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Description
The problem of catastrophic damage purveys in any material application, and minimizing its occurrence is paramount for general health and safety. Thus, novel damage detection schemes are required that can sense the precursors to damage. Mechanochemistry is the area of research that involves the use of mechanical force to induce

The problem of catastrophic damage purveys in any material application, and minimizing its occurrence is paramount for general health and safety. Thus, novel damage detection schemes are required that can sense the precursors to damage. Mechanochemistry is the area of research that involves the use of mechanical force to induce a chemical change, with recent study focusing on directing the mechanical force to embedded mechanophore units for a targeted chemical response. Mechanophores are molecular units that provide a measureable signal in response to an applied force, often in the form of a visible color change or fluorescent emission, and their application to thermoset network polymers has been limited. Following preliminary work on polymer blends of cyclobutane-based mechanophores and epoxy, dimeric 9-anthracene carboxylic acid (Di-AC)-based mechanophore particles were synthesized and employed to form stress sensitive particle reinforced epoxy matrix composites.

Under an applied stress, the cyclooctane-rings in the Di-AC particles revert back to their fluorescent anthracene form, which linearly enhances the overall fluorescence of the composite in response to the applied strain. The fluorescent signal further allows for stress sensing in the elastic region of the stress-strain curve, which is considered to be a form of damage precursor detection. This behavior was further analyzed at the molecular scale with corresponding molecular dynamics simulations. Following the successful application of Di-AC to an epoxy matrix, the mechanophore particles were incorporated into a polyurethane matrix to show the universal nature of Di-AC as a stress-sensitive particle filler. Interestingly, in polyurethane Di-AC could successfully detect damage with less applied strain compared to the epoxy system.

While mechanophores of varying chemistries have been covalently incorporated into elastomeric and thermoplastic polymer systems, they have not yet been covalently incorporated a thermoset network polymer. Thus, following the study of mechanophore particles as stress-sensitive fillers, two routes of grafting mechanophore units into an epoxy system to form a self-sensing nanocomposite were explored. These involved the mechanophore precursor and mechanophore, cinnamamide and di-cinnamamide, respectively. With both molecules, the free amine groups can directly bond to epoxy resin to covalently incorporate themselves within the thermoset network to form a self-sensing nanocomposite.
ContributorsNofen, Elizabeth (Author) / Dai, Lenore L (Thesis advisor) / Chattopadhyay, Aditi (Thesis advisor) / Emady, Heather (Committee member) / Mu, Bin (Committee member) / Nielsen, David (Committee member) / Arizona State University (Publisher)
Created2016
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Description
While the solution diffusion model and pore flow model dominate pervaporation transport mechanism modeling, a new model combining the solution diffusion and viscous flow models is validated using membranes with large scale defects exceeding 2 nm in diameter. A range of membranes was characterized using scanning electron microscopy and

While the solution diffusion model and pore flow model dominate pervaporation transport mechanism modeling, a new model combining the solution diffusion and viscous flow models is validated using membranes with large scale defects exceeding 2 nm in diameter. A range of membranes was characterized using scanning electron microscopy and x-ray diffraction (XRD) to determine quality and phase characteristics. MFI zeolite membranes of He/SF6 pure gas permeation ideal selectivities of 25, 15, and 3 for good, medium, and poor quality membranes were subjected to liquid pervaporations with a 5% ethanol in water feed, by weight. Feed pressure was increased from 1 to 5 atm, to validate existence of viscous flow in the defects. Component molar flux is modeled using the solution diffusion model and the viscous flow model, via J_i=F_i (γ_i x_i P_i^sat )+(ρ )/M_W ∅/μ_ij x_i P_h. A negative coefficient of thermal expansion is observed as permeances drop as a function of temperature in all three membranes, where ϕ=((ϵr_p^2)/τ∆x). Experimental parameter ϕ increased as a function of temperature, and increased with decreasing membrane quality. This further proves that zeolitic pores are shrinking in one direction, and pulling intercrystalline voids larger, increasing the (ϵ/τ) ratio. Permiabilities of the bad, medium, and good quality membrane also decreased over time for both ethanol and water, meaning that fundamental membrane characteristics changed as a function of temperature. To conclude, the model reasonably fits empirical data reasonably well.
ContributorsWilliams, Suzanne Jean (Author) / Lin, Jerry Y.S. (Thesis advisor) / Emady, Heather (Committee member) / Mu, Bin (Committee member) / Arizona State University (Publisher)
Created2016
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Description
Water recovery from impaired sources, such as reclaimed wastewater, brackish groundwater, and ocean water, is imperative as freshwater resources are under great pressure. Complete reuse of urine wastewater is also necessary to sustain life on space exploration missions of greater than one year’s duration. Currently, the Water Recovery System (WRS)

Water recovery from impaired sources, such as reclaimed wastewater, brackish groundwater, and ocean water, is imperative as freshwater resources are under great pressure. Complete reuse of urine wastewater is also necessary to sustain life on space exploration missions of greater than one year’s duration. Currently, the Water Recovery System (WRS) used on the National Aeronautics and Space Administration (NASA) shuttles recovers only 70% of generated wastewater.1 Current osmotic processes show high capability to increase water recovery from wastewater. However, commercial reverse osmosis (RO) membranes rapidly degrade when exposed to pretreated urine-containing wastewater. Also, non-ionic small molecules substances (i.e., urea) are very poorly rejected by commercial RO membranes.

In this study, an innovative composite membrane that integrates water-selective molecular sieve particles into a liquid-barrier chemically resistant polymer film is synthetized. This plan manipulates distinctive aspects of the two materials used to create the membranes: (1) the innate permeation and selectivity of the molecular sieves, and (2) the decay-resistant, versatile, and mechanical strength of the liquid-barrier polymer support matrix.

To synthesize the membrane, Linde Type A (LTA) zeolite particles are anchored to the porous substrate, producing a single layer of zeolite particles capable of transporting water through the membrane. Thereafter, coating the chemically resistant latex polymer filled the space between zeolites. Finally, excess polymer was etched from the surface to expose the zeolites to the feed solution. The completed membranes were tested in reverse osmosis mode with deionized water, sodium chloride, and rhodamine solutions to determine the suitability for water recovery.

The main distinguishing characteristics of the new membrane design compared with current composite membrane include: (1) the use of an impermeable polymer broadens the range of chemical resistant polymers that can be used as the polymer matrix; (2) the use of zeolite particles with specific pore size insures the high rejection of the neutral molecules since water is transported through the zeolite rather than the polymer; (3) the use of latex dispersions, environmentally friendly water based-solutions, as the polymer matrix shares the qualities of low volatile organic compound, low cost, and non- toxicity.
ContributorsKhosravi, Afsaneh Khosravi (Author) / Lind, Mary Laura (Thesis advisor) / Dai, Lenore (Committee member) / Green, Matthew (Committee member) / Lin, Jerry (Committee member) / Seo, Don (Committee member) / Arizona State University (Publisher)
Created2016
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Description
Ionic liquids (ILs), or low-temperature liquid salts, are a class of materials with unique and useful properties. Made up entirely of ions, ILs are remarkably tunable and diverse as cations and anions can be mixed and matched to yield desired properties. Because of this, IL/water systems range widely—from homogeneous mixtures

Ionic liquids (ILs), or low-temperature liquid salts, are a class of materials with unique and useful properties. Made up entirely of ions, ILs are remarkably tunable and diverse as cations and anions can be mixed and matched to yield desired properties. Because of this, IL/water systems range widely—from homogeneous mixtures to multiphasic systems featuring ionic liquid/liquid interfaces. Even more diversity is added when particles are introduced to these systems, as hard particles or soft-matter microgels interact with both ILs and water in complex ways. This work examines both miscible ionic liquid/water mixture and two-phase, immiscible ionic liquid/water systems. Extensive molecular dynamics (MD) simulations are utilized in conjunction with physical measurements to inform theoretical understanding of the nature of these systems, and this theoretical understanding is related to practical applications—in particular, the development of a low-temperature liquid electrolyte for use in molecular electronic transducer (MET) seismometers, and particle self-assembly and transport at ionic liquid/liquid interfaces such as those in Pickering emulsions.

The homogenous mixture of 1-butyl-3-methylimidazolium iodide and water is examined extensively through MD as well as physical characterization of properties. Molecular ordering within the liquid mixture is related to macroscopic properties. These mixtures are then used as the basis of an electrolyte with unusual characteristics, specifically a wide liquid temperature range with an extremely low lower bound combined with relatively low viscosity allowing excellent performance in the MET sensor. Electrolyte performance is further improved by the addition of fullerene nanoparticles, which dramatically increase device sensitivity. The reasons behind this effect are explored by testing the effect of graphene surface size and through MD simulations of fullerene and a silica nanoparticle (for contrast) in [BMIM][I]/water mixtures.

Immiscible ionic liquid/water systems are explored through MD studies of particles at IL/water interfaces. By increasing the concentration of hydrophobic nanoparticles at the IL/water interface, one study discovers the formation of a commingled IL/water/particle pseudo-phase, and relates this discovery to previously-observed unique behaviors of these interfaces, particularly spontaneous particle transport across the interface. The other study demonstrates that IL hydrophobicity can influence the deformation of thermo-responsive soft particles at the liquid/liquid interface.
ContributorsNickerson, Stella Day (Author) / Dai, Lenore L (Thesis advisor) / Yu, Hongyu (Committee member) / Lind, Mary Laura (Committee member) / Mu, Bin (Committee member) / Emady, Heather (Committee member) / Arizona State University (Publisher)
Created2016
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Description
The accurate and fast determination of organic air pollutants for many applications and studies is critical. Exposure to volatile organic compounds (VOCs) has become an important public health concern, which may induce a lot of health effects such as respiratory irritation, headaches and dizziness. In order to monitor the personal

The accurate and fast determination of organic air pollutants for many applications and studies is critical. Exposure to volatile organic compounds (VOCs) has become an important public health concern, which may induce a lot of health effects such as respiratory irritation, headaches and dizziness. In order to monitor the personal VOCs exposure level at point-of-care, a wearable real time monitor for VOCs detection is necessary. For it to be useful in real world application, it requires low cost, small size and weight, low power consumption, high sensitivity and selectivity.

To meet these requirements, a novel mobile device for personal VOCs exposure monitor has been developed. The key sensing element is a disposable molecularly imprinted polymer based quartz tuning fork resonator. The sensor and fabrication protocol are low cost, reproducible and stable. Characterization on the sensing material and device has been done. Comparisons with gold standards in the field such as GC-MS have been conducted. And the device’s functionality and capability have been validated in field tests, proving that it’s a great tool for VOCs monitoring under different scenarios.
ContributorsDeng, Yue, Ph.D (Author) / Forzani, Erica S (Thesis advisor) / Lind, Mary L (Committee member) / Mu, Bin (Committee member) / LaBelle, Jeffery (Committee member) / Emady, Heather (Committee member) / Arizona State University (Publisher)
Created2017
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Description
Amine-modified solid sorbents and membrane separation are promising technologies for separation and capture of carbon dioxide (CO2) from combustion flue gas. Amine absorption processes are mature, but still have room for improvement. This work focused on the synthesis of amine-modified aerogels and metal-organic framework-5 (MOF-5) membranes for CO2 separation. A

Amine-modified solid sorbents and membrane separation are promising technologies for separation and capture of carbon dioxide (CO2) from combustion flue gas. Amine absorption processes are mature, but still have room for improvement. This work focused on the synthesis of amine-modified aerogels and metal-organic framework-5 (MOF-5) membranes for CO2 separation. A series of solid sorbents were synthesized by functionalizing amines on the surface of silica aerogels. This was done by three coating methods: physical adsorption, magnetically assisted impact coating (MAIC) and atomic layer deposition (ALD). CO2 adsorption capacity of the sorbents was measured at room temperature in a Cahn microbalance. The sorbents synthesized by physical adsorption show the largest CO2 adsorption capacity (1.43-1.63 mmol CO2/g). An additional sorbent synthesized by ALD on hydrophilic aerogels at atmospheric pressures shows an adsorption capacity of 1.23 mmol CO2/g. Studies on one amine-modified sorbent show that the powder is of agglomerate bubbling fluidization (ABF) type. The powder is difficult to fluidize and has limited bed expansion. The ultimate goal is to configure the amine-modified sorbents in a micro-jet assisted gas fluidized bed to conduct adsorption studies. MOF-5 membranes were synthesized on α-alumina supports by two methods: in situ synthesis and secondary growth synthesis. Characterization by scanning electron microscope (SEM) imaging and X-ray diffraction (XRD) show that the membranes prepared by both methods have a thickness of 14-16 μm, and a MOF-5 crystal size of 15-25 μm with no apparent orientation. Single gas permeation results indicate that the gas transport through both membranes is determined by a combination of Knudsen diffusion and viscous flow. The contribution of viscous flow indicates that the membranes have defects.
ContributorsRosa, Teresa M (Author) / Lin, Jerry (Thesis advisor) / Pfeffer, Robert (Thesis advisor) / Dai, Lenore (Committee member) / Nielsen, David (Committee member) / Arizona State University (Publisher)
Created2010
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Description
Membrane-based technology for gas separations is currently at an emerging stage of advancement and adoption for environmental and industrial applications due to its substantial advantages like lower energy and operating costs over the conventional gas separation technologies. Unfortunately, the available polymeric (or organic) membranes suffer a trade-off between permeance and

Membrane-based technology for gas separations is currently at an emerging stage of advancement and adoption for environmental and industrial applications due to its substantial advantages like lower energy and operating costs over the conventional gas separation technologies. Unfortunately, the available polymeric (or organic) membranes suffer a trade-off between permeance and selectivity. Mixed matrix membranes (MMMs) containing two-dimensional (2D) metal-organic frameworks (MOFs) as fillers are a highly sought approach to redress this trade-off given their enhanced gas permeabilities and selectivities compared to the pure polymeric membrane. These MMMs are increasingly gaining attention by researchers due to their unique properties and wide small- and large-scale gas separation applications. However, straightforward and scalable methods for the synthesis of MOFs nanosheets have thus far been persistently elusive. This study reports the single-phase preparation, and characterization of MMMs with 2D MOFs nanosheets as fillers. The prepared MOF and the polymer matrix form the ‘dense’ MMMs which exhibit increased gas diffusion resistance, and thus improved separation abilities. The single-phase approach was more successful than the bi-phase at synthesizing the MOFs. The influence of sonication power and time on the characteristics and performance of the membranes are examined and discussed. Increasing the sonication power from 50% to 100% reduces the pore size. Additionally, the ultimate effect on the selectivity and permeance of the MMMs with different single gases is reported. Analysis of results with various gas mixers indicates further performance improvements in these MMMs could be achieved by increasing sonication time and tuning suitable membrane thicknesses. Reported results reveal that MMMs are excellent candidates for next-generation gas mixture separations, with potential applications in CO2 capture and storage, hydrogen recovery, alkene recovery from alkanes, and natural gas purification.
ContributorsNkuutu, John (Author) / Mu, Bin (Thesis director) / Shan, Bohan (Committee member) / Chemical Engineering Program (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
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Description
ABSTRACT



Large-pore metal-organic framework (MOF) membranes offer potential in a number of gas and liquid separations due to their wide and selective adsorption capacities. A key characteristic of a number of MOF and zeolitic imidazolate framework (ZIF) membranes is their highly selective adsorption capacities for CO2.

ABSTRACT



Large-pore metal-organic framework (MOF) membranes offer potential in a number of gas and liquid separations due to their wide and selective adsorption capacities. A key characteristic of a number of MOF and zeolitic imidazolate framework (ZIF) membranes is their highly selective adsorption capacities for CO2. These membranes offer very tangible potential to separate CO2 in a wide array of industrially relevant separation processes, such as the separation from CO2 in flue gas emissions, as well as the sweetening of methane.

By virtue of this, the purpose of this dissertation is to synthesize and characterize two linear large-pore MOF membranes, MOF-5 and ZIF-68, and to study their gas separation properties in binary mixtures of CO¬2/N2 and CO2/CH4. The three main objectives researched are as follows. The first is to study the pervaporation behavior and stability of MOF-5; this is imperative because although MOF-5 exhibits desirable adsorption and separation characteristics, it is very unstable in atmospheric conditions. In determining its stability and behavior in pervaporation, this material can be utilized in conditions wherein atmospheric levels of moisture can be avoided. The second objective is to synthesize, optimize and characterize a linear, more stable MOF membrane, ZIF-68. The final objective is to study in tandem the high-pressure gas separation behavior of MOF-5 and ZIF-68 in binary gas systems of both CO2/N2 and CO2/CH4.

Continuous ZIF-68 membranes were synthesized via the reactive seeding method and the modified reactive seeding method. These membranes, as with the MOF-5 membranes synthesized herein, both showed adherence to Knudsen diffusion, indicating limited defects. Organic solvent experiments indicated that MOF-5 and ZIF-68 were stable in a variety of organic solvents, but both showed reductions in permeation flux of the tested molecules. These reductions were attributed to fouling and found to be cumulative up until a saturation of available bonding sites for molecules was reached and stable pervaporation permeances were reached for both. Gas separation behavior for MOF-5 showed direct dependence on the CO2 partial pressure and the overall feed pressure, while ZIF-68 did not show similar behavior. Differences in separation behavior are attributable to orientation of the ZIF-68 membranes.
ContributorsKasik, Alexandra Marie (Author) / Lin, Jerry (Thesis advisor) / Tasooji, Amaneh (Committee member) / Alford, Terry (Committee member) / Arizona State University (Publisher)
Created2015
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Description
Corrosion is one of the key failure modes for stainless steel (SS) piping assets handling water resources managed by utility companies. During downtime, the costs start to incur as the field engineer procures its replacement parts. The parts may or may not be in stock depending on how old, complex,

Corrosion is one of the key failure modes for stainless steel (SS) piping assets handling water resources managed by utility companies. During downtime, the costs start to incur as the field engineer procures its replacement parts. The parts may or may not be in stock depending on how old, complex, and common the part model is. As a result, water utility companies and its resilience to operate amid part failure are a strong function of the supply chain for replacement piping. Metal additive manufacturing (AM) has been widely recognized for its ability to (a) deliver small production scales, (b) address complex part geometries, (c) offer large elemental metal and alloy selections, (d) provide superior material properties. The key motive is to harvest the short lead time of metal AM to explore its use for replacement parts for legacy piping assets in utility-scale water management facilities. In this paper, the goal was to demonstrate 3D printing of stainless steel (SS) 316L parts using selective laser melting (SLM) technology. The corrosion resistance of 3D printed SS 316L was investigated using (a) Chronoamperometry (b) Cyclic Potentiodynamic Polarization (CPP) and Electrochemical Impedance Spectroscopy (EIS) and its improved resistance from wrought (conventional) part was also studied. Then the weldability of 3D printed SS 316L to wrought SS 316L was illustrated and finally, the mechanical strength of the weld and the effect of corrosion on weld strength was investigated using uniaxial tensile testing. The results show that 3D printed part compared to the wrought part has a) lower mass loss before and after corrosion, (b) higher pitting potential, and (c) higher charge transfer resistance. The tensile testing of welded dog bone specimens indicates that the 3D printed parts despite being less ductile were observed to have higher weld strength compared to the wrought part. On this basis, metal AM holds great value to be explored further for replacement piping parts owing to their better corrosion resistance and mechanical performance.
ContributorsSampath, Venkata Krishnan (Author) / Azeredo, Bruno (Thesis advisor) / Torres, Cesar (Committee member) / Mu, Bin (Committee member) / Arizona State University (Publisher)
Created2021
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Description
Lithium-ion batteries are widely used for high energy storage systems and most of the commercially manufactured lithium-ion batteries use liquid electrolytes and polymeric separators. However, these electrolytes and polymeric separators pose safety issues under high temperatures and in the event of short circuit which may lead to thermal runaway and

Lithium-ion batteries are widely used for high energy storage systems and most of the commercially manufactured lithium-ion batteries use liquid electrolytes and polymeric separators. However, these electrolytes and polymeric separators pose safety issues under high temperatures and in the event of short circuit which may lead to thermal runaway and cause fire. The application of fire-retardant high salt concentrated electrolytes can be used to address the safety issues that arises in the use of liquid electrolytes, but these electrolytes have high viscosity and low wettability when used on polymeric separators which are commercially used in lithium-ion batteries. To address this issue, zeolite powder has been synthesized and separators were prepared by coating on the electrode using scalable blade coating method. Zeolite separators have higher wettability and electrolyte uptake compared to polymeric separators such as polypropylene (PP) due to their intra-particle micropores. The zeolite separators also have higher porosity compared to PP separators resulting in higher electrolyte uptake and better electrochemical performance of the lithium-ion batteries. Zeolite separators have been prepared using spherical-silicalite and plate-silicalite to analyze the effect of morphology of the particles on the electrochemical performance of the cells. The platesilicalite separators have higher capacity retention during long-term cycling at low Crates and better capacity performance at high C-rates compared to spherical-silicalite. Therefore plate-silicalite is very promising for the development of high-performance safe lithium-ion batteries.
ContributorsLINGAM MURALI, DHEERAJ RAM (Author) / Lin, Jerry (Thesis advisor) / Muhich, Christopher (Committee member) / Torres, Cesar (Committee member) / Arizona State University (Publisher)
Created2022