Дисертації з теми "Macromolecular materials"
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Zhang, Borui. "Novel Dynamic Materials Tailored by Macromolecular Engineering." Miami University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=miami1564157701522666.
Повний текст джерелаReinsel, Anna Michele. "Spectroscopic Characterization of Organic and Inorganic Macromolecular Materials." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1312823530.
Повний текст джерелаEden, E. G. "Analysis of solution-phase macromolecular materials by diffusion NMR." Thesis, University of Liverpool, 2017. http://livrepository.liverpool.ac.uk/3006567/.
Повний текст джерелаKuttner, Christian [Verfasser]. "Macromolecular Interphases and Interfaces in Composite Materials / Christian Kuttner." München : Verlag Dr. Hut, 2014. http://d-nb.info/1063222036/34.
Повний текст джерелаPrice, Erik Joshua. "EXTREME-ENVIRONMENT PROTECTION USING MACROMOLECULAR COMPOSITE TECHNOLOGY." Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1617027732923331.
Повний текст джерелаMohin, Jacob W. "Nanostructured π-Electron Materials for Energy Applications Derived from Macromolecular Self-Assembly". Research Showcase @ CMU, 2015. http://repository.cmu.edu/dissertations/1045.
Повний текст джерелаStimson, Lorna M. "Phase behaviour of macromolecular liquid crystalline materials : computational studies at the molecular level." Thesis, Durham University, 2003. http://etheses.dur.ac.uk/3144/.
Повний текст джерелаDe, Alwis Watuthanthrige Nethmi Thanurika. "Application of Photochemistry and Dynamic Chemistry in Designing Materials tuned through Macromolecular Architecture." Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1626694956739651.
Повний текст джерелаZang, Xu. "Encapsulation of Proteinaceous materials in Macromolecular Organic Matter as a mechanism for environmental preservation /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486400446370061.
Повний текст джерелаStark, Andreas. "Advancement and optimization of an electrospray injection based in-vacuum patterning system for macromolecular materials." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002534.
Повний текст джерелаAcosta, Sullcahuamán Julio Arnaldo. "Fractura de materiales poliméricos a altas velocidades de solicitación." Doctoral thesis, Universitat Politècnica de Catalunya, 2001. http://hdl.handle.net/10803/6034.
Повний текст джерелаComo resultado y según la orientación del objetivo de la Tesis, se proponen dos metodologías de ensayo de impacto de baja energía: flexión por impacto de baja energía e indentación por impacto. Asimismo, cada metodología incluye el diseño de un "modelo" que permite una aproximación al fenómeno de impacto de baja energía en las geometrías de flexión e indentación respectivamente.
Se ha verificado la validez de los mencionados modelos en el estudio del comportamiento mecánico del polimetilmetacrilato, poliestireno y compuestos de poliestireno y microesferas de vidrio. Las técnicas de impacto de baja energía aplicadas según las metodologías de ensayo propuestas fueron apropiadas y permitieron evaluar la respuesta de estos materiales en el campo elástico, determinar sus características elásticas a elevadas velocidades, así como estimar el inicio del daño en los mismos. Los resultados de estos ensayos, tanto el módulo elástico como las tensiones a las cuales comienzan los fenómenos de emblanquecimiento, crazing y rotura, fueron interpretados según los modelos propuestos. Finalmente, por extensión, las metodologías y modelos propuestos son válidos y apropiados para el estudio de los plásticos, cuando menos similares a los estudiados.
Este trabajo se ha estructurado en concordancia con la metodología utilizada en la investigación correspondiente. Así, en el primer capítulo se ha hecho una revisión sobre los temas afines a la tesis, desde sus aspectos conceptuales hasta los más avanzados; para examinar la evolución y el estado actual del tema en cuestión y precisar los conocimientos que sirvan de base a esta investigación. En el segundo capítulo se describen las características generales y particulares de los materiales sometidos a estudio experimental. En el tercer capítulo se exponen los métodos de ensayo utilizados y las herramientas experimentales necesarias para su realización.
Finalmente, antes de exponer las conclusiones, fue de rigor abordar un cuarto capítulo referido a la flexión por impacto de baja energía y otro quinto capítulo similar que versa sobre la indentación por impacto, para la presentación, interpretación y análisis de resultados, así como la correspondiente discusión.
This work is situated in a perspective highlighted by two inputs of inspiration and exigency, that complement each other: the first input is related with the technology field, and the second comes from a scientific field. On one hand, it is known that plastic products and composites of polymeric matrix are used increasingly in the engineering industry, and as many of the materials used in this field, they are usually exposed to dynamic charges.
Therefore, it is necessary the study of their properties like the development of methods and tests to be able to characterize them under different conditions of charge applications, being of special interest to know the results at high speeds. On the other hand, from the material science point of view, the relation between the structure and the behavior of fracture of the polymers is one of the most important subjects, in which the impact tests play a fundamental role. The knowledge of fracture behavior, in terms of science of the materials, requires a group of additional techniques in order to supply (theoretically and experimentally) the basic impact test methods specified by the normalization entities. In this sense, the principal objective of this thesis is the design and development of test techniques for the study of the fracture of polymers at high speeds of solicitation and in the domain of low energy.
As a result and based in the objective of this thesis, it is proposed two methods of test for impact of low energy: flexion by impact of low energy and indentation by impact. In the same way, every methodology includes the design of a "model" that allows an approximation for the phenomenon of impact of low energy in the geometric of flexion and indentation, respectively. The validity of the models mentioned above in the study of the mechanic behavior of the polymethylmetacrilate, polystyrene and polystyrene filled with different percentages of glass beads has been verified. The techniques for impact of low energy applied according to the methodology of proposed test were appropriate and allowed to evaluate the response of these materials in the elastic field, to determine its elastic characteristics at high speeds, and to estimate the initial damage of components. The results of these tests, likewise the elastic module and the tensions at which begin the whitening phenomena, crazing and rupture, where interpreted according to the proposed models.
Finally, per extension, the methodology and proposed methods are valid and appropriate for the study of plastics, at least similar to the ones studied.
This work has been structured in accordance with the methodology utilized in the correspondent investigation. Thus, in the first chapter, a revision of the subjects corresponding to the thesis were made, from its conceptual aspects to the more advanced, in order to examine the evolution and estate of the actual subject in question and precise the knowledge that can be use as a base for this investigation. In the second chapter, the general and particular characteristics of the materials submitted to the experimental studies are described. In the third chapter the methods of test utilized and the necessary experimental tools for its realization are exposed.
Finally, before the conclusions are presented, it was consistent to add a fourth chapter that refers to the flexion by impact, and another fifth chapter similar that contains the indentation by impact for the presentation, interpretation and analysis of results, and the related discussion.
Lenart, William R. "EXPANDING EXPERIMENTAL AND ANALYTICAL TECHNIQUES FOR THE CHARACTERIZATION OF MACROMOLECULAR STRUCTURES." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1584358701735061.
Повний текст джерелаCarrillo, Navarrete Fernando. "Caracterización estructural de fibras lyocell y su comportamiento frente a procesos de degradación." Doctoral thesis, Universitat Politècnica de Catalunya, 2002. http://hdl.handle.net/10803/6428.
Повний текст джерелаDebido a la reciente aparición de las fibras de lyocell en el mercado, se han suscitado una serie de incógnitas respecto tanto de su estructura como de su comportamiento en las condiciones de trabajo y/o utilización. Por esta razón, el objetivo del presente trabajo es el de contribuir a un mejor conocimiento sobre su estructura y evaluar su comportamiento frente a la acción de diversos tratamientos: absorción de colorantes, acción enzimática y fibrilación.
En el capítulo II, se ha realizado la caracterización estructural de la fibra de lyocell, mediante las técnicas de espectroscopía infrarroja por transformada de Fourier (FT-IR) y análisis térmico por calorimetría diferencial (DSC) y termogravimetría (TG). Las bandas de absorción FT-IR indican que la fibra de lyocell está formada principalmente por celulosa cristalizada II y celulosa amorfa y que la fibra de lyocell presenta mayor cristalinidad que las fibras de celulosa regenerada tradicionales. Por otra parte, el análisis térmico demuestra que la fibra de lyocell es térmicamente más estable que la fibras de celulosa regenerada obtenidas por el proceso tradicional del xantato de celulosa.
En el capítulo III, se ha caracterizado la influencia de la estructura de la fibra en el rendimiento de absorción del colorante directo C.I. direct blue 1, mediante el estudio de las isotermas de equilibrio, estimándose el valor del volumen libre característico de la fibra lyocell. También se han calculado las magnitudes termodinámicas que gobiernan el proceso de absorción. Los resultados indican que la fibra de lyocell presenta una menor estabilidad de los enlaces colorante/fibra que las fibras de celulosa regenerada tradicionales, como consecuencia de su mayor cristalinidad. Además, se ha desarrollado un modelo de absorción que reproduce los resultados experimentales satisfactoriamente.
Por otra parte, en el capítulo IV, se han determinado las cinéticas de hidrólisis enzimática con celulasas de las fibras de lyocell. A partir de estos resultados se han calculado los parámetros cinéticos característicos de la hidrólisis, comparándolos con los obtenidos para las fibras de modal y viscosa de referencia. Del estudio se destaca la menor velocidad de hidrólisis obtenida para las fibras de lyocell, lo que constata la presencia de una estructura de celulosa menos degradable.
Finalmente, en el capítulo V, se ha evaluado la influencia de los tratamientos industriales de fibrilación y desfibrilación enzimáticos en las propiedades mecánicas (curvas carga/alargamiento), morfológicas (microscopía electrónica), estructurales (FT-IR), de accesibilidad (absorción de colorantes) y reactividad (hidrólisis enzimática). El tratamiento de fibrilación produce una extensa fibrilación sobre la superficie de las fibras, mientras que un gran número de estas fibrillas son eliminadas posteriormente durante la etapa de desfibrilación enzimática. Ambos tratamientos disminuyen significativamente las propiedades de resistencia mecánica, aunque en el tratamiento con enzimas la reducción es más intensa debido a la especificidad de la hidrólisis catalítica. Los tratamientos mejoran la accesibilidad y reactividad del sustrato, debido al incremento de la superficie específica de la fibra provocado durante la fibrilación, aunque los resultados indican que se produce una descristalización de la estructura por transformación de la celulosa cristalizada II a celulosa amorfa.
Castiglione, Andrea. "Liquid crystalline macromolecular architectures based on regioregular poly(3-alkylthiophene) as backbone and calamitic mesogens as side-groups : towards ambipolar materials." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066693.
Повний текст джерелаVery recently ambipolar organic semi-conductors (OSC) have gaining attention for their potential use in numerous technologically relevant applications. Representative technological examples are the area of organic microelectronics where patterning of p- and n-channel semiconductors is one of the major hurdles for the implantation of OSC in organic complementary logic circuit. To achieve this objective, well-ordered ambipolar semiconducting materials are needed. In this work we investigated the self-organization and the electronic properties of a series of side chain liquid crystal (SCLC) semiconducting polymers where: (i) the backbone is a π-conjugated polymer and (ii) the side-groups are π-conjugated calamitic mesogens. We present our results on the design, synthesis, and structural characterization of this new liquid crystal regioregular poly(3-alkylthiophene) polymer family post-functionalized with side-on calamitic moieties. The parameters of these materials are: (i) the chemical nature of the side-group moieties and (ii) the degree of polymerization. As a result we will show that this strategy leads to the supramolecular self-assembly of this SCLC semiconducting polymer in a peculiar lamello-lamellar mesophase, where the two different lamellas present two different electronic properties, such as electron donor and electron acceptor behaviors
Etok, S. E. "Structural characterisation and in vitro behaviour of apatite coatings and powders." Thesis, Faculty of Medicine and Biosciences, 2009. http://hdl.handle.net/1826/3973.
Повний текст джерелаEtok, Susan Essien. "Structural characterisation and in vitro behaviour of apatite coatings and powders." Thesis, Cranfield University, 2005. http://dspace.lib.cranfield.ac.uk/handle/1826/3973.
Повний текст джерелаSandouk-Lincke, Nadia Anna Al [Verfasser]. "Application of advanced pyrolysis for the analysis of biogeochemically and environmentally significant macromolecular organic materials : microfossils, macerals and drilling fluid additives / Nadia Anna Al Sandouk-Lincke." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2015. http://d-nb.info/1073885941/34.
Повний текст джерелаXiao, Yiming. "Engineering, Synthesis and Characterization of New - π Conjugated (Macro)molecular Architectures for Organic Optoelectronics : application toward ambipolar materials". Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066638/document.
Повний текст джерелаIn the general field of organic electronics, including Organic Photovoltaic (OPV), Organic Light-Emitting Diode (OLED) and Organic Field-Effect Transistor (OFET), the interest for the ambipolar organic materials have increased remarkably during the recent years.In this context, we were interested, in this present work, in designing and preparing different new self-organized semiconducting architectures in which it could be possible to inject and transport both holes and electrons. Our approach is based on liquid crystalline (LC) materials incorporating different kinds of electron-donor (p-type) and electron acceptor (n-type) π-conjugated systems in a unique molecular or macromolecular architecture. Thus, we synthesized and characterized different series of organic semiconductors such as donor-σ-acceptor discotic LC dyads and triads, donor-σ-acceptor calamitic LC dyads, and donor-σ-acceptor side-chain LC polymers bearing discotic side-groups. Their thermal behaviors, optical and electronic properties, self-organization properties both in bulk and in thin films, and finally charge transport properties are presented and discussed.Based on different characterization techniques, we demonstrated that all these series of materials present liquid crystalline properties in self-organizing in different structure such as columnar, lamellar, and lamella-columnar organizations. More particularly, these materials exhibit spontaneous nanosegregation of p-type and n-type entities in bulk, leading to well defined distinct conductive channels for each type of charge carriers as evidenced by the preliminary ambipolar charge transport properties observed by Time-of-flight and Field effect transistor measurements
Shebani, Anour N. "The effect of wood composition and compatibilisers on polyethylene/wood fibre composites." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5270.
Повний текст джерелаENGLISH ABSTRACT: The effects of the macromolecular composition and content of different wood species on the properties of wood-polymer composites (WPCs) achieved when using poly(vinyl alcohol-co-ethylene) (EVOH) as a compatibiliser and linear low density polyethylene (LLDPE) as a matrix, were investigated. Four wood different species (A. cyclops (acacia), E. grandis (eucalyptus), P. radiata (pine) and Q. alba (oak)) with different macromolecular composition and contents and average particle lengths were used. WPCs filled with these species and WPCs filled with the same species but without extractives were prepared using 10% wood content and different amounts (0, 2, 5, 7 and 10%) of EVOH. An EVOH content of 7% was found to be optimum. Unextracted woods produced WPCs with higher mechanical properties and better resistance to ultraviolet (UV) degradation, while the extracted woods produced WPCs with lower water absorption (WA) rates and better thermal stability. Use of unextracted A. cyclops resulted in composites with superior mechanical and thermal properties compared with the other unextracted species, most probably due to its higher cellulose and lignin contents and a favourable average wood particle length (0.225 mm). A. cyclops composites also had higher WA and thickness swelling (TS) rates most likely due to the greater number of free hydroxyl groups present in these composites because of higher cellulose content. Composites containing wood species with a high lignin and extractive content, such as A. cyclops and Q. alba, exhibited higher resistance to UV degradation. Poly(vinyl alcohol-co-ethylenes) (EVOHs) with different ethylene content (27, 32, 38 and 44%) and A. cyclops with different particle sizes (180, 250 and 450 ìm) were used to prepare WPCs with 10% A. cyclops content. The effect of the contact area between the A. cyclops particles and LLDPE achieved when using EVOHs as compatibilisers on the properties of WPCs was also investigated. The greatest improvements in the mechanical and thermal properties of composites made with A. cyclops with particle size 180 ìm were obtained when EVOH with 44% ethylene content was used. The greatest improvements in the composites made with A. cyclops with particle size 250 ìm were achieved when EVOH with 38% ethylene content was used. Composites made with A. cyclops with particle size 450 ìm exhibited better properties when EVOH with 27% ethylene content was used. All the composites that had better mechanical and thermal properties, also exhibited better compatibility and interface adhesion. Two successful approaches were used to impart more attractive ecological and economical advantages to WPCs. In the first approach, (0, 2, 5 and 7%) degraded LLDPE was used as a compatibiliser in WPCs at levels of 10, 30 and 50% wood content. The resulting mechanical properties, such as tensile strength and hardness, thermal and morphological properties of the compatibilised composites were slightly higher than those of noncompatibilised composites and virgin LLDPE. Elongation at break and impact properties of the compatibilised composites were lower than in virgin LLDPE, but higher than in noncompatibilised composites. In the second approach, polyethylene (PE) and various functionalised polyethylenes (PEs) were synthesised by copolymerising ethylene and 10-undecen-1-ol using a soluble metallocene/methylaluminoxane catalyst at room temperature. The incorporation of functional groups increased with increasing comonomer content. WPCs with 10 and 30% wood content were prepared. The composites prepared with functionalised PEs had better mechanical, thermal and morphogical properties than the composites prepared with PE. Composites made with functionalised PE with higher hydroxyl groups content exhibited better properties than composites made with functionalised PE with lower hydroxyl groups content. Composites with 10% wood content exhibited better properties and performance than composites with 30% wood content.
AFRIKAANSE OPSOMMING: Die gevolg van die makromolekulere samestelling van verskillende houtspesies op die eienskappe van hout-polimeer saamgestelde materiale (HPS) wanneer poli(viniel alcohol-ko-etileen) (EVOH) as versoeningsmiddel gebruik word saam met linieere lae digtheid poli(etileen) (LLDPE) as matriks is ondersoek. Vier houtspesies (A. cyclops (acacia), E. grandis (eucalyptus), P. radiata (pine) and Q. alba (oak)) met verskillende makromolekulere samestelling and partikelgrootte-verspreiding is gebruik in die studie. HPS materiale is berei met hierdie vesels, beide voor en na ekstraksie van die houtpartikels met onderskeidelik warm water en oplosmiddels (alleen en in kombinasie). In hierdie HPS materiale is 10% hout gebruik en 0, 2, 5, 7 en 10% EVOH. 'n EVOH inhoud van 7% is as optimum bepaal. Houtpartikels voor ekstraksie het HPS materiale met beter meganiese eienskappe en beter weerstand teen UV bestraling, terwyle partikels wat ekstraksie ondergaan het HPS materiale met laer water-absorpsie en beter hitte-stabiliteit to gevolg gehad het. Die gebruik van ongeekstraheerde A. cyclops het samegestelde materiale met die beste meganiese en termiese eienskappe tot gevolg gehad in vergelyking met die ander houtspesies (voor ekstraksie), as gevolg van die hoer sellulose en lignien inhoud van die spesie, sowel as 'n voordelige partikelgrootte-verspreiding. A. Cyclops saamgestelde materiale he took hoer waterabsorpsie (WA) en dikte-swelling (DS) tempos gehad, weens die groter hoeveelheid vrye hidroksielgroepe teenwoording in die materiale, direk in verwantskap met die sellulose-inhoud. Saamgestelde materiale met 'n hoe hoevellheid lignien en ekstraheerbare materiale (A. cyclops and Q. alba) het beter weerstand teen UV-degradasie geopenbaar. Verskillende poli(viniel alkohol-ko-etileen) polimere (EVOHs) met wisselende etileen-inhoud (27, 32, 38 en 44%) en A. Cyclops met verskillende partikel-groottes (180, 250 en 250 µm) is gebruik om HPS materiale met 10% hout te vervaardig. Die gevolg van die kontak-area tussen die houtpartikels en die LLDPE wanneer EVOHs as versoeningsmiddel gebruik is, is ook ondersoek. Die beste verbetering in die meganiese en termiese eienskappe van die saamgestelde materiale met A. cyclops met partikel-grootte 180 µm is gekry met EVOH met 44% etileen-inhoud, terwyl die beste resultate met 250 µm partikels verkry is met 'n EVOH met 38% etileen, en met 27% etileen in die geval van die 450 µm partikels. Twee benaderinge om meer aantreklike ekologiese en ekonomiese eienskappe by die HPS materiale te bewerkstellig was suksesvol. In die eerste geval is gedegradeerde LLDPE as versoeningsmiddel gebruik. Die resulterende meganiese eienskappe van die HPS materiale met LLDPE as versoeningsmiddel was beter as die HPS mateirale daarsonder. Samegestelde materiale met 10, 30 en 50% hout is vervaardig. Die trekverlenging by die breekpunt sowel as die impaksterkte van die HPS materiale was laer as LLDPE alleen, maar beter as die nie-versoende HPS materiale. In die tweede benadering is polietileen (PE) en gefunksionaliseerde PE gesintetiseer deur etileen en 10-undekeen-1-ol te koplimeriseer met ‘n oplosbare metalloseen/metiel alumoksaan katalis. Die hoeveelheid funskionele (OH) groepe is verhoog deur toenemend ekomonommer-inhoud. HPS materiale met 10 en 30% hout is vervaardig. Die saamgestelde materiale met funksionele PE het beter maganiese eienskappe gehad as die met gewone PE. Hoe hoër die hidroksielgroep-inhoud, hoe beter die eienskappe van die HPS materiale, terwyl die materiale met 10% hout beter eienskappe openbaar het as materiale met 30% hout.
Menzel, Jan Philipp. "Wavelength-dependent photoreactivity for macromolecular material design." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/210196/1/Jan%20Philipp_Menzel_Thesis.pdf.
Повний текст джерелаNolan, Christine Marie. "Microgel Based Materials for Controlled Macromolecule Delivery." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6874.
Повний текст джерелаLis, Arias Manuel J. (Manuel José). "Comportamiento cinético de fibras Tencell con colorantes directos." Doctoral thesis, Universitat Politècnica de Catalunya, 2002. http://hdl.handle.net/10803/6490.
Повний текст джерелаEl objetivo principal de la presente Tesis, Cinética de Tintura de Tencel ,se centra en dos objetivos parciales: la sensibilidad a la temperatura y el efecto de la variación de la concentración de electrolito en la misma.
La evaluación cinética del sistema fibra-colorante, se ha realizado mediante la evolución de la expresión Ct/Cinf, relación entre colorante absorbido por la fibra en un tiempo t y la concentración del mismo en el equilibrio, en función de los distintos parámetros estudiados a través del análisis de varios modelos.
Metodología empleada
La aproximación a dicha evaluación puede realizarse mediante: Modelos cinéticos semi-empíricos y Modelos matemáticos provenientes de la segunda ley de Fick. En los primeros, es la constante cinética k el parámetro definitorio del proceso, mientras que, en los modelos matemáticos es el adimensional Dt/r2.
Ambos enfoques describen la evolución del mismo fenómeno y, por lo que debería existir algún tipo de relación entre k y Dt/r2. El estudio del proceso desde ambos puntos de vista y, cuando sea posible, establecer la relación mencionada, es otro de los objetivos de la Tesis. Con ello, se podrá comparar la incidencia estructural del sustrato respecto al comportamiento cinético.
Fases del trabajo
Siendo Tencel una fibra celulósica, se ha realizado un análisis comparativo con Viscosa , mediante un estudio experimental en celda de tintura en flujo continuo con medición espectrofotométrica on line .
Las condiciones experimentales escogidas han sido: Temperaturas de 30, 40, 50, 60, 70 y 80ºC y [NaCl] de 0.5, 1.0 y 1.5 g/L, valorando la cantidad de colorante que la fibra absorbe, en función del tiempo.
Conclusiones y valoración de los resultados obtenidos
La comparación de D/r2 entre ambas fibras indica que:
Exceptuando el modelo de Chrastil, los valores de D/r2 obtenidos, disminuyen con el aumento de la concentración de electrolito .
Los valores obtenidos a partir de la aproximación de Crank y de la de Rais-Militky presentan gran similitud.
Hay un estrecho paralelismo entre los valores obtenidos a partir de la ecuación de Cegarra-Puente-Valldeperas y los de las aproximaciones matemáticas de Crank y Rais-Militky.
Para algunos modelos matemáticos, a la concentración máxima de electrolito, los valores de D/r2 son muy similares en Viscosa y prácticamente coincidentes en Tencel.
El orden de magnitud de los Dap para Tencel pueden apreciarse en la Tabla siguiente.
Dap (cm2/s) Modelo
10-11-10-14 Cegarra-Puente-Valleperas
10-12-10-14 Chrastil
10-11-10-16 Urbanik
10-11-10-14 Crank
10-11-10-14 Rais-Militky
10-13-10-16 Kilby
A pesar de las diferencias según la ecuación considerada, existe en Tencel una variación del Dap en función de los tres niveles de agotamiento en los que se ha estructurado el estudio cinético.
A través de la cinética de tintura se ha podido demostrar la existencia de varias capas de distinto nivel de ordenación microestructural que implicará, la necesidad de reconsiderar los procesos de tintura a fin de obtener unos niveles de penetración del colorante en la fibra similares a los de otras fibras celulósicas, al existir en Tencel velocidades de difusión diferenciadas en sus distintas capas.
Filion, Potts Tera M. "Biomimetic Synthetic Tissue Scaffolds for Bone Regeneration: A Dissertation." eScholarship@UMMS, 2011. https://escholarship.umassmed.edu/gsbs_diss/556.
Повний текст джерелаFerrer, Balas Dídac. "Aplicación del método del trabajo esencial de fractura al estudio de films de polipropileno y de copolímeros propileno-etileno en bloques." Doctoral thesis, Universitat Politècnica de Catalunya, 2001. http://hdl.handle.net/10803/6033.
Повний текст джерелаEn una primera part, s'estudien les condicions òptimes d'assaig de la técnica EWF per aplicar-la a films de polímers dúctils, analitzant la influència de variables d'assaig com són les dimensions de la proveta, la velocitat d'assaig o el mode de fractura.
En una segona part, s'ha estudiat la relació entre els paràmetres de fractura obtinguts mitjançant la tècnica EWF i diferents propietats referents a l'estructura del material. Entre aquestes, s'ha analitzat la influència de les característiques cristal·lines, modificades per un procés de recuit previ als assajos, i del contingut d'etilè a diferents temperatures d'assaig. S'han aplicat nombroses tècniques de caracterització tant mecàniques i de fractura com físico-químiques.
Els resultats mostren que el mètode EWF s'adapta bé a la necessitat de caracteritzar la fractura de films polimèrics, i permet estudiar la relació entre la seva estructura i les propietats de fractura que presenten. Alhora, es plantegen diferents modificacions del mètode que permeten potenciar les seves possibilitats. S'observa que al millorar la perfecció cristalina dels materials estudiats, el terme essencial augmenta en detriment del terme no essencial. També es demostra que la presència d'etilè en els EPBC minimitza la gran dependència que presenten les propietats de fractura del PP homopolímer en variar la temperatura, i es relaciona aquest comportament amb els canvis dels mecanismes de deformació predominants en el material.
En este trabajo, se presenta el estudio de las propiedades de fractura de films de polipropileno (PP) y copolímeros etileno-propileno (EPBC) por medio de la técnica del Trabajo Esencial de Fractura (EWF). Esta técnica se muestra como una alternativa muy adaptada para la aplicación de la Mecánica de la Fractura en films dúctiles, y permite separar la energía total de fractura en un término esencial, que hace referencia al trabajo real de fractura, y un término no esencial, relativo a la disipación de energía de deformación plástica alrededor del camino de fractura.
En una primera parte, se estudian las condiciones óptimas de ensayo de la técnica WF para aplicarla a films de polímeros dúctiles, estudiando la influencia de variables de ensayo como son las dimensiones de probeta, la velocidad de ensayo o el modo de fractura.
En una segunda parte, se ha estudiado la relación entre los parámetros de fractura obtenidos mediante la técnica EWF y distintas propiedades referentes a la estructura del material. Entre éstas, se ha analizado la influencia de las características cristalinas, modificadas por un proceso de recocido previo a los ensayos, y del contenido de etileno a diferentes temperaturas de ensayo. Se han aplicado numerosas técnicas de caracterización, tanto mecánicas y de fractura como físico-químicas.
Los resultados muestran que el método EWF se adapta bien a la necesidad de caracterizar la fractura de films poliméricos, y permite estudiar la relación entre su estructura y las propiedades de fractura que presentan. También se plantean diferentes modificaciones del método que permiten potenciar sus posibilidades. Se observa que al mejorar la perfección cristalina de los materiales estudiados, el término esencial aumenta en detrimento del término no esencial. También se demuestra que la presencia de etileno en los EPBC minimiza la gran dependencia que presentan las propiedades de fractura del PP homopolímero al variar la temperatura, y se relaciona este comportamiento con los cambios de los mecanismos de deformación predominantes en el material.
In this work, the study of the fracture properties of polypropylene (PP) and ethylene-propylene block copolymers (EPBC) films by means of the Essential Work of Fracture (EWF) method is presented. This method is considered as a suitable alternative for applying Fracture Mechanics to ductile films, allowing the separation of the total fracture energy into two different items: an essential term, related to the actual fracture work, and a non essential term, related to the plastic deformation energy dissipation occurring in the region surrounding the fracture path.
In a first part, the optimal EWF method test conditions for ductile plastic films are studied, by analysing the influence of such test variables as the specimen dimensions, the test rate or the fracture mode.
In a second part, the relationship between the fracture parameters obtained by applying the EWF method and different materials structural properties are studied. Among these properties, the influence of the crystalline characteristics, modified by an annealing process before the tests, and that of the ethylene content at different test temperatures have been analysed.
Various mechanical, fracture and physico-chemical characterisation techniques have been applied.
The results show that the EWF method is very suitable to assess the fracture of polymeric films, and therefore to study the relationship between their structure and the fracture properties that they present. In addition, various modifications of the method are proposed in order to improve its possibilities.
It is observed that as the crystalline perfection grows, the essential term increases but the non-essential term decreases. It is also shown that the ethylene presence in the EPBC minimises the strong temperature dependence shown by the fracture properties of the PP homopolymer. This behaviour is related to the predominant deformation mechanisms in the material.
Cet ouvrage présente l'étude des propriétés de rupture de films de polypropylène (PP) et de copolymères éthylène-propylène en blocs (EPBC) par moyen de la methode du Travail Essentiel de Rupture (EWF). Cette technique se révèle comme une alternative très adaptée à l'application de la Mécanique de la Rupture aux films ductiles, et permet la séparation de l'énergie totale de rupture en un terme essentiel, qui fait référence au travail réel de rupture, et en un terme non essentiel, relatif à la dissipation d'énergie de déformation plastique autour du chemin de rupture.
Dans une première partie, les conditions optimales d'essai de la technique EWF pour l'application aux polymères ductiles sont étudiées, tout en analysant l'influence de variables d'essai telles que les dimensions de l'éprouvette, la vitesse de l'essai, ou le mode de rupture.
La deuxième partie est consacrée à l'étude de la relation entre les paramètres de rupture obtenus par la méthode EWF et différentes propriétés de la structure du matériau. Parmis celles-ci, nous avons analysé l'influence des caractéristiques cristallines, modifiées par un processus de recuit préalable aux essais, et de l'effet du contenu en éthylène à différentes températures d'essai. Plusieurs techniques de caractérisation, aussi bien mécaniques, que de rupture, que physico-chimiques ont été utilisées.
Les résultats montrent que la méthode EWF est très adaptée à la caractérisation de la rupture de films de polymères, et permet d'étudier la relation entre leur structure et leurs propriétés de rupture. Nous présentons, aussi, différentes approches modifiées de la technique EWF qui permettent d'accroître son potentiel. Il est observé que, quand la perfection cristalline des matériaux étudiés augmente, le terme essentiel augmente lui aussi, mais le terme non essentiel présente une tendance opposée. De même, il est démontré que la présence d'ethylène dans les EPBC a un effet de minimisation de l'importante dépendence que le PP homopolymère présente vis-à-vis de la température, et ce comportement est relié aux changements des mécanismes de déformation prédominants dans le matériau.
Höfling, Felix. "Dynamics of Rod-Like Macromolecules in Heterogeneous Materials." Diss., lmu, 2006. http://nbn-resolving.de/urn:nbn:de:bvb:19-105831.
Повний текст джерелаHöfling, Felix. "Dynamics of rod like macromolecules in heterogeneous materials." Münster Verl.-Haus Monsenstein und Vannerdat, 2006. http://deposit.d-nb.de/cgi-bin/dokserv?id=2930009&prov=M&dok_var=1&dok_ext=htm.
Повний текст джерелаHöfling, Felix. "Dynamics of Rod-Like Macromolecules in Heterogeneous Materials /." Münster, Westf : Monsenstein und Vannerdat, 2007. http://deposit.d-nb.de/cgi-bin/dokserv?id=2930009&prov=M&dok_var=1&dok_ext=htm.
Повний текст джерелаHan, Lin Ph D. Massachusetts Institute of Technology. "Nanomechanics of cartilage extracellular matrix macromolecules." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42134.
Повний текст джерелаIncludes bibliographical references (p. 187-201).
In this thesis, the shear and self-adhesion nanomechanical properties between opposing cartilage aggrecan macromolecules were probed. In addition, nanoscale dynamic oscillatory mechanical properties of cartilage and its type II collagen network was measured. Aggrecan shear nanomechanics was assessed via microcontact printing and lateral force microscopy. Lateral force between aggrecan and the probe tip, and compression of aggrecan was simultaneously measured in 0.001 - 1.0 M NaCl aqueous solutions. Using the microsized tip (Rtip ~ 2.5 [mu]m) enabled a large assembly of ~ 103 aggrecan molecules to interact simultaneously, closely mimicking the in vivo conditions.Both electrostatic and nonelectrostatic components were identified to importantly contribute to aggrecan shear. At near physiological IS (0.1 M), significant rate dependence was observed, suggestive of visco/poroelastic interactions within the aggrecan layer. By using an aggrecan end-functionalized colloidal tip, shear of two opposing aggrecan layers was assessed in a similar fashion. Lower lateral force and a more marked rate dependence were measured compared to the shear of a single layer, due to the aggrecan inter-layer molecular interpenetration and the different local z-dependent charge density distribution. The addition of Ca2+, at physiological-like 2 mM concentration, significantly affects cartilage shear by its electrostatic screening and binding effects. Marked aggrecan self-adhesion upon separation was discovered after static compression in the presence of electrostatic repulsion in physiological-like conditions.
(cont.) Aggrecan self-adhesion increases as increasing equilibration time and bath IS. Molecular origins of the adhesion, also present in vivo, include van der Waals, hydrogen bonding, Ca2+-mediated bridging, and molecular entanglements between the glycosaminogly-can branches of aggrecan. This self-adhesion could be an important factor in protecting cartilage matrix structural integrity and function via these energy-dissipative mechanisms. The nanoscale oscillatory dynamic deformation properties of both nontreated and proteoglycan(PG)-depleted (left mostly type II collagen) calf knee cartilage disks (- 0.5 mm thick) was measured by connecting an external electronic wave generator to the AFM. A significant increase in effective stiffness E and phase lag A (deformation with respect to force) as increasing frequency for both disks suggests poro/viscoelasticity are more critical at higher frequency. The PG-depleted disk shows a more marked dependence of E and A on deformation amplitude - 2 - 100 nm, as the nanostructure and nanomechanical properties of porous collagen network are more heterogeneous without the entrapment of aggrecan motif. A unique - 23 nm banding pattern along the type II collagen fibrils was observed, which may be relative to the cartilage swelling properties and the molecular interaction between aggrecan and the collagen network. Taken together, this study provides insights into molecular-level deformation of cartilage extracellular matrix (ECM) macromolecules (e.g., aggrecan, type II collagen) that are important to the understanding of cartilage biomechanical function. Ongoing studies are probing the age, disease (osteoarthritis), source and species related variations of cartilage ECM properties at the molecular level.
by Lin Han.
Ph.D.
Eleftheriou, Lygia. "Study of macromolecule-mineral interactions on nuclear related materials." Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/16816/.
Повний текст джерелаHöfling, Felix [Verfasser]. "Dynamics of rod-like macromolecules in heterogeneous materials / Felix Höfling." Münster : Verl.-Haus Monsenstein und Vannerdat, 2006. http://d-nb.info/997139641/34.
Повний текст джерелаGottlieb, Ronny, and Karl-Friedrich Arndt. "Intelligente Werkstoffe - Vom Makromolekül zum intelligenten Material." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1188378259921-41093.
Повний текст джерелаUmgebungssensitive Polymere ändern in Abhängigkeit von Umgebungsbedingungen, wie zum Beispiel dem Licht, der Temperatur, dem pH-Wert oder der Konzentration einer zweiten Komponente neben dem Polymer, drastisch ihre Molekülgestalt. Vernetzt und in Wasser gequollen, bilden sie sogenannte smarte Hydrogele. Dabei werden die Besonderheiten eines Makromoleküls, dessen Eigenschaften durch die Umgebung beeinflusst werden, auf ein polymeres Material übertragen. Dies kann ein großer Körper, eine dünne Schicht oder ein Nanopartikel sein. Das Volumen der smarten Hydrogele kann zwischen zwei Zuständen geschaltet werden. Dabei können die Hydrogele wie Aktoren eine Kraft ausüben. Da das Schalten durch die Umgebung stimuliert wird, sind sie als Sensoren verwendbar. Die Polymerstrukturen sind miniaturisierbar, sodass smarte Hydrogele als Komponenten in Mikrosystemen angewendet werden können. Zum Beispiel werden die Partikel zur kontrollierten Abgabe von Arzneimittelwirkstoffen verwendet
Del, Regno Annalaura. "Microscopic behaviour of porous macromolecules." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/microscopic-behaviour-of-porous-macromolecules(d1eb5218-a2f3-41db-a6ee-7e7d45e37f4d).html.
Повний текст джерелаAlmqvist, Nils. "Studies of plasma-facing materials and macromolecules using scanning probe microscopy." Doctoral thesis, Luleå tekniska universitet, Materialvetenskap, 1995. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-16824.
Повний текст джерелаGodkänd; 1995; 20070410 (ysko)
Van, Schalkwyk Welmarie. "Self-assembly of amphiphilic discotic materials." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/79799.
Повний текст джерелаENGLISH ABSTRACT: The creation of nanometer-scale (nanoscale) materials has fascinated and inspired the scientific community for more than a quarter of a century because of the wide range of applications of these materials, e.g. applications in drug delivery, medicine, tissue engineering, memory storage, display and audio devices, semiconductors, etc. π-Conjugated dendrimers have a proposed flat packing arrangement. An alternating phenyl isoxazole dendrimer system was developed to investigate this phenomenon. The synthesis of this dendritic system was attempted by divergent and convergent approaches. Preparation of the second generation failed because some functional groups inhibited the monomers to react to the first generation. Other examples of nano materials that have attracted a vast amount of interest are the so-called discotic amphiphiles. Discotic amphiphilic molecules have the potential to self-assemble into helical architectures. Discotic systems bearing chiral polar side chains (one and three respectively) were developed. Their self-assembly was investigated in variable concentration and variable solvent composition experiments. These systems did show signs of aggregation in UV-vis and CD spectroscopy experiments. Thread-like helical structures were observed with transmission electron microscopy.
AFRIKAANSE OPSOMMING: Nanometer-skaal materiale inspireer en fassineer wetenskaplikes al vir meer as 25 jaar as gevolg van hulle wye verskeidenheid toepassings bv.: die vervoer van geneesmiddels, weefsel ontwerp, geheue stoorspasie, digitale skerms, klank toerusting, geleiers, ens. π-Gekonjugeerde dendrimere het 'n plat drie dimmensionele rangskikking. 'n Afwisselende feniel isoxazole dendrimer stelsel was ontwikkel om hierdie verskynsel te ondersoek. Die sintese van hierdie dendritiese stelsel is aangepak deur divergerende en konvergerende benaderings. Sintese van die tweede generasie het misluk omdat sommige funksionele groepe die monomere geïnhibeer het om te reageer met die eerste generasie. Ander interessante voorbeelde van nano materiale, is die sogenaamde skyfvormige amphiphiles. Skyfvormige amphiphiles het die potensiaal om spontaan te versamel in heliese strukture. Skyfvormige molekules met chirale polêre sykettings (een en drie onderskeidelik) is ontwikkel. Hulle potensiaal om spontaan te versamel is ondersoek met wisselende konsentrasie en wisselende oplosmiddel samestelling eksperimente. Hierdie stelsels het tekens van versameling gewys in UV-vis en CD-spektroskopiese eksperimente. Staaf-vormige heliese strukture is waargeneem met transmissie-elektronmikroskopie.
Ehrlich, Deborah J. C. "Synthetic strategies for control of structure from individual macromolecules to nanoscale materials to networks." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122451.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references.
Chapter 1. Aqueous self-assembly of prodrug macromonomers. A series of highly tunable micelles for drug delivery were made from norbornene based poly(ethylene glycol) macromonomers with covalently linked drugs. A total of five macromonomers were made using three different drugs (telmisartan, paclitaxel, and SN-38) and three different drug loadings. Combinations of these macromonomers were then allowed to self assemble into micellar aggregates. The size, stability, and shape of these micellar aggregates were controlled with the highly versatile structure. Chapter 2. Post micellization modification of norbornene-containing prodrug macromonomers. Highly tunable micelles for drug delivery were functionalized after their selfassembly. Post-micellization inverse electron demand Diels-Alder reactions of norbornenes and tetrazines were used to signal changes in micelle size and stability through the addition of either hydrophilic or hydrophobic tetrazines.
Thiol-ene additions reactions were used to increase micelle size and form chemically crosslinked nanoparticles. These modifications of norbornene-containing prodrug macromonomer assemblies illustrate their versatility. Chapter 3. Synthesis of polymers by iterative exponential growth. A scalable synthetic route that enables absolute control over polymer sequence and structure has remained a key challenge in polymer chemistry. Here, we report an iterative exponential growth plus side-chain functionalization (IEG+) strategy for the production of macromolecules with defined sequence, length, and stereoconfiguration. Each IEG+ cycle begins with the azide opening of an enantiopure epoxide, followed by side chain functionalization, alkyne deprotection, and copper-catalyzed azide-alkyne cycloaddition (CuAAC). These cycles have been conducted to form unimolecular macromolecules with molar masses of over 6,000 g/mol.
Subsequent modifications to IEG+ allow for the functionalization of monomers prior to the IEG+ cycle, expanding the library of compatible side chain chemistries. Chapter 4. Introduction to elastomer toughening strategies. Silicone elastomers are ubiquitous. Here, silicone elastomers are discussed in terms of network structure, the impact of network structure upon physical properties, and modifications of network structure in order to achieve desired physical properties. Fillers, the standard toughening strategy, are discussed in conjunction with entanglement density. Focus is placed on the impact of entanglement density on material properties. Topological networks are discussed and noted for their stress dissipative properties. Chapter 5. Topology modification of polydimethylsiloxane elastomers through loop formation. Topological networks are well known for their stress dissipation through the pulley effect leading to soft, extensible materials.
Combining these properties with a traditionally crosslinked network to produce a hybrid material allows for enhanced extensibility without a loss in modulus. Here, such hybrid networks were made with poly(dimethyl siloxane) polymers of a range of molecular weights. Side-loop polymer brushes were synthesized and then crosslinked to create hybrid networks with the statistical formation of topological bonds. These materials were characterized through tensile testing. Elastomers formed with the same molecular weight polymer in both side-loops and network formation did not show mechanical properties that depended upon the fraction of networks used for brush formation. Elastomers made with long polymers in brush formation and shorter polymers for network formation resulted in highly extensible systems without significant loss in modulus.
by Deborah J.C. Ehrlich.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Chemistry
Durmus, Asuman. "Realization Of Neutral State Green Polymeric Materials." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610738/index.pdf.
Повний текст джерелаacceptor approach can be utilized to solve this puzzle. It has been shown that insertion of alternating donor&ndash
acceptor units on the polymer backbone leads to a significant decrease in band gap due to the increased double bond character in the structure. In this study novel donor-acceptor type polymers were synthesized, and electrochromic properties were investigated in detail. PBDT is the first green electrochromic material which has a highly transmissive sky blue oxidized state. PDETQ was shown to be one of the few examples of neutral state green polymeric materials in literature. PDEQ has a bluish green color in the neutral state and a highly transmissive light blue oxidized state.
Park, Juhyun Ph D. Massachusetts Institute of Technology. "Adsorption and multilayer assembly of charged macromolecules on neutral hydrophobic surfaces and applications to surface patterning." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36210.
Повний текст джерелаIncludes bibliographical references.
Micrometer- and nanometer-scale chemical patterns are indispensable and ubiquitous in a range of applications, such as optoelectronic devices and (bio) chemical sensors. This thesis studies chemical surface patterning utilizing polyelectrolyte multilayers for electronic and biological applications. It focuses on both fundamental study and application development in the field of layer-by-layer self-assembled composite thin films, with the goal of defining new concepts allowing for technological breakthrough. In the process of completing it, a multicomponent patterning technology that has been a bottleneck in realizing practical devices utilizing the multilayers has been developed. To achieve this goal, a multilayer transfer printing concept was applied to serial printing of individual device components. The main achievements include fundamental studies about uniform multilayer assembly of charged macromolecules on neutral hydrophobic surfaces as the principle of the technique, and the demonstration of multicomponent patterning of polyelectrolyte/nanoparticle composite thin films on a flexible substrate.
(cont.) Extending the technique toward nanometer-scale patterning, a new polymeric mold material that was suitable for sub-100 nm structuring was studied and used for chemical patterning for flow control in microfuidic devices and nanoparticle assembly for potential biological applications, combined with polyelectrolyte multilayers.
by Juhyun Park.
Ph.D.
Kumar, Abhishek. "Development, characterization and experimental validation of metallophthalocyanines based microsensors devoted to monocyclic aromatic hydrocarbon monitoring in air." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22635/document.
Повний текст джерелаThis PhD work is dedicated to investigate potentialities of phthalocyanines materials to realize a Quartz Crystal Microbalance (QCM) sensor for Benzene, Toluene and Xylenes (BTX) detection in air. The goal is to develop a sensor-microsystem capable of measuring BTX concentrations quantitatively below the environmental guidelines with sufficient accuracy. To achieve these objectives, our strategies mainly focused on experimental works encompassing sensors realization, sensing material characterizations, development of gas-testing facility and sensor testing for different target gases. One of the main aims is to identify most appropriate phthalocyanine material for sensor development. After comparative sensing studies, tert-butyl-copper phthalocyanine based QCM device is found as most sensitive and detail metrological characteristics are further investigated. Results show repeatable, reversible and high magnitude of response, low response and recovery times, sub-ppm range detection limit, high resolutions and combined selectivity of BTX gases among common atmospheric pollutants. Special focus is given to understand the gas/material interactions which are achieved by (a) XRD and SEM characterizations of sensing layers, (b) formalization of a two-step adsorption model and (c) assessing extent of diffusion of target gas in sensing layer. At last, possible ageing of sensor and suitable storage conditions to prevent such effect are investigated
PATWARDHAN, SIDDHARTH VIJAY. "SILICIFICATION AND BIOSILICIFICATION: THE ROLE OF MACROMOLECULES IN BIOINSPIRED SILICA SYNTHESIS." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1054325597.
Повний текст джерелаSmall, Aaron Charles. "Novel hybrid materials and their applications : a thesis submitted to the Victoria University of Wellington in fulfilment of the requirements for the degree of Doctor of Philosophy in Chemistry /." RestrictedArchive@Victoria -- VUW staff and students only, 2008. http://restrictedarchive.vuw.ac.nz.helicon.vuw.ac.nz/handle/123456789/1298.
Повний текст джерелаYu, Tingting. "Solid state luminescent molecules, macromolecules and materials, their response to stimuli and their applications in devices." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEN061.
Повний текст джерелаIn this thesis, we developed new luminescent conjugated chromophores presenting an alternation of electron donor and acceptor groups, with a specific focus on their emission properties in aggregates or solid states in far-red or near infrared region. We studied the influence of chain length and donor/acceptor substitution not only on the optical properties of the isolated compounds, but also (and especially) on the material in its aggregated state. Finally, taking advantages of these specific properties of some of the as-designed candidates, we explored their potential applications ranging from fluorochromic stimuli-responsive sensors (in film form) to red and NIR luminescent two-photon probes for biological imaging. The main achievements of this thesis are the following: 1) new alternating triarylamine or carbazole / tetraphenylethylene (TPE) polymers were synthesized. Their solid state luminescence poseeses typical J-aggregates emission features in solid state, unusual in TPE derivatives that we relate to the linear polymeric nature of the object; 2) A new family of diphenylamine / benzobisthiazole chromophores and derived oligomers were synthesized . Their luminescence properties present a marked sensitivity to protonation, which we took advantage of in the making of acid-base responsive luminescent devices; 3) we explored the possibility of additional chemical transformations of the newly designed chromophore, in order to achieve solid state NIR emission, in particular by means of a change in the character of the electronic transition from Intra-Molecular Charge Tranfer (ICT) to Cyanine transition owing to benzothiazole quaternarization. Other modifications resulted in improvement of their AIE properties, bioavailability and selectivity of their cellular compartments staining ability; 4) These new compounds present a reversible photoinduced “on-off” switching of their luminescence properties, which might present an interest in the design of contrast-agents for super resolution imaging
San, Juan Ocete Alexis. "Nuevos materiales macromoleculares formados por la unión de moléculas con estado birradical triplete asequible térmicamente." Doctoral thesis, Universitat de Barcelona, 2018. http://hdl.handle.net/10803/587192.
Повний текст джерелаStudies carried out previously by our research group show that there are heterocyclic organic molecules, seemingly closed layers and without any metal atom, presenting thermally affordable triplet biradical character. The formation of these biradical species comes from an imine double bond break by simple conformational changes of this bond. A stabilization factor of the biradical formed is to be included in an electron acceptor part (e.g. acridine) and another electron donor part (e.g. benzothiazole), with the consequent relocation of the unpaired electrons independently in each of such parts. In addition, if the studied molecules contain acidic protons, the formation of the corresponding conjugated base make increase significantly the population of molecules in a triplet biradical state, due to the negative charge generated, that stabilizes better the unpaired electrons. More than 50 compounds have been synthesized and have shown the studied feature, being able to get a general molecular model for all of them. Bibliographic search have also shown that there are natural products which include this model in its structure, and for this reason, paramagnetic response (EPR). These biomolecules are Dasatinib and its analogues, and p-HBDI, chromophore of green fluorescent protein (GFP), being the last one included in this Thesis in order to give validity to the model made up of molecules previously studied. Firstly, our molecules have been functionalized properly to be united on the different polymeric supports. Then, the work has consisted of getting macromolecular materials formed by these molecules to see how affects the property when these molecules are in a polymeric environment. To do this simpler, analog auxiliary models of macromolecular systems have been synthesized and have been used as a guide, for its both synthesis and characterization. Polymers with different structures have been used by the possible influence on the formation of biradical species. The union of these molecules have been carried out on polyacrylic acid (PAA), polyethyleneimine branched (PEI), the (aminomethyl) cross-linked polystyrene as well as dendrimeric structures, focusing, exclusively, in obtaining polymeric analogues of the p- HBDI and its derivatives. For the study of these products have been carried out using the Electron Paramagnetic Resonance (EPR), comparing the macromolecular systems obtained with their low molecular weight precursors. Furthermore, other systems with possible poliradical states as dimers and tetramers have been proposed.
Noell, John Lee Watson. "The preparation and characterization of PEK/TEOS glasses by the sol-gel method." Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/44056.
Повний текст джерелаMaster of Science
Atak, Samed. "Soluble Alkyl Substituted Poly(3,4propylenedioxyselenophne)s: A Novel Platform For Optoelectronic Materials." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613106/index.pdf.
Повний текст джерела1.64 eV) and they are exceptionally stable under ambient atmospheric conditions. For example, polymer films retained 84-96 % of their electroactivity after five thousands cycles. The percent transmittance of PProDOS-Cn (n= 4, 6, 10) films found to be between 55-59 %. Furthermore, these novel soluble PProDOS-Cn polymers showed electrochromic behavior: a color change form pure blue (L = 57.31, a = -13.18, b = - 42.68) to highly transparent state (L = 91.74, a = 2.52, b = -1.30) state in a low switching time (1.0 s) during oxidation with high coloration efficiencies (328 &ndash
864 cm2/C) when compared to their close analogues.
Wu, Huangli. "Computational simulation of dynamics of nematic liquid crystals in the presence of nanoparticles and biological macromolecules." Master's thesis, Mississippi State : Mississippi State University, 2006. http://sun.library.msstate.edu/ETD-db/ETD-browse/browse.
Повний текст джерелаEroglu, Gulden. "Isocyanate Functionalization Of Nano-boehmite For The Synthesis Of Polyurethane Organic-inorganic Hybrid Materials." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12612930/index.pdf.
Повний текст джерела-methylene diphenyl diisocyanate. Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, Differential Thermal Analysis-Thermal Gravimetric Analysis, and elemental analysis were performed for both functionalized and non-functionalized particles to confirm the functionalization of the particles. The polyester polyol used in the production of polyurethane was synthesized from 1,4-butanediol and adipic acid (PE-PO-1), and phthalic anhydride (PE-PO-2). Molecular structure of the polyester polyols was confirmed by Fourier Transform Infrared Spectroscopy analysis and molecular weight of the polymers were determined by end group analysis. Then, the produced functionalized nano-particles and polyester polyols were used for producing polyurethane organic-inorganic hybrid materials. Furthermore, polyurethane polymer and polymer-nonfunctionalized boehmite organic-inorganic hybrids were also synthesized for property comparison. Hardness, impact resistance, scratch resistance, abrasion resistance, and gloss property of the samples were determined. It was observed that mechanical properties of organic-inorganic hybrid materials improved significantly. The hardness of the PU produced with PE-PO-1 increased from 82 to 98 Persoz, and the hardness of the PU produced with PE-PO-2 increased from 52 to 78 Persoz when one weight percentage functionalized boehmite was used. The impact resistance of the coatings was found to depend on the type of the polyols used in PU but not in the inorganic component. Therefore PE-PO-2 used PU has higher impact resistance than PE-PO-1 used PU. Scratch resistance of the coatings improved from 2B to 2H when using functionalized boehmite. Abrasion resistance of PUs produced with PE-PO-1 increased from 2 to 10 l/micrometer and abrasion resistance of PUs produced with PE-PO-2 increased from 12 to 20 l/micrometer by addition of functionalized boehmite.
Koysuren, Ozcan. "Preparation And Characterization Of Conductive Polymer Composites, And Their Assessment For Electromagnetic Interference Shielding Materials And Capacitors." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609452/index.pdf.
Повний текст джерелаGunbas, Gorkem E. "Novel Donor-acceptor Type Polymers Towards Excellent Neutral State Green Polymeric Materials For Realization Of Rgb Based Electrochromic Device Applications." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12609002/index.pdf.
Повний текст джерелаEndres, Kevin J. "Mass Spectrometry Methods For Macromolecules: Polymer Architectures, Cross-Linking, and Surface Imaging." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1553096604194835.
Повний текст джерелаWu, Haiyan. "Design and Development of New Chemistry for Biosensing." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1502459975409826.
Повний текст джерела