Matching Items (13)
Description
Amphipathic molecules consist of hydrophilic and hydrophobic regions, which make them surface-active molecules. The uniqueness of these compounds results in inducing low surface tension and self-assembly of the molecules inside a solvent which have been exploited in personal care, the oil industry and agriculture industry. Amphipathic molecules are also used in the healthcare industry as drug delivery systems and other bio-nanotechnology applications.
In this thesis, a novel series of grafted siloxanes have been explored for their probable application in the healthcare industry. The siloxanes are grafted with poly(ethylene glycol) (PEG) and quaternary ammonium salt (QUAT). The effects of varying 1) molar ratios of QUAT to PEG and 2) PEG chain length on contact angle, surface tension, critical micelle concentration (CMC), and micelle assembly properties were studied. In contact angle experiments, the hydrophilicity of grafted siloxanes increased by grafting PEG and QUAT. The amphiphilicity increases and CMC decreases as the PEG chain length shortens. Adding QUAT also reduces CMC. These trends were observed in surface tension and Isothermal Titration Calorimetry experiments. A change in self-assembly behaviour was also observed in Dynamic Light Scattering experiments upon increasing the PEG chain length and its ratio relative to the quaternary ammonium in the siloxane polymer.
These polymers have also been studied for their probable application as a sensitive 1H NMR spectroscopy indicator of tissue oxygenation (pO2) based on spectroscopic spin-lattice relaxometry. The proton imaging of siloxanes to map tissue oxygenation levels (PISTOL) technique is used to map T1 of siloxane polymer, which is correlated to dynamic changes in tissue pO2 at various locations by a linear relationship between pO2 and 1/T1. The T1-weighted echo spin signals were observed in an initial study of siloxanes using the PISTOL technique.
The change in the ratio of QUAT to PEG and the varying chain length of PEG have a significant effect on the physical property characteristics of siloxane graft copolymers. The conclusions and observations of the present work serve as a benchmark study for further development of adaptive polymers and for the creation of integrated “nanoscale” probes for PISTOL oximetry and drug delivery.
In this thesis, a novel series of grafted siloxanes have been explored for their probable application in the healthcare industry. The siloxanes are grafted with poly(ethylene glycol) (PEG) and quaternary ammonium salt (QUAT). The effects of varying 1) molar ratios of QUAT to PEG and 2) PEG chain length on contact angle, surface tension, critical micelle concentration (CMC), and micelle assembly properties were studied. In contact angle experiments, the hydrophilicity of grafted siloxanes increased by grafting PEG and QUAT. The amphiphilicity increases and CMC decreases as the PEG chain length shortens. Adding QUAT also reduces CMC. These trends were observed in surface tension and Isothermal Titration Calorimetry experiments. A change in self-assembly behaviour was also observed in Dynamic Light Scattering experiments upon increasing the PEG chain length and its ratio relative to the quaternary ammonium in the siloxane polymer.
These polymers have also been studied for their probable application as a sensitive 1H NMR spectroscopy indicator of tissue oxygenation (pO2) based on spectroscopic spin-lattice relaxometry. The proton imaging of siloxanes to map tissue oxygenation levels (PISTOL) technique is used to map T1 of siloxane polymer, which is correlated to dynamic changes in tissue pO2 at various locations by a linear relationship between pO2 and 1/T1. The T1-weighted echo spin signals were observed in an initial study of siloxanes using the PISTOL technique.
The change in the ratio of QUAT to PEG and the varying chain length of PEG have a significant effect on the physical property characteristics of siloxane graft copolymers. The conclusions and observations of the present work serve as a benchmark study for further development of adaptive polymers and for the creation of integrated “nanoscale” probes for PISTOL oximetry and drug delivery.
ContributorsGupta, Srishti (Author) / Green, Matthew D (Thesis advisor) / Kodibagkar, Vikram (Committee member) / Holloway, Julianne (Committee member) / Arizona State University (Publisher)
Created2018
Description
New forms of carbon are being discovered at a rapid rate and prove to be on the frontier of cutting edge technology. Carbon possesses three energetically competitive forms of orbital hybridization, leading to exceptional blends of properties unseen in other materials. Fascinating properties found among carbon allotropes, such as, fullerenes, carbon nanotubes, and graphene have led to new and exciting advancement, with recent applications in defense, energy storage, construction, and electronics. Various combinations of extreme strength, high electrical and thermal conductivity, flexibility, and light weight have led to new durable and flexible display screens, optoelectronics, quantum computing, and strength enhancer coating. The quest for new carbon allotropes and future application persists.
Despite the advances in carbon-based technology, researchers have been limited to sp3 and sp2 hybridizations. While sp3 and sp2 hybridizations of carbon are well established and understood, the simplest sp1 hybridized carbon allotrope, carbyne, has been impossible to synthesize and remains elusive. This dissertation presents recent results in characterizing a new sp1 carbon material produced from using pulsed laser ablation in liquid (PLAL) to ablate a gold surface that is immersed in a carbon rich liquid. The PLAL technique provides access to extremely non-thermal environmental conditions where unexplored chemical reactions occur and can be explored to access the production of new materials. A combination of experimental and theoretical results suggests gold clusters can act as stabilizing agents as they react and adsorb onto the surface of one dimensional carbon chains to form a new class of materials termed “pseudocarbynes”. Data from several characterization techniques, including Raman spectroscopy, UV/VIS spectroscopy, and transmission electron microscopy (TEM), provide evidence for the existence of pseudocarbyne. This completely new material may possess outstanding properties, a trend seen among carbon allotropes, that can further scientific advancements.
Despite the advances in carbon-based technology, researchers have been limited to sp3 and sp2 hybridizations. While sp3 and sp2 hybridizations of carbon are well established and understood, the simplest sp1 hybridized carbon allotrope, carbyne, has been impossible to synthesize and remains elusive. This dissertation presents recent results in characterizing a new sp1 carbon material produced from using pulsed laser ablation in liquid (PLAL) to ablate a gold surface that is immersed in a carbon rich liquid. The PLAL technique provides access to extremely non-thermal environmental conditions where unexplored chemical reactions occur and can be explored to access the production of new materials. A combination of experimental and theoretical results suggests gold clusters can act as stabilizing agents as they react and adsorb onto the surface of one dimensional carbon chains to form a new class of materials termed “pseudocarbynes”. Data from several characterization techniques, including Raman spectroscopy, UV/VIS spectroscopy, and transmission electron microscopy (TEM), provide evidence for the existence of pseudocarbyne. This completely new material may possess outstanding properties, a trend seen among carbon allotropes, that can further scientific advancements.
ContributorsFujikado, Nancy (Author) / Sayres, Scott G (Thesis advisor) / Rege, Kaushal (Thesis advisor) / Green, Matthew D (Committee member) / Arizona State University (Publisher)
Created2018
Description
Pseudo-steady state (PSS) flow is an important time-dependent flow regime that
quickly follows the initial transient flow regime in the constant-rate production of
a closed boundary hydrocarbon reservoir. The characterization of the PSS flow
regime is of importance in describing the reservoir pressure distribution as well as the
productivity index (PI) of the flow regime. The PI describes the production potential
of the well and is often used in fracture optimization and production-rate decline
analysis. In 2016, Chen determined the exact analytical solution for PSS flow of a
fully penetrated vertically fractured well with finite fracture conductivity for reservoirs
of elliptical shape. The present work aimed to expand Chen’s exact analytical solution
to commonly encountered reservoirs geometries including rectangular, rhomboid,
and triangular by introducing respective shape factors generated from extensive
computational modeling studies based on an identical drainage area assumption. The
aforementioned shape factors were generated and characterized as functions for use
in spreadsheet calculations as well as graphical format for simplistic in-field look-up
use. Demonstrative use of the shape factors for over 20 additional simulations showed
high fidelity of the shape factor to accurately predict (mean average percentage error
remained under 1.5 %) the true PSS constant by modulating Chen’s solution for
elliptical reservoirs. The methodology of the shape factor generation lays the ground
work for more extensive and specific shape factors to be generated for cases such as
non-concentric wells and other geometries not studied.
quickly follows the initial transient flow regime in the constant-rate production of
a closed boundary hydrocarbon reservoir. The characterization of the PSS flow
regime is of importance in describing the reservoir pressure distribution as well as the
productivity index (PI) of the flow regime. The PI describes the production potential
of the well and is often used in fracture optimization and production-rate decline
analysis. In 2016, Chen determined the exact analytical solution for PSS flow of a
fully penetrated vertically fractured well with finite fracture conductivity for reservoirs
of elliptical shape. The present work aimed to expand Chen’s exact analytical solution
to commonly encountered reservoirs geometries including rectangular, rhomboid,
and triangular by introducing respective shape factors generated from extensive
computational modeling studies based on an identical drainage area assumption. The
aforementioned shape factors were generated and characterized as functions for use
in spreadsheet calculations as well as graphical format for simplistic in-field look-up
use. Demonstrative use of the shape factors for over 20 additional simulations showed
high fidelity of the shape factor to accurately predict (mean average percentage error
remained under 1.5 %) the true PSS constant by modulating Chen’s solution for
elliptical reservoirs. The methodology of the shape factor generation lays the ground
work for more extensive and specific shape factors to be generated for cases such as
non-concentric wells and other geometries not studied.
ContributorsSharma, Ankush, M.S (Author) / Chen, Kang Ping (Thesis advisor) / Green, Matthew D (Thesis advisor) / Emady, Heather (Committee member) / Arizona State University (Publisher)
Created2017
Description
Microplastics are emerging to be major problem when it comes to water pollution and they pose a great threat to marine life. These materials have the potential to affect a wide range of human population since humans are the major consumers of marine organisms. Microplastics are less than 5 mm in diameter, and can escape from traditional wastewater treatment plant (WWTP) processes and end up in our water sources. Due to their small size, they have a large surface area and can react with chlorine, which it encounters in the final stages of WWTP. After the microplastics accumulate in various bodies of water, they are exposed to sunlight, which contains oxidative ultraviolet (UV) light. Since the microplastics are exposed to oxidants during and after the treatment, there is a strong chance that they will undergo chemical and/or physical changes. The WWTP conditions were replicated in the lab by varying the concentrations of chlorine from 70 to 100 mg/L in increments of 10 mg/L and incubating the samples in chlorine baths for 1–9 days. The chlorinated samples were tested for any structural changes using Raman spectroscopy. High density polyethylene (HDPE), polystyrene (PS), and polypropylene (PP) were treated in chlorine baths and observed for Raman intensity variations, Raman peak shifts, and the formation of new peaks over different exposure times. HDPE responded with a lot of oxidation peaks and shifts of peaks after just one day. For the degradation of semi-crystalline polymers, there was a reduction in crystallinity, as verified by thermal analysis. There was a decrease in the enthalpy of melting as well as the melting temperature with an increase in the exposure time or chlorine concentration, which pointed at the degradation of plastics and bond cleavages. To test the plastic response to
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UV, the samples were exposed to sunlight for up to 210 days and analyzed under Raman spectroscopy. Overall the physical and chemical changes with the polymers are evident and makes a way for the wastewater treatment plant to take necessary steps to capture the microplastics to avoid the release of any kind of degraded microplastics that could affect marine life and the environment.
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UV, the samples were exposed to sunlight for up to 210 days and analyzed under Raman spectroscopy. Overall the physical and chemical changes with the polymers are evident and makes a way for the wastewater treatment plant to take necessary steps to capture the microplastics to avoid the release of any kind of degraded microplastics that could affect marine life and the environment.
ContributorsKelkar, Varun (Author) / Green, Matthew D (Thesis advisor) / Tongay, Sefaattin (Committee member) / Halden, Rolf U. (Committee member) / Arizona State University (Publisher)
Created2017
Description
The natural healing process for bone has multiple signaling cascades where several soluble factors are expressed at specific times to encourage regeneration. Human mesenchymal stromal cells (hMSCs) have three stages of osteogenic differentiation: an increase in cell number (day 1-4), early cell differentiation showing alkaline phosphatase (ALP) expression (day 5-14), and deposition of calcium and phosphate (day 14-28). The first two stages are of particular interest since cell adhesion peptides have been shown to have biological significance during these early stages of bone regeneration. However, far less is known about the temporal dependence of these signals. To mimic these complex systems, developing dynamic biomaterials has become a popular research area over the past decade. Advances in chemistry, materials science, and manufacturing have enabled the development of complex biomaterials that can mimic dynamic cues in the extracellular matrix. One specific area of interest is spatiotemporal control of multiple biomolecules; however, this has generally required diverse chemical approaches making the process difficult and impractical. To circumvent these issues, I developed a novel method that combines a photoresponsive hydrogel with single-stranded DNA to spatiotemporally control multiple biomolecules using a single conjugation scheme.
Here, I describe a detailed protocol to manufacture a fully reversible, spatiotemporal platform using DNA handles. Norbornene-modified hyaluronic acid hydrogels were used to spatially control biomolecule presentation while single-stranded DNA was used to temporally control biomolecule presentation via toehold-mediated strand displacement. This platform was used to orthogonally control the presentation of multiple biomolecules with simple and complex spatial patterning, as well as control the cell morphology of hMSCs by tuning the presentation of the cell adhesion peptide RGDS.
Then, this system was applied to study the temporal presentation of cell adhesion peptides and their effect on early osteogenic differentiation of hMSCs in vitro. The peptides used were RGDS, HAVDI, and OGP. OGP alone expressed higher ALP when presented from day 7-14 than day 0-7 or 0-14. When RGDS, HAVDI, and OGP were combined, there was an increase in ALP activity when HAVDI was presented from day 0-3 indicating that HAVDI plays an important role at earlier time points during osteogenic differentiation.
ContributorsFumasi, Fallon Marie (Author) / Holloway, Julianne L (Thesis advisor) / Stephanopoulos, Nicholas (Committee member) / Green, Matthew D (Committee member) / Stabenfeldt, Sarah E (Committee member) / Acharya, Abhinav (Committee member) / Arizona State University (Publisher)
Created2021
Description
The excessive use of fossil fuels over the last few centuries has led to unprecedented changes in climate and a steady increase in the average surface global temperatures. Direct Air Capture(DAC) aims to capture CO2 directly from the atmosphere and alleviate some of the adverse effects of climate change. This dissertation focuses on methodologies to make advanced functional materials that show good potential to be used as DAC sorbents. Details on sorbent material synthesis and post-synthesis methods to obtain high surface area morphologies are described in detail. First, by incorporating K2CO3 into activated carbon (AC) fiber felts, the sorption kinetics was significantly improved by increasing the surface area of K2CO3 in contact with air. The AC-K2CO3 fiber composite felts are flexible, cheap, easy to manufacture, chemically stable, and show excellent DAC capacity and (de)sorption rates, with stable performance up to ten cycles. The best composite felts collected an average of 478 µmol of CO2 per gram of composite during 4 h of exposure to ambient (24% RH) air that had a CO2 concentration of 400-450 ppm over 10 cycles. Secondly, incorporating the amino acid L-arginine (L-Arg) into a poly(vinyl alcohol) (PVA) nanofiber support structure, created porous substrates with very high surface areas of L-Arg available for CO2 sorption. The bio-inspired PVA-Arg nanofiber composites are flexible and show excellent DAC performance compared to bulk L-Arg. The nanofiber composites are fabricated from an electrospinning process using an aqueous polymer solution. High ambient humidity levels improve sorption performance significantly. The best performing nanofiber composite collected 542 µmol of CO2 per gram of composite during 2 h of exposure to ambient, high humidity (100% RH) air that had a CO2 concentration of 400-450 ppm. Finally, poly(vinyl guanidine) (PVG) polymer was synthesized and tested for sorption performance. The fabrication of PVG nanofibers, divinyl benzene crosslinked PVG beads and glutaraldehyde crosslinked PVG were demonstrated. The sorption performance of the fabricated sorbents were tested with the glutaraldehyde crosslinked PVG having a dynamic sorption capacity of over 1 mmol of CO2 per gram of polymer in 3 h. The sorption capability of liquid PVG was also explored.
ContributorsModayil Korah, Mani (Author) / Green, Matthew D (Thesis advisor) / Lackner, Klaus (Committee member) / Long, Timothy E (Committee member) / Thomas, Marylaura L (Committee member) / Jin, Kailong (Committee member) / Arizona State University (Publisher)
Created2024
Description
Freshwater is becoming more and more scarce, and the need to make use of other water resources is critical. Although processes such as Sea Water Reverse Osmosis (SWRO) exist, these processes are not without drawbacks, such as a brine with a high salt concentration being a byproduct of SWRO. Pervaporation is a potential solution to this problem, however the membranes used in these processes are prone to fouling and the high salt conditions are difficult to work around. Incorporating zwitterions into the polymeric backbone of these membranes has proven to be an effective way to increase fouling resistance. In this work, sulfobetaine – based zwitterions were incorporated into the backbone of poly(arylene ether sulfone) to synthesize sulfobetaine – modified poly(arylene ether sulfone) (SB-PAES) membranes, which were then tested in a cross-flow pervaporation apparatus to analyze salt rejection. SB-PAES membranes were cast with two different methods to create a consistent casting protocol. It was determined that casting solutions with a lower weight percent in petri dishes was optimal, but still needs more exploration. The SB-PAES membranes were tested with feed solutions of pure water and salt solutions with concentrations of 1 g/L, 5 g/L, and 10 g/L. Both 50% and 25% charge SB-PAES membranes were tested. The 50% charge membranes showed good flux and salt rejection over 99.9% for a 10 g/L feed solution, while the 25% charge membranes showed less flux and salt rejection around 85% for a feed solution of 10 g/L.
ContributorsMartin, Adam Lau (Author) / Green, Matthew D (Thesis advisor) / Lind, Mary L (Committee member) / Seo, Soyoung E (Committee member) / Arizona State University (Publisher)
Created2022
Description
CO2 capture from ambient air (often referred to as direct air capture or DAC) is one of the Carbon Dioxide Removal methodologies that may limit Global Warming. High energy demand and high cost are currently serious barriers for large-scale DAC deployments. Moisture-controlled CO2 sorption is a novel technology for DAC, where CO2 sorption cycles are driven solely by changes in surrounding humidity. In contrast to traditional temperature-swing adsorption cycles, water is a cheaper source of exergy than high-grade heat or electricity and moisture-controlled CO2 sorption may reduce the cost of DAC. However, analytic models that describe this sorption system have not been well established, especially in a quantitative manner. In this dissertation the author first establishes both static and kinetic models analytically with bottom-up approaches from the governing equations. These models are of scientific interest and also of industrial importance. They were validated by literature data and custom experiments. In a second part of the dissertation, the author explores the application of moisture-controlled materials in the form of membranes that actively pump CO2 against a concentration gradient. These explorations are guided by the quantitative models developed in the first part of the dissertation. In CO2 separation technologies relying on actively pumping membranes, a moisture-controlled CO2 sorbent is used as either a gas-gas membrane contactor or a gas-liquid membrane contactor. The author experimentally and theoretically determined that a specific commercial anion exchange membrane that was considered a plausible candidate does not satisfy the requirements for such an active membrane as a consequence of its slow kinetics of carbon transport. Requirements for materials to serve as active membranes have been clarified, which is of great interest for industrial application and will provide a starting point for future material design and development.
ContributorsKaneko, Yuta (Author) / Lackner, Klaus S (Thesis advisor) / Green, Matthew D (Thesis advisor) / Dirks, Gary W (Committee member) / Wade, Jennifer L (Committee member) / Freeman, Benny D (Committee member) / Arizona State University (Publisher)
Created2022
Description
Zwitterionic polymers, due to their supurior capability of electrostatically induced hydration, have been considered as effective functionalities to alleviate bio-fouling of reverse osmosis (RO) membranes. Bulk modification of polysulfone-based matrices to improve hydrophilicity, on the other hand, is favored due to the high membrane performance, processibility, and intrinsic chlorine resistance. Here a novel synthetic method was demonstrated to prepare zwitterionic poly(arylene ether sulfone) (PAES) copolymers, which was blended with native polysulfone (PSf) to fabricate free-standing asymmetric membranes via non-solvent induced phase separation process. Both the porosity of the support layer and surface hydrophilicity increased drastically due to the incorporation of zwitterion functionalities in the rigid polysulfone matrix. The water permeance and antifouling ability of the blend membranes were both remarkably improved to 2.5 Lm−2 h−1 bar−1 and 94% of flux recovery ratio, respectively, while salt rejection remained at a high level (98%) even under the high exposure to chlorine (8,000 ppm•h). Besides the preliminary blended membrane design, for the future membrane property enhancement, this dissertation also focused on polymer structure optimizations via elucidating the fundamentals from two perspectives: 1). Synthetic reaction kinetics and mechanisms on polycondensation of PAES. Interestingly, in combination of experiments and the computational calculations by density functional theory (DFT) methods in this work, only the aryl chlorides (ArCl) monomer follows the classical second-order reaction kinetics of aromatic nucleophilic substitution (SNAr) mechanism, while the kinetics of the aryl fluorides (ArF) reaction fit a third-order rate law. The third order reaction behavior of the ArF monomer is attributed to the activation of the carbon-fluorine bond by two potassium cations (at least one bounded to phenolate), which associate as a strong three-body complex. This complex acts as the predominant reactant during the attack by the nucleophile. 2). Optimized copolymer structures were developed for controlled high molecular weight (Mw ~ 65 kDa) and zwitterionic charge content (0~100 mol%), via off-set stoichiometry during polycondensations, following with thiol-ene click reaction and ring-opening of sultone to introduce the sulfobetaine functional groups. The structure-property-morphology relationships were elucidated for better understanding atomic-level features in the charged polymers for future high-performance desalination applications.
ContributorsYang, Yi, Ph.D (Author) / Green, Matthew D (Thesis advisor) / Lin, Jerry Y.S. (Committee member) / Lind, Marylaura (Committee member) / Perreault, Francois (Committee member) / Deng, Shuguang (Committee member) / Arizona State University (Publisher)
Created2019
Description
An evolving understanding of elastomeric polymer nanocomposites continues to expand commercial, defense, and industrial products and applications. This work explores the thermomechanical properties of elastomeric nanocomposites prepared from bisphenol A diglycidyl ether (BADGE) and three amine-terminated poly(propylene oxides) (Jeffamines). The Jeffamines investigated include difunctional crosslinkers with molecular weights of 2,000 and 4,000 g/mol and a trifunctional crosslinker with a molecular weight of 3,000 g/mol. Additionally, carbon nanotubes (CNTs) were added, up to 1.25 wt%, to each thermoset. The findings indicate that the Tg and storage modulus of the polymer nanocomposites can be controlled independently within narrow concentration windows, and that effects observed following CNT incorporation are dependent on the crosslinker molecular weight.
Polymer matrix composites (PMCs) offer design solutions to produce smart sensing, conductive, or high performance composites for a number of critical applications. Nanoparticle additives, in particular, carbon nanotubes and metallic quantum dots, have been investigated for their ability to improve the conductivity, thermal stability, and mechanical strength of traditional composites. Herein we report the use of quantum dots (QDs) and fluorescently labeled carbon nanotubes (CNTs) to modify the thermomechanical properties of PMCs. Additionally, we find that pronounced changes in fluorescence emerge following plastic deformation, indicating that in these polymeric materials the transduction of mechanical force into the fluorescence occurs in response to mechanical activation.
Segmented ionenes are a class of thermoplastic elastomers that contain a permanent charged group within the polymer backbone and a spacer segment with a low glass transition temperature (Tg) to provide flexibility. Ionenes are of interest because of their synthetic versatility, unique morphologies, and ionic nature. Using phase changing ionene-based nanocomposites could be extended to create reversible mechanically, electrically, optically, and/or thermally responsive materials depending on constituent nanoparticles and polymers. This talk will discuss recent efforts to utilize the synthetic versatility of ionenes (e.g., spacer composition of PTMO or PEG) to prepare percolated ionic domains in microphase separated polymers that display a range of thermomechanical properties. Furthermore, by synthesizing two series of ionene copolymers with either PEG or PTMO spacers at various ratios with 1,12-dibromododecane will yield a range of ion contents (hard contents) and will impact nanoparticle dispersion.
Polymer matrix composites (PMCs) offer design solutions to produce smart sensing, conductive, or high performance composites for a number of critical applications. Nanoparticle additives, in particular, carbon nanotubes and metallic quantum dots, have been investigated for their ability to improve the conductivity, thermal stability, and mechanical strength of traditional composites. Herein we report the use of quantum dots (QDs) and fluorescently labeled carbon nanotubes (CNTs) to modify the thermomechanical properties of PMCs. Additionally, we find that pronounced changes in fluorescence emerge following plastic deformation, indicating that in these polymeric materials the transduction of mechanical force into the fluorescence occurs in response to mechanical activation.
Segmented ionenes are a class of thermoplastic elastomers that contain a permanent charged group within the polymer backbone and a spacer segment with a low glass transition temperature (Tg) to provide flexibility. Ionenes are of interest because of their synthetic versatility, unique morphologies, and ionic nature. Using phase changing ionene-based nanocomposites could be extended to create reversible mechanically, electrically, optically, and/or thermally responsive materials depending on constituent nanoparticles and polymers. This talk will discuss recent efforts to utilize the synthetic versatility of ionenes (e.g., spacer composition of PTMO or PEG) to prepare percolated ionic domains in microphase separated polymers that display a range of thermomechanical properties. Furthermore, by synthesizing two series of ionene copolymers with either PEG or PTMO spacers at various ratios with 1,12-dibromododecane will yield a range of ion contents (hard contents) and will impact nanoparticle dispersion.
ContributorsWang, Meng, Ph.D (Author) / Green, Matthew D (Thesis advisor) / Green, Alexander (Committee member) / Yarger, Jeffery (Committee member) / Arizona State University (Publisher)
Created2019