials have attracted a great deal of research efforts due to the potential unprecedented properties these materials may provide. Carbon nanotubes (CNTs) are of particular interest because of their exceptional mechanical, thermal and electrical properties. The purpose of this research is to develop poly (methyl methacrylate) (PMMA) carbon nanotubes (CNTs) nanocomposite foams with improved energy dissipation capabilities (toughness). PMMA CNTs nanocomposites were first synthesized by anti-solvent precipitation process (ASP). Nanocomposites with different CNTs concentrations were prepared. The dispersion of the CNTs in the polymer matrix was observed by scanning electron microscopy (SEM). Nanocomposite foams were prepared by a batch process using carbon dioxide as the foaming agent. The foaming was conducted from the retrograde phase that enabled high CO2 solubility and facilitated formation of foams of high bubble density and small bubble size. The effects of foaming temperature, foaming time and CNTs concentration on the foam expansion ratio was investigated. The morphology of the prepared foams was studied by SEM. The compressive properties of the foams were measured and toughness determined. The nanocomposite foams with 0.5% CNT show improvement in energy absorbing capabilities. Upon further increasing CNT concentration, the capability decreases. Further analysis revealed that this was due to the non-uniform foam morphology in those nanocomposite foams. This in turn resulted in from the mixed nucleation mechanisms because of the insufficient CNT dispersion when foamed from the retrograde phase. Enhancement of CNT dispersion in the matrix is needed in order to improve the uniformity of the foams and realize the potential of these materials. / A Thesis submitted to the Department of Industrial and Manufacturing Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Summer Semester, 2011. / June 30, 2011. / PMMA Nanocomposite Foams, Compressive Properties, Energy Absorbtion, Multi-walled Carbon Nanotubes / Includes bibliographical references. / Changchun Zeng, Professor Directing Thesis; Okenwa Okoli, Committee Member; Arda Vanli, Committee Member.

The evolution of the manufacturing industry may be viewed as proceeding from Dedicated Manufacturing Systems (DMS) to Reconfigurable Manufacturing Systems (RMS). Customer requirements change unpredictably, and so DMS are no longer able to meet modern manufacturing requirements. RMS are designed with the focus of providing rapid response to a change in product design, within specified part families. The movement from DMS to RMS facilitates mass-production of custom products. Custom parts require inspection routines that can facilitate variations in product parameters such as dimensions, shape, and throughputs. Quality control and part inspection are key processes in the lifecycle of a product. These processes are able to verify product quality; and can provide essential feedback for enhancing other processes. Mass-producing custom parts requires more complex and frequent quality control and inspection routines, than were implemented previously. Complex, and higher frequencies of inspection negatively impact inspection times, and inherently, production rates. For manufacturers to successfully mass-produce custom parts, processes which can perform complex and varying quality control operations need to be employed. Furthermore, such processes should perform inspections without significantly impacting production rates. A method of reducing the impact of high frequency inspection of customized parts on production rates is needed. This dissertation focuses on the research, design, construction, assembly, and testing of a Non- Contact Automated Inspection System (NCAIS). The NCAIS was focused on performing quality control operations whilst maintaining the maximum production rate of a particular Computer Integrated Manufacturing (CIM) cell. The CIM cell formed part of a research project in the School of Mechanical Engineering, University of KwaZulu-Natal; and was used to simulate mass-production of custom parts. Two methods of maintaining the maximum production rate were explored. The first method was the automated visual inspection of moving custom parts. The second method was to inspect only specified Regions of Interest (ROIs). Mechatronic engineering principles were used to integrate sensor articulation, image acquisition, and image processing systems. A specified maximum production rate was maintained during inspection, without stoppage of parts along the production line occurring. The results obtained may be expanded to specific manufacturing industries. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2009.

Thesis (Ph. D.)--University of Michigan, 1996. / Includes bibliographical references (leaves 251-268).

published_or_final_version / abstract / Mechanical Engineering / Master / Master of Philosophy

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--Lehigh University, 2004. / Includes vita. Includes bibliographical references (leaves 294-307).