Dissertations / Theses on the topic 'Supramolecular transport'
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Kim, Jinsang 1969. "Supramolecular assemblies of conjugated sensory polymers and the optimization of transport properties." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/28246.
Full textIncludes bibliographical references.
(cont.) The vectorial energy transfer design of sensory films to harvest and direct energy to the surface detection layer toward ultimate signal amplification has been discussed. Third, the role of chemical structure of a sensory polymer in the selectivity of a conjugated polymer-based fluorescent sensor has been examined. In two different sensory systems for the detection of potassium ions and a nitroaromatic explosive TNT, respectively, key chemical design parameters governing their selectivity have been rationalized. Finally, the combination of the conclusions of this thesis provided an idealized structure of a fluorescent conjugated polymer-based sensory film with optimized sensitivity and selectivity.
A sensor is one of the many important applications of conjugated polymers. Poly(p-phenylene ethynylene)s (PPEs) have been studied for fluorescence-based sensor applications. The chemical structure and nano-structure of a polymer in the solid-state are two critical parameters that determine sensitivity and selectivity of a conjugated polymer-based sensor. In this thesis, both parameters have been systematically investigated. First, the Langmuir-Blodgett method was used to control the nano-structure of PPEs in the solid-state. Rational design of surfactant PPEs made it possible to control the conformation of a single polymer strand and interpolymer spatial arrangement at the air-water interface. In situ UV-Vis and fluorescence spectroscopy on the Langmuir film in controlled nano-structures revealed the effects of conformation and spatial arrangement of conjugated polymers on their intrinsic optical properties. Since the controlled structure of a monolayer at the air-water interface can be transferred to a solid substrate, structurally well-defined multilayer LB films of PPEs with confined optical properties were fabricated. This made it possible to study the role of interpolymer aggregation in the photophysical properties of conjugated polymer films. The results provided a general design principle to make a highly emissive conjugated polymer film. Second, an ideal thickness of a sensory film for optimizing sensitivity was determined by experimental and theoretical analysis of energy transport phenomena in multilayer PPE films.
y Jinsang Kim.
Ph.D.
Wittmann, Bernd [Verfasser], and Richard [Akademischer Betreuer] Hildner. "Tailoring long-range energy transport in supramolecular architectures / Bernd Wittmann ; Betreuer: Richard Hildner." Bayreuth : Universität Bayreuth, 2021. http://d-nb.info/1241183716/34.
Full textSchönle, Joachim. "Quantum transport studies for spintronics implementation : from supramolecular carbon nanotube systems to topological crystalline insulator." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAY022/document.
Full textMolecular electronics is one of the most intriguing fields of modern research, which could bring forth a modular and scalable building system for nanoscale spintronics applications. A particularly promising example are single-molecule magnets, which have already successfully shown to be suitable for spin valve or spin qubit operations. One of the biggest challenges of the field is the integration of these nanometer-sized objects in complex circuits in order to allow for detection and manipulation of moleculear spin states. As shown in recent years by the NanoSpin group, carbon nanotubes (CNTs) can serve as such type of carrier for the single-molecule magnets, combining features of both constituents.A corner stone of this thesis project was hence the development of a dependable fabrication technique for high-quality CNT devices, controllable by multiple local gate electrodes in order to enable local control of molecular hybrid systems. A process based on conventional one-chip fabrication was developed from scratch, for which optimization of sample design, lithography and deposition techniques as well as material choices had to be carefully incorporated, in order to accomodate the restrictions imposed by the CNT growth conditions on the prevention of leakage currents. We succeeded in producing clean CNT devices, which could support a double dot configuration, tunable from p- to n-type characteristics. The segments created in this way can be stabily controlled over the entire device length and should hence provide a suitable backbone to study molecular physics.Topological matter constitutes an enticing platform to investigate both fundamental principles as well as possible applications from spintronics to quantum computation. Topological crystalline insulators, with tin telluride ( SnTe ) as a prime example, represent a new state of matter within this zoo of 3D topological materials. Soon after first experimental realizations, suggestions were made about the possibility of an unconventional type of superconductivity hosted at the interface between topological matter and conventional superconductors. Possible implications of such systems include Cooper pairing with finite momentum, the FFLO phase, or topological quantum computing, based on peculiar excitations, called Majorana bound states.This thesis project aimed to participate in the investigation of signs of unconventional superconductivity in SnTe . Transport experiments on bare films in Hall bar geometries and superconducting hybrid devices, realized as both Josephson junctions and SQUIDs, are discussed. A surprisingly strong coupling of SnTe to Ta superconductor was found and dependencies of superconductivity on sample geometries, temperature and magnetic field were investigated. The current-phase relation was analyzed in the limit of strong kinetic effects. Electrostatic gating and rf exposure was explored, but predominant physics in such configurations turned out to be of purely conventional type, pointing out the importance of improvements on the material side.In-plane magnetic field measurements gave rise to the manifestation of ϕ0-SQUIDs with tunable 0−π-transitions, providing evidence for possible controlled transitions from trivial superconductivity to unconventional coupling regimes in SnTe
Gence, Valérie. "Auto-assemblage dynamique de nano-objets pour de nouvelles voies de transport membranaire dirigé." Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20263/document.
Full textThe main topic of this thesis concerns the synthesis and characterization of novel bioinspired membrane materials whose primary function is the transport of chemical species directed . The realization of these systems is based on the self-assembly of building blocks ( molecular , polymeric ) whose properties will induce directional transport in new materials.First, the synthesis of new bola - amphiphilic compounds was shown . They were then examined by fluorescence spectroscopy and dynamic light scattering allowed to highlight their ability to form ion channels, proton channels and water channels in a lipid bilayer.A second study involved the development of mesoporous nanomaterials membrane. These have been functionalized with hydrophobic groups to allow the confinement of the compounds in the mesopores via van der Waals interactions.Finally, a recent study has focused on the development of materials membrane based on artificial Aquaporins in order to obtain a material to transport water directed through the membrane
Chen, Ying. "NMR Applications in Soft Materials Science: Correlation of Structure, Dynamics, and Transport." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/75177.
Full textPh. D.
López, Brito Kenia Amelia. "Síntesis de compuestos híbridos nanoestructurados y evaluación de su comportamiento supramolecular y actividad biológica." Doctoral thesis, Universitat de les Illes Balears, 2013. http://hdl.handle.net/10803/127218.
Full textMarmin, Thomas. "Premiers nanovecteurs supramoléculaires ciblant le cerveau par transport actif." Mémoire, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/10492.
Full textAbstract : Delivering drug into the body to target specific organs, while minimizing side effects, is an enormous scientific challenge. Current research reveals that there are many pitfalls for delivering therapeutic compounds to the central nervous system. Many diseases (autism, schizophrenia, Alzheimer's, etc.) linked to the central nervous system affect the quality of life and entail significant costs for society. This thesis is based on the improvement in the accessibility of therapeutic compounds to the brain by passing the blood-brain barrier, a biological barrier difficult to cross. To introduce drugs into the central nervous system, this barrier must be overcome. This is very difficult because it is remarkably effective in protecting the brain. This is why we will develop a new strategy based on a new type of transporter. We propose to use macrolactams having the property of stacking in the form of supramolecular tubes of adequate stability. It will then be possible to graft medicines and also agents capable of opening the blood-brain barrier. This manuscript describes the development of these new chiral macrocycles, the results of various structural analyses proving the presence of robust tubes and systems, and finally the functionalization of the macrocycles by a medicinal agent (doxorubicin).
Walker, Glen William, and not available. "Electron Transfer Reactivity, Synthesis, Surface Chemistry and Liquid-Membrane Transport of Sarcophagine-Type Poly-Aza Cage Complexes." The Australian National University, 1997. http://thesis.anu.edu.au./public/adt-ANU20010702.124104.
Full textWang, Chien-Lung. "Synthesis and Characterization of C60-Porphyrin Derivatives for Enhanced Photovoltaic Performance through Efficient Charge Generation and Transport." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1301353045.
Full textChang, Mincheol. "Processing parameter effects on the molecular ordering and charge transport of poly(3-hexylthiophene) thin films." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/54281.
Full textAfsari, Mamaghani Sepideh. "The Formation of Two Dimensional Supramolecular Structures and Their Use in Studying Charge Transport at the Single Molecule Level at the Liquid-Solid Interface." Diss., Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/350915.
Full textPh.D.
Understanding charge transport through molecular junctions and factors affecting the conductivity at the single molecule level is the first step in designing functional electronic devices using individual molecules. A variety of methods have been developed to fabricate metal-molecule-metal junctions in order to evaluate Single Molecule Conductance (SMC). Single molecule junctions usually are formed by wiring a molecule between two metal electrodes via anchoring groups that provide efficient electronic coupling and bind the organic molecular backbone to the metal electrodes. We demonstrated a novel strategy to fabricate single molecule junctions by employing the stabilization provided by the long range ordered structure of the molecules on the surface. The templates formed by the ordered molecular adlayer immobilize the molecule on the electrode surface and facilitate conductance measurements of single molecule junctions with controlled molecular orientation. This strategy enables the construction of orientation-controlled single molecule junctions, with molecules lacking proper anchoring groups that cannot be formed via conventional SMC methods. Utilizing Scanning Tunneling Microscopy (STM) imaging and STM break junction (STM-BJ) techniques combined, we employed the molecular assembly of mesitylene to create highly conductive molecular junctions with controlled orientation of benzene ring perpendicular to the STM tip as the electrode. The long range ordered structure of mesitylene molecules imaged using STM, supports the hypothesis that mesitylene is initially adsorbed on the Au(111) with the benzene ring lying flat on the surface and perpendicular to the Au tip. Thus, long range ordered structure of mesitylene facilitates formation of Au-π-Au junctions. Mesitylene molecules do not have standard anchoring groups providing enough contact to the gold electrode and the only assumable geometry for the molecules in the junction is via direct contact between Au and the π system of the benzene ring in mesitylene. SMC measurements for Au/mesitylene/Au junctions results in a molecular conductance value around 0.125Go, two orders of magnitude higher than the measured conductance of a benzene ring connected via anchoring groups. We attributed this conductance peak to charge transport perpendicular to the benzene ring due to direct coupling between the π system and the gold electrode that happens in planar orientation. The conductance we measured for planar orientation of benzene ring is two order of magnitude larger than conductance of junctions formed with benzene derivatives with conventional linkers. Thus, altering the orientation of a single benzene-containing molecule between the two electrodes from planar orientation to the upright attached via the linkers, results in altering the conductivity in a large order. Based on these findings, by utilizing STM imaging and STM-BJ in an electrochemical environment including potential induced self-assembly formation of terephthalic acid, we designed an electrochemical single molecule switch. Terephthalic acid forms large domains of ordered structure on negatively charged Au(111) surface under negative electrochemical surface potentials with the benzene ring lying flat on the surface due to hydrogen bonding between carboxylic acid groups of neighboring molecules. Formation of long range ordered structure facilitates direct contact between the π system of the benzene ring and the gold electrodes resulting in the conductance peak. On positively charged Au(111), deprotonation of carboxylic acid groups leads to absence of long range ordered structure of molecules with planar orientation and absence of the conductance peak. In this case alternating the surface (electrode) potential from negative to positive charge densities induces a transition in the adlayer structure on the surface and switches conductance value. Hence, electrochemical surface potential can, in principle, be employed as an external stimulus to switch single molecule arrangement on the surface and the conductance in the junction. The observation of conductance switching due to molecule’s arrangement in the junction lead to the hypothesis that for any benzene derivative, an orientation-dependent conductance in the junction due to the contact geometry (i.e. electrode-anchoring groups versus direct electrode-π contact) should be expected. Conventional techniques in fabricating single molecule junctions enable accessing charge transport along only one direction, i.e., between two anchoring groups. However, molecules such as benzene derivatives are anisotropic objects and we are able to measure an orientation-dependent conductance. In order to systematically study anisotropic conductivity at single molecule level, we need to measure the conductance in different and well-controlled orientations of single molecules in the junction. We employed the same EC-STM-BJ set up for SMC measurements and utilize electrochemical potential of the substrate (electrode) as the tuning source to variate the orientation of the single molecule in the junction. We investigated single molecule conductance of the benzene rings with carboxylic acid functional groups in two orientations: one with the benzene ring bridging between two electrodes using carboxylic acids as anchoring groups (upright); and one with the molecule lying flat on the substrate perpendicular to the STM tip (planar). Physisorption of these species on the Au (111) single crystal electrode surface at negative electrochemical potentials results in an ordered structure with the benzene ring in a planar orientation. Positive electrochemical potentials cause formation of the ordered structure with molecules standing upright due to coordination of a deprotonated carboxyl groups to the electrode surface. Thus, formation of the single molecule junction and consequently conductivity measurements is facilitated in two directions for the same molecule and anisotropic conductivity can be studied. In engineering well-ordered two-dimensional (2-D) molecular structures with controlled assembly of molecular species, pH can be employed as another tuning source for the molecular structures and adsorption in experiments conducted in aqueous solutions. Based on simple chemical principles, amine (NH2) groups are hydrogen bond acceptors and donors. Amines are soluble in water and protonation results in protonated (NH3+) and unprotonated (NH2) amine groups in acidic and moderately acidic/neutral solutions, respectively. Thus, amines are suitable molecular building blocks for fabricating 2-D supramolecular structures where pH is employed as a knob to manipulate intermolecular hydrogen bonding leading to phase transitions. We investigated pH induced structural changes in the 1,3,5–triaminobenzene (TAB) monolayer and the formation/disruption of hydrogen bonds between neighboring molecules. Our STM images indicate that in the concentrated acidic solution, the protonated amine groups of TAB are not able to form H-bonds and long range ordered structure of TAB does not form on the Au(111) surface. However, in moderately acidic solution (pH ~ 5.5) at room temperature, protonation on the ring carbon atom generates species capable of forming H-bonds leading to the formation of the long range ordered structures of TAB molecules. Utilizing EC-STM set up, we investigated the controllable fabrication of a TAB 2-D supramolecular structure based on amine-amine hydrogen bonding and effect of pH in formation of ordered/disordered TAB network.
Temple University--Theses
Cristian, Alina. "Systèmes moléculaires et matériaux structurés pour la conduction ionique et le transport d’eau." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS114/document.
Full textThe aim of this work is the study of ion and water transport either across bilayer membranes or polymeric membranes used for reverse osmosis. In the first part, this transport through self-assembled synthetic systems was studied; the transport selectivity is in strong relation with the supramolecular structure, formed by weak intra and intermolecular bonds. Ion transport is studied by fluorescence spectroscopy and water transport is studied by light scattering using “stopped flow” technique. The objective is to obtain systems that could imitate transport functions of biomolecules as transmembrane proteins. This functional mimicry is achieved through self-assembly of organic molecules containing imidazole cycle and urea function that can self-assembly and form selective pathways for ion transport. To create the equivalent of the cell membrane, we used unilamellar lipid vesicles. Then, we determined a structure - transport activity relationship for a series of synthesized compounds. For the second part of this work we described the fabrication and the characterization of new thin film composite membranes for water desalination that can present a good balance between permeability and salt rejection. A series of hydrazides as molecular precursors was synthesized in order to replace the metaphenylene diamine (MPD), classically used. Again, hydrogen bonds play an important role, because the rejection is due to a high cross-linking. The polymers synthesized by interfacial polymerization were characterized by infrared spectroscopy, thermogravimetric analysis, and X-Ray diffraction. The membrane films were characterized by scanning electron microscopy, atomic force microscopy and contact angle measurements. Membrane performances were then tested in cross-flow filtration of water and saline solutions
Grauwels, Glenn. "Physico-Chemical Characterisation of Chloride Transmembrane Transport using Calix[6]arene-based Receptors." Doctoral thesis, Universite Libre de Bruxelles, 2020. https://dipot.ulb.ac.be/dspace/bitstream/2013/311902/5/contratGG.pdf.
Full textDoctorat en Sciences de l'ingénieur et technologie
info:eu-repo/semantics/nonPublished
Schneider, Susanne. "Synthesis and functional properties of triarylamine self-assemblies in conducting devices : electronic, ionic, and water transport systems." Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAF037.
Full textBased on the navel and highly interesting self-assembly properties found for certain triarylamines, together with the resulting conducting properties, this PhD project investigates the synthesis and properties of triarylamines towards the transport of electrons, ions or water molecules. The thesis starts with an introduction on supramolecular chemistry and supramolecular polymers, and then discuss in its second chapter the synthesis and properties of macrocyclic triarylamine analogues with interesting electromagnetic properties. ln the following third chapter this thesis work explores the applicability of triarylamines towards the biomimetic transport of metal ions and water molecules through lipid bilayer membranes. The last chapter of this thesis then deals with the fabrication of hybrid organic/inorganic conducting surfaces through doping of non-conducting surfaces with triarylamine assemblies
Li, Xuesong. "Synthesis and physical properties of helical nanosized quinoline-based foldamers : structure, dynamics and photoinduced electron transport." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0013/document.
Full textHerein, synthesis, characterization and application (photoinduced electron transport) of nanosized quinoline-based foldamers have been explored. With double segment strategy, a variety of helical nanosized foldamers (up to 96 quinoline units) were successfully prepared based on 8-aminoquinoline-2-carboxylic acid monomer.The dynamic properties in gas phase and solution were investigated. Ion mobility mass spectrometry afforded access to the conformation state of foldamers ingas phase; DOSY and fluorescence anisotropy assessed the diffusion (translational and rotational, respectively) of foldamers in solution. All of these techniques revealed that quinoline-based foldamers are rigid and that helical conformation is conserved. Photoinduced electron transport through nanosized foldamer was also studied and the mechanism and the transport ratios were revealed
Sampedro, Palerm Angel. "Oligoescuaramidas cíclicas: síntesis y actividad biológica." Doctoral thesis, Universitat de les Illes Balears, 2015. http://hdl.handle.net/10803/294603.
Full textA aquesta Tesi Doctoral, titulada “Oligoesquaramides cícliques: síntesis i activitat biològica”, es recull la síntesis de diferents derivats esquaramídics amb aplicacions biològiques. La Tesi es divideix en quatre capítols. El primer capítol és una introducció i els tres capítols restants recullen els resultats obtinguts seguint un flux de treball temporal, ja que els objectius de cada capítol deriven dels resultats del capítol anterior. El primer capítol és una introducció on es descriu la unitat esquaramida i les aplicacions biològiques d’alguns composts que inclouen aquesta estructura. Al segon capítol es presenta la síntesis d’oligoesquaramides cícliques amb diferents modificacions estructurals. Una vegada resolta la síntesis i elucidació estructural, s’ha estudiat la seva activitat antitumoral comparant els resultats amb els obtinguts a un estudi previ. Les noves oligoesquaramides cícliques sintetitzades tenen una activitat tumoral similar o inferior que aquelles estudiades prèviament. En aquest capítol es detallen a més les diferents alternatives sintètiques que s’han seguit per fer front als inconvenients que s’han anat presentant durant les etapes d’elongació i macrociclación. Al tercer capítol es descriu la síntesis de sondes fluorescent amb la finalitat de seguir l’evolució temporal i la localització intracel•lular de les oligoesquaramides una vegada realitzat el tractament. L’estudi s’ha realitzat emprant l’oligoesquaramida cíclica més petita degut a la seva baixa citotoxicitat. En total s’han preparat tres sondes fluorescent que es diferencien al fluoròfor emprat i al mètode de conjugació. Els millors resultats s’han obtingut amb una sonda que inclou un derivat de BODIPY com a marcador fluorescent. Aquesta sonda s’internalitza mitjançant transport actiu i es fotoestable. La facilitat d’internalització cel•lular s’ha explicat en base a l’afinitat observada entre l’oligoesquaramida cíclica i molècules fosforilades presents a la membrana cel•lular i al citoplasma. Per suportar aquesta hipòtesis, es descriuen els estudis realitzats amb ITC per determinar l’afinitat entre una oligoesquaramida cíclica quaternitzada i models d’algunes biomolècules rellevants tals com: manosa 6-fosfat, fosfocolina, etc. Els conjugats covalents d’oligoesquaramides cícliques poden facilitar el transport de fàrmacs. Per aquest motiu i amb les evidències de la internalització cel•lular, s’ha plantejat la seva utilització futura com a transportadors autoimmolatius. Així doncs, el quart capítol s’ha dedicat al disseny, síntesis i avaluació d’un sistema autoimmolatiu format per una unitat esquaramida i un model de “càrrega”, en aquest cas un fluoròfor. Després de diversos intents s’ha aconseguit optimitzar un sistema basat en l’ús de grups disulfur com a gallet. El sistema desenvolupat allibera la totalitat de la “càrrega” en condicions fisiològiques pròpies d’un entorn intracel•lular en un període de dues hores. D’aquesta forma s’obre la possibilitat de funcionalizar un dels seus extrems amb oligoesquaramides cícliques o altres transportadors, activant l’alliberació de la “càrrega” únicament a l’interior cel•lular i separant d’aquesta forma el transportador de la “càrrega”.
This Doctoral thesis, entitled “Cyclic oligosquaramides: synthesis and biological activity”, describes the synthesis of different squaramidic derivatives with biological applications. The Thesis is divided in four chapters. Chapter 1 is an introduction and the remaining chapters compile the results obtained. They are organized following the temporal workflow. Thus, the objectives of every chapter arise from the results of the previous one. Chapter 1 describes the squaramide unit properties and the biological applications of some compounds with this structure. Chapter 2 presents the synthesis of cyclic oligosquaramides with different structural modifications. Once solved the synthesis and structural elucidation, their antitumor activity has been evaluated, comparing the results with those obtained in a previous assay. The new synthetized cyclic oligosquaramides have similar or lower antitumoral activity that those studied before. In this chapter are also included the different synthetic strategies followed in order to overcome the drawbacks arisen during the elongation and macrocyclization stages. Chapter 3 reports the synthesis of cyclic oligosquaramides fluorescent probes with the aim to investigate the cell permeabilization process and the inner cell localization of these compounds once the treatment is done. The study has been done with the smallest cyclic oligosquaramide due to its low cytotoxicity. Altogether, three fluorescent probes have been prepared, differing in the fluorophore used and the conjugation procedure. Best results have been achieved with a probe containing a BODIPY derivative as a fluorescent marker. This probe is internalized by active transport, has a great photostability and remains located at late endosomes within the cell. The easily achieved cell internalization has been explained with the affinity observed between the cyclic oligosquaramide and phosphorylated molecules found in cell membranes and in the cytoplasm. To support this hypothesis, this chapter includes the experiments done with ITC in order to determine the affinity between a cyclic quaternized oligosquaramide and models from some relevant biomolecules as: mannose 6-phosphate, phosphocholine, etc. The covalent conjugates with cyclic oligosquaramides are able to facilitate drugs transportation. Because of this, and with the evidence of the observed cell internalization, their utilization as autoimmolative carriers has been proposed. So, Chapter 4 describes the design, synthesis and evaluation of an autoimmolative system consisting in a squaramide unit and a load, in this case a fluorophore. After some attempts, the system has been optimized using a disulfide bond as the trigger. The developed autoimmolative system releases the entire load in physiological conditions after two hours.
Song, Enfeng. "Self-assembly of Benzenesulfonate Amphiphiles and Synthesis of Membranes Containing Self-assembled Supramolecular Transport Channels." Doctoral thesis, 2014. https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-2014010712224.
Full textMartins, Joana Mafalda Nunes Paulo Silva. "Supramolecular Sensors and Actuators for Biologically Relevant Analytes." Master's thesis, 2020. http://hdl.handle.net/10362/111125.
Full textIn the field of biochemistry, the study of peptides is of great interest, not only due to the variety of functions these molecules present in biological systems (e.g. in signalling, neuromodulation, immune response and metabolism) but also as tools in biotechnology and as pharmaco-logical agents, as is the case of antimicrobial cell-penetrating peptides. Supramolecular receptors have had a rising application in the transport, modulation and sensing of these biomolecules, due to the strong interactions they can establish with affinities up to the nM range. In this thesis, a group of supramolecular dual emission sensors and a light-controlled transporter for cationic peptides were synthesized and characterized. These consist of a modular amphiphilic system based on a p-sulfonatocalix[4]arene receptor, monosubstituted in its lower rim with different functional groups, depending on the target application. The sensors SCnPy present an aliphatic chain of variable size (n = 4, 6), with a pyrene fluorescent moiety at its end, while the transporter SC6Azo presents a six-carbon aliphatic chain with an azobenzene moiety. SCnPy have shown to have the pyrene’s characteristic monomer emission at low concentration and, when at high enough concentrations or in the presence of organic cations, they can form ground state dimers that emit at higher wavelengths. The variation of chain length successfully modulated the capacity of the SCnPy sensors to aggregate. SC4Py showed this dual emission for polyarginines of four or more residues, presenting a critical aggregation concentration (CAC) of 9.8 μΜ for a 1:2 molar ratio of sensor to a six-residue polyarginine. SC6Py is able to aggregate in the presence of peptides with only 3 cationic residues, with CAC of 0.11 μM, with the same peptide and in the same conditions as for SC4Py. Furthermore, SC6Py showed selectivity for a fragment of the peptide Humanin, over a similar sequence of another mitochondrial signaling peptide, SHLP4, all the while presenting a dual emission that enables the correction of the measurement for instrumental factors and sensor concentration variations. Other phenomena and modes of detection (resonance energy transfer and dye displacement assays) were also explored for the SCnPy system. The light-controlled transporter, SC6Azo, also binds to polyarginines and presents an efficient light induced isomerization, with quantitative photochemical conversion from trans to cis, when irradiated at 382 nm, and reaching 73% of maximum conversion for the reverse reaction, upon irradiation at 500 nm. This enabled a great decrease in polarity of the tail, when irradiating the cis isomer and converting it to trans, showing a maximum increase of peptide transport in phosphatidylcholine liposomes of, approximately, 30%.
Chen, Chien Yu, and 陳建佑. "Novel Supramolecular Hole Injection/Transport Materials And Application Of High Performance Organic Light-Emitting Diode Device." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/90531445608437229326.
Full text國立交通大學
應用化學系碩博士班
100
According to the experiments, we successfully connect RNA-like group, Uracil and Adenine, on PTC, one of the traditional hole transporting materials, and then synthesize PTC-U and PTC-A. The hydrogen bond renders physical cross-link between polymer main-chains and escalates materials’ thermal stability, and electro-chemical stability. Physical cross-links make polymer film less eroded and increase the possibility of the exercise on the multi-layer of PLED devise. In addition, the hydrogen bond brought by side-chain’s functional group reduces the distance between the main-chain and increases materials’ hole transporting ability. The functional group renders HOMO energy level of polymer closer to the work function of the glass substrate of Indium Tin Oxide and improves materials’ hole injection ability. The result shows that PTC-A with strong hydrogen bond is the best on thermal stability, electro-chemical stability, the ability of hole injection, and hole transporting ability. Glass transition temperature of PTC-A is 192℃. Among the devises made by ITO/HITMs/NPB/Alq3/LiF/Al, PTC-A devise performs the best. Its external quantum efficiency achieves 2.4%, luminance efficiency is 8 cd/A. The other devise made by ITO/HTMs/Ir(ppy)3:PVK/BCP/Alq3/LiF/Al, PTC-A’s devise external quantum efficiency achieves 9.5% which is better than PEDOT’s device 5.9%. Yet, PTC-A’s devise luminance efficiency is 36 cd/A, PEDOT’s device is only 21 cd/A. Based on the experiments, the new hole injecttion/transporting materials through RNA-like group connecting show enormous potential in application use.
Huang, Pei-Hsiu, and 黃培修. "A New Supramolecular Thiophene-Based Hole-Transport Material for Advanced Light-Emitting Diodes and optoelectronic devices." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/92598397299276924957.
Full text國立交通大學
應用化學系碩博士班
99
A new concept to modify and enhance properties of existed functional polymers through bio-complementary interaction has been exploited. In this thesis, new DNA-mimetic π-conjugated poly(3-thiophene)s (P3HT) have been prepared which exhibits high thermal stability, non-corrosion, excellent hole injection and electron-blocking abilities in the solid state owing to the uracil induced physical cross-linking. The self-complementary phenomena were investigated by 1H NMR titration, DSC, WAXD and AFM in cast film provided further details into the nature of the self-assembly of these systems. Moreover, electrochemical studies reveal that the energy level of the highest occupied molecular orbital (HOMO) for these materials is between -5.12 and -5.17 eV, which is a good match for the work function of indium tin oxide (ITO), a commonly used anode for organic and polymer light-emmitting diodes (OLED and PLED). When the uracil-containing P3HTs are utilized as a hole-transporting layer (HTL) in the double layers OLED device, we found that the performance of the resulting device can be “ten times” higher than the high regularity and low regularity P3HTs and the performances are comparable to devices composed of the conventional PEDOT-PSS as HTLs with relatively less corrosive. This newly developed material may provide a potential route towards next-generation high-efficiency LED devices.
Walker, Glen William. "Electron Transfer Reactivity, Synthesis, Surface Chemistry and Liquid-Membrane Transport of Sarcophagine-Type Poly-Aza Cage Complexes." Phd thesis, 1997. http://hdl.handle.net/1885/49260.
Full textChui, Jonathan Ka Wang. "A new paradigm for voltage-clamp studies of synthetic ion channels." Thesis, 2011. http://hdl.handle.net/1828/3494.
Full textGraduate
Gravel, Julien. "Perturbation de la membrane cellulaire par des composés cationiques : transport transmembranaire contrôlé et applications biologiques." Thèse, 2017. http://hdl.handle.net/1866/20440.
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