Dissertations / Theses on the topic 'Macromolecular and materials chemistry'
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1
Zhang, Borui. "Novel Dynamic Materials Tailored by Macromolecular Engineering." Miami University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=miami1564157701522666.
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Reinsel, Anna Michele. "Spectroscopic Characterization of Organic and Inorganic Macromolecular Materials." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1312823530.
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De, 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.
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Stimson, 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/.
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Molecular simulations provide an increasingly useful insight into the static and dynamic characteristics of materials. In this thesis molecular simulations of macro-molecular liquid crystalline materials are reported. The first liquid crystalline material that has been investigated is a side chain liquid crystal polymer (SCLCP). In this study semi-atomistic molecular dynamics simulations have been conducted at a range of temperatures and an aligning potential has been applied to mimic the effect of a magnetic field. In cooling the SCLCP from an isotropic melt, microphase separation was observed yielding a domain structure. The application of a magnetic field to this structure aligns the domains producing a stable smectic mesophase. This is the first study in which mesophases have been observed using an off-lattice model of a SCLCP. The second material that has been investigated is a dendrimer with terminal mesogenic functionalization. Here, a multi-scale approach has been taken with Monte Carlo studies of a single dendrimer molecule in the gas phase at the atomistic level, semi-atomistic molecular dynamics of a single molecule in liquid crystalline solvents and a coarse-grained molecular dynamics study of the dendrimer in the bulk. The coarse-grained model has been developed and parameterized using the results of the atomistic and semi-atomistic work. The single molecule studies showed that the liquid crystalline dendrimer was able to change its structure by conformational changes in the flexible chains that link the mesogenic groups to the core. Structural change was seen under the application of a mean field ordering potential in the gas phase, and in the presence of liquid crystalline solvents. No liquid crystalline phases were observed for the bulk phase studies of the coarse-grained model. However, when the length of the mesogenic units was increased there was some evidence for microphase separation in these systems.
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Van, Schalkwyk Welmarie. "Self-assembly of amphiphilic discotic materials." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/79799.
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Thesis (MSc)--Stellenbosch University, 2013.ENGLISH 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.
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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.
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Wu, Haiyan. "Design and Development of New Chemistry for Biosensing." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1502459975409826.
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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.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemistry, 2019Cataloged 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
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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.
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Hydroxyapatite (HAP) coatings are used in orthopaedic surgery for bone regeneration.
Current methods of phase quantification of HAP coatings suffer from drawbacks. A
novel methodology of quantitative phase analysis of HAP coatings has been devised and
validated. This method, based on whole pattern fitting with a fundamental parameters
approach, incorporates amorphous calcium phosphate (ACP) and apatite phases into
structural refinements.
A comparison of the structural and chemical properties of plasma sprayed (PS) and novel
electrodeposited (ED) HAP coatings has been conducted. ED coatings contained less
ACP and more preferred orientation than the PS coatings, although the stoichiometry was
similar.
In vitro investigations of PS and ED coatings in simulated body fluid and foetal calf
serum revealed that both are bioactive. A carbonated apatite layer produced on the ED
coatings was -0.7μm thick with a stoichiometry and chemical constituents similar to that
of natural bone apatite.
PS coatings produced a nanocrystalline carbonated apatite layer (-4μm). For the first
time it has been possible to model crystalline HAP and nanocrystalline apatite as
independent phases and obtain accurate lattice parameters for each.
A positive linear correlation has been made between microstrain and the solubility of
HAP and carbonated apatites. Dissolution studies have shown that the behaviour of HAP
and carbonated apatite is dominated by crystallite size at low undersaturation and by
crystallite size and microstrain at high undersaturation for crystallites between -30OA-
1000A. Metastable equilibrium occurred for crystallites <_400A at low undersaturation.
Carbonate content did not affect the solubility or dissolution behaviour.
A novel technology for coating polymeric tape with HAP for potential use in anterior
cruciate ligament reconstruction has been devised. Mechanical tests have demonstrated
that no adverse properties are induced by the coating technology. Cell culture studies
have shown that the HAP layer is capable of enhanced attachment, proliferation and
differentiation of osteoblast cells compared to uncoated tape.
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Etok, 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.
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Hydroxyapatite (HAP) coatings are used in orthopaedic surgery for bone regeneration. Current methods of phase quantification of HAP coatings suffer from drawbacks. A novel methodology of quantitative phase analysis of HAP coatings has been devised and validated. This method, based on whole pattern fitting with a fundamental parameters approach, incorporates amorphous calcium phosphate (ACP) and apatite phases into structural refinements. A comparison of the structural and chemical properties of plasma sprayed (PS) and novel electrodeposited (ED) HAP coatings has been conducted. ED coatings contained less ACP and more preferred orientation than the PS coatings, although the stoichiometry was similar. In vitro investigations of PS and ED coatings in simulated body fluid and foetal calf serum revealed that both are bioactive. A carbonated apatite layer produced on the ED coatings was -0.7μm thick with a stoichiometry and chemical constituents similar to that of natural bone apatite. PS coatings produced a nanocrystalline carbonated apatite layer (-4μm). For the first time it has been possible to model crystalline HAP and nanocrystalline apatite as independent phases and obtain accurate lattice parameters for each. A positive linear correlation has been made between microstrain and the solubility of HAP and carbonated apatites. Dissolution studies have shown that the behaviour of HAP and carbonated apatite is dominated by crystallite size at low undersaturation and by crystallite size and microstrain at high undersaturation for crystallites between -30OA- 1000A. Metastable equilibrium occurred for crystallites <_400A at low undersaturation. Carbonate content did not affect the solubility or dissolution behaviour. A novel technology for coating polymeric tape with HAP for potential use in anterior cruciate ligament reconstruction has been devised. Mechanical tests have demonstrated that no adverse properties are induced by the coating technology. Cell culture studies have shown that the HAP layer is capable of enhanced attachment, proliferation and differentiation of osteoblast cells compared to uncoated tape.
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Small, 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.
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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.
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Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2010.ENGLISH 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.
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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.
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Endres, 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.
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Riba, Moliner Marta. "Supramolecular Strategies to Control the Assembly of Organic-Based Materials." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/378647.
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The focus of this thesis is the use of supramolecular chemistry to functionalize polymers to obtain organic-based materials with a control of their structure and properties.
The non-covalent functionalization of polymers via supramolecular chemistry is a potentially efficient route to introduce a particular property with which a new functional molecular material can be originated. This strategy has specially been explored to incorporate conjugated structures in polymeric constructs for new semiconducting materials. Although important advances have been made in this field, the incorporation of π-electron functional units to polymeric backbones with well-controlled arrangement between the donor and acceptor parts is still an area of huge interest for material science.
Following this idea, the supramolecular functionalization of the homopolymer poly(4-vinyl pyridine) (P4VP) with an electron donating unit based on an tetrathiafulvalene (TTF) has been explored. Tetrathiafulvalenes (TTFs) are excellent π-electron donor units that are widely studied in molecular electronic applications due to their p-type character and stable doped states. Through complementary hydrogen bonding components of a derivative TTF (TTFCOOH), uniform films incorporating the redox active components have been prepared. When the films were doped using different oxidising agents, Electrostatic Force Microscopy (EFM) studies indicated that a reorganisation at the surface of the films occurred and of charges in their surfaces appeared.
Once the application of the P4VP-TTFCOOH films as charge-carrier hybrid material was demonstrated, the next step was to use the block copolymer poly(styrene-b-4-vinyl pyridine) (PS-b-P4VP) due to its amphiphilic behavior. Therefore, different molar ratios of PS and P4VP blocks have been used to prepare new PS-b-P4VP-TTFCOOH thin films. The influence of the phase segregation of the PS-b-P4VP-TTFCOOH film to the charge transportation upon oxidation was performed correlating the Small-Angle X-ray Scattering (SAXS) and EFM results.
On the other hand, microfluidics is a microfabrication technique that relies on the manipulation of fluids, which can be used to control the final microstructure and self-assembly of compounds, by the simple adjusting of the values of the hydrodynamic flow focusing (confinement effect). Moreover, microfluidics offers respect to the bulk conditions important advantages such as larger relation surface-to-volume, lower consumption values and a better control of the concentration gradients. The improvement of the intermolecular contact of disk-shaped C3-symmetric tris(TTF) system has been studied using microfluidics. This molecule possesses three bonded derivative TTF units through a central aromatic ring that, under determined conditions, large coiled helical fibers could be obtained by their aggregation. A de-doping process of the C3-symmetric tris(TTF) molecule has been studied using microfluidics, towards the study of the influence of the technique on the organization of this compound. Afterwards, a new characterization methodology was suggested, based on bimodal-Atomic Force Microscopy (bimodal-AFM) in order to draw a distinction between electrostatic and mechanical contributions of the coiled fibers and, corroborating that the charge transportation phenomenon occurred.
Furthermore, hydrogels have been in the spotlight due to their biocompatibility in, for instance, tissue engineering applications. Then, the structural enhancement of an ionically-driven coacervated hydrogel obtained via microfluidics platform by tuning flow focusing parameters was studied. In a further step, the functionalization of this hydrogel with TTFCOOH molecules under bulk and microfluidic conditions and its charge-carrier character were also analyzed. Additionally, with the objective to immobilize the hydrogel on surfaces, micro-contact printing, technique was tested.
Finally, the organization and phase segregation of the PS-b-P4VP coordinated with a metalloporphyrin system has also been approached. Porphyrins, in general, possess exceptional inherent optical and electronic properties that make them suitable for application related with solar cells. Moreover, due to their electrochemical and photophysic characteristics they can easily be modified with other functional groups. Porphyrins can be found free or complexed with metals and in both states they have self-assembly properties. The coordination between PS-b-P4VP and chiral and an achiral zinc (II) metalloporphyrin has been explored in order to study the chirality transfer from the porphyrin to the hybrid materials. In the last instance, and in an exploratory attempt to use porphyrins as molecular rotors, different strategies of surface immobilization of the porphyrin-block copolymer system were also approached by micro-contact printing.
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Hall, P. J. "The macromolecular chemistry of coals." Thesis, University of Newcastle Upon Tyne, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377435.
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Capadona, Jeffrey R. "Surface-directed assembly of fibrillar extracellular matrices." Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-04142005-221724/.
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Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2005.Elliot Chaikof, Committee Member ; Loren Williams, Committee Member ; David M. Collard, Committee Chair ; Andres J. Garcia, Committee Chair ; Marcus Weck, Committee Member.
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Zhu, Zhixue. "Cyclic oligomers in macromolecular and supramolecular chemistry." Thesis, University of Reading, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272293.
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Eden, E. G. "Analysis of solution-phase macromolecular materials by diffusion NMR." Thesis, University of Liverpool, 2017. http://livrepository.liverpool.ac.uk/3006567/.
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Molecules such as covalent cages can adopt several shapes, in which the ratio of starting materials is the same, but the number of starting materials, and the shape of the resulting molecule is different. However, determining this in the absence of a crystal structure can be challenging. Pulsed field gradient (PFG) NMR has been used for two decades to characterise large macromolecules in solution, but it is still difficult to determine precise structural information, because of the rotational-averaging experienced in experimental measurements. Here, we develop experimental techniques for collecting PFG-NMR data that break this barrier, and allow characterisation of several useful molecular descriptors. By measuring the diffusion coefficients of molecules in a range of solvents, incurvate surfaces are probed to map the outer surface of nanometre-sized molecular species. This technique allows details about the geometrical shape of covalent cages to be determined without the need for isolation. Furthermore, we compare experimental PFG-NMR data to structures produced by computational modelling and produce a new molecular descriptor, ρr, which describes the isotropy of covalent cages. This descriptor is used to determine the quality of agreement between proposed structures and experimental PFG-NMR data. In analysing polymers, we develop a new mathematical model for determining the molar-mass dispersity (ÐM) by PFG-NMR. We find a single parameter is sufficient to determine the dispersity of a system, which eliminates the need for data modelling and enhances the reliability of analysis. We hope this will make the technique more accessible to polymer scientists, and will help test the validity of molar-mass dispersity measurements made by other means. Finally, we synthesise five novel dodecaamide cages, which contain functional groups that offer the opportunity to extend functionality beyond the cage via further reaction. We take significant steps towards producing singly functionalised species, which could be incorporated into polymeric materials for the development of robust membranes and coatings.
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Kuttner, Christian [Verfasser]. "Macromolecular Interphases and Interfaces in Composite Materials / Christian Kuttner." München : Verlag Dr. Hut, 2014. http://d-nb.info/1063222036/34.
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Price, 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.
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Akeroyd, Niels. "Click chemistry for the preparation of advanced macromolecular architectures." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/3985.
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Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: Different click chemistry methods have been used together with Reversible Addition- Fragmentation chain Transfer (RAFT) mediated polymerization to synthesize macromolecular architectures. A new leaving group for RAFT was introduced. This triazole leaving group allows for easy conjugation of the RAFT agent to various substrates via the copperI catalyzed Huisgen 1,3-dipolar cycloaddition reaction. Subsequently monomer can be polymerized onto the substrate using the RAFT agent. This connects the polymer to the substrate via a hydrolytically stable 1,2,3-triazole. The Mitsunobu reaction was used to chain-end functionalize polymers. The Mitsunobu reaction allows for the substitution of primary and secondary alcohols with a nucleophile. The modification of polymer chain-ends was done in two ways. Firstly, thiol-functional chain-ends were used as the nucleophile in the Mitsunobu reaction using propargyl alcohol as the alcohol. This yielded alkyne-functional polymers. Thiol chain-end functional polymers were obtained by the aminolysis of polymers synthesized via RAFT. Secondly, alcohol-functional polymers were modified. In the case of poly(vinylpyrrolidone), the RAFT group was hydrolyzed and alcohols were obtained. Hydroxyl functional PEG was obtained commercially. The hydroxyl functionality was reacted in the Mitsunobu reaction using hydrazoic acid (HN3) as the nucleophile. Azide chain end functional polymers were obtained. These alkyne and azide chain end functional polymers were subsequently used in the copperI catalyzed Huisgen 1,3-dipolar cycloaddition reaction. Ultra Fast Hetero Diels-Alder click chemistry (UFHDA) was used to synthesizes norbornenelike structures (substituted 2-thiabicyclo[2.2.1]hept-5-ene moieties). Norbornene-like structures can be polymerized via Ring Opening Metathesis Polymerization (ROMP). Monomers were synthesized using phenethyl(diethoxyphosphoryl)dithioformate and cyclopentadiene. Macromonomers were obtained from the UFHDA of Polystyrene (PSTY) synthesized via RAFT, using phenethyl(diethoxyphosphoryl) dithioformate as the RAFT agent, and cyclopentadiene or cyclopentadienyl-terminated PEG as the dienes. The obtained (macro) monomers were homo- and copolymerized using Ring Opening Metathesis Polymerization (ROMP). For the ROMP, four different Grubbs type catalysts were tested.The ring-strain promoted Huisgen 1,3-dipolar cycloaddition reaction uses cyclooctynes as the alkyne. The ring-strain in this molecule allows for a fast reaction at room temperature. This reaction is potentially very interesting for biological applications because it doesn’t require the toxic copper catalyst. In this work three routes towards cyclooctynes are investigated. PEG was chain end functionalized with the obtained cyclooctyne derivatives. Overall, click chemistry methodologies were applied to synthesize different macromolecular architectures. Results include a new type of RAFT agent that allows for easy conjugation to substrates, reaction methods for chain end modification of polymers, and the synthesis of new monomers and polymers.
AFRIKAANSE OPSOMMING: Verskillende kliek chemie metodes, tesame met Omkeerbare Addisie Fragmentasie ketting Oordrag beheerde polimerisasie (OAFO), is gebruik vir die sintese van makromolekulêre argitekture. ʼn Nuwe verlatende groep vir OAFO was bekend gestel. Die triazool verlatende groep bied die moontlikheid vir gemaklike koppeling van die OAFO agente met ‘n verskeidenheid van substrate via die koperI gekataliseerde Huisgen 1,3-dipolêre siklo-addisie reaksie. Gevolglik kan monomere gepolimeriseer word op die substraat deur middel van die OAFO agent. Dit laat toe vir die koppeling van die polimeer op die substraat via a hidrolitiese stabiele 1,2,3-triazool. Die Mitsunobu reaksie was gebruik vir die funksionaliseering van die end groepe van die polimeer ketting. Die Mitsunobu reaksie laat toe vir die substitusie van primêre en sekondêre alkohole met ‘n nukleofiel. Die verandering van die polimeer ketting end groepe was uitgevoer op twee verskillende maniere. Eerstens is ketting end groepe met ‘n tiol funktionaliteit gebruik as a nukleofiel in die Mitsunobu reaksie deur gebruik te maak van propargiel alkohol as die alkohol. Dit het alkyn funktionele polimere opgelewer. Tiol ketting end funktionele polimere was verkry deur middel van aminolise van die polimere gesintetiseer via OAFA. Tweedens is alkohol funktionele polimere gemodifiseer. In die geval van poli(N-vinielpirolidoon) is die OAFA grope gehidroliseer en gevolglik is alkohole verkry op hierdie manier. Kommersiële funksionele PEG was gebruik. Die hidroksie funksionele groep was gereageer in die Mitsunobu reaksie deur gebruik te maak van waterstof asied (HN3) as die nukleofiel. Dit het asied funksionele ketting eindes opgelewer. Die alkyne en asied ketting end funksionele polimere was gevolglik gebruik in die koperI gekataliseerde Huisgen 1,3- dipolêre siklo-addisie reaksie. Ultra Vinnige Hetero Diels-Alder kliek chemie (UVHDA) was gebruik vir die sintese van norborneen agtige strukture (gesubstitueerde 2-tiabisiklo[2.2.1]hept-5-een groepe). Monomere was gesintetiseer deur gebruik te maak van fenieletiel(di-etoksifosforiel)di-tioformaat en siklopentadiëen of siklopentadiëen-getermineerde PEG. Die sintese van makromonomere is verkry via UVHDA deur gebruik te maak van polistireen, gesintetiseer deur middel van OAFO (waar fenieletiel(dietoksifosforiel) di-tioformaat gebruik is as OAFO agent), en siklopentadiëen of siklopentadiëengetermineerde PEG. Die makromonomere wat verkry is, is verder gebruik vir homo- en kopolimerisasie deur middel van Ring Opening Metatesis Polimerisasie, ROMP. Vir die ROMP is vier verskillende Grubbs tipe kataliste gebruik. Die ring-spanning bevorderde die Huisgen 1,3,-dipolêre siklo-addissie reaksie waar siklooketyne gebruik is as die alkyne. Die ring-spanning in die molekule laat toe vir vinninge reaksies by kamer temperatuur. Die reaksie het die potensiaal vir interessante biologiese toepassings aangesien dit nie ’n kopper katalis vereis nie wat toksies van aard is. In die studie word drie roetes ten einde to siko-oktyn ondersoek. PEG was geketting end gefunksionaliseerd met die gevolgde siko-oktyne afgeleides. Verskillende kliek chemie metodologiëe was toegepas vir die sintese van verskillende makromolekulêre argitekture. Resultate sluit in een nuwe tipe OAFO agent wat maklike konjugasie met substrate bewerkstellig, ketting einde modifikasie van polimere, nuwe monomere en polimere wat gesintetiseer is.
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Barker, Philip. "The introduction of supramolecular architectures into macromolecular arrays." Thesis, University of Warwick, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250967.
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Withe, D. "Some studies of macromolecular initiators of vinyl polmerisation." Thesis, University of Liverpool, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370867.
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Hansell, Claire F. "Tetrazine-norbornene cycloadditions in macromolecular synthesis and functionalisation." Thesis, University of Warwick, 2013. http://wrap.warwick.ac.uk/58244/.
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This thesis explores the use of the tetrazine–norbornene inverse electron demand Diels-Alder cycloaddition reaction in polymer and materials science. Chapter 1 gives an introduction to the main concepts and techniques used throughout the thesis. Chapter 2 applies the tetrazine–norbornene reaction to polymer endfunctionalisation and polymer–polymer coupling, in both organic media and water, and establishes the methods (UV/vis and 1H NMR spectroscopies) for monitoring the coupling reaction. Chapter 3 applies the reaction to the modification of a self-assembled polymer micelle and demonstrates its use in tandem with the coppercatalysed azide–alkyne click reaction. The synthesis of an amphiphile bearing both norbornene and alkyne groups is described, the amphiphile is self-assembled and a one-pot dual functionalisation of both the core and shell carried out. Chapter 4 describes the formation and analysis by a variety of methods of sub-20 nm sized polystyrene nanoparticles through the single chain collapse of a norbornene-decorated polymer, ligated with a bisfunctional tetrazine. Chapter 5 discusses attempts to further expand the use of the reaction of tetrazines to polymers bearing pendent alkene groups. The synthesis and characterisation of such polymers is detailed, and attempts to functionalise with a variety of tetrazines described.
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Becerril-Garcia, Hector Alejandro. "DNA-Templated Nanomaterials." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1823.pdf.
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Carlmark, Anna. "Complex Macromolecular Architectures by Atom Transfer Radical Polymerization." Doctoral thesis, KTH, Fibre and Polymer Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3740.
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Controlled radical polymerization has proven to be a viableroute to obtain polymers with narrow polydispersities (PDI's)and controlled molecular weights under simple reactionconditions. It also offers control over the chain-]ends of thesynthesized polymer. Atom transfer radical polymerization(ATRP) is the most studied and utilized of these techniques. Inthis study ATRP has been utilized as a tool to obtain differentcomplex macromolecular structures.
In order to elaborate a system for which a multitude ofchains can polymerize in a controlled manner and in closeproximity to one another, a multifunctional initiator based onpoly(3-ethyl-3-(hydroxymethyl)oxetane was synthesized. Themacroinitiator was used to initiate ATRP of methyl acrylate(MA). The resulting dendritic-]linear copolymer hybrids hadcontrolled molecular weights and low PDI's. Essentially thesame system was used for the grafting of MA from a solidsubstrate, cellulose. A filter paper was used as cellulosesubstrate and the hydroxyl groups on the cellulose weremodified into bromo-]ester groups, known to initiate ATRP.Subsequent grafting of MA by ATRP on the cellulose made thesurface hydrophobic. The amount of polymer that was attached tothe cellulose could be tailored. In order to control that thesurface polymerization was -eliving-f and hence that thechain-]end functionality was intact, a second layer of ahydrophilic monomer, 2-hydroxyethyl methacrylate, was graftedonto the PMA- grafted cellulose. This dramatically changed thehydrophilicity of the cellulose.
Dendronized polymers of generation one, two and three weresynthesized by ATRP of acrylic macromonomers based on2,2-bis(hydroxymethyl)propionic acid. In the macromonomerroute, macromonomers of each generation were polymerized byATRP. The polymerizations resulted in polymers with low PDI's.The kinetics of the reactions were investigated, and thepolymerizations followed first-order kinetics when ethyl2-bromopropionate was used as the initiator. In the-egraft-]onto-f route dendrons were divergently attached to adendronized polymer of generation one, that had been obtainedby ATRP.
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Van, De Walle Matthias. "Continuous photoflow for macromolecular design." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/208293/1/Matthias_Van%20De%20Walle_Thesis.pdf.
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The current thesis critically advances the synthesis of precision macromolecular structures via photochemical approaches. The work examines the use of continuous photoflow setups to facilitate scalable synthesis of various polymeric architectures, and helps to overcome limitations that hinder photochemistry to be incorporated more frequently into industrial processes. This thesis demonstrates the flexibility and versatility of continuous photoflow and its potential to be developed further, to exceed currently existing photochemical procedures based on traditional batch approaches.
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Oguzkaya, Funda. "Synthesis Of Macromolecular Catalyst Systems And Applications." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613565/index.pdf.
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SYNTHESIS OF MACROMOLECULAR CATALYST SYSTEMS
AND
APPLICATIONS
Oguzkaya, Funda
PhD., Department of Chemistry
Supervisor: Prof. Dr. Cihangir Tanyeli
September 2011, 144 pages
The thesis mainly proposed to design macromolecular catalyst systems. Such catalysts should follow the way of "Green Chemistry"
with including no metallic ions and have also the ability of reusability. Hence, nitroxide chemistry was chosen as the key point. Catalysts were synthesized with surely including TEMPO as the functional part as the most preferable nitroxide derivative. As a skeleton, norbornene was chosen firstly. Following obtaining 3-(methoxycarbonyl) bicyclo[2.2.1]hept-5-ene-2-carboxylic acid (49), 4-aminoTEMPO was attempted to be inserted in the structure. In this case, 4-aminoTEMPO was preferred as a TEMPO derivative so as to include reactive amine functional group. As a result, two different monomers were obtained. Then, Ring Opening Metathesis Polymerization via first generation Grubbs catalyst was adjusted to reach target macromolecules. Furthermore, as a second type skeleton for the catalyst, Thiophene-Pyrrole-Thiophene (SNS) structure was chosen, since these well-known structures have the ability to polymerize easily. Anelli Oxidation protocol including corresponding catalysts in combination with NaOCl+NaHCO3 (pH 9.1) and KBr resulting in remarkable high activity with low catalyst concentrations typically 1 mol % was chosen for the oxidation of alcohols so as to reach to target aldehydes and ketones. Investigation of other applicable areas via collaborative studies was thought to open the way of electrochromic and biosensor studies as the different points of view. Electropolymerization was performed in a three-electrode cell consisting of an Indium Tin Oxide coated glass slide (ITO) as the working electrode, platinum wire as the counter electrode and Ag wire as the pseudo reference electrode. As the biosensor part, glucose oxidase (GOx) was used as the model enzyme for glucose oxidation in the presence of molecular oxygen. Poly-SNS-based carboxylic acid served as an excellent immobilization matrix for glucose sensing. Key words: TEMPO, Anelli Oxidation
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Mohin, Jacob W. "Nanostructured π-Electron Materials for Energy Applications Derived from Macromolecular Self-Assembly." Research Showcase @ CMU, 2015. http://repository.cmu.edu/dissertations/1045.
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Globalization and climate change have driven the need to develop new technologies which can provide clean, plentiful energy from renewable sources. This work was focused on the application of nanostructured π-electron materials derived from carbon-based macromolecules towards capturing, converting, and storing energy. Nanostructures are beneficial in this role as they provide high interfacial area and unique electronic properties which can be harnessed to perform chemistry relevant to energy conversion and storage. This work was focused on the characterization, materials development, and device application of two nanostructured systems: (i) poly(3-hexyl)thiophene (P3HT) blended with phenyl(C-61)butyric acid methyl ester (PCBM), and (ii) copolymer-templated nitrogen-doped nanoporous carbons (CTNCs). In both systems, nanomorphology has pronounced impact on the performance of devices made from such materials. P3HT/PCBM blends find application as a photovoltaic material, where the phase-separated morphology is crucial for efficient photogenerated charge collection. Despite widespread recognition of the importance of morphology in P3HT/PCBM photovoltaics, a robust understanding of the unique packing motif of P3HT on the morphology of blended structures has yet to emerge. This thesis addresses this deficiency by developing methods which connects real-space atomic force microscopy images with inverse space x-ray scattering patterns to analyze poorly ordered two-phase systems. The application of this method allowed for quantitative measurement of the phase ratios of P3HT/PCBM nanostructured blends, utilizing the Porod length of inhomogeneity and the Bragg length associated with pseudo-fibrillar P3HT morphologies. The results showed that P3HT possesses void space originating from molecular weight dispersity inherent to polymerization, which accounts for solid-phase solubility of PCBM in P3HT. X-ray scattering and atomic force microscopy were also used in part to characterize CTNCs. Past success using CTNCs as electrocatalysts and supercapacitors motivated research towards increasing their surface area by utilizing a lower molecular weight precursor polymer. Atom-transfer radical polymerization was utilized to synthesize block copolymers consisting of polystyrene and polyacrylonitrile, but it was found their surface areas were lower than those achieved in previous work. Careful structural analysis by variable temperature x-ray scattering showed that crystallization of polyacrylonitrile drives morphological changes on heating, increasing domain spacing. Further thermal analysis showed that polystyrene interferes with the crosslinking of polyacrylonitrile, which may cause morphological collapse leading to low surface area. A feature of CTNCs noted in past and present studies is their sizeable surface area consisting of pores <1 nanometer (micropores). Differential scanning calorimetry showed that reactive chain ends left behind by polymerization might play a role in disrupting the crosslinking process, resulting in a material with sizeable microporosity, which could be used to engineer dual pore-size materials. Finally, CTNCs were utilized for heterogeneous catalytic production of hydrogen from water, with electrons provided by both light and external circuitry. Their performance was correlated with nitrogen heteroatom content, conductivity, and nanomorphology, and shown to match that of noble metals. The lessons learned about nanomorphology in P3HT/PCBM and CTNCs highlight the importance of nanomorphology in energy devices and will serve as insight for materials design in future studies.
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Wiltshire, James Thomas. "Design and synthesis of star macromolecular architectures with degradable functionality /." Connect to thesis, 2007. http://eprints.unimelb.edu.au/archive/00004014.
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Shreif, Zeina. "Multiscale theory of nanosystems applications to self-assembly, macromolecular dynamics, and nanomedicine /." [Bloomington, Ind.] : Indiana University, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3330802.
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Thesis (Ph. D.)--Indiana University, Dept. of Chemistry, 2008.Title from PDF t.p. (viewed Jul 23, 2009). Source: Dissertation Abstracts International, Volume: 69-10, Section: B, page: 6130. Adviser: Peter Ortoleva.
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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.
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Estudios previos de nuestro grupo de investigación describieron moléculas orgánicas heterocíclicas, aparentemente de capas cerradas que presentan carácter birradical triplete asequible térmicamente.
La formación de esta especie birradicalaria proviene de la rotura de un doble enlace exocíclico por rotación de dicho enlace. Un factor de estabilización del biradical formado es la conjugación de uno de los electrones desapareados con un ciclo aromático aceptor de electrones y el otro con otro ciclo dador de electrones, con la consiguiente deslocalización de los mismos, de manera independiente, en cada una de dichas partes. Además, tanto los datos experimentales como los teóricos han mostrado que, si las moléculas estudiadas contienen protones ácidos, la formación de los correspondientes aniones hacen aumentar de manera considerable la población de moléculas en estado birradical triplete.
Se exploró un elevado número de estructuras buscando cuales eran las características mínimas que debían presentar para tener el citado estado birradical triplete asequible térmicamente y, por lo tanto, un posible carácter paramagnético. Este trabajo dio como resultado una gran familia de nuevas moléculas (más de 50 compuestos) que presentaban la propiedad estudiada y de las que se pudo deducir un modelo molecular general para todas ellas.
A partir del modelo anterior se buscó en la literatura moléculas que pudieran presentar las anteriores características electrónicas y se encontraron el Dasatinib y sus análogos, fármaco de segunda generación que se utiliza en el tratamiento de algunos tipos de cáncer y el p-HBDI, cromóforo de la proteína verde fluorescente (‘Green Fluorescent Protein’, GFP). Este último compuesto, de fácil síntesis y estudiado desde muchos puntos de vista pero no desde el nuestro, se tomó como modelo para la mayor parte de nuestros trabajos.
Ante los precedentes anteriores, la presente Tesis Doctoral ha consistido en obtener materiales macromoleculares formados por dichas moléculas, con el objetivo de analizar la propiedad que nos interesa cuando éstas moléculas se hallan en entornos poliméricos. Para ello, se han desarrollado diversos métodos de síntesis.
Previamente, ha sido necesario sintetizar derivados de las unidades de menor tamaño que presentan un mayor carácter birradical triplete asequible térmicamente
funcionalizadas adecuadamente para ser unidas sobre los diferentes soportes poliméricos. Se han introducido diversos tipos de funcionalización para intentar anclar dichas moléculas, empleando diversas opciones de síntesis, siendo la funcionalización principal introducida una cadena de 2-hidroxietilo, un grupo funcional versátil que permite llevar a cabo bastantes transformaciones sintéticas. Además, se han preparado y estudiado modelos auxiliares simples, análogos de los sistemas macromoleculares objetivo de nuestro trabajo, con el objeto de estudiar previamente las reacciones que posteriormente se ensayarían a nivel macromolecular.
Una vez obtenidas las moléculas con carácter birradical triplete asequible térmicamente funcionalizadas adecuadamente, se unieron a diferentes soportes poliméricos. El primero fue el ácido poliacrílico (PAA), mediante esterificación entre los grupos ácidos de la cadena polimérica y los grupos hidroxilo de las moléculas anteriores. Además, se intentaron llevar a cabo sin éxito polimerizaciones radicalarias para generar el mismo tipo de material macromolecular. Dada la dificultad de purificación de estos compuestos se decidió utilizar soportes poliméricos con grupos funcionales NH2. Estos soportes fueron la polietileimina ramificada (PEI) y el (aminometil)poliestireno reticulado. Asimismo, se estudió la posibilidad de emplear estructuras dendriméricas como alternativa a los sistemas anteriores, por su estructura química bien definida.
Intentar unir todas las moléculas que han presentado carácter birradical triplete asequible térmicamente sobre soportes poliméricos sería un trabajo sumamente extenso, con lo que, básicamente, nos hemos centrado en la obtención de análogos poliméricos del p-HBDI y derivados.
La técnica de elección para el estudio de estos productos poliméricos de los que se esperaban que fueran paramagnéticos ha sido la Resonancia Paramagnética Electrónica (RPE, ‘Electron Paramagnetic Resonance’, EPR).
Los resultados obtenidos han confirmado los estudios previos que nos permiten predecir qué moléculas presentan la propiedad indicada en el título de esta Memoria.Studies 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.
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Shell, Elizabeth. "Chemical Unfolding and Macromolecular Crowding of Alpha-1-Acid Glycoprotein." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1115047649.
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Harling, Michael G. W. "The synthesis of poly-#beta#-ketides and their application to rigid macromolecular systems." Thesis, University of Reading, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317649.
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Ménard, Amélie. "P450 enzymes in biocatalysis: exploration of chemical auxiliaries, macromolecular crowding, bioconjugation and oriented-immobilization." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114213.
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Cytochrome P450 enzymes (CYPs or P450s) form a ubiquitous family of heme-dependent monooxygenases known mainly for their role in xenobiotic metabolism and their remarkable ability to regio- and stereoselectively oxidize inactivated C-H bonds, a feat that is difficult to achieve by chemical methods. Unfortunately, our ability to study and exploit these enzymes as in vitro biocatalysts has been limited by their low activity, low stability and poor product predictability. This thesis focuses on the study of human drug metabolizing P450 isoforms, namely CYP2E1, CYP3A4 and CYP2D6 because of their exceptional ability to accept a large variety of substrates. In Chapter 2, we demonstrate the utility of "type II ligands" as chemical auxiliaries for biocatalysis with human CYP2E1. We show that linking the chemical auxiliary nicotinate to a variety of short hydrocarbon substrates can promote their oxidation with predictable regioselectivity at the secondary aliphatic or alkenyl C-H bond furthest from the auxiliary. The origin of this selectivity was rationalized through docking studies of our auxiliary-substrate compounds with reported X-ray crystals structures of CYP2E1. These results not only confirm the general utility of the chemical auxiliary approach pioneered by our lab to direct the predictable oxidation of inactivated C-H bonds by P450 enzymes, but also provide a system with complementary regioselectivity.A short study of the effects of macromolecular crowding on the activity of human CYP3A4 and CYP2D6 is presented in Chapter 3. We found that certain crowding agents were not detrimental to enzyme activity while others had a negative effect. Moreover, certain conditions (initially tested as controls) that improved enzymatic activity were uncovered. In Chapter 4, the non-covalent oriented-immobilization of CYP3A4 via its C-terminal histidine-tag is described. We show that immobilization on Ni-NTA agarose resin via this strategy has no detrimental effect on enzyme activity or stability. The lyoprotectant properties of Ni-NTA were also investigated. In Chapter 5, we designed and characterized a mutant of CYP3A4 that retains its enzymatic activity upon modification with a variety of fluorescent maleimide dyes via a single cysteine residue on its surface, namely C64. We also show that the activity of this mutant is preserved upon immobilization onto solid supports via this same cysteine residue. Finally, results of a preliminary feasibility study towards applying this immobilization strategy to eventual single-molecule fluorescence microscopy studies are presented.Les enzymes cytochrome P450 (CYPs ou P450) forment une famille omniprésente de mono-oxygénases possédant un noyau hème au site-actif. Ces enzymes sont surtout connues pour leur rôle dans le métabolisme de produits pharmaceutiques et pour leur capacité remarquable à oxyder les liens C-H non-activés de façon régio- et stéréosélective. Malheureusement, notre capacité d'étudier et d'utiliser ces enzymes comme biocatalyseurs in vitro est limitée par leur faible activité, instabilité et une incapacité des connaissances actuelles à prédire leurs produits.Dans le chapitre 2, nous démontrons l'utilité des ligands de type II comme auxiliaires chimiques pour la biocatalyse avec CYP2E1 humaine. Nous démontrons que l'auxiliaire chimique nicotinate, lorsque lié à une variété d'hydrocarbures courts, peux promouvoir leur oxydation avec une régiosélectivité prévisible pour le lien C-H secondaire aliphatique ou alcényle le plus éloigné de l'auxiliaire. L'origine de cette sélectivité a été rationalisée à l'aide de «docking» moléculaire de nos composés auxiliaire-substrats à l'intérieure de structures cristallines de CYP2E1 publiées par d'autres chercheurs. L'utilité d'auxiliaires chimiques pour contrôler la régiosélectivité des enzymes P450 avait déjà été démontrée par notre groupe de recherche. Les résultats présentés dans ce chapitre offrent non seulement une confirmation du potentiel de cette stratégie, mais aussi un système complémentaire pour l'oxydation prévisible de liens C-H non-activés par les enzymes P450. Ces résultats confirment également la généralité de l'approche mis au point dans notre laboratoire qui décrit l'utilisation d'une auxiliaire chimique pour diriger l'oxydation prévisible de liens C-H non-activés par les enzymes P450.Une étude des effets de l'encombrement macromoléculaire sur l'activité enzymatique des CYP3A4 et CYP2D6 humaines est présentée dans le chapitre 3. Nous avons trouvé que leur activité demeure inchangée par la présence de certains agents encombrants alors que d'autres ont un effet négatif. De plus, certaines conditions (testées initialement comme contrôle) qui améliorent l'activité enzymatique ont été découvertes.Dans le chapitre 4, l'immobilisation orienté non-covalente de CYP3A4 par son étiquette de type his-tag C-terminale est décrite. Nous démontrons que son immobilisation sur une résine Ni-NTA à base d'agarose via cette stratégie n'a aucun effet négatif sur l'activité ou la stabilité de l'enzyme. Les propriétés lyoprotectrices de cette résine ont aussi été investiguées.Dans le chapitre 5, nous concevons et caractérisons un mutant actif de CYP3A4 lors de modifications avec une variété de maléimides fluorescentes à l'endroit d'un unique résidu cystéinique à sa surface, soit le C64. Nous démontrons aussi que ce mutant préserve son activité lorsqu'immobilisé sur des supports solides par ce même résidu cystéinique. Finalement, les résultats d'études préliminaires sont présentés qui envisagent l'application de cette stratégie d'immobilisation envers des études éventuelles de spectroscopie de fluorescence à la résolution d'une seule molécule.
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Zang, 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.
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Goldmann, Anja Sabrina. "Click chemistry as efficient ligation strategy for complex macromolecular architecture and surface engineering." kostenfrei, 2009. http://opus.ub.uni-bayreuth.de/volltexte/2010/679/.
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Normand, Mickaël. "Group 13 organometallic chemistry and macromolecular catalytic engineering for polymers issued from bioresources." Rennes 1, 2012. http://www.theses.fr/2012REN1S091.
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Poly(lactic acid) (PLA) is a biocompatible and biodegradable polymer produced by ring-opening polymerization (ROP) of lactide (LA), which is used in a wide-range of applications. A large number of highly efficient catalysts/initiators have been introduced, such as alkoxides of Al, Zn and rare-earth metals. For instance, aluminium catalysts/initiators have been extensively exploited for the ROP of rac-LA to provide remarkable control over molecular weights and polydispersities, good stereocontrol being achieved in some cases. At the same time, due to very specific synthetic chemistry the ROP precursors incorporating indium still remain rare. We report in this thesis five main chapters dealing with the following topics: i) synthesis of new indium complexes of fluorinated dialkoxy-diimino salen-like ligands and their use in the ROP of rac-LA; ii) preparation of new {phenoxy-imine}-aluminum and indium complexes and their catalytic properties in the immortal ROP of lactide; iii) synthesis of new bimetallic aluminum and indium initiators supported by bis(phenoxy-imine) ligands and their use in the ROP of rac-LA; iv) Meerwein-Pondorf-Verley reduction processes in aluminum and indium isopropoxide complexes of imino-phenolate ligands; v) cyclodextrin-centered polyesters: controlled ROP of cyclic esters from beta-cyclodextrinLe poly(acide lactique) (PLA) est un polymère biocompatible et biodégradable dont les applications sont très diverses et qui est principalement produit par polymérisation par ouverture de cycle (ROP) du lactide (LA). Un grand nombre de catalyseurs/initiateurs particulièrement efficaces ont été synthétisés au cours des trente dernières années, tels que les dérivés alcoxy d'aluminium, de zinc et de métaux des terres rares. Par exemple, les catalyseurs/initiateurs à base d'aluminium furent largement exploités pour la ROP du lactide racémique (rac-LA) pour conduite à de remarquables contrôles des masses moléculaires et des distributions de masses ainsi qu'à un bon contrôle de la stéréochimie du polymère final. Encore aujourd'hui, en raison de voies de synthèses chimiques très spécifiques, les exemples de ROP du lactide impliquant des catalyseurs/initiateurs à base d'indium restent rares. Ainsi, nous reportons dans ce manuscrit de thèse cinq principaux chapitres traitant des sujets suivants : i) synthèse de nouveaux complexes d'indium supportés par des ligands dialcoxy-diimino fluorés de type hémi-salen and leur utilisation en ROP du rac-LA ; ii) préparation de nouveaux complexes {phenoxy-imine} d'aluminium et d'indium et leur propriétés catalytiques en ROP immortelle du lactide ; iii) synthèse de complexes bimétalliques d'aluminum et d'indium supportés par des ligands bis(phenoxy-imine) et leur utilisation en ROP du rac-LA ; iv) processus de réduction de type Meerwein-Pondorf-Verley dans des complexes isopropylate imino-phenolate d'aluminum et d'indium ; v) synthèse de polyesters centrés sur la béta-cyclodextrine par ROP contrôlée d'esters et de carbonate cycliques
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Stark, 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.
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Su, Hao. "Macromolecular Structure Evolution of Giant Molecules Via "Click" Chemistry: Asymmetric Giant Gemini Surfactants Based on Polyhedral Oligomeric Silsesquioxane." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1398727473.
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O'Brien, Stephen. "The chemistry of mesoporous materials." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390532.
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Patel, Harish M. "Biomimetic templating in materials chemistry." Thesis, University of Bath, 1998. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390225.
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Narayan, Urja Vidya. "Synthesis and characterization of phosphorous containing macromolecular polyether compounds." Scholarly Commons, 2006. https://scholarlycommons.pacific.edu/uop_etds/640.
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A radioisotope of rubidium, 82Rb is used in positron emission tomography. Neutral crown ethers and cryptands have been studied as carrier ligands for Rb+ but exhibit low ion carrying capacity and high toxicity. The present study involved investigating a lariat ether containing an ionizable phosphoryl moiety and a lipophilic sidearm. This kind of molecule is expected to be ionized at physiological pH. It should be able to form neutral complexes with Rb+ and may be able to cross the blood-brain barrier.
Molecular modeling of crown ether-alkali metal cation complexes indicates that a macrocycle containing more than 18 but less than 21 atoms can incorporate Rb+ ion in its cavity. Molecular modeling of some of the complexes of phospho-lariat ethers with rubidium using the Spartan'02 software package revealed that a lariat ether containing 20 member macrocycle will probably form the most stable complex with Rb+ion. Also, it was thought that more flexibility could be imparted to the macrocycle if it contains propyleneoxy units instead of ethyleneoxy units which form most crown ethers. Molecular modeling of two phospho-lariat ethers with 16 and 20 membered rings revealed that 20 membered macrocycle may be a better choice due to the side arm's participation in the complexation with Rb+ to a greater extent. Molecular modeling was used to find the bond angles and bond distances in this molecule.
The synthesis to obtain ionizable phospho-bipodands was performed using subsequent benzylation, phosphorylation and hydrogenation steps. The characterization of products was done using HPLC, NMR and ESI-MS techniques. The synthetic scheme used was demonstrated to be plausible and could be used to obtain ionizable phoshobipodands. Extraction using solid phase anion exchange columns proved to be a good clean up procedure for obtaining pure bipodand. This bipodand could be used as a precursor for synthesizing an ionizable 20 membered lariat ether.
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Gossett, John Jared. "Analysis of macromolecular structure through experiment and computation." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/51925.
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This thesis covers a wide variety of projects within the domain of computational structural biology. Structural biology is concerned with the molecular structure of proteins and nucleic acids, and the relationship between structure and biological function. We used molecular modeling and simulation, a purely computational approach, to study DNA-linked molecular nanowires. We developed a computational tool that allows potential designs to be screened for viability, and then we used molecular dynamics (MD) simulations to test their stability. As an example of using molecular modeling to create experimentally testable hypotheses, we were able to suggest a new design based on pyrrylene vinylene monomers. In another project, we combined experiments and molecular modeling to gain insight into factors that influence the kinetic binding dynamics of fibrin "knob" peptides and complementary "holes." Molecular dynamics simulations provided helpful information about potential peptide structural conformations and intrachain interactions that may influence binding properties. The remaining projects discussed in this thesis all deal with RNA structure. The underlying approach for these studies is a recently developed chemical probing technology called 2'-hydroxyl acylation analyzed by primer extension (SHAPE). One study focuses on ribosomal RNA, specifically the 23S rRNA from T. thermophilus. We used SHAPE experiments to show that Domain III of the T. thermophilus 23S rRNA is an independently folding domain. This first required the development of our own data processing program for generating quantitative and interpretable data from our SHAPE experiments, due to limitations of existing programs and modifications to the experimental protocol. In another study, we used SHAPE chemistry to study the in vitro transcript of the RNA genome of satellite tobacco mosaic virus (STMV). This involved incorporating the SHAPE data into a secondary structure prediction program. The SHAPE-directed secondary structure of the STMV RNA was highly extended and considerably different from that proposed for the RNA in the intact virion. Finally, analyzing SHAPE data requires navigating a complex data processing pipeline. We review some of the various ways of running a SHAPE experiment, and how this affects the approach to data analysis.
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Livshits, Maksim Y. "Fundamental Investigation of PhotoActive Materials From Small Molecules to Materials." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1490713190973503.
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Acosta, 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.
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Este trabajo se ubica en una perspectiva marcada por dos fuentes de inspiración y exigencia, que se complementan mutuamente: La primera está relacionada con el campo tecnológico y la segunda viene del ambiente científico. Por un lado, es sabido que los productos plásticos y compuestos de matriz polimérica se usan cada vez más en ingeniería y, como la mayoría de los materiales utilizados en este ámbito, muchos están sometidos a cargas dinámicas; de tal manera que en este momento resulte tan necesario el estudio de sus propiedades como el desarrollo de métodos de ensayo fiables para poder caracterizarlos bajo diferentes condiciones de aplicación de carga, siendo de especial interés conocer la respuesta de los mismos a altas velocidades de solicitación. Por otro lado, desde la óptica de la ciencia de los materiales, la relación entre la estructura y el comportamiento de fractura de los polímeros es una de sus más importantes ramas, en la que los ensayos de impacto juegan un rol principal. Cada vez más un conocimiento cuantitativo del comportamiento a impacto, en términos de la ciencia de los materiales, requiere de un conjunto de técnicas adicionales para suplir -teórica y experimentalmente- los métodos de ensayo de impacto básicos especificados por las entidades de normalización. En este sentido, el objetivo central de la presente Tesis es el diseño y puesta a punto de técnicas de ensayo para el estudio de la fractura de los materiales poliméricos, a altas velocidades de solicitación y en el dominio de baja energía.Como 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.
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Thomas, Paul Matthew. "Structural chemistry of organically templated materials." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670194.
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Strange, Gregory Alan. "RESPONSIVE MATERIALS VIA DIELS-ALDER CHEMISTRY." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/710.
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The corrosion of infrastructure imposes a significant monetary cost, and at times human cost, upon society. Methods to improve corrosion resistance of materials are described herein which utilize the reversibility of the Diels-Alder reaction to impart thermal responsiveness upon materials. Such stimuli responsiveness can potentially play a role in self healing properties which lead to reduced cracking and thus increased corrosion protection.
Reversible Diels-Alder chemistry was utilized to manipulate the surface energy of glass substrates. Hydrophobic dieneophiles were prepared and attached to glass slides and capillaries to yield a nonwetting surface. Thermal treatment of the surfaces cleaved the Diels-Alder linkage, and resulted in the fabrication of a hydrophilic surface. Preliminary analysis utilized contact angle (CA) measurements to monitor the change in surface energy, and observed a hydrophilic state (CA - 70±3°) before attachment of the dieneophile to a hydrophobic state (CA - 101±9°) followed by regeneration of the hydrophilic state (CA - 70±6°) upon cleavage of the Diels-Alder linkage. The treatments were then applied to glass capillaries, with effective treatment confirmed by fluid column measurements. Patterned treatments were also demonstrated to provide effective fluid flow gating.
Reversible Diels-Alder linkages were incorporated into polymer thermoset binding resins in order to provide a means by which a crosslinked thermoset could undergo stimuli responsive reversible crosslinking. The binder systems which were utilized included two types of amine curing agents, polydimethylsiloxane (PDMS) and Jeffamine® polyetheramines (PEA), and two types of epoxy resins, EPON resin based on diglycidyl ether of Bisphenol-A and epoxidized soybean oil. Various dienes and dienophiles were employed to functionalize the selected binder systems and were met with various degrees of success. The synthetic technique which proved to be the most promising was the Diels-Alder modification of the epoxidized soybean oil.
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Bengtsson, Jonas. "POLYMERIZATION OF δ-VALERO LACTONE BY NOVEL CYCLODEXTRIN DIMER." Thesis, KTH, Skolan för kemivetenskap (CHE), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-156213.
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På senare tid har forskning syftat till att främja miljövänligare teknik inom alla fält. Det visar sig inom materialframställningen som en önskan att använda material som inte är beroende av olja, inte tillverkade med tungmetaller samt nedbrytbara med en minimal miljöpåverkan. Detta har bland annat gett organiska katalysatorer en större plats inom forskningen. En av dessa är cyclodextrin, en cyklisk oligosackarid som har påvisats bilda makromolekylara komplex med andra molekyler. En aspekt av detta är att den kan hydrolysera polymerer då den bildar komplex med hydrofila molekyler och kan aktivera dessa genom vätebindning. Vilket Harada et. al. visade kunde utnyttjas for att polymerisera cycliska estrar. Detta examensarbete utforskar en del av det arbetet genom att dels verifiera polymerisationstekniken som ar en lösningsmedelsfri polymerisation dels försök till att framstalla en ny dimer av cyclodextrin som ska effektivt kunna polymerisera cycliska estrar mer effektivt an tidigare. Den nya dimern bygger på en thiourea-länk. Aven om polymerisation med vanlig cyclodextrin har visats fungera sa kan den föreslagna dimern inte polymerisera lika effektivt. Syntesen ar problematisk och annars åtråvarda egenskaper hos cyclodextrin, som makromolekylär komplexbildning, kan inhibera polymerisationen och tidigare uppreningssteg.