Das Ziel der Arbeit war die Kombination von 1,3,5-Triethynylbenzen (TEB)-basierten konjugierten mikroporösen Polymeren (CMPs) mit den unterschiedlichen Materialien Silica, Chitosan und Silizium um Hybridmaterialien herzustellen. Als Grundprämisse galt dabei die anwendungsorientierte Verbesserung der Eigenschaften, wobei sich an den literaturbekannten Hauptanwendungen von CMPs – als Adsorber oder als Photokatalysator – orientiert wurde. Die Optimierung von Hybridmaterialien erfordert drei Grundvoraussetzungen: Genaue Kenntnisse der CMPs, dasselbe Verständnis von den Eigenschaften der zu kombinierenden Materialien und die Möglichkeit der umfassenden Charakterisierung. Nur unter diesen Voraussetzungen lassen sich die kollektiven und die aus der Kombination entstehenden Eigenschaften des Hybridmaterials definiert einstellen. Die erste Studie ist der Grundvoraussetzung, der Struktur-Eigenschaftsbeziehung in CMPs, gewidmet. Dabei wurden neuartige CMPs auf Basis von TEB gekuppelt mit Dibromophenanthren-diol Monomeren hergestellt (Polymer TEB-Phenanthren =PTPh). Diese Monomere wurden über die Diolgruppe mit Methyl-(OMe), Trimethylsilyl- (TMS) oder Tertbutyldimethylsilyl (TBDMS) funktionalisiert, wodurch eine homologe Reihe mit steigendem sterischen Anspruch und variierender Polarität entstand. Diese Monomere wurden jeweils mit TEB zu CMPs umgesetzt, um den Einfluss der Sterik auf die CMP Eigenschaften zu analysieren. Über dynamische Kontaktwinkelmessung wurde ermittelt, dass mit Ausnahme von PTPh-TMS, alle PTPh-CMPs mit Kontaktwinkeln zwischen 136° und 148° stark hydrophob sind. Für PTPh-TBDMS ergab sich eine weitere ungewöhnliche Eigenschaft: entgegen den klassischen CMP-Eigenschaften, war es in hydrophoben Lösungsmitteln löslich. Aus Kernspinresonanzspektroskopie (NMR), dynamischen Lichtstreuungs- (DLS) und Transmissionselektronenmikroskop- (TEM) Messungen ging hervor, dass es in Form gequollener, stärker vernetzter Nanopartikel vorliegt, die von weniger vernetztem, quasi-linearem Polymer kolloidal stabilisiert werden. Für potentielle Anwendungen in der Sensortechnik ist dabei relevant, dass dieses PTPh-TBDMS bei einer Anregung mit Licht von 400 nm fluoreszierende Eigenschaften aufweist. Die zweite Studie befasst sich mit dem ersten Hybridmaterial aus mesoporösen Silica-Mikrosphären (40 – 70 µm Durchmesser) ummantelt mit CMPs zur Adsorption organischer Schadstoffe. Während die CMPs in ihren Funktionalitäten genau auf die zu adsorbierende Substanz eingestellt werden können, verbessern die SiO2 Partikel die Dispergierbarkeit und die technische Handhabung der ansonsten schwierig abzutrennenden CMPs. In der ersten Teilstudie wurde das literaturbekannte CMP aus Dibromopyrimidin und TEB (CMP = Polymer TEB Pyrimidin = PTP) für die Ummantelung verwendet. Die in der Synthese eingesetzte Menge an SiO2 beeinflusst die Adsorption des Diclofenacs (DCF), eines weitverbreiteten Pharmazeutikums, welches als Modelladsorptiv verwendet wurde. Die ermittelten maximalen Beladungskapazitäten zeigen ein Maximum bei 3.0 g Silica auf die Standardmenge CMP. Das Silica selbst adsorbiert DCF in vernachlässigbaren Mengen, weshalb die CMP-spezifische Kapazität aus dem tatsächlich im Material enthaltenen CMP-Massenanteil (Thermogravimetrische Analyse (TGA) -Bestimmung) berechnet wurde. Hier ergibt sich für das Maximum bei 3.0 g Silica eine maximale Beladung von 422 mg DCF pro Gramm CMP, welche mit den besten bekannten Adsorbern konkurrieren kann. In der zweiten Teilstudie wurde das Prinzip der Silicasphären-Ummantelung auf andere CMPs aus jeweils TEB und Dibromonaphtalen, Dibromoanilin und Dibromopyridin übertragen. Es konnte gezeigt werden, dass die Monomerpolarität starken Einfluss auf den Erfolg der Ummantelung hat: Nur bei gleicher Polarität von Monomer und Silicaoberfläche war eine Beschichtung möglich. Mittels Präfunktionalisierung des Silicas war eine Ummantelung auch für die hydrophoberen Monomere möglich. Diese Beschichtungen wurden mit Fourier-Transformations-Infrarotspektroskopie (FTIR), Festkörper-NMR, REM, REM-EDX, TGA und TEM analysiert. Im Anschluss wurde erneut die DCF-Adsorption untersucht, wobei das Dibromoanilin basierte CMP@SiO2 die höchste CMP-spezifische DCF-Adsorptionskapazität mit 228 mg/g lieferte. Ein anderes Hybridmaterial, bestehend aus den in der ersten Studie entwickelten CMPs eingebettet in das biobasierte Polymer Chitosan, wird in der dritten Studie thematisiert. Das Ziel war, analog zu den vorhergehenden Studien, eine bessere Verteilung und Zugänglichkeit der CMPs für Adsorptive bei gleichzeitiger Retention in definierten Strukturen zur Vereinfachung der Handhabung. Chitosan als biobasiertes und biokompatibles Polymer ist vergleichsweise nachhaltig, ermöglicht medizinische Applikationen und ist gut über die Aminogruppe funktionalisierbar. Daher wurde die Aminofunktionalität mit Hexanoylchlorid umgesetzt, um eine hydrophobe Hexanoylgruppe in das Chitosan einzuführen. Das modifizierte Hexanoyl Chitosan (H-chitosan) wurde auf verschiedene Weise analysiert, wobei besonders die Änderung der rheologischen Eigenschaften aufgrund der Unterbrechung der Wasserstoffbrückenbindung zwischen den Chitosanketten durch die hydrophobe Modifizierung bedeutend waren. Anschließend wurden sowohl das reine Chitosan als auch das H-chitosan verwendet, um CMP@Chitosan Gel-Beads herzustellen. Da das CMP das teurere Material ist, wurde es im Massenverhältnis von 1:4 eingesetzt, wobei über REM und REM-EDX nachgewiesen wurde, dass die CMPs großflächig in den Chitosanmatrizen verteilt sind. Beim Trocknen wurde beobachtet, dass die luftgetrockneten Beads zu kompakten Strukturen kollabieren, während die vakuumgetrockneten Beads die gequollene Form beibehalten. Dies wirkt sich auf die Quellung der trockenen Beads im wässrigen Adsorptionsmedium aus, wobei die luftgetrockneten Beads nur geringfügig und die vakuumgetrockneten Beads deutlich stärker quellen. Dabei quellen die H-chitosan Beads generell besser, was auf die gehinderte Zusammenlagerung der Chitosanketten durch die hydrophobe Gruppe zurückgeführt wurde. Mittels Batchversuchen wurde die Adsorption von DCF bei einer niedrigen Konzentration von 1 mg/L und einer hohen Konzentration von 300 mg/L untersucht, wobei sich die vakuumgetrockneten Beads als effektiver erwiesen. Die Hybridmaterialbeads adsorbierten mehr DCF als sowohl die reinen Chitosan- bzw. H-chitosan Beads als auch die reinen CMPs. Die CMP@H-chitosan Beads adsorbierten aufgrund der verbesserten Quellung die höchsten Mengen an DCF. Die CMP-spezifische Adsorption wurde durch die Einbindung und Verteilung in den Chitosanmatrizen deutlich gesteigert, während gleichzeitig die Handhabbarkeit erleichtert wurde, da die Beads mittels eines Siebes aus der Adsorptionslösung abgetrennt werden können. Die letzte Studie ist auf Silizium-Nanopartikel (SiNPs)@CMP-Hybridmaterialien zur Anwendung als Photokatalysator in der solaren Wasserstoffgenerierung (HER) ausgerichtet. In diesem Prozess wird solare Energie direkt genutzt, um aus Wasser Wasserstoff herzustellen. Die für CMP-typischen geringen HER-Raten sollen durch die, von der AG Dasog (Dalhousie Universität, Halifax, Kanada) hergestellten, SiNPs angehoben werden. Mittels FTIR Spektroskopie wurde bestätigt, dass diese CMPs auch im Beisein der SiNPs gebildet wurden. Über TGA wurde der Massenanteil der SiNPs in den jeweiligen Hybridmaterialien bestimmt, welcher von 4 wt% bis 22 wt% variiert und vor allem vom eingesetzten Monomer abhängt. REM-EDX Analysen zeigten eine lösungsmittelunabhängige, flächendeckende Verteilung der SiNPs in den jeweiligen CMPs. Die Einbindung der SiNPs, analysiert über DLS und TEM Messungen, ergab in einem Fall eine vollständige Einbindung, in einem anderen Fall eine schlechte Einbindung und in allen übrigen Fällen partielle Einbindung. Diese partielle Einbindung, bei der Teile der SiNPs nicht mit CMP bedeckt sind, erwies sich als vorteilhaft in den Wasserstoffgenerierungsversuchen. Bei diesen SiNP@CMP Hybridmaterialien waren die HER Raten gegenüber den reinen CMPs deutlich gesteigert, wobei das beste Material 32 µmol/g*h Wasserstoff produzierte. Dieses Material wurde durch Dotierung mit H2PtCl4 weiter optimiert und in Zyklisierungsstudien eingesetzt. Während die Langzeitstabilität sich als optimierungsbedürftig erwies, war die Dotierung erfolgreich und steigerte die HER Rate auf 42 µmol/g*h. Im Rahmen dieser Arbeit wurden CMPs mit je einem Vertreter der anorganischen Isolatoren, der biobasierten Polymere und der anorganischen Halbleiter kombiniert. Die grundlegende Unterschiedlichkeit dieser Materialien zeigt, dass der Kombinationsvielfalt nur wenige Limitationen gesetzt sind. Die anwendungsbezogenen Machbarkeitsstudien zeigen die daraus erwachsenden Vorteile auf. Dabei befindet sich die Erforschung der CMP-Hybridmaterialien noch in ihren Anfängen, enthält jedoch bereits vielversprechende Strategien und Ansätze zur Lösung gesellschaftlich relevanter Problemstellungen.:Abstract V Kurzfassung VIII Abbreviations XI Symbols XII List of publications XIII List of figures XVI List of schemes XVIII List of tables XIX 1. Introduction 1 2. Theoretical background 4 2.1. Synthesis and properties of conjugated microporous polymers (CMPs) 4 2.1.1. Conjugated microporous polymers - a new class of materials 4 2.1.2. Synthesis of CMPs 5 2.1.3. Properties of CMPs 8 2.2. Fundamentals of adsorption and application of CMPs as adsorbers 11 2.2.1. Basic adsorption models 12 2.2.2. CMPs as adsorbers 16 2.3. Fundamentals and application of CMPs for hydrogen evolution 19 2.3.1. Physicochemical fundamentals of photocatalysis 19 2.3.2. Reaction and conditions of solar-driven hydrogen evolution 22 2.3.3. CMPs for solar-driven hydrogen evolution 24 2.4. Hybrid materials based on CMPs 26 2.4.1. CMPs combined with nanoparticulate systems 26 2.4.2. Macroscale CMP-based hybrid materials 30 2.5. Fundamentals of instrumental analysis 31 2.5.1. Fourier transform infrared spectroscopy 31 2.5.2. Nuclear magnetic resonance 34 2.5.3. Gas sorption analysis 37 3. Results and discussion 41 3.1. Synthesis and characterization of conjugated microporous polymers 41 3.1.1. Dibromophenanthrene-based monomers 42 3.1.2. CMPs of the basic monomers 43 3.1.3. CMPs of the functionalized monomers 46 3.1.4. Properties of the PTPh-CMPs 48 3.1.5. PTPh-TBDMS - a special case 50 3.2. CMP@Silica microspheres 52 3.2.1. Conjugated Microporous Polymer Hybrid Microparticles for Enhanced Applicability in Silica-boosted Diclofenac Adsorption 53 3.2.2. Polarity and Functionality Tailored Conjugated Microporous Polymer Coatings on Silica Microspheres for Enhanced Pollutant Adsorption 71 3.3. CMP@Chitosan 86 3.3.1. A Complementary and Revised View on the N-Acylation of Chitosan with Hexanoyl Chloride 88 3.3.2. CMP@Chitosan synthesis and characterization 106 3.3.3. Diclofenac adsorption of CMP@Chitosan beads 110 3.4. Silicon nanoparticles@CMPs 115 3.4.1. New materials for solar-driven hydrogen evolution 115 3.4.2. Synthesis and characterization of selected SiNP@CMP hybrid materials 116 3.4.3. Distribution and incorporation of SiNPs in the CMP matrices 121 3.4.4. Hydrogen evolution reaction 124 4. Experimental section 128 4.1. Synthesis 128 4.1.1. Synthesis of the CMPs 129 4.1.2. Synthesis of dibromo-phenanthrene based monomers 129 4.1.3. Synthesis of CMP@Chitosan beads 131 4.1.4. Synthesis of the SiNP@CMP hybrid materials 132 4.2. Characterization and application-related studies 133 4.2.1. Characterization of the PTPh-monomers and CMPs 133 4.2.2. Characterization of the CMP@Chitosan beads 133 4.2.3. Characterization of the SiNP@CMP 134 5. Conclusion and outlook 135 6. References 141 7. Appendix 151 Danksagung / The thesis aimed to combine 1,3,5-triethynylbenzene (TEB)-based conjugated microporous polymers (CMPs) with the different materials silica, chitosan, and silicon to produce hybrid materials. The basic premise was an application-oriented improvement of properties, guided by the main applications of CMPs known from the literature - as adsorbers or as photocatalysts. Optimization of hybrid materials requires three basic prerequisites: Precise knowledge of the CMPs, the same understanding of the properties of the materials to be combined, and the possibility of comprehensive characterization. Only under these conditions the collective properties and those resulting from the combination of the hybrid material can be adjusted in a defined way. The first study is devoted to the basic premise, the structure-property relationship in CMPs. Here, novel CMPs based on TEB coupled with dibromo phenanthrene-diol monomers were prepared (polymer TEB-phenanthrene =PTPh). These monomers were functionalized with methyl-(OMe), trimethylsilyl- (TMS), or tertbutyldimethylsilyl (TBDMS) via the diol group, resulting in a homologous series with increasing steric demand and varying polarity. These monomers were each coupled with TEB to form CMPs in order to analyze the influence of steric demand on the CMP properties. Via dynamic contact angle measurement, it was determined that except PTPh-TMS, all PTPh-CMPs are highly hydrophobic with contact angles between 136° and 148°. For PTPh-TBDMS, another unusual property emerged: Contrary to the classical CMP properties, it was soluble in hydrophobic solvents. From nuclear magnetic resonance (NMR), dynamic light scattering (DLS), and transmission electron microscopy (TEM) measurements, it was found to consist of swollen, more cross-linked nanoparticles colloidally stabilized by less cross-linked quasi-linear polymer. Further, PTPh-TBDMS exhibits fluorescent properties when excited with light at 400 nm, which is of relevance to potential applications in sensor technology. The second study deals with the first hybrid material consisting of mesoporous silica microspheres (40 – 70 µm diameter) coated with CMPs for the adsorption of organic pollutants. While the functionalities of the CMPs can be precisely adjusted to interact with the pollutant, the SiO2 particles improve dispersibility and technical handling of the CMP that is otherwise difficult to recover. The first sub-study used the literature-known CMP of dibromo pyrimidine and TEB (CMP = polymer TEB pyrimidine = PTP) for the coating. From scanning electron microscopy (SEM) images, it can be seen that the PTP grows on the SiO2 spheres in the form of hemispheres. The amount of SiO2 used in the synthesis affects the adsorption of diclofenac (DCF), a widely applied pharmaceutical used as a model adsorptive. The maximum loading capacities determined show a maximum at 3.0 g of silica to the standard amount of CMP. The silica itself adsorbs DCF in negligible amounts, which is why the CMP-specific capacity was calculated from the CMP mass fraction actually contained in the material (thermogravimetric analysis -TGA determination). Here, the maximum loading at 3.0 g silica is 422 mg DCF per gram CMP, which is competitive with the best-known adsorbents. In the second sub-study, the principle of silica sphere coating was transferred to other CMPs from TEB and dibromo naphthalene, dibromo aniline, and dibromo pyridine, respectively. It was shown that the monomer polarity has a strong influence on the success of the coating: The coating was only possible if the monomer and the silica surface featured the same polarity. Through pre-functionalization of the silica, the coating was also made possible for the more hydrophobic monomers. Fourier transform infrared spectroscopy (FTIR), solid-state NMR, SEM, SEM-EDX, TGA, and TEM were used to analyze these coatings. DCF adsorption was then investigated, with the dibromo aniline-based CMP@SiO2 providing the highest CMP-specific DCF adsorption capacity of 228 mg/g. Another hybrid material, consisting of the CMPs developed in the first study embedded in the biobased polymer chitosan, is investigated in the third chapter. The goal, analogous to the previous studies, was to improve the distribution and accessibility of the CMPs for adsorptives while retaining them in defined structures for ease of handling. As a biobased and biocompatible polymer, chitosan is comparatively sustainable, enables medical applications, and is well-functionalizable via the amino group. Therefore, the amino functionality was converted with hexanoyl chloride to introduce a hydrophobic hexanoyl group into the chitosan. The modified hexanoyl chitosan (H-chitosan) was analyzed in several ways. The change in rheological properties due to the disruption of hydrogen bonding between the chitosan chains by the hydrophobic modification was particularly significant. Subsequently, the pure chitosan and the H-chitosan were used to prepare CMP@Chitosan gel beads. Since the CMP is the more expensive material, it was used in a mass ratio of 1:4. It was verified via SEM and SEM-EDX that the CMPs were distributed over a large area in the chitosan matrices. Upon drying, it was observed that the air-dried beads collapsed into compact structures, while the vacuum-dried beads retained the swollen shape. This affects the swelling of the dry beads in the aqueous adsorption medium, with the air-dried beads swelling only slightly and the vacuum-dried beads swelling significantly stronger. In general, the H-chitosan beads swell better, which was attributed to the hydrophobic group's hindered assembly of the chitosan chains. Batch experiments were used to investigate the adsorption of DCF at a low concentration of 1 mg/L and a high concentration of 300 mg/L, in which the vacuum-dried beads were found to be more effective. The hybrid material beads adsorbed more DCF than pure chitosan or H-chitosan beads and the pure CMPs. The CMP@H-chitosan beads adsorbed the highest amounts of DCF due to improved swelling. Overall, the CMP-specific adsorption was significantly enhanced by incorporation and distribution in the chitosan matrices. At the same time, handling was facilitated because the beads can be separated from the adsorption solution using a sieve and do not need to be centrifuged like the CMPs. The final study is focused on silicon nanoparticles (SiNPs)@CMP hybrid materials for use as photocatalysts in solar-driven hydrogen evolution reaction (HER). In this process, solar energy is directly used to produce hydrogen from water. The low HER rates typical for CMPs are to be raised by the SiNPs produced by the Dasog group (Dalhousie University, Halifax, Canada). In turn, the SiNPs are to be protected from oxidative influences by the CMPs. For this purpose, the CMPs known from the literature and investigated in the previous studies were used. By FTIR, it was confirmed that all CMPs were also formed in the presence of the SiNPs. Via TGA, the mass fraction of SiNPs in the respective hybrid materials was determined, which varied from 4 wt% to 22 wt% and depended mainly on the monomer used. SEM-EDX analyses showed a solvent-independent, areal distribution of SiNPs in the respective CMPs. The incorporation of the SiNPs analyzed via DLS and TEM measurements showed complete incorporation in one case, poor incorporation in another, and partial incorporation in all other cases. This partial incorporation, where parts of the SiNPs are not covered with CMP, proved beneficial in the hydrogen evolution experiments. For these SiNP@CMP hybrid materials, the HER rates were significantly increased compared to the pure CMPs, with the best material producing 32 µmol/g*h of hydrogen. This material was further optimized by doping with H2PtCl4 and used in cyclization studies. While long-term stability proved to require more optimization, doping was successful as it increased the HER rate to 42 µmol/g*h. In this work, CMPs were combined with one representative of inorganic insulators, biobased polymers, and inorganic semiconductors. The fundamental difference between these materials shows that there are few limitations set to the variety of combinations. The application-related feasibility studies showed the advantages that arise from this. Although research into CMP hybrid materials is still in its infancy, it already holds promising strategies and approaches for solving socially relevant problems.:Abstract V Kurzfassung VIII Abbreviations XI Symbols XII List of publications XIII List of figures XVI List of schemes XVIII List of tables XIX 1. Introduction 1 2. Theoretical background 4 2.1. Synthesis and properties of conjugated microporous polymers (CMPs) 4 2.1.1. Conjugated microporous polymers - a new class of materials 4 2.1.2. Synthesis of CMPs 5 2.1.3. Properties of CMPs 8 2.2. Fundamentals of adsorption and application of CMPs as adsorbers 11 2.2.1. Basic adsorption models 12 2.2.2. CMPs as adsorbers 16 2.3. Fundamentals and application of CMPs for hydrogen evolution 19 2.3.1. Physicochemical fundamentals of photocatalysis 19 2.3.2. Reaction and conditions of solar-driven hydrogen evolution 22 2.3.3. CMPs for solar-driven hydrogen evolution 24 2.4. Hybrid materials based on CMPs 26 2.4.1. CMPs combined with nanoparticulate systems 26 2.4.2. Macroscale CMP-based hybrid materials 30 2.5. Fundamentals of instrumental analysis 31 2.5.1. Fourier transform infrared spectroscopy 31 2.5.2. Nuclear magnetic resonance 34 2.5.3. Gas sorption analysis 37 3. Results and discussion 41 3.1. Synthesis and characterization of conjugated microporous polymers 41 3.1.1. Dibromophenanthrene-based monomers 42 3.1.2. CMPs of the basic monomers 43 3.1.3. CMPs of the functionalized monomers 46 3.1.4. Properties of the PTPh-CMPs 48 3.1.5. PTPh-TBDMS - a special case 50 3.2. CMP@Silica microspheres 52 3.2.1. Conjugated Microporous Polymer Hybrid Microparticles for Enhanced Applicability in Silica-boosted Diclofenac Adsorption 53 3.2.2. Polarity and Functionality Tailored Conjugated Microporous Polymer Coatings on Silica Microspheres for Enhanced Pollutant Adsorption 71 3.3. CMP@Chitosan 86 3.3.1. A Complementary and Revised View on the N-Acylation of Chitosan with Hexanoyl Chloride 88 3.3.2. CMP@Chitosan synthesis and characterization 106 3.3.3. Diclofenac adsorption of CMP@Chitosan beads 110 3.4. Silicon nanoparticles@CMPs 115 3.4.1. New materials for solar-driven hydrogen evolution 115 3.4.2. Synthesis and characterization of selected SiNP@CMP hybrid materials 116 3.4.3. Distribution and incorporation of SiNPs in the CMP matrices 121 3.4.4. Hydrogen evolution reaction 124 4. Experimental section 128 4.1. Synthesis 128 4.1.1. Synthesis of the CMPs 129 4.1.2. Synthesis of dibromo-phenanthrene based monomers 129 4.1.3. Synthesis of CMP@Chitosan beads 131 4.1.4. Synthesis of the SiNP@CMP hybrid materials 132 4.2. Characterization and application-related studies 133 4.2.1. Characterization of the PTPh-monomers and CMPs 133 4.2.2. Characterization of the CMP@Chitosan beads 133 4.2.3. Characterization of the SiNP@CMP 134 5. Conclusion and outlook 135 6. References 141 7. Appendix 151 Danksagung

Tesis por compendio / [ES] Esta tesis doctoral titulada "Nanopartículas de sílice mesoporosas funcionalizadas con puertas moleculares para aplicaciones biomédicas" está centrada en el diseño y la síntesis de nuevos nanosistemas sensores y terapéuticos con aplicaciones en el campo clínico y medioambiental. En la introducción de esta tesis (capítulo uno) se presenta una visión general de conceptos básicos de nanotecnología, química supramolecular, nanopartículas de sílice mesoporosa y de puertas moleculares. A continuación, se presentan los objetivos generales y específicos que se van a desarrollar en los capítulos experimentales siguientes. En el tercer capítulo se presenta el diseño, síntesis y caracterización de un nanodispositivo para la detección de endotoxina en medios acuosos. El nanodispositivo está basado en nanopartículas de sílice mesoporosa con los poros cargados con rodamina B y su superficie externa funcionalizada con grupos carboxilato. Los poros se bloquean, para evitar la liberación de la rodamina B, con polimixina B, un péptido con carga positiva. En presencia de la endotoxina, la polimixina B es desplazada de la superficie de las nanopartículas y se activa la liberación de la rodamina B del interior de los poros a la disolución. Esta liberación genera un aumento significativo de la fluorescencia en la disolución permitiendo la detección de la endotoxina. La respuesta obtenida con el nanodispositivo es muy selectiva ya que otras especies como el arabinogalactan, el ß-(1,3)-D-glucano, la pectina, el EDTA, la glucosa, el GTP y el polvo no son capaces de inducir la apertura de los poros y la liberación de la rodamina B. Además, el nanodispositivo presenta un límite de detección para la endotoxina en el rango picomolar. En el cuarto capítulo se describe un nanodispositivo, basado en nanopartículas de sílice mesoporosa cargadas con rodamina B y tapadas con curcumina, que se emplea para la detección selectiva de seroalbúmina humana (HSA) mediante medidas de fluorescencia. En este nanodispositivo, de nuevo, la presencia de HSA es capaz de desplazar la curcumina de la superficie de las nanopartículas permitiendo la liberación controlada de la rodamina B. El nanodispositivo preparado presentó una respuesta muy selectiva hacia la HSA con un límite de detección tan bajo como 0.1 mg/mL en PBS (pH 7.4)-acetonitrilo 95:5 v/v. El capítulo cinco está centrado en la preparación de un nanodispositivo para la liberación sinérgica del antibiótico linezolida en presencia de bacterias Gram negativas. Este nanomaterial está basado en el empleo de nanopartículas de sílice mesoporosa (como soporte inorgánico) con los poros cargados con linezolida y con la superficie externa funcionalizada con el antibiótico disruptor de membrana polimixina B (mediante interacciones electrostáticas). Cuando estas nanopartículas entran en contacto con bacterias Gram negativas el lipopolisacárido (LPS) de sus membrabas induce el desplazamiento de la polimixina B que actúa eficientemente como permeador y permite la liberación de la linezolida. La liberación simultánea de linezolida y la polimixina B en forma de nanoformulación inducen una reducción significativa de los valores del IC50 para bacterias cuando se compara con los valores obtenidos empleando de forma individual ambas especies. El capítulo sexto está dedicado a la discusión de los resultados experimentales descritos en los capítulos tres, cuatro y cinco. Finalmente, el capítulo siete de esta tesis doctoral, presenta las conclusiones generales que se derivan del trabajo experimental realizado. También se presentan las perspectivas futuras en el campo de las aplicaciones biomédicas de las nanopartículas de sílice mesoporosa con puertas moleculares. Esperamos que los resultados que se presentan en esta tesis doctoral puedan abrir nuevas oportunidades de investigación en el desarrollo de nuevos nanodispositivos inteligentes que puedan actuar como agentes antimicrobianos. / [CAT] Aquesta tesi doctoral titulada "Nanopartícules de sílice mesoporoses funcionalitzades amb portes moleculars per a aplicacions biomèdiques" està centrada en el disseny i la síntesi de nous nanosistemes sensors i terapèutics amb aplicacions en el camp clínic i mediambientals. En la introducció d'aquesta tesi (capítol un) es presenta una visió general de conceptes bàsics de nanotecnologia, química supramolecular, nanopartícules de sílice mesoporosa i de portes moleculars. A continuació, es presenten els objectius generals i específics que es desenvoluparan en els capítols experimentals següents. En el tercer capítol es presenta el disseny, síntesi i caracterització d'un nanodispositiu per a la detecció d'endotoxina en mitjans aquosos. El nanodispositiu està basat en nanopartícules de sílice mesoporosa amb els porus carregats amb rodamina B i la seua superfície externa funcionalitzada amb grups carboxilat. Els porus es bloquegen, per a evitar l'alliberament de la rodamina B, amb polimixina B, un pèptid amb càrrega positiva. En presència de l'endotoxina, la polimixina B és desplaçada de la superfície de les nanopartícules i s'activa l'alliberament de la rodamina B de l'interior dels porus a la dissolució. Aquest alliberament genera un augment significatiu de la fluorescència en la dissolució permetent la detecció de l'endotoxina. La resposta obtinguda amb el nanodispositiu és molt selectiva ja que altres espècies com l'arabinogalactan, el ß-(1,3)-D-glucà, la pectina, l'EDTA, la glucosa, el GTP i la pols no són capaços d'induir l'obertura dels porus i l'alliberament de la rodamina B. A més, el nanodispositiu presenta un límit de detecció per a l'endotoxina en el rang picomolar. En el quart capítol es descriu un nanodispositiu, basat en nanopartícules de sílice mesoporosa carregades amb rodamina B i tapades amb curcumina, que s'empra per a la detecció selectiva de seroalbúmina humana (HSA) mitjançant mesures de fluorescència. En aquest nanodispositiu, de nou, la presència de HSA és capaç de desplaçar la curcumina de la superfície de les nanopartícules permetent l'alliberament controlat de la rodamina B. El nanodispositiu preparat va presentar una resposta molt selectiva cap a la HSA amb un límit de detecció tan baix com 0.1 mg/ml en PBS (pH 7.4)-acetonitril 95:5 v/v. El capítol cinc està centrat en la preparació d'un nanodispositiu per a l'alliberament sinèrgic de l'antibiòtic linezolida en presència de bacteris Gram negatives. Aquest nanomaterial està basat en l'ús de nanopartícules de sílice mesoporosa (com a suport inorgànic) amb els porus carregats amb linezolida i amb la superfície externa funcionalitzada amb l'antibiòtic disruptor de membrana polimixina B (mitjançant interaccions electroestàtiques). Quan aquestes nanopartícules entren en contacte amb bacteris Gram negatives el lipopolisacàrid (*LPS) de les seues membranes indueix el desplaçament de la polimixina B que actua eficientment com permeador i permet l'alliberament de la linezolida. L'alliberament simultani de linezolida i la polimixina B en forma de nanoformulació indueixen una reducció significativa dels valors de l'IC50 per a bacteris quan es compara amb els valors obtinguts emprant de manera individual totes dues espècies. El capítol sisé està dedicat a la discussió dels resultats experimentals descrits en els capítols tres, quatre i cinc. Finalment, el capítol set d'aquesta tesi doctoral, presenta les conclusions generals que es deriven del treball experimental realitzat. També es presenten les perspectives futures en el camp de les aplicacions biomèdiques de les nanopartícules de sílice mesoporosa amb portes moleculars. Esperem que els resultats que es presenten en aquesta tesi doctoral puguen obrir noves oportunitats d'investigació en el desenvolupament de nous nanodispositius intel·ligents que puguen actuar com a agents antimicrobians / [EN] This PhD thesis entitled "Gated mesoporous silica nanoparticles for biomedical applications" is focused on the design and synthesis of novel nanodevices for sensing and therapeutic applications in clinical and environmental fields. The first introductory chapter presented an overview of the different concepts related to nanotechnology, supramolecular chemistry, mesoporous silica nanoparticles (MSNs), and molecular gates. Next, the general and specific objectives of this PhD thesis, that are addressed in the different experimental chapters, are presented. The third chapter presented the design, synthesis, and characterization of a nanodevice for endotoxin detection in aqueous environments. The prepared nanodevice is based on mesoporous silica nanoparticles loaded rhodamine B and with its external surface functionalized with carboxylates. Pores are finally capped upon addition of cationic polymyxin B peptide. In the presence of endotoxin, polymyxin B is detached from the surface of the nanoparticles with subsequent rhodamine B release from the inner of the pores to the solution. This release generated a marked emission enhancement in solution which allow endotoxin detection. The obtained response was highly selective to endotoxin because other interfering agents such as arabinogalactan, ß-(1,3)-D-glucan, pectin, EDTA, glucose, GTP and dust were unable to induce pore opening and rhodamine B release. Besides, the system detects endotoxin with a limit of detection in the picomolar range. The fourth chapter presented a nanodevice, based on mesoporous silica nanoparticles loaded with rhodamine B and capped with anionic curcumin, which is used for the selective and sensitive fluorogenic detection of human serum albumin (HSA). Again, in the presence of HSA, curcumin was detached from nanoparticles surface allowing rhodamine B release. Prepared nanodevice showed a highly selective response toward HSA with a limit of detection for HSA as low as 0.1 mg/mL in PBS (pH 7.4)-acetonitrile 95:5 v/v. Chapter five focus on the design and synthesis of a nanodevice for the synergic release of linezolid antibiotic in the presence of Gram-negative bacteria. This nanodevice is based on the use of mesoporous silica nanoparticles (as inorganic support) with the pores loaded with linezolid and capped with the membrane disruptor polymyxin B through electrostatic interactions. When these particles enter in contact with Gram-negative bacterium, lipopolysaccharide (LPS) present in the cell membrane induces the detachment of polymyxin B, which acts as membrane permeator, from the nanodevice allowing linezolid release. Simultaneous release of linezolid and polymyxin B as a nanoformulation induced a marked reduction in the IC50 values for bacteria when compared to the values obtained using free linezolid and polymyxin B alone. The sixth chapter is devoted to the discussion of the experimental results described in the previous chapters. Finally, the seventh chapter of this PhD thesis, presented the main conclusions, derived from the experimental work, and future perspectives in the field of gated mesoporous silica nanoparticles for biomedical applications. We hope that the results achieved in this PhD thesis will open new research opportunities to develop advanced smart nanodevices as antimicrobial drugs / Otri, I. (2023). Gated Mesoporous Silica Nanoparticles for Biomedical Applications [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/194710 / Compendio

<p dir="ltr">This work focuses on the fracture behavior and failure mechanisms of Prepreg Platelet Molded Composites (PPMCs), which are characterized by meso-structural variability. The study investigates the interlaminar fracture toughness of PPMCs using both experimental and computational approaches, with a particular focus on Mode-I fracture testing. Cohesive zone models are developed to simulate interfacial behavior in composite laminates. The research introduces the concept of the platelet critical length problem and explores how platelet geometry, arrangement, and meso-structural features affect fracture toughness and energy absorption. Findings indicate that smaller platelets enhance fracture toughness through mechanisms like platelet bridging and crack deflection, while larger platelets provide more consistent fracture properties but exhibit greater variability in stiffness. This work offers valuable insights for optimizing PPMC performance in high-performance applications.</p>

[ES] Uno de los retos más importantes de la sociedad actual es la obtención de energía de forma sostenible, limpia y eficiente. Por ello, gran parte de la investigación actual en el campo de la química y la ciencia de los materiales centra sus esfuerzos en la búsqueda y estudio de nuevas generaciones de materiales que permitan una transición energética desde el modelo energético tradicional hacia un modelo más sostenible. En este contexto, las propiedades eléctricas de los materiales, relacionadas con la generación y transformación de energía, juegan un papel esencial. En esta tesis se estudian dos tipos de materiales híbridos con distinta estructura y composición, pero que combinan excelentes propiedades eléctricas y ópticas. Por una parte, los clústeres octaédricos de molibdeno, ya conocidos desde hace décadas, han demostrado ser excelentes materiales en catálisis. En los últimos tiempos, la investigación alrededor de este material se ha centrado en el estudio de sus propiedades ópticas y electrónicas y sus aplicaciones en sensores y dispositivos emisores de luz. Por otra parte, las perovskitas híbridas halogenadas son ampliamente conocidas en el campo de la generación energética por sus elevadas eficiencias, movilidad de cargas y alta eficiencia de emisión de luz. Se han estudiado dos estructuras de perovskita híbrida halogenada: una 3D, cuyas propiedades son ampliamente conocidas, y otra con estructura multidimensional 2D-3D, donde el carácter laminar le confiere una mejora en la estabilidad. Con el propósito de comprender mejor su interacción luz-materia, en los trabajos desarrollados en la presente tesis, se han realizado mediciones optoelectrónicas a nivel monocristalino. Esto incluye un análisis combinando de medidas de emisión, fotocolección y transporte de carga. Además, se ha investigado su comportamiento como cavidad resonante, así como sus propiedades como generador de energía. Por lo tanto, se ha corroborado que los materiales objeto de estudio, presentan unas propiedades que les confieren diferentes posibilidades de aplicación en diversos ámbitos dentro del campo de la generación energética. / [CA] Un dels reptes més importants de la societat actual és obtenir energia de forma sostenible, neta i eficient. Per això, gran part de la investigació actual en el camp de la química i la ciència dels materials centra els seus esforços en la cerca i l'estudi de noves generacions de materials que permeten una transició energètica des del model energètic tradicional cap a un model més sostenible. En aquest context, les propietats elèctriques dels materials, relacionades amb la generació i la transformació d'energia juguen un paper essencial. En aquesta tesi s'estudien dos tipus de materials híbrids amb diferent estructura i composició, però que combinen propietats elèctriques i òptiques excel·lents. D'una banda, els clústers octaèdrics de molibdè, ja coneguts des de fa dècades, han demostrat ser materials idonis en catàlisi. De fet, en els darrers temps, la recerca al voltant d'aquest material s'ha centrat en l'estudi de les propietats òptiques i electròniques i les aplicacions en sensors i dispositius emissors de llum. D'altra banda, les perovskites híbrides halogenades són àmpliament conegudes al camp de la generació energètica per les seues elevades eficiències, mobilitat de càrregues i alta eficiència d'emissió de llum. S'han estudiat dues estructures de perovskita híbrida halogenada: una de 3D, les propietats de la qual són àmpliament conegudes, i una altra amb estructura multidimensional 2D-3D, el caràcter laminar de la qual li confereix una millora en l'estabilitat. Amb el propòsit de comprendre millor la seua interacció llum-matèria, en els treballs desenvolupats en aquesta tesi, s'han realitzat mesuraments optoelectrònics a nivell monocristal·lí. Això inclou una anàlisi que combina mesures d'emissió, fotocol·lecció i transport de càrrega. A més, s'ha investigat el seu comportament com a cavitat ressonant, així com les seues propietats com a generador d'energia. Per tant, s'ha corroborat que els materials objecte d'estudi presenten unes propietats que els confereixen diferents possibilitats d'aplicació en diversos àmbits dins del camp de la generació energètica. / [EN] One of the most important challenges of today's society is obtaining energy in a sustainable, clean, and efficient way. For this reason, much of the current research in the field of chemistry and materials science focuses its efforts on the search and study of new generations of materials that allow an energy transition from the traditional energy model to a more sustainable model. In this context, the electrical properties of materials, related to the generation and transformation of energy, play an essential role. In this thesis, two types of hybrid materials with different structure and composition, but which combine excellent electrical and optical properties, are studied. On the one hand, octahedral molybdenum clusters have been known for decades and have proven to be excellent materials in catalysis. In fact, in recent times, research around this material has focused on the study of its optical and electronic properties and its applications in sensors and light-emitting devices. On the other hand, halogenated hybrid perovskites are widely known in the field of energy generation for their high efficiencies, charge mobility and high light emission efficiency. Two halogenated hybrid perovskite structures were studied: one 3D, whose properties are widely known, and another with a 2D-3D multidimensional structure, where the laminar character confers an improvement in stability. To better understand its light-matter interaction, in the work developed in this thesis, optoelectronic measurements have been carried out at the monocrystalline level. This includes a combined analysis of emission, photocollection and charge transport measurements. In addition, its behavior as a resonant cavity has been investigated, as well as its properties as an energy generator. Therefore, it has been confirmed that the materials under study have properties that give them different application possibilities in various areas within the field of energy generation. / Segura Sanchis, E. (2024). Propiedades ópticas y eléctricas de monocristales de materiales híbridos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/202755

Chapter 1. General Introduction This chapter gives an introduction to supramolecular organo/hydrogels and the related bile acid chemistry touching upon the gelation properties of the bile acid derivatives. Diverse applications of the supramolecular gels are illustrated with several examples. In the concluding section of this chapter, a brief introduction on the semiconductor nanocrystals is provided. Finally, the content of the thesis is outlined. Chapter 2. Bile Acid Derived Novel Organo/hydrogelators Part 1. Bile Acid Derived Organo/hydrogelators With a Basic Side Chain Cationic analogues of bile acids which showed remarkable gelation properties in water were reported from our laboratory. This led us to investigate the aggregation behaviour of some of the lithocholic and deoxycholic acid derivatives having a basic side-chain. Figure 1. Bile acid based organo/hydrogelators containing a basic side-chain. In this part, an organogelator 1 and a hydrogelator 2 derived from parent bile acids have been described with respect to their gelation properties, morphology, thermal and mechanical stability of the gels. The organo/hydrogels were shown to be responsive to acid-base stimuli as the organogel formed only in the protonated state and the hydrogel formed in the neutral form of the tertiary amines. The xerogel fibres obtained from the organogel were found to be solid-like and stable up to 200 oC as confirmed by variable temperature polarizing optical microscopy. The non-fluorescent organogel was doped with a fluorescent dye (coumarin 153) to design a novel dye-organogel composite material which was investigated with laser scanning confocal fluorescence microscopy showing the dye molecules were uniformly deposited on the organogel fibres. Part 2. Serendipitous Organogelation by Dimeric Bile Acid Esters This section highlights our work on the organogelators based on a number of dimeric esters consisting of different bile acid units. Figure 2. The three different dimeric bile acid esters as organogelators. In this part, three bile acid derived dimeric esters (1, 2 and 3) were shown to possess organogelation properties in aromatic and halogenated aromatic solvents. We studied the morphological features and rheological properties of these organogels. Next, the organogel matrix was exploited to generate and stabilize gold nanoparticles and prepare AuNP/gel hybrid material. Chapter 3. Cholate Hydrogels and Soft Gel-nanoparticle Hybrid Materials Sodium cholate does not form gel in water under any condition as compared to other sodium salts of other bile acids such as sodium deoxycholate and lithocholate which show pH-dependent gelation behaviour. Figure 3. Metal cholate hydrogels derived from sodium cholate and a variety of metal ions. In this chapter, super hydrogelation of sodium cholate induced by a variety of metal ions (Ca2+, Cu2+, Co2+, Zn2+, Cd2+, Hg2+ and Ag+) is highlighted with respect to their morphology and mechanical strength/stability. The calcium cholate supramolecular system showed the presence of helically twisted nanofibres which were utilised in the synthesis of soft hybrid materials containing metal (Au and Ag) and metal sulphide (CdS, ZnS, HgS, etc.) nanoparticles. Chapter 4. Cadmium Deoxycholate and Highly Luminescent CdSe Nanocrystals Bile acid derivatives have very high chemical and thermal stability owing to the presence of a rigid steroidal nucleus. We explored the possibility of utilizing the bile salt derived from Cd as a metal complexes as precursor to high quality nanocrystals (NCs) which can only be accessed at high temperatures (>200 oC). Figure 4. Synthesis of high quality CdSe NCs from cadmium deoxycholate. In this chapter, the synthesis of high quality CdSe nanocrystals is discussed using a novel bile acid based precursor: cadmium salt of 7-deoxycholic acid, which has high thermal stability and can be conveniently used at very high temperatures (>300 oC) required for the synthesis of high quality nanocrystals. Syntheses were done both by ‘injection’ and ‘non-injection’ modes. The as-prepared nanocrystals have high photoluminescence quantum yield, multiple excitons, narrow size-distributions and zinc blende/wurtzite crystalline cores. Appendix. Steroidal Thiols in Design of Novel Quantum dot (QD)/Gel Hybrid Materials Bile acid derived steroidal thiols were reported to be efficient capping agents for silver and gold nanoparticles from our laboratory. So, we wanted to check whether they could stabilize the semiconductor nanocrystals as well. Figure 5. Steroidal thiols as stabilizers of semiconductor quantum dots. In this short report, we describe the efficient capping by bile acid derived thiols of group II-VI semiconductor nanocrystals/quantum dots (QDs) (CdS, CdSe). After synthesizing the thiol capped QDs, we tried to disperse the capped nanoparticles into the gel fibres. The hybrid gels showed the presence of nanoparticles inside the fibres as observed by transmission electron microscopy, although the photoluminescence of the QDs was very low in the gel matrix, which might be due to the inefficient surface passivation of the nanoparticles in the gel.

The germylenes, germanium(II) 2-(oxidomethyl)phenolate (1), germanium(II) 4-methyl-2-(oxidomethyl)phenolate (2) and germanium(II) 4-bromo-2-(oxidomethyl)phenolate (3) were synthesized and their thermally induced twin polymerization to give organic–inorganic hybrid materials was studied. The compounds 1–3 form oligomers including dimers, trimers and tetramers as a result of intermolecular coordination of the benzylic oxygen atom to germanium. The structural motifs were studied by single crystal X-ray diffraction analysis and DFT-D calculations. Thermally induced twin polymerization of these germylenes gave hybrid materials based on germanium-containing phenolic resins. Carbonization of these resins under reductive conditions resulted in porous materials that are composed of germanium and carbon (Ge@C materials), while oxidation with air provided non-porous germanium dioxide. The porous Ge@C materials were tested as potential anode materials for rechargeable Li-ion batteries. Reversible capacities of 540 mA h g−1 were obtained at a current density of 346 mA g−1 without apparent fading for 100 cycles, which demonstrates that germanium is well accessible in the hybrid material. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Four molecular germanates based on salicyl alcoholates, bis(dimethylammonium) tris[2-(oxidomethyl)phenolate(2-)]germanate (1), bis(dimethylammonium) tris[4-methyl-2-(oxidomethyl)phenolate(2-)]germanate (2), bis(dimethylammonium) tris[4-bromo-2-(oxidomethyl)phenolate(2-)]germanate (3) and dimethylammonium bis[2-tert-butyl-4-methyl-6-(oxidomethyl)phenolate(2-)][2-tert-butyl-4-methyl-6-(hydroxymethyl)phenolate(1-)]germanate (4), were synthesized and characterized including single crystal X-ray diffraction analysis. In the solid state, compounds 1 and 2 exhibit one-dimensional hydrogen bonded networks, whereas compound 4 forms separate ion pairs, which are connected by hydrogen bonds between the dimethylammonium and the germanate moieties. The potential of these compounds for thermally induced twin polymerization (TP) was studied. Germanate 1 was converted by TP to give a hybrid material (HM-1) composed of phenolic resin and germanium dioxide. Subsequent reduction with hydrogen provided a microporous composite containing crystalline germanium and carbon (Ge@C – C-1, germanium content ∼20%). Studies on C-1 as an anode material for Li-ion batteries revealed reversible capacities of ∼370 mA h gGe@C−1 at a current density up to 1384 mA g−1 without apparent fading for 500 cycles. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Hybrid materials consisting of three different components were synthesized by the polymerization of one heterotrifunctional monomer in just one reaction step using, at the most, one catalyst. The polymerization of 2-furfuyloxy-2-methyl-4H-1,3,2-benzodioxasiline leading to a hybrid material consisting of phenolic resin, poly(furfuryl alcohol), and polymethylsilsesquioxane is, to the best of our knowledge, the first polymerization of this kind. The influence of different catalysts on the polymerization behavior and thus on the structure of the hybrid material was investigated. In accordance with the term “twin polymerization”, which is used for the polymerization of one monomer yielding two separate polymers, this type of polymerization could be called “triple polymerization”. The term “multiple polymerization” is introduced as a general term for the underlying concept of the synthesis of multiple polymers starting from one monomer in one process step. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Le procédé sol-gel permet la réalisation de matériaux optiquement performants et la possibilité d’intégrer diverses molécules dans ces systèmes ouvre les portes à des applications dans de nombreux domaines. Nous nous sommes intéressés en particulier à la réalisation de matériaux sol-gel monolithiques, fortement dopés avec des molécules actives, dans le cadre de la réalisation de limiteurs optiques performants dans le visible et dans l’infrarouge.La mise au point de procédés et de matrices sol-gel compatibles avec divers types de chromophores a tout d’abord été effectuée. Une investigation des paramètres expérimentaux et de la nature des précurseurs influençant la microstructure des matériaux a été réalisée, ainsi que la mise au point de méthodes de gélification accélérée capables de piéger efficacement les chromophores dans les matrices sol-gel même à de très hautes concentrations.Le dopage des matrices obtenues avec différents chromophores pour la limitation optique dans le visible et dans l’infrarouge s’en est suivi, avec une étude de l’impact des matrices sur les propriétés optiques des dopants. L’évaluation des performances en limitation a révélé les performances exceptionnelles des systèmes étudiés dans le visible, et des résultats prometteurs pour l’infrarouge.Enfin, la synthèse de nanoparticules d’or isotropes et anisotropes et leur incorporation dans les matériaux préparés a permis de mettre en évidence des effets d’exaltation importants sur les propriétés non-linéaires des chromophores au sein des matrices sol-gel et permettent d’améliorer les performances en limitation de manière considérable. / Sol-gel chemistry is a potent approach for the realization of optical materials, and enables chromophores incorporation in materials making the soft process a gateway for many applications. In this work, we focused on monolithic sol-gel materials, heavily doped with optically active chromophores for the realization of solid-sate optical power limiting devices in the visible and near-infrared range.The elaboration and optimization of compatibles sol-gel matrices with those chromophores was the first step. An investigation of the different synthesis parameters and the nature of the precursors on the materials nanostructure were done, together with the creation of high speed gelation processes to enable the incorporation of very high chromophores contents.Using these approaches, the preparation of highly doped materials for optical power limiting in the visible and the near infrared range was successful, and the impact of the matrices on chromophores properties was studied. Evaluation of optical limiting properties of these materials revealed exceptional performance in the visible range and promising results for the NIR range.Finally, isotropic and anisotropic gold spheres were prepared and incorporated inside the materials. The resulting composites showed enhancements of the non-linear properties of the chromophores inside the matrix, and dramatic improvement of the optical power limiting efficiency was achieved.

Les ligands carbéniques N-hétérocycliques sont généralement décrits comme des analogues aux ligands phosphines car ils présentent des propriétés électroniques comparables, bien que leur caractère σ-donneur soit plus prononcé. Ils ont donc été utilisés pour la synthèse de complexes organométalliques en remplacement des ligands phosphines et un nombre très important de complexes métal-NHC ont été développés ces 15 dernières années. Toutefois, ces complexes bien que très actifs dans de nombreuses réactions catalytiques clefs (métathèse des oléfines, couplages C-C, échange H/D…), présentent des problèmes de désactivation rapide et sont difficilement séparables des produits de réaction. L'hétérogénéisation de tels complexes pourrait remédier à ces inconvénients, et c'est la raison pour laquelle ce domaine a attiré beaucoup d'attention ces dix dernières années. La stratégie la plus courante pour l’immobilisation de tels complexes sur supports oxydes consiste à faire réagir des précurseurs de type organosilane avec des solides présentant des groupements hydroxyles de surface. Bien que cette méthode offre un moyen simple et efficace de fonctionnaliser des supports solides avec un éventail très large de fonctionnalités organiques, il ne permet cependant pas un contrôle de leur distribution et de la nature des espèces de surface dans le matériau final. La méthodologie alternative au greffage sur supports oxydes développée dans ce travail de thèse a consisté donc à générer des matériaux hybrides organiques-inorganiques mésostructurés, contenant des unités NHC dans leurs pores ou dans leurs murs. Ces matériaux sont obtenus par sol-gel hydrolytique en milieu structurant via des réactions de co-hydrolyse et de co-polycondensation d’un précurseur de type organotrialcoxysilane et de tétraalcoxysilane (TEOS). Cette voie de synthèse a été utilisée car elle permet de contrôler : la distribution des groupements organiques au sein de la matrice silicique, la nature des espèces siliciques de surface, et la concentration en fonctions organiques. Après synthèse des matériaux hybrides, des réactions in-situ ont permis l’obtention de matériaux contenant des unités uniques de type Au-NHC régulièrement distribuées au sein du support d’oxyde. Les matériaux ainsi obtenus ont été caractérisés à chacune des étapes menant au solide final par de nombreuses techniques : adsorption-désorption d’azote à 77 k, microscopie électronique à transmission, diffraction des rayons X aux petits angles, spectroscopie RMN multinoyaux à l'état solide et analyses élémentaires. Après avoir testé et comparé les performances catalytiques de ces matériaux avec celles de leurs homologues en phase homogène et ce, dans plusieurs réactions catalytiques (oxydation sélective des alcools, couplage croisé de Suzuki et diboration des oléfines), nous nous sommes focalisés sur la réaction d’addition d’alcools sur les alcynes et plus particulièrement sur l’addition du méthanol sur le 3-hexyne. C'est d’ailleurs, à notre connaissance, le premier exemple en littérature de l'usage des complexes carbéniques N-hétérocycliques d’or dans cette réaction. / N-heterocyclic carbene ligands have been described as interesting alternatives to tertiary phosphines in term of bonding and reactivity and have been therefore extensively studied as metallocarbene promotors. As a result, a large variety of homogeneous metal-NHC complexes have been developed and their impressive catalytic properties have been studied. However, such highly active homogeneous catalysts suffer from fast deactivation and separation problems from the reaction products. The immobilization of such complexes could overcome these drawbacks and that is the reason why this area has attracted much attention in the last ten years. The most common strategy for complexes immobilisation involves covalent grafting oforganosilane precursors onto solid support surfaces, via reaction with surface OH groups. Although this method provides a convenient way for introducing all kinds of organic moieties into solids, it does not permit the control of either their distribution in the final material or the nature of the surface species. The alternative methodology, to classical grafting, developed in this PhD project, is based on the design of organic-inorganic hybrid mesostructured materials containing NHC units along their pore channels or into their walls and the subsequent coordination on the NHC units with the Au organometallic precursor. These materials were prepared by sol-gel process using a templating route, via co-hydrolysis and co-polycondensation of an organotrialkoxysilane precursor and tetraethoxysilane. This strategy permits a control of: the ligands distribution into the silica matrix, the nature of the silica surface species and the organic moieties concentration. All the solids, from the starting hybrid material to the Au-NHC containing one, were fully characterized using various techniques: nitrogen adsorption-desorption at 77 K, transmission electron microscopy, small angle X-Ray diffraction, solid state NMR spectroscopy and elementary analysis. After screening the catalytic performances of these Au-NHC containing materials in several catalytic reactions (selective oxidation of alcohols, Suzuki cross-coupling and olefins diboration), their high catalytic activity in alcohols addition to alkynes reactions prompted us to study more deeply their catalytic behaviour (and that of their homogeneous homologues) in the reaction of methanol addition to 3-hexyne. To the best of our knowledge, it is the first use in catalysis of gold Nheterocyclic carbene complexes in this reaction.