The scope of this work is to fathom different possibilities to create functional coatings with polymer brushes. The immobilization of nanoparticles and enzymes is investigated, as well as the affection of their properties by the stimuli-responsiveness of the brushes. Another aspect is the coating of 3D-nanostructures by polymer brushes and the investigation of the resulting functional properties of the hybrid material. The polymer brush coatings are characterized by a variety of microscopic and spectroscopic techniques, with a special emphasis on the establishment of the combinatorial quartz crystal microbalance/spectroscopic ellipsometry technique as a tool to characterize the functional properties of the polymer brush systems insitu. The pH-responsive swelling of the polyelectrolyte brushes poly(acrylic acid) and poly(2-vinylpyridine), as well as the thermoresponsive swelling of poly(N-isopropylacryl amide) is studied in detail by this technique. Poly(2-vinylpyridine) and binary poly(N-isopropylacryl amide)-poly (2-vinylpyridine) brushes are used as templates for the insitu-synthesis of palladium and platinum nanoparticles with catalytic activity. As an example for the use of polymer brushes to immobilize enzymes, the model enzyme glucose oxidase is physically adsorbed to poly (2-vinylpyridine) and poly (acrylic acid) brushes and also covalently bound to poly (acrylic acid) brushes. In the last part of this thesis, sculptured thin films are coated with poly (acrylic acid) and poly (N-isopropylacryl amide) brushes and the swelling characteristics as well as the adsorption behavior of the model protein bovine serum albumin are investigated.

Im Rahmen dieser Arbeit wurden für die Herstellung neuartiger funktioneller Oberflächenbeschichtungen Polymerbürstensysteme basierend auf linearen, thermoresponsiven Poly-2-oxazolinen (POX) entwickelt und ausführlich charakterisiert. Als Grundbaustein für die Herstellung von POX-Bürsten wurden drei endfunktionalisierte thermoresponsive POX mittels kationisch ringöffnender Polymerisation synthetisiert, wobei jeweils 2-Cyclopropyl-2-oxazolin (cPrOX) als thermoresponsive Wiederholungseinheit und 2-Methyl-2-oxazolin (MeOX) als hydrophiles Comonomer zu verschiedenen Anteilen verwendet wurden. Mittels VIS-spektroskopischen Trübungsmessungen wurde für alle POX in Wasser ein LCST-Entmischungsverhalten mit einem reversiblen und scharfen Phasenübergang nachgewiesen, wobei die Trübungstemperaturen stark von der Polymerhydrophilie sowie der Molmasse und der Polymerkonzentration in Lösung abhingen. Die Herstellung der POX-Polymerbürsten auf der Basis der synthetisierten POX erfolgte über einen „grafting to“-Ansatz, bei welchem die Polymere in einem thermisch initiierten Prozess über ein funktionalisiertes Kettenende kovalent an ein Substrat angebunden wurden. Als Hauptmethode zur Charakterisierung der physikochemischen Eigenschaften der hergestellten Schichten, insbesondere deren temperaturabhängiges Schaltverhalten in Wasser, wurde spektroskopische Ellipsometrie verwendet. Zusätzlich kamen Rasterkraftmikroskopie, Kontaktwinkel und Quarzkristallmikrowaage mit Dissipationsaufzeichnung zum Einsatz. Im Gegensatz zum sehr scharfen, diskontinuierlichen Phasenübergang der POX in Lösung konnte für alle POX-Bürsten ein kontinuierlicher Übergang von einem gestreckten Bürstenzustand bei niedrigen Temperaturen in einen kollabierten Zustand bei hohen Temperaturen bestimmt werden, wobei das Quellvermögen und die temperaturabhängigen Quellkurvenverläufe durch die Polymereigenschaften und die Bürstenparameter beeinflussbar waren. Durch die Kombination eines POX mit Polyacrylsäure (PAA) als zweite Komponente konnten zudem neuartige binäre Polymerbürstensysteme hergestellt werden, welche ein komplexes pH- und temperaturabhängiges Schaltverhalten sowie ein steuerbares Proteinadsorptionsvermögen in Abhängigkeit von der Bürstenpräparationsmethodik, der POX-PAA-Zusammensetzung sowie der Temperatur und dem pH-Wert der umgebenden Pufferlösung aufwiesen. Zur ausführlichen Charakterisierung der Schichteigenschaften wurde neben den bereits benannten Methoden der spektroskopischen Ellipsometrie, Rasterkraftmikroskopie und der Kontaktwinkelmessung auch Röntgenphotoelektronenspektroskopie genutzt. Abschließende Zelladhäsionsexperimente mit humanen mesenchymalen Stammzellen auf den bürstenmodifizierte Oberflächen unter physiologischen Bedingungen offenbarten deutliche Unterschiede in der Affinität der Zellen zur Adhäsion auf POX-Homopolymerbürsten in Abhängigkeit der Bürstenhydrophilie. Darüber hinaus konnte die Zelladhäsion auch auf POX-PAA-Mischbürstensystemen gesteuert werden.

abstract: One of the major issues confronting education in Arizona and across the United States has been the consistent low performance of culturally and linguistically diverse (CLD) students in comparison to their peers as evidenced by the disparity of the achievement gap at every level in the educational pipeline. A contributing factor has been the lack of teacher preparation focused on teaching CLD students. Preparation focused on a culturally responsive curriculum about dispositions and pedagogical knowledge and skills as well as field experience placement with CLD students have been previously identified areas to consider when training preservice teachers (PSTs). Therefore, this study examined how a Culturally Responsive and Linguistic Teaching (CRLT) Framework would raise preservice teacher’s critical consciousness about teaching CLD students. The CRLT Framework focused on two specific areas; (a) a culturally responsive curriculum and (b) a team-based service-learning experience. The CRP curriculum included lessons designed to increase PSTs understanding about how their sociolinguist views influenced their pedagogical knowledge about teaching CLD students. In addition, the team-based service-learning approach, as a community of practice, provided experiences for PSTs to apply theory to practice. A mixed method analysis was employed to collect and analyze the quantitative data (surveys) and qualitative data (interviews and photovoice). Results from this study suggested increases in PSTs’ knowledge, self-efficacy, and perceptions of usefulness of CRP in their future practices. The team-based, service-learning component, which was based on a community of practice framework, enhanced the learning experience by allowing students to move from theory to practice and served as an important contributing factor to the overall results. Given the findings of this research study, it appeared that an introductory course focused on a culturally responsive and linguistic teaching influenced PSTs’ dispositions, knowledge, and skills. Thus, providing an introductory course, earlier rather than later, has the potential to change the trajectory of preparing PSTs so they were more prepared to teach CLD students as they continued through their program of study. Results showed effective work with CLD students was about so much more than ‘just good teaching.’ / Dissertation/Thesis / Doctoral Dissertation Educational Leadership and Policy Studies 2019

The @lab is a group dedicated to the research and development of electronic textiles for architectural applications; this thesis presents the structural analyses performed by the author to improve the @lab’s projects. Also included are three investigations performed by the author that pertain to smart material applications in responsive architecture and textiles. The first investigation evaluated the feasibility of using piezoelectric materials to harvest power from human foot traffic; overall, it was determined to not be feasible. The second investigation experimentally tested how six parameters of shape memory alloy spring actuators affect their reaction times and stroke; all six parameters affected the reaction times and/or stroke. The third investigation experimentally tested how three parameters of superelastic SMA springs influence their stiffness and resonant frequencies; overall, it was found that traditional spring mechanics can be used to predict their behavior providing the internal stress does not reach the upper plateau stress.

In many ways, traditional arts in schools bear the bruises of the early years of multicultural education, and the failed practices that created what has been termed a tourist curriculum, comprised of the superficial study of folktales, festivals, foods, and facts. Consequently, the use of art forms of cultures is often approached with caution by teachers, or avoided altogether. This thesis re-frames the use of traditional arts in the classroom through current research and knowledge, defining their efficacy and role in today’s classroom. Traditional arts are examined through the lenses of arts integration, culturally responsive pedagogical practice and creative processes. A qualitative, research portraiture methodology was employed, and executed through the lens of four case studies in order to more coherently incorporate the arts-based nature of this research. The research sites include classes studying Maori visual arts, waiata (song), and haka (dance) in Christchurch, New Zealand, chant, hula, and plant weaving at an Hawaiian charter school, and social dance and song of the Oneida tribe in the US. Research results indicated that when teachers facilitate experiences in traditional arts in such a way that students are exposed to entry points for their own interaction with the forms, students respond with self reflection, engagement, and a tendency to elevate the status of affiliation with the culture undertaken. While students and teachers do not become conversant in the culture as a result of such study, working with traditional arts in this way may serve to break down culturally bound ways of seeing the world. When traditional arts are employed in classrooms, they may engage students in a creative process that takes the form of embodied or physicalized, interpretive, or improvisational interactions with the forms. When traditional arts are employed in this way, relying on creative process, they also meet goals for culturally responsive learning, legitimizing how students experience and make sense of the world. Traditional arts provide a critical, under-utilized, strategy for embedding culture in the educational setting. In order to best meet the goals of the learning setting, traditional arts must incorporate creative processes. Hybridization of the forms, while increasing accessibility for teachers and students, must be carefully undertaken. Traditional arts utilized in this way hold potential for addressing broader curricular content.

abstract: Polymer-gold composite particles are of tremendous research interests. Contributed by their unique structures, these particles demonstrate superior properties for optical, catalytic and electrical applications. Moreover, the incorporation of “smart” polymers into polymer-gold composite particles enables the composite particles synergistically respond to environment-stimuli like temperature, pH and light with promising applications in multiple areas. A novel Pickering emulsion polymerization route is found for synthesis of core-shell structured polymer-gold composite particles. It is found that the surface coverage of gold nanoparticles (AuNP) on a polystyrene core is influenced by gold nanoparticle concentration and hydrophobicity. More importantly, the absorption wavelength of polystyrene-gold composite particles is tunable by adjusting AuNP interparticle distance. Further, core-shell structured polystyrene-gold composite particles demonstrate excellent catalyst recyclability. Asymmetric polystyrene-gold composite particles are successfully synthesized via seeded emulsion polymerization, where AuNPs serve as seeds, allowing the growth of styrene monomers/oligomers on them. These particles also demonstrate excellent catalyst recyclability. Further, monomers of “smart” polymers, poly (N-isopropylacrylamide) (PNIPAm), are successfully copolymerized into asymmetric composite particles, enabling these particles’ thermo-responsiveness with significant size variation around lower critical solution temperature (LCST) of 31°C. The significant size variation gives rise to switchable scattering intensity property, demonstrating potential applications in intensity-based optical sensing. Multipetal and dumbbell structured gold-polystyrene composite particles are also successfully synthesized via seeded emulsion polymerization. It is intriguing to observe that by controlling reaction time and AuNP size, tetrapetal-structured, tripetal-structured and dumbbell-structured gold-polystyrene are obtained. Further, “smart” PNIPAm polymers are successfully copolymerized into dumbbell-shaped particles, showing significant size variation around LCST. Self-modulated catalytic activity around LCST is achieved for these particles. It is hypothesized that above LCST, the significant shrinkage of particles limits diffusion of reaction molecules to the surface of AuNPs, giving a reduced catalytic activity. Finally, carbon black (CB) particles are successfully employed for synthesis of core- shell PNIPAm/polystyrene-CB particles. The thermo-responsive absorption characteristics of PNIPAm/polystyrene-CB particles enable them potentially suitable to serve as “smart” nanofluids with self-controlled temperature. Compared to AuNPs, CB particles provide desirable performance here, because they show no plasmon resonance in visible wavelength range, whereas AuNPs’ absorption in the visible wavelength range is undesirable. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2015

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No description available.

The scope of this work is to fathom different possibilities to create functional coatings with polymer brushes. The immobilization of nanoparticles and enzymes is investigated, as well as the affection of their properties by the stimuli-responsiveness of the brushes. Another aspect is the coating of 3D-nanostructures by polymer brushes and the investigation of the resulting functional properties of the hybrid material. The polymer brush coatings are characterized by a variety of microscopic and spectroscopic techniques, with a special emphasis on the establishment of the combinatorial quartz crystal microbalance/spectroscopic ellipsometry technique as a tool to characterize the functional properties of the polymer brush systems insitu. The pH-responsive swelling of the polyelectrolyte brushes poly(acrylic acid) and poly(2-vinylpyridine), as well as the thermoresponsive swelling of poly(N-isopropylacryl amide) is studied in detail by this technique. Poly(2-vinylpyridine) and binary poly(N-isopropylacryl amide)-poly (2-vinylpyridine) brushes are used as templates for the insitu-synthesis of palladium and platinum nanoparticles with catalytic activity. As an example for the use of polymer brushes to immobilize enzymes, the model enzyme glucose oxidase is physically adsorbed to poly (2-vinylpyridine) and poly (acrylic acid) brushes and also covalently bound to poly (acrylic acid) brushes. In the last part of this thesis, sculptured thin films are coated with poly (acrylic acid) and poly (N-isopropylacryl amide) brushes and the swelling characteristics as well as the adsorption behavior of the model protein bovine serum albumin are investigated.

No description available.