Master of Science (MS), Ohio University, 2024, Mechanical Engineering (Engineering and Technology)

This work investigated the influence of selective heat treatment through a Laser-Heat- Treatment (LHT) process on the bending fatigue performance of AISI 1045 steel. Staircase tests were performed on normalized and LHT (or ‘irradiated') specimens in resonance-based flexural bending for quantitative and qualitative comparison of fatigue behavior at endurance (106 cycles). Irradiated samples were subjected to a LHT process focused at localized sections of higher stress caused by changes in geometry before undergoing fatigue testing. The mean endurance limits between the two conditions did not have a statistically significant difference (p = 0.116), but different trends of crack initiation sites were seen between the two sample types. Post-mortem samples were analyzed to determine high-density crack initiation sites. Normalized samples showed a much higher crack location density in high stress regions near stress concentrations caused by geometry changes. When this same section of material was subjected to the LHT process, a sharp drop in crack initiation sites was seen.

Committee: Timothy Cyders (Advisor) Subjects: Materials Science; Mechanical Engineering

MS, University of Cincinnati, 2024, Engineering and Applied Science: Mechanical Engineering

Electroplating is a technique used to coat components with a protective layer of metal which has better resistance against wear and tear, corrosion, surface finish, and overall performance compared to the substrate material. Electroplating with zinc, zinc-nickel, or cadmium is widely used to prevent corrosion and increase the product's lifespan. Zinc-nickel alloy electroplating is a cost-effective and non-toxic alternative to other plating methods and is therefore preferred over cadmium coating. However, since zinc-nickel is a bi-metal alloy, the electroplating process is complex and affects the phase, structure, and surface of the plating. The properties of the plating rely heavily on the working conditions of the electroplating process and on the electrolyte. The composition of the electrolyte, applied voltage or current, time required for electroplating, and mass transport of ions in the electrolyte are a few of the many parameters that affect the plating. The characteristics of the workpiece, like surface finish, surface treatment methods, or machining process, also impact the properties of the plating. As the overall performance of the plated component depends on the microstructure and composition of the plating, it is necessary to understand and evaluate the plating to predict the product's performance successfully at the macro level. The aim of this research is to determine the electrolyte composition that provides good surface properties and the desired nickel content and evaluate the corrosion performance of the plating. The performance of the electrolyte is assessed by electroplating workpieces using different fluid circulation techniques like stationary, vibration-assisted, and stirring-assisted. In addition, the workpiece's surface finish and the surface treatment sequence were varied by conducting ultrasonic nano surface modification and, before, after, or both, electroplating these workpieces to determine if the electrolyte would perform equally well. (open full item for complete abstract)

Committee: Murali Sundaram Ph.D. (Committee Chair); Dinc Erdeniz Ph.D. (Committee Member); Jing Shi Ph.D. (Committee Member) Subjects: Mechanical Engineering

Master of Science in Engineering, Youngstown State University, 2022, Department of Civil/Environmental and Chemical Engineering

Microbially-induced concrete corrosion (MICC) is a key deterioration mechanism in wastewater infrastructure. MICC in wastewater infrastructure has caused economic loss in addition to health and environmental risks. A suitable long-term mitigation strategy would help reduce maintenance costs and related problems. Surface treatment is one such strategy that may help reduce MICC-related maintenance costs and increase service life. In this research, the effectiveness of four treatments applied to concrete surfaces was evaluated in a laboratory experiment at YSU along with in-situ testing in a wet well located in Ellsworth Ohio. Epoxy mastic, acid-resistant coating (ARC), sodium nitrite, and a commercial biocide admixture were evaluated in this study. Among these selected treatments, the first two were selected based on the literature review, while the remaining two were recommended by manufacturers of concrete admixture and surface treatment. Laboratory and field exposure experiments were conducted to determine the efficacy of treatment strategies for mitigating MICC. The applicability of each treatment in different MICC environments was evaluated from the results of surface pH and sulfide uptake rate (SUR) tests. A Live/Dead staining test was then performed to compare the viability of bacteria in the biofilm. Based on the test results, the epoxy coating provided the best level of protection. The biocide treatment indicated better performance than the control but was less effective than the epoxy. The ARC treatment had mixed performance and should not be used unless it is combined with an effective biocide to limit microbial growth. Similarly, a single treatment of sodium nitrite was ineffective. However, reapplication of sodium nitrite (or free nitrous acid) was effective in inactivating the sulfur-oxidizing bacteria (SOB) within the corrosion interface, which remained effective for up to six months between treatments.

Committee: Richard Deschenes PhD (Advisor); Holly Martin. PhD (Committee Member); Byung-Wook Park PhD (Committee Member) Subjects: Civil Engineering; Environmental Engineering; Materials Science; Sustainability

Master of Sciences (Engineering), Case Western Reserve University, 2022, Biomedical Engineering

This study investigated the effects of Ar/H2O plasma treatment on the surface and bulk properties of polytetrafluoroethylene (PTFE) and polyethylene terephthalate (PET) surgical mesh materials as a method to modify and mitigate biofouling events that reduce their performance. With regards to bulk properties, findings from uniaxial tensile testing of these substrates in mesh and suture form show that plasma treatment can weaken their tensile properties. Increasing treatment duration and surface area to volume ratio were found to be major factors that resulted in further reduction of these properties. With regards to surface properties, the direct application of plasma on these substrates was not found to reduce biofouling in the form of protein adsorption and S. aureus attachment compared to untreated control surfaces. These experiments suggest that the deposition of a subsequent coating after plasma treatment is needed to further control biofouling events and is a future direction worth investigating.

Committee: Horst von Recum PhD (Advisor); Julie Renner PhD (Committee Member); Sam Senyo PhD (Committee Member) Subjects: Biomedical Engineering

Doctor of Philosophy, University of Akron, 2016, Chemical Engineering

Saturation, directly related to capture efficiency and pressure drop, plays an important role in performance of gas-liquid coalescence filters. In prior works, a `U' shape saturation profile along the depth was observed in a monolith filter medium. The trend of higher saturation at both ends is induced by the interface between porous media and open air. The existence of the interface is due to the difference of multiple parameters, such as material, fiber size, pore size, wettability and so forth. These parameters collectively contribute to the overall performance. To determine how the parameters individually affect the filter performance ideally experiments should be conducted to vary one parameter while holding others constant. This work studied the effect of a jump (ie, abrupt change) in surface wettability. The filters were fabricated by stacking thin layers of fibrous media. Each thin layer had the same properties including fiber diameter, porosity, permeability, thickness and basis weight. All layers were made of non-woven glass fibers provided by Hollingsworth &Vose with average fiber diameter of about 6 microns. The as-supplied fiber mat had a high surface energy (highly wetting), but with surface treatment with silane coatings the surface energy was modified without altering the other properties of the fiber mat. The results of the experiments show that low surface energy media tend to have lower saturation. Where layers are stacked with flow first through a low surface energy layer followed by a high surface energy layer, the saturation tends to increase near the junction between the layers. In the reverse where flow first passes through high surface energy followed by low surface energy layer the saturation tends to be lower at the junction between the layers. The existing separation media are mostly designed either via empirical application-specific correlations or massive trial-and-errors manufacturing. This is because of complex kinetics of multiphase (open full item for complete abstract)

Committee: George Chase (Advisor); Jiahua Zhu (Committee Member); Rajeev Gupta (Committee Member); Alex Povitsky (Committee Member); Kevin Cavicchi (Committee Member) Subjects: Chemical Engineering

Doctor of Philosophy (Ph.D.), Bowling Green State University, 2020, Photochemical Sciences

We present the study of Fe(III)-carboxylate photochemistry of natural polyuronates in aqueous solutions and in soft hydrogel materials with near UV and violet light. Described in this dissertation are the use of Fe(III)-carboxylate photochemistry for sustainable material applications such as surface modifications and controlled plant nutrient delivery. Quantitative photochemistry of the Fe(III)-alginate system in aqueous solutions was studied using near UV light, and the effect of factors such as alginate composition and solution pH was studied. Degradation of alginate chain with the photochemical reaction was observed by the changes in the solution viscosity. The photochemical reaction seemed to proceed through a radical species and the generation of carbon dioxide anion radical (CO2.-) was identified using Electron Paramagnetic Resonance (EPR) spectroscopy. We present all polysaccharide hydrogels prepared with agarose and carboxylate group containing pectin which showed photoresponsive behavior. Upon Fe(III) coordination and irradiation with 405 nm LED for various time intervals, these gels changed their pH, mechanical properties, porous structure and swelling properties. Based on the radical generation phenomenon, studies on polymerization of selected acrylic monomers using this Fe(III)-carboxylate photochemical system was studied. Other than polyuronate based hydrogels, fabrics with introduced carboxylate functionality showed their ability to polymerize acrylic monomers on their surface, and change their physical and mechanical properties with the use of light. Hydrogel beads prepared with alginate or alginate and other polysaccharide mixtures with Fe(III) showed their ability to absorb phosphate ions from model waste solutions. The solution phosphate concentration dependent phosphate uptake showed a maximum phosphate uptake around 1.5 mgg-1. Phosphate uptake above 1 mgg-1 was seen for a wide pH range of 4.8 - 11.5 due to the strong binding betwe (open full item for complete abstract)

Committee: Alexis Ostrowski PhD (Advisor); Pavel Anzenbacher PhD (Committee Member); George Bullerjahn PhD (Committee Member); Lewis Fulcher PhD (Other) Subjects: Agriculture; Biogeochemistry; Chemistry; Environmental Science; Geochemistry; Inorganic Chemistry; Materials Science; Polymers

Doctor of Philosophy, University of Akron, 2019, Mechanical Engineering

Titanium is used in many applications due to its variety of desirable properties such as high specific strength and excellent corrosion resistance. However, titanium possesses poor tribological properties and many surface treatments either lower the corrosion resistance or experience an “egg-shell” effect. Titanium alloy Ti-6Al-4V was studied in untreated, nitrided, thermally oxidized (TO), supplementary duplex treated (SDT), and complementary duplex treated (CDT) conditions. Characterization, tribological, critical load, corrosion, and tribo-corrosion studies were performed on each surface. Characterization was performed using optical microscopy, x-ray diffraction (XRD), nanoindentation, scanning electron microscopy with energy dispersion spectroscopy (SEM/EDS), x-ray photoelectron spectroscopy (XPS), and transmission electron spectroscopy (TEM). SDT was determined to be a titanium nitride-doped titanium dioxide coating. Tribological testing was performed in dry and lubricated environments. In both environments, Ti-6Al-4V experienced severe wear with a high wear rate. Lubrication was not effective in stabilizing the coefficient of friction and could not prevent the `stick-slip' behavior of Ti-6Al-4V. All of the engineered surfaces tested showed improved tribological properties over untreated Ti-6Al-4V and were compatible with lubricants. The wear seen in Ti-6Al-4V with engineered surfaces was mild and was reduced by one and two orders of magnitude with single stage and duplex treatments, respectively. Nitrided and TO surfaces failed at 4 N and 3 N, respectively. Both duplex treatments were tested at 10 N without failure. Corrosion testing was performed using polarization and electrochemical impedance spectroscopy (EIS) in Ringer's and 3.5% NaCl solutions. TO showed lower corrosion resistance in 3.5% NaCl solution because of defects in the coating allowed the corrosion to penetrate the thick oxide layer. All surfaces showed an increase in impedance in Ringer's (open full item for complete abstract)

Committee: Gary Doll (Committee Chair); Gregory Morscher (Committee Member); Chang Ye (Committee Member); Hongbo Cong (Committee Member); Robert Mallik (Committee Member) Subjects: Chemical Engineering; Materials Science; Mechanical Engineering; Metallurgy

MS, University of Cincinnati, 2018, Engineering and Applied Science: Materials Science

The microstructure and stress states bestowed by the manufacturing process administer the reliability and performance of each component in its final application. Additive Manufacturing (AM) is the trending process among all the innovative methods to produce uniform distribution of microstructure and properties in the constituent parts in a cost-effective manner. However, most of the fusion based manufacturing techniques possess a drawback in the form of residual stresses developed during the processing stage. This demands for the development of more effective AM methods having the potential for near-net shape manufacturing of the parts with minimized residual stresses which has led to the inception of a novel solid-state AM process named “MELD”. This study investigated the microstructure and properties developed in the multi-layer Alloy 600 deposit on 304L stainless steel manufactured by MELD process. Unlike other fusion based AM processes, MELD showed a compressive residual stress (~ -380 MPa) on the surface of the deposited material. The average hardness of the deposit (~ 3.29 GPa) was comparable with that of Alloy 600 manufactured by other AM processes. Additionally, a localized increase in the hardness could be observed at the interfaces between two subsequent layers which was attributed to the grain refinement resulting from dynamic recrystallization in the interfacial areas during the MELD process. Large amount of carbide precipitates formed during the recrystallization at the interface restricted the grains size by pinning them together. High temperature in areas away from interface caused dissolution of carbides leading to grain coarsening. This trend of grains size and carbide precipitates was repeated in each of the deposited layers. The point and space group of the carbide precipitate was determined from TEM analysis. The deposit possessed very low dislocation density and hence low plasticity. Though, the distribution of sub-grains and low angle bounda (open full item for complete abstract)

Committee: Vijay Vasuedevan Ph.D. (Committee Chair); Ashley Pazy Puenta Ph.D. (Committee Member); Matthew Steiner Ph.D. (Committee Member) Subjects: Materials Science

MS, University of Cincinnati, 2018, Engineering and Applied Science: Materials Science

Stress Corrosion cracking of Aluminium 7075 has been an important concern in aerospace industry. AA7075 is one of the three alloys that contribute to 90 percent of the service failures in aluminium-based structures. Hence, there is a need to improve SCC resistance of this alloy. This can be done by introducing compressive residual stresses in the material to counteract the tensile stress arising from manufacturing processes and service conditions. Shot peening, water jet peening, low plasticity burnishing, Ultrasonic Nanocrystal Surface Modification (UNSM), Laser Shock Peening are examples of the surface treatments that induce compressive residual stresses in materials, together with changes in microstructure and properties. This study is an investigation for Laser Shock Peening (LSP) as a mitigation technique to improve corrosion and stress corrosion cracking resistance of Al 7075 - T6 alloy. Different experimental trials were conducted to determine the optimal parameters of LSP for the mitigation. The specimens peened using these optimal parameters were tested and compared with the unpeened (baseline) samples under similar conditions. Polarization tests show that there is 65.5% reduction in the corrosion rate of the laser peened material as compared to the baseline. Slow strain rate tests were conducted in sodium chloride environment to evaluate the stress corrosion cracking resistance of the baseline and laser peened specimens. LSP leads to a 14% increase in yield strength of the alloy which contributes to the improvement in stress corrosion cracking resistance of the material in sodium chloride environment. The increase in yield strength and corrosion resistance, along with microstructural changes induced by LSP could have a combined effect in improving the SCC resistance. Thus LSP is effective in improving the corrosion and stress corrosion cracking resistance of Al 7075 alloy.

Committee: Vijay Vasudevan Ph.D. (Committee Chair); Ashley Paz y Puente Ph.D. (Committee Member); Matthew Steiner Ph.D. (Committee Member) Subjects: Materials Science

Master of Science in Occupational Health, University of Toledo, 2018, Occupational Health (Industrial Hygiene)

Although research on the prevalence of the Hepatitis A Virus (HAV) has been conducted among wastewater workers very little has examined and identified surfaces impacted with HAV in Wastewater Treatment Plants (WWTPs). Wastewater treatment employees may be exposed to HAV from contact with the working surfaces, water, or air throughout various stages of the wastewater treatment process. This study examined working surfaces at a wastewater treatment plant for the presence or absence of HAV. The areas assessed by swab samples (3M Enviro Swabs) were similar to those of a prior study and included door handles, bin handles, and railings in the preliminary treatment building (screens) and grit channels. A lunchroom and control location were also sampled. The locations were identified as those with the highest potential for splash of wastewater and in places employees routinely spend time. One influent sample was also collected daily. The study was conducted over three days, two weekdays and one weekend day. All surface and water samples were sent to a laboratory in Cincinnati, Ohio for qualitative detection of Hepatitis A Virus. HAV was detected/100mL in one of three influent samples. All swab samples were negative for HAV. Future studies may use a wipe or other alternative sampling approach since adherence and recovery of viral materials from swabs is difficult. Employees should receive training on HAV to include information on the health effects and infectivity of HAV, appropriate hygiene practices, and proper personal protective equipment.

Committee: April Ames PhD, CIH (Committee Chair); Michael Valigosky PhD, CIH, CSP (Committee Chair); Sheryl Milz PhD, CIH (Committee Member) Subjects: Occupational Health

Doctor of Philosophy, The Ohio State University, 2013, Food, Agricultural and Biological Engineering

Too much of a good thing can become a problem. This is certainly the case with nutrients in surface waters. Excess nutrients are a concern in streams and lakes. While there are direct health risks related to drinking water contamination among vulnerable populations including infants, harmful algal blooms are a more prevalent concern since they manifest themselves at enrichment levels well below accepted drinking water standards. Half of the lakes in the United States have elevated nutrient levels, a condition that can ultimately lead to oxygen depletion. This problem is exported across state and national boundaries into coastal waters. Agricultural nutrient discharges are particularly difficult to address because, unlike end-of-pipe discharges, fertilizer runoff is hard to capture and treat in a cost effective manner. Appropriate technologies are needed that promote agricultural production through the sustainable management of natural resources. Treatment wetlands are a low-tech alternative to conventional water treatment. Constructed wetlands provide passive treatment of nutrient enriched runoff and other diffuse non-point sources of contamination through nutrient uptake, absorption, or chemical reduction. Hydraulic inefficiencies can substantially limit nutrient reductions when stagnant zones and preferential flow paths exist that reduce contact time. Optimally configured wetlands cost less and perform better. Unfortunately, it is not clear what constitutes an optimal configuration. Many factors, including shape, depth, and botanical structure, influence hydraulic efficiency. The various factors also influence each other, which makes it difficult to ascribe an effect to any one particular factor. Conventional investigative methods using controlled experiments focusing on a response to a single factor cannot tell the whole story. A more comprehensive approach is described here. Scaled models were used to investigate treatment wetland hyd (open full item for complete abstract)

Committee: Larry Brown (Advisor); Alfred Soboyejo (Committee Member); Norman Fausey (Committee Member) Subjects: Agricultural Engineering; Civil Engineering; Conservation; Ecology; Engineering; Environmental Engineering; Environmental Studies; Water Resource Management

Doctor of Engineering, Cleveland State University, 2013, Fenn College of Engineering

The use of dyes has become very significant across various industries such as textiles, paper, and clothing. The organic chemical composition of dyes is a major concern when discharging wastewater not only into the environment, but also within wastewater treatment plants. Dye effluent consists of high chemical oxygen demand (COD) and also color, components that require treatment before discharge. As a result, federal legislation has required industries that discharge high components in wastewater to undergo treatment within the plants. Within literature, authors have considered various biological, physical, and chemical methods of treating dye wastewater. Recently, electrocoagulation/electroflotation (ECF) has been an additional method of treatment that has been considered for the treatment of dye wastewater. Two separate studies are considered. First, Acid Yellow 11 (AY11) at a concentration of 25 mg/L (by weight) underwent treatment from three different coagulants (Alum, Ferric Sulfate, and Ferric Chloride) , under three different strengths (5 mg/L, 10 mg/L, and 15 mg/L), and two different initial pH considerations (4 and 7) for the purpose of analyzing color removal. Following the study, the results were collaborating into a response surface methodology, developing an equation for the three different coagulants. In addition, a Box-Behnken design has been setup for the purpose of considering the effects of pH, dye concentration, dye type, coagulant type and strength on the efficiency of electrocoagulation. These values will be analyzed using statistical analysis, along with toxicity study done on the effectiveness of removing toxic contaminants from the wastewater. Finally, a photo-oxidation study was completed on Acid Orange 7 (AO7) synthetic dye wastewater for the purpose of determining the effects of photo-oxidation based on dye concentration, catalyst type and dose. Langmuir-Hinshelwood coefficients were developed based on the results of this experiment.

Committee: Yung-Tse Hung (Advisor); Walter Kocher (Committee Member); Lili Dong (Committee Member); Chung-Yi Suen (Committee Member); Sally Saiilai Shao (Committee Member) Subjects: Environmental Engineering

MS, University of Cincinnati, 2005, Engineering : Environmental Engineering

Wastewaters from textile dyeing operations often contain organics compounds with strong color accompanied by a high concentration of sodium chloride (NaCl), and electrochemical treatment is a promising way to treat the waste. The objective of this investigation was to evaluate the impact of design and operational parameters on decolorization efficiency and effluent toxicity during electrochemical treatment of wastewater containing the dye Acid Alizarin Violet N (AAVN; 14.65 mg/L) and NaCl (0.35 M). Cell configuration (split and undivided) and electrical current density (4 and 8 mA/cm 2 ) were the chosen reactor design parameters and pH (4, 7 and 10) and applied current (72 and 144 mA) were the chosen operational parameters. Extent of removal, power consumption, and effluent toxicity were the design criteria signifying efficiency, cost effectiveness, and environmental impact of the process. The split cell configuration provided the highest color removal, consuming significantly lower power than the undivided cell. Extent of decolorization was higher at pH 4 than that at pH 10 and pH 7. Increasing applied current increased the extent of color removal in the split cell whereas performance was unaffected in the undivided cell. Microtox ® toxicity test showed that effluents collected from more efficient conditions (split cell at pH 4) revealed the highest toxicity. In contrast, negligible toxicity was found in the effluent from the least efficient undivided cell - pH 10 conditions. A design strategy that maximizes the efficiency is in direct conflict with the goal of minimizing effluent toxicity. This study demonstrates the importance of considering end product toxicity in addition to more traditional criteria in making suitable decisions for electrochemical reactor design.

Committee: Dr. Margaret Kupferle (Advisor) Subjects: Engineering, Environmental

PhD, University of Cincinnati, 2005, Engineering : Materials Science

The need for toxic chromate replacements in metal-finishing industries has prompted an intensive search for replacement technologies in recent years. Among the replacements that have been proposed, those that are based upon the use of organofunctional silanes rank very high in terms of performance, broad applicability as well as ease of application. This dissertation presents a four-part work: (1) structural characterization of silane films on metals, (2) mechanism studies of silane-treated metal systems, (3) development of water-based silane systems, and (4) measurements of other properties of silane films. In part 1, silane films, i.e., bis-[triethoxysilylpropyl]tetrasulfide (bis-sulfur silane) and bis-[trimethoxysilylpropyl]amine (bis-amino silane) were deposited on AA 2024-T3 and were characterized mainly using reflection-absorption Fourier-transform infrared spectroscopy (FTIR-RA) and electrochemical impedance spectroscopy (EIS) techniques. The results showed that further hydrolysis and crosslinking occurs in the applied bis-sulfur silane films in the presence of water and moisture. This is because the bis-sulfur silane is difficult to hydrolyze completely in its water/ethanol solution. The remaining ester groups would hydrolyze to silanols when water or moisture presents (e.g., in the processes of curing in the atmosphere and immersion in an aqueous solution). The as-formed silanols would further condense either with themselves or with aluminum hydroxyl groups at the alloy surface, forming siloxanes and aluminum-siloxanes. Three different regions were clearly detected by EIS in the bis-sulfur silane-treated AA 2024-T3 system, and were further observed in the SEM/EDX studies. According to these studies, the three regions are assigned to, from outside to inside, outermost silane film dominated with siloxanes (SiOSi), interfacial layer with both siloxanes and aluminum-siloxanes (AlOSi), and innermost aluminum oxide. In part 2, the mechanistic study of corrosion p (open full item for complete abstract)

Committee: Dr. Wim van Ooij (Advisor) Subjects: Engineering, Materials Science

Doctor of Philosophy, Case Western Reserve University, 1993, Macromolecular Science

The work presented next is focused on the combination of two major polymer fields: polymer blends and composites. The goal was to use the established interphase concepts to obtain composites with desired properties to enhance the compatibility of immiscible blends. However, during the course of this work a new mechanism of property enhancement was established. An extensive study of the effect of the particle size, filler concentration and filler surface treatment on the immiscible polymer blends at different ratios is described. Basically two polymer blends are studied, polypropylene-polystyrene and polystyrene-poly(methyl methacrylate) and two fillers, glass beads and fumed silica, are used. The enhancement of the compatibility is achieved by two different mechanisms. The first mechanism is through interphase control by surface treatment of large particles, such as glass beads. The filler surface is treated in order to promote an interaction of both blend components with the filler surface. Through such interaction a new compatibilized interphase near the filler surface is originated. Therefore, the silane coupling agent selection is very important, since it should promote interaction of both polymers with the filler, as described in Chapter 2. The behavior of polypropylene-polystyrene and polystyrene-poly(methyl methacrylate) blends as a function of filler content and blend composition is extensively studied in Chapters 3, 4 and 5. The second mechanism is not due to surface treatment but due to filler-filler interaction when the particle size is very small. As the filler concentration starts to increase a filler network is formed, when a polymer preferentially adsorbs onto the filler network the adsorbed polymer have the same pattern originating a polymer network superstructure. As one blend component forms a network the other one is left to fill the remaining space, resulting in a much more homogeneous and smaller phase separation system, as described in Chapter (open full item for complete abstract)

Committee: Hatsuo Ishida (Advisor) Subjects: Engineering, Materials Science