Дисертації з теми "Metal Nano-particles"

The application of nanowires (NWs) in solar cells (SCs) is of great interest due to their new promising aspects established in nanoelectronics. Semiconductors associated with plasmonic metal nanoparticles (NPs) such as Silver (Ag), Gold (Au) and Copper (Cu), show enhanced performance in solid state light absorbing SCs owing to plasmonic characteristic of noble metal NPs. Plasmonic NPs presented a significant role in development of visible light harvesting for many applications such as photocatalytic materials, photodynamic in Surface Enhanced Raman Spectroscopy (SERS) and photovoltaics (PVs). Integration of plasmonic NPs in semiconductor materials have opened the routes to expand new PV systems with high efficiency light absorption. In this project, we introduce the synthesis ZnO and TiO2 NWs used as N-type semiconducting substrates and various methods for isolating plasmonic metal NPs, which are later deposited on the semiconducting substrates. Vertically aligned ZnO and TiO2 NWs arrays were grown on the fluorine-doped tin oxide (FTO) conductive glass substrates via hydrothermal method at low temperature and the plasmonic NPs were synthesized by wet chemistry procedures and finally decorated on the NW films by using electrophoretic deposition.  The impact of metal NPs loaded on the ZnO and TiO2 NWs substrates was studied by means of UV-vis spectroscopy and Photoluminescence (PL) spectroscopy. The absorbance spectra of individual NPs were recorded. Remarkably, the reflectance spectra of produced samples presented an enhancement in light absorption of the substrates after uptake of NPs on the ZnO and TiO2 NWs. The optical properties of the as grown ZnO NWs films decorated with Ag NPs (I) in direct contact with substrate and (II) in presence of an Al2O3 insulating spacer layer have been investigated. Both systems exhibited an enhancement in the UV band-edge emission from the ZnO when excited at 325 nm. In contrast, the broad bend defect emission of the samples did not have a significant change compare to bare ZnO substrates. The observed results suggested that the ZnO and TiO2 NWs decorated with plasmonic nanoparticles can boost the optical properties of MOs NWs substrates and hence effectively enhance the separation of photoexcited electron-hole pairs and photo-conversion applications.

Les systèmes à délivrance de médicaments sont des technologies conçues pour administrer des molécules actives de façon optimisée afin d’améliorer leurs effets thérapeutiques tout en minimisant les effets secondaires. En effet, ces systèmes permettent une libération au niveau d’une cible thérapeutique. Les particules de type «cage» ont récemment attiré une attention particulière en raison de leur capacité accrue à (co)incorporer et à protéger des molécules actives vis-à-vis de dégradations in vivo. Les cyclodextrines (CDs) sont des exemples type de molécules "cage", possédant une cavité hydrophobe et une surface extérieure hydrophile. Nous avons élaboré tout d’abord des assemblages supramoléculaires à base de CDs d'environ 100 nm par une méthode douce consistant à mélanger deux solutions aqueuses de polymères neutres : 1) polymère de β-CD et 2) dextrane greffé avec la benzophénone, molécule invitée formant des complexes d’inclusion avec les CDs. La procédure de préparation « verte» en une seule étape rend la formulation attractive, malgré sa relativement faible capacité d’encapsulation (5%pds). Afin d'améliorer cete charge, nous avons élaboré des particules hybrides organiques-inorganiques (MOFs) à base de CDs. Avantageusement, les CD-MOF comportent non seulement des cavités de CD, mais aussi de larges pores engendrés lors l’auto-assemblage de CDs. Le lansoprazole a été incorporé avec succès (23%pds) dans les CD-MOFs et nous avons montré que chaque CDs était capable d’accueillir une molécule de principe actif. Cependant, l’inconvénient majeur des CD-MOFs est leur faible stabilité en milieu aqueux, limitant leur domaine d’application. Une modification de surface est apparue donc nécessaire pour améliorer leur stabilité. Notre stratégie a été d’incorporer les CD-MOFs dans des matrices d'acide polyacrylique (PAA). Des microsphères composites d’environ 650 nm ont été élaborées avec succès et ont permis une bonne stabilité et une libération prolongée sur plus de 48 h. Avantageusement, ces particules composites n’étaient pas toxiques in vitro même à des concentrations élevées. Ainsi, nous nous sommes orientés vers l’étude comparative de MOFs plus stables dans l’eau, à base de trimesate de fer. Les MIL-100 (Fe) (Material of Institute Lavoisier) figurent parmi les premiers MOF étudiés en tant que nanomédicaments (nanoMOFs). Ces particules, parfaitement stables dans l'eau, se dégradent dans des milieux contenant des phosphates en perdant rapidement leur caractère cristallin et leurs ligands constitutifs. De façon étonnante, nous avons constaté que malgré leur dégradation, ces MOFs conservent leur taille intacte. Une analyse approfondie basée sur la microscopie de Raman a permis d’obtenir des informations pertinentes sur la morphologie et la composition chimique de particules individuelles. Ainsi, il a été montré qu’un front d'érosion délimitait nettement un cœur intact et une coquillé inorganique érodée. Cependant, ni l’encapsulation ni la modification de surface des MOFs n’altérait leur intégrité. Enfin, nous avons étudié la co-encapsulation de deux molécules actives utilisées en combinaison (amoxicilline et clavulanate de potassium) dans les nanoMOFs stables à base de MIL-100 (Fe). Les antibiotiques ont été incorporées par imprégnation et chaque molécule s’est localisée préférentiellement dans un compartiment (large ou petite cage) corroborant parfaitement les simulations par modélisation moléculaire. De plus, il a été découvert, de manière surprenante, qu’un grand nombre de nanoMOFs se localisait au voisinage des bactéries (S.aureus) dans des cellules infectées. En se dégradant dans ces cellules, les nanoMOFs contenant les antibiotiques ont réduit de manière importante la charge bactérienne intracellulaire. Ces études révèlent le potentiel des particules de type «cage» pour une incorporation efficace de molécules actives et leur libération contrôlée et ouvrent de nombreuses possibilités d’application
Drug delivery systems are engineered technologies to administer pharmaceutical ingredients to improve their therapeutic effects, aiming at minimizing their side effects by means of targeted delivery and/or controlled release. “Cage” particles recently drew special attention since they could act as “drug containers” which potentially load large amount of drugs, improve their stability and offer the possibilities to co-encapsulate synergetic drugs. Cyclodextrins (CDs) are typical “cage” molecules with a hydrophobic cavity and a hydrophilic outer surface. Taking advantage of the host-guest interactions between β-CD and benzophenone (Bz), CD based nanoparticles (CD-NPs) were the first formulation investigated. CD-NPs of around 100 nm were instantaneously produced by mixing two aqueous solutions of neutral polymers: 1) poly-CD containing β-CDs, and 2) Bz grafted Dex (Dex-Bz). The “green” and facile preparation procedure makes it attractive formulation, whereas its limitation lies on the low drug payloads (~ 5 wt%). In order to improve the drug loading capacity of CDs, porous CD based metal organic frameworks (CD-MOFs) were synthesized, which contain not only CD cavities, but also large pores built up by CDs self-assembly. Lansoprazole (LPZ) was incorporated in CD-MOF microcrystals (~ 6 µm) reaching payloads as high as 23.2 ± 2.1% (wt). Remarkably, each CD cavity was able to host a drug molecule, offering new opportunities for the use of CD-MOFs for drug delivery purposes. However, these particles disassembled in aqueous media, which limits their application for oral and intravenous administration. Surface modification is therefore necessary to improve their stability in water. The drug loaded CD-MOF nanocrystals (~ 650 nm) were successfully embedded in polyacrylic acid (PAA) polymer matrices. The composite microspheres exhibited spherical shapes and sustained drug release over a prolonged period of time (over 48 h). Drug loaded MOF/PAA composite microspheres were not toxic in vitro (cell viability ~ 90%) even at very high concentrations up to 17.5 mg/mL. MOF/PAA composite microspheres constitute an efficient and pharmaceutically acceptable MOF-based carrier for sustained drug release. However, the process of surface modification was complicated and lead to larger particles and reduced drug payloads. Water-stable MOFs are a novel type of hybrid particles, showing a high potential as drug carriers. Iron trimesate MOFs, namely, MIL-100 (Fe) (MIL stands for Material of Institute Lavoisier) was among the first nano-scaled MOFs used for drug delivery. These particles were stable in water but degraded in phosphate buffer saline (PBS) losing their crystallinity and constitutive trimesate linkers. However, it was discovered that they kept their morphology intact. A thorough analysis based on Raman microscopy was carried on to gain insights on both the morphology and chemical composition of individual particles. It was evidenced the formation of a sharp erosion front during particle degradation. Noteworthy, the MOFs did not degrade during drug loading nor surface modification. Co-encapsulation of two synergic antibiotics (amoxicillin and potassium clavulanate) in MIL-100 (Fe) nanoMOFs was achieved following a “green” procedure by soaking nanoMOFs in aqueous solutions of both drugs. Molecular modelling showed that each drug preferentially located in a separate nanoMOF compartment. Surprisingly, nanoMOFs were prone to co-localize with bacteria once internalized in infected macrophages. NanoMOFs acted synergistically with the entrapped drugs to kill intracellular S. aureus, in vitro. These results pave the way towards the design of engineered nanocarriers in which each component synergistically plays a role in fighting the disease. These studies unravel the potential of “cage” particles for efficient drug entrapment and controlled release and open numerous possibilities for applications

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2016.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 195-208).
Carbon nanostructures (CNS) such as carbon nano-fibers (CNFs), -tubes (CNTs), and graphene are of interest for a diverse set of applications. Currently, these CNS are synthesized primarily by chemical vapor deposition (CVD) techniques, using metal catalysts. However, after CNS synthesis, those metals are oftentimes detrimental to the intended application, and extra steps for their removal, if available, have to be taken. As an alternative to metallic catalysts, metal oxide catalysts are investigated in order to better understand metal-free CVD processes for CNS synthesis. This thesis furthers the mechanistic understanding of metal oxide mediated CNS growth, especially metal oxide nanoparticles (MONPs) for CNTs, thereby addressing yield and expanding the range of known catalysts and atmospheric CVD conditions for CNS growth. CNT and CNF growth from zirconia nanoparticles (NPs) are first studied, and a technique is developed to grow CNTs and CNFs from metal NP (MNP) and MONP catalysts under identical CVD conditions. The morphologies of the catalyst-CNT and -CNF interface for zirconia NPs are found to be different than for iron or chromium NPs via high resolution transmission electron microscopy (HRTEM) including elemental and phase analyses, and evidence of surface-bound base growth mechanisms are observed for the zirconia NPs. Titania NP growth conditions are investigated parametrically to achieve homogeneous and relatively (vs. zirconia) high growth yield, where clusters of CNTs and CNFs separated by only tens of nanometers are observed. Catalytic activity of titania NPs are estimated to be an order of magnitude lower than iron NPs, and a lift-off mechanism for titania NP catalysts is described, indicating that several layers of graphene will cause lift-off, consistent with HRTEM observations of 4-5 layer graphite within the CNFs. Potential catalytic CNS activity of chromia, vanadia, ceria, lithia and alumina NPs are explored, establishing for the first time CNT growth from chromia and vanadia precursor-derived NPs, although the phases of those NPs are not determined during growth. The insights acquired from MONP-mediated CNS growth are applied to demonstrate continuous, high-yield, few-layer graphene formation on titania nanowires.
by Akira Kudo.
Ph. D.

Diese Arbeit präsentiert eine vollständige quantenmechanische Beschreibung eines Systems bestehend aus einem Molekül und einem metallischem Nanopartikel (MNP) in der Gegenwart eines Strahlungsfeldes. Zuerst wird ein System aus einem Molekül und einem Gold-MNP betrachtet. Das Emissionsund Absorptionsspektrum zeigt viele scharfe molekulare Schwingungssatelliten auf einem breiten Plasmonmaximum. Eine Verstärkung der Schwingungssatelliten um drei Größenordnungen ist auf effiziente Absorption und Emission durch die MNP zurückzuführen. Dann wird ein System aus einer molekularen Kette mit einem Gold-MNP untersucht. Alle zuvor genannten Phänomene treten auch hier auf, jedoch werden die Schwingungssatelliten durch das Exzitonenband der molekularen Kette ersetzt. Anschließend wird ein Nano-Laser aus vielen Molekülen und einem Gold-MNP betrachtet. Die Moleküle werden durch inkohärentes optisches Pumpen angeregt. Dabei wird eine starke Plasmonanregung durch die gemeinsame Kopplung an die Moleküle erreicht. Die Photonenemission des Lasers zeigt, dass die Intensität ansteigt, während die Linienbreite schmaler wird. Die Korrelationsfunktion in zweiter Ordnung für die Photonen in Verbindung mit der schmaler Emission könnte dabei sogar einen Hinweis auf Lasing geben. Zuletzt wird eine Nanoverbindung aus einem Molekül und zwei sphärischen metallischen Elektroden betrachtet. Das Molekül wird durch den sequentiellen Ladungstransfer angeregt. Durch die Kopplung an die Moleküle werden die Elektrodenplasmonen angeregt. Die Photonenemission der Verbindung zeigt, dass die scharfen molekularen Schwingungssatelliten um das Tausendfache verstärkt werden. Anschließend ist ein System aus zwei pyramidalen Elektroden, die seitlich von zwei Gold-MNP eingeschlossen werden, untersucht. Hier können die Schwingungssatelliten einzeln verstärkt werden, indem der Abstand zwischen den MNP variiert wird. Wir zeigen auch, dass das Lasing in einer Verbindung aus vielen Molekülen theoretisch möglich ist.
This thesis presents a unified quantum description of the combined molecule-metal nano-particle system in the presence of a radiation field. Firstly, a single molecule coupled to a gold nano-sphere is investigated. The emission and absorption spectrum show many sharp molecular vibrational satellites over one broad plasmon peak. The three orders of magnitude enhancement of the vibrational satellites is due to the great ability of the sphere to absorb and emit photons. Secondly, a molecular chain coupled to a gold nano-sphere is investigated. All the phenomena mentioned above appear also for such system, except that the vibrational satellites are replaced by the Frenkel exciton band of the molecular chain. Thirdly, a plasmonic nano-laser consisting of many dye molecules and a gold nano-sphere is considered. The molecules are initially excited by incoherent optical pump. The strong plasmon excitation of the sphere is achieved due to the concerted coupling with the molecules. The emission of the laser shows that the intensity is enlarged while the line-width is reduced. The second-order correlation function of photons together with the emission narrowing can be utilized to determine lasing operation. Finally, a nano-junction formed by a molecule and two spherical metallic leads is investigated. The molecule is excited through sequential electron transfer. The lead plasmons get excited due to the coupling with the excited molecule. The emission of the junction shows that the molecular vibrational satellites are about one thousand times enhanced by the lead plasmons. Then, a junction with two pyramidal metallic leads sandwiched by two gold nano-spheres is investigated. The simulations show that the molecular vibrational satellites can be selectively enhanced by varying the inter-sphere distance. It is also proved that the lasing can be realized by a junction with many molecules.

Interest in rare-earth-doped crystalline materials, e.g., M(RE)F4 (M – alkali metal, RE – rare-earth metal), featuring unique optical properties such as light upconversion and downshifting is experiencing a surge due to the broad spectrum of applications that these photonic systems are facilitating. The development of reliable synthetic methods that grant rapid access to these materials is therefore of great importance. Microwave-assisted synthesis is appealing in this regard, because microwave radiation enables rapid and uniform heating of the reaction mixture and allows for rigid control of the reaction conditions, factors that facilitate the production of high-quality materials within minutes. Surprisingly, the investigation around microwave-assisted synthesis of M(RE)F4 materials featuring upconversion and downshifting luminescence is limited. Methods that have already been developed predominately target Na-based systems, despite the evidence that the Li-based analogues also display excellent optical properties. In fact, only a single microwave-assisted approach toward a nanoscale Li-based system has been reported to date, while to my knowledge, no report of a microwave-assisted synthesis of a microscale Li-based system existed prior to the commencement of the work presented in this thesis. The challenge lies in the fact that access to Li(RE)F4 is not easily achieved through a simple substitution of the alkali metal source in the established protocols that yield Na(RE)F4; rather, a complete re-optimization of the synthesis method is required. This particular challenge was successfully addressed in this work. Presented and discussed in Chapter 3 of this thesis is a rapid microwave-assisted solvothermal synthesis approach toward both upconverting and downshifting LiYF4:RE3+ microparticle systems. More specifically, it is detailed how the rigorous optimization of the reaction temperature/duration profile, initial reaction mixture pH, and ratio of the metal precursors was necessary in gaining control over the crystalline phase, morphology, and size of the microparticles under microwave-induced solvothermal conditions. Importantly, a materials growth mechanism involving the depletion of a Li-free crystal phase, followed by a particle ripening process is also proposed. Moreover, the versatility of the developed method is highlighted by showcasing how it can be extended toward the synthesis of other relevant Li- and Na-based M(RE)F4 nano- and microscale materials (i.e., LiYbF4, NaYF4, and NaGdF4) featuring upconversion luminescence. Lastly, potential challenges associated with microwave-assisted synthesis are discussed, and appropriate solutions are proposed. The upconversion and downshifting luminescence of the M(RE)F4 materials attained via the developed synthesis approach is investigated in Chapter 4. The first part of the chapter provides a general assessment of the characteristic luminescence generated by the M(RE)F4 materials featuring various RE3+ dopant systems. The second part of the chapter is devoted to a much more thorough single-particle investigation of the anisotropic luminescence behaviour exhibited by the LiYF4:RE3+ microparticles via hyperspectral imaging, polarized emission spectroscopy, and optical trapping. It is my hope that you, the reader, will find the work presented in this thesis stimulating from two vantage points – from the development of the most rapid microwave-assisted solvothermal synthesis of upconverting and downshifting M(RE)F4 nano/microscale materials reported to date, as well as from the utilization of specialized luminescence characterization techniques to provide fundamental insight into a seldom-considered luminescence property of crystalline materials such as LiYF4.

En 1920, le moteur Diesel marque l'histoire en se faisant une place dans le milieu de l'automobile. Toutefois, malgré la révolution que représente le moteur Diesel notamment en terme de technologie (moteur à combustion interne dont l'allumage n'est pas commandé mais spontané par phénomène d'auto-inflammation (absence de bougie d'allumage)), des inconvénients majeurs subsistent, tout particulièrement au niveau environnemental et sanitaire (émission de gaz à effet de serre, prélèvement accru d'énergie fossile, impact direct sur la santé). Afin de lutter contre ces émissions, l'Union Européen à mit en place les normes EURO (depuis 1993) incitant les constructeurs automobiles à concevoir des procédés d'élimination des particules carbonées et à apporter des évolutions au niveau des motorisations. C'est dans ce contexte qu'a vu le jour la technologie Filtre à Particules initié par Peugeot en 1999 pour évoluer d'années en années jusqu'à être considérées aujourd'hui comme une avancée majeur en terme de traitement des particules Diesel. Encore aujourd'hui les problèmes d'émanations demeurent en raison des imbrûlés générés par le moteur diesel (suies, HC aromatiques polycycliques, d'oxyde de soufre, d'oxyde d'azote…). Les dégagements de particules de suies fines demeurant un problème particulièrement important au niveau de la santé. Cette thèse s'inscrit dans l'optique d'optimisation du procédé FàP en proposant l'élaboration de membrane à base de SiC supportée. Plus généralement, notre étude concerne l'élaboration de céramiques poreuses (membranes supportées et mousses) à base de silicium pour application environnementale et sanitaire (Filtration des particules fines, dépollution et séquestration de CO2).Le Chapitre I traite du contexte général de l'étude. La problématique des émissions de particules est abordée d'un point de vue sanitaire et environnemental en précisant les normes en vigueurs pour leur contrôle. La technologie FàP est décrite avant d'introduire le SiC et la voie dite des « polymères précéramiques » (PDCs). L'aspect catalytique est ensuite abordé avant de développer le principe d'élaboration de membrane SiC et leur intérêt pour une application de dépollution automobile.Le Chapitre II traite de l'élaboration de membranes SiC supportées. L'étude concerne l'élaboration d'un procédé optimale pour déposer une membrane au sein de la porosité du FàP qui modifierait les caractéristiques de porosité de ce dernier sans pour autant engendrer des répercussions néfastes sur la filtration. Le polymère précéramique, précurseur de SiC, sera alors décrit et nous étudierons sa mise en forme par la technique dite de « trempage-tirage » (dip-coating) afin d'élaborer, après pyrolyse, une membrane SiC. Cette dernière sera caractérisée par de nombreux outils expérimentaux.Le Chapitre III reprend le procédé d'élaboration des membranes de SiC élaboré dans le Chapitre II mais il proposera d'aller plus loin avec la réalisation et l'étude de catalyseurs pour la combustion des suies, et leur intégration au sein d'une microémulsion de type SiC-MxOy utilisée pour revêtir les FàP.Le Chapitre IV propose une étude sur la préparation de mousses à base de SiC. Ce chapitre d'aspect plus fondamental consistera à développer des mousses cellulaires et à porosité hiérarchisée à base des éléments silicium (Si), bore (B), carbone (C) et azote (N). Cette phase de carbonitrure de silicium et de bore (Si/B/C/N) sera élaborée par couplage de la voie PDCs avec soit des agents sacrificiels soit par réplication. Une étude préliminaire sur la séquestration de CO2 sera alors décrite pour finir
Since the 90's, Diesel engines are widely used though they are criticized because of the pollution emitted. The constant updates of the Europeans norms (since 1993) concerning the diesel emissions imply a perpetual improvement of filtration techniques. The Diesel Particles Filter (DPF) technology used by the car manufacturer PSA Peugeot Citroën is one of the best ways to fulfill the limitation for diesel emissions. However, particles emission issue is still a problem and future legislations more and stricter, so an improvement of the DPF process is required to respect them. In this context, we have considered the elaboration of two different types of porous membranes on the DPF channels. The first one was in SiC, and had the aim to enhance the filtration efficiency. In this way, the smallest particles matter could be locked in the filter. The second kind of membrane integrates a catalytic phase inside the ceramic matrix, so in addition to the filtration aspect, it could improve soot combustion during the regeneration step of the DPF.The first chapter of my thesis deals with the literature corresponding to the subject, i.e. the DPF technology, non-oxides Si-based ceramics, and in particular those obtained through polymer-derived ceramics route (also called PDCs route). Then, ceramic coatings and catalytic phases are also treated. In the second chapter, we have considered the PDCs route and preceramic polymers to elaborate a SiC coating inside the DPF channels. We employed the dip-coating technique to overlay the channel surface with the AHPCS precursor of SiC (allylhydridopolycarbosilane), then, a pyrolysis under argon allows obtaining a SiC coating, in order to decrease the average pore diameter of the DPF (keeping an efficient filtration while avoiding overpressure) to catch soot nanoparticles evolving from Diesel engine.The third part of my PhD deals with the elaboration of another kind of coating for the DPF channels including a catalytic phase in the ceramic membrane. For this purpose, the microemulsion synthesis has been considered to prepare SiC-MxOy membrane. Further, we incorporated various catalytic phases based on Ce, Fe and Pt as activators of soot combustion. By employing the dip-coating technique, we successfully covered the DPF channels of our monoliths with the aforementioned microemulsion and after a heat treatment under controlled atmosphere; a porous coating consisting of the catalytic phase and the ceramic matrix was obtained. From this film, the porosity has been modified by lowering the diameter of the initial pores, but also by getting an additional porosity due to the polymer conversion and the surfactant decomposition. Catalytic sites in the ceramic have improved the soot combustion by lowering the temperature of the combustion.The fourth chapter introduces the elaboration of porous SiBCN materials through two approaches, replication and warm-pressing with sacrificial template (polymethylmethacrylate, PMMA). The SiBCN ceramic is a promising material due to its high mechanical properties and its stability at high temperature (1700-1800°C). By coupling the PDCs way with those two techniques, we are able to elaborate SiBCN porous materials which features can be tuned according to the technological application envisaged

The application of ICP-MS to the fields of proteomics and genomics has arisen in part due to its ability to detect and quantify trace levels of S and P, which are major constituents in proteins and nucleic acids respectively. The development of collision/reaction cell technology and high resolution instruments has enabled these biologically important elements to be measured and quantified at the pg - ng ml-1 level. Despite these advances, the detection limits of P and S are still inferior compared to other elements. Oligonucleotides containing biotin functionality were labelled with Au nano-particles attached to a streptavidin protein to achieve site specific labelling, with 100% labelling efficiency. Each nano-particle contained ~86 Au atoms, resulting in an 882 fold signal enhancement for 24 base length oligonucleotides. However, this enhancement factor was only observed when one oligonucleotide bound to one nano-particle in a 1:1 ratio. Much lower Au labelling efficiencies and signal enhancements were observed when thiolated oligonucleotides were labelled with maleimide functionalised gold nano-particles. This was attributed to the extensive and difficult sample preparation steps that were required prior to labelling. The detection and quantification of adducts formed between DNA and the Pt anti-cancer drugs cisplatin and oxaliplatin were also investigated with ICP-MS. Acid digestion of the carbon based DNA matrix enabled Pt adducts to be quantified at low dose rates of 1 Pt atom per 1 500 000 nucleotides in ~12 μg DNA. Such sensitive mass spectrometric determinations could be employed in clinical tests to detect and quantify low level adducts formed in patients in-vivo. To complement ICP-MS analysis, electrospray ionisation linear ion trap mass spectrometry was employed to study the interaction of oxaliplatin with the four DNA nucleobases. Multiple stage mass spectrometry enabled detailed Pt-nucleobase adduct fragmentation pathways to be established. The method of DNA detection using P in conjunction with the collision cell, or cool plasma to form PO+ was also demonstrated and the limitations of the method, namely, polyatomic interferences and severe matrix effects were highlighted.

Le présent travail de thèse décrit le développement de systèmes actifs de polymérisation d’oléfines basés sur des métaux de fin de transition (nickel et fer) supportés sur des nanomatériaux. Le chapitre I décrit l’état de l’art des systèmes catalytiques supportés ou non pour la polymérisation d’oléfines. Dans le chapitre II, nous décrivons la polymérisation de l’éthylène en utilisant des catalyseurs de nickel contenant un groupement –NH2 pour leur immobilisation covalente sur nanotubes de carbone ; montrant l’influence positive de l’immobilisation : les catalyseurs ainsi supportés sont en effet à la fois plus actifs et conduisant à des polymères de plus haut poids moléculaire. Dans le chapitre III, des complexes de fer contenant un groupement pyrène sont décrits et immobilisés sur nanotubes de carbone par interaction non covalente π-π. Dans ce cas, à la fois les systèmes homogènes et leurs analogues supportés catalysent la réaction de polymérisation de l’éthylène avec des activités particulièrement élevées. Il a également pu être mis en évidence l’importante influence du support carboné sur les performances du système catalytique ainsi que sur la structure des polymères obtenus. Différents types de complexes de nickel contenant un ligand imino-pyridine et différents groupes polyaromatiques ont été synthétisés et leur utilisation en polymérisation de l’éthylène est décrite dans le chapitre IV. L’influence de l’addition de faibles quantités de matériaux nanocarbonés (nanotubes de carbone ou graphène) au milieu réactionnel a ainsi été étudiée. Le graphène s’est dans ce cas révélé particulièrement bénéfique sur les performances du catalyseur. Enfin, le chapitre V décrit la polymérisation de l’isoprène à l’aide de catalyseurs de fer contenant des groupements polyaromatiques permettant leur immobilisation à la surface de nanoparticules de fer. Ces systèmes ont ensuite pu être confinés dans des nanotubes de carbone. Les systèmes catalytiques décrits sont particulièrement actifs produisant des polyisoprènes à température de transition vitreuse élevée et avec une haute sélectivité trans-1,4-polyisoprène
This present thesis deals with the development of active olefin polymerization catalysts based on late transition metal (nickel and iron) imino-pyridine complexes supported on nanomaterial. Chapter I gives a comprehensive literature review of unsupported and supported ethylene polymerization catalyst. In Chapter II we report the ethylene polymerization studies using nickel complexes containing an –NH2 group for covalent immobilization on multi-walled carbon nanotubes (MWCNTs) of the corresponding precatalysts. Comparison of the homogeneous catalysts with their supported counterparts evidenced higher catalytic activity and higher molecular weights for the polymers produced. In Chapter III, iron complexes containing a pyrene group have been synthesized and immobilized on MWCNTs through non-covalent π-π interactions between pyrene group and surface of MWCNTs. Activated by MMAO, both the iron complexes and immobilized catalysts show high activities for ethylene polymerization. It was possible to evidence that MWCNTs have a great influence on the catalytic activity and on the structure of the resulting polyethylenes. Imino-pyridine nickel complexes containing various kinds of aromatic groups have been synthesized in Chapter IV and polymerization conditions in the presence and in the absence of nanocarbon materials, such as MWCNTs or few layer graphene (FLG), are discussed. For those nickel catalysts bearing 1-aryliminoethylpyridine ligands, the presence of MWCNTs in the catalytic mixture allows the formation of waxes of lower molecular weight and polydispersity, whereas the presence of FLG proved to be beneficial for the catalytic activity. In Chapter V, isoprene polymerization catalyzed by iron complexes containing polyaromatic groups and non-covalently supported on nanoparticles and confined into the inner cavity of MWCNTs (Cat@NPs and Cat@NPs@MWCNTs) are investigated. Iron complexes show excellent activity for the isoprene polymerization and produced high glass temperature polyisoprene with a high trans-1,4-polyisoprene selectivity. Polymer nanocomposites are produced by supported catalysts and, transmission electron microscopy (TEM) evidenced efficient coating of the resulting polyisoprene around the oxygen sensitive iron nanoparticles

Accurately anticipating the toxic risks and specific factors contributing to the toxic risks of nanomaterials is a necessary step for the safe and effective proliferation, utilization, and regulation of these unique materials. This thesis addresses this problem through meta-analysis on existing nanomaterial pulmonary toxicity experiments as enabled by the use of machine learning algorithms including regression trees and random forests models at a time when the completeness of the data do not support traditional meta-analysis techniques like multiple linear regression. This thesis presents the results of analysis using these models to identify the most important nanomaterial characteristics contributing to toxicity as well as the magnitude of changes in toxicity expected from changes in those characteristics. This thesis presents predictive models for the pulmonary toxicity of carbon nanotubes and titanium dioxide nanoparticles showing the degree to which changes in experimental design, nanomaterial dimensions, impurities, and aggregation might explain differences in observed toxicity. Secondly, this thesis presents the predictions of random forest models revealing interactions between 2 or 3 nanomaterial characteristics and exposure attributes in a manner such that a material designer might minimize risk while continuing to meet functional objectives.

Ce travail a concerné l'étude de la fonctionnalisation métallique et du contrôle morphologique de nanoparticules de silice mésoporeuse appelées MSN. La voie de fonctionnalisation par synthèse directe a été privilégiée et a consisté en une encapsulation des précurseurs métalliques dans la phase porogène. L'insertion de cuivre, palladium, platine, argent or et de bimétalliques Cu/Pd et Pd/Pt a été réalisée. Il résulte de cette approche une localisation des nanoparticules métalliques dans les pores et d'une grande accessibilité des fonctionnalités à l'origine des excellentes performances catalytiques mesurées. Ces performances et le recyclage du catalyseur Cu@MSN ont été démontrés pour des réactions de Huisgen et de Sonogashira. Il a également été étudié l'adsorption de l'iode moléculaire en phase gaz sur des MSN fonctionnalisées par des nanoparticules d'argent avec d'excellentes capacités de rétention
The objective of this thesis was to develop efficient synthesis routes to prepare mesoporous silica-based nano-sized particles, designated as MSN, with controllable morphology and derivatised with selected transition metals. One-pot preparation and surface functionalisation procedures based on the insertion of the metal-phase precursor into the porogen aggregates were thoroughly optimised leading to silica particles containing such single metals as copper, palladium, platinum, silver or gold, as well as a two-metal phase of copper and palladium or that of palladium and platinum. It was demonstrated that the highly dispersed metal phase was localised on the pore surface and therefore it was readily accessible to the target chemicals on which to base the catalytic performance of the resulting materials. Among others, the remarkable catalytic performance of the Cu@MSN material in Huisgen and Sonogashira reactions and its propensity to undergo efficient recycling were proven through laboratory-scale testing. Experimental study of the selective adsorption of iodine vapour onto MSN supports functionalised with silver nanoparticles indicated an excellent retention capacity of such materials

L'assemblage de nanoparticules (NPs) couplées a suscité un grand intérêt ces dernières années, en vue d'application dans la détection de composés chimiques (molécule, explosifs, drogues,') appartenant au domaine de la spectroscopie Raman exaltée de surface (SERS) par exemple. Récemment, le couplage de structures périodiques de nanoparticules métalliques NPs a permis de mettre en avant des résonances dites résonances collectives de surface (SLR) résultant du couplage entre les modes plasmon de surface localisé et les modes de diffraction. Ces résonances se caractérisent par une largeur spectrale très fine impliquant une forte exaltation du champ électrique au voisinage des nanoparticules. Dans cette thèse, nous proposons une étude expérimentale vérifiée par le biais de modélisations par la méthode des Différences Finies dans le Domaine Temporel (FDTD), des résonances plasmoniques individuelles et collectives de surfaces supportées par des réseaux périodiques de NPs métalliques élaborés par la technique lithographie électronique. La première partie de cette thèse, mets en évidence les principales caractéristiques optiques, de la NP unique à l'assemblage de NPs en réseau périodique. Ce chapitre est illustré de quelques exemples tirés de la littérature sur l'excitation de ces plasmons de surface, pour engendrer une fonctionnalisation localisée de surface. Dans un deuxième temps, une étude approfondie sur l'amélioration des conditions de morphologie des substrats plasmoniques, en vue d'améliorer le greffage moléculaire au niveau des NPs, est présentée. Puis, nous présentons les résultats obtenus pour une méthode de greffage chimique, mise en place au laboratoire, et qui permet la visualisation directe des modes de réseau, par greffage de films moléculaires organiques dérivés de sels de diazonium, en excitant des modes SLRs. Enfin, la dernière partie porte sur l'étude des réseaux binaires de nanoparticules qui ont révélé l'émergence de deux modes plasmoniques hybrides, provenant de l'asymétrie du motif élémentaire. Nous avons ensuite mené, à l'aide de notre stratégie de greffage, une étude sur la fixation de molécules uniquement dans les zones de maximum d'exaltions des champs électriques en excitant tantôt dans le mode symétrique, tantôt, dans le mode anti-symétrique. Pendant ce doctorat, ces travaux de recherche ont permis une nette amélioration de la compréhension et du contrôle de la localisation du dépôt à l'échelle de la nanoparticule. C'est sur cette base solide qu'il est envisageable d'associer des matériaux déjà connus pour leurs propriétés optiques remarquables (NPs métalliques, boîtes quantiques 'QD), avec un polymère thermosensible (le pNIPAM), permettant un contrôle actif et réversible de l'exaltation (ou l'inhibition) de l'émission de lumière par les QDs, à l'échelle de la NP métallique. Un tel contrôle permettrait une avancée majeure des performances optiques des QDs incorporés dans des composants optiques
The assembly of coupled nanoparticles (NPs) has aroused great interest in recent years, with a view to applications in the detection of chemical compounds (molecules, explosives, drugs,...) belonging to the field of surface exalted Raman spectroscopy (SERS) for example. Recently, the coupling of periodic structures of metallic nanoparticles NPs has allowed to highlight resonances called surface collective resonances (SLR) resulting from the coupling between localized surface plasmon modes and diffraction modes. These resonances are characterized by a very fine spectral width implying a strong exaltation of the electric field in the vicinity of the nanoparticles. In this thesis, we propose an experimental study verified by means of Finite Difference Time Domain (FDTD) modeling, of individual and collective plasmonic resonances of surfaces supported by periodic arrays of metallic NPs elaborated by the electron lithography technique. The first part of this thesis, highlights the main optical characteristics, from the single NP to the assembly of NPs in periodic array. This chapter is illustrated with some examples from the literature on the excitation of these surface plasmons, to generate a localized surface functionalization. In a second step, an in-depth study on the improvement of the morphology conditions of the plasmonic substrates, in order to improve the molecular grafting at the level of the NPs, is presented. Then, we present the results obtained for a chemical grafting method, implemented in the laboratory, which allows the direct visualization of lattice modes, by grafting organic molecular films derived from diazonium salts, by exciting SLRs modes. Finally, the last part deals with the study of binary arrays of nanoparticles which revealed the emergence of two hybrid plasmonic modes, originating from the asymmetry of the elementary pattern. We then carried out, with the help of our grafting strategy, a study on the attachment of molecules only in the regions of maximum exaltions of the electric fields by exciting sometimes in the symmetric mode, sometimes in the anti-symmetric mode. During this PhD, these research works have allowed a clear improvement of the understanding and control of the deposition localization at the nanoparticle scale. It is on this solid basis that it is possible to associate materials already known for their remarkable optical properties (metallic NPs, quantum dots -QDs), with a thermosensitive polymer (pNIPAM), allowing an active and reversible control of the exaltation (or inhibition) of light emission by QDs, at the scale of the metallic NP. Such a control would allow a major advance in the optical performances of QDs incorporated in optical components

碩士
大同大學
材料工程學系(所)
93
Sol-gel process is widely used to prepare thin films. However sol-gel ITO conducting films have lower conductivity than that from sputtering. Therefore, I attempted to disperse nano metal particles in ITO film in hope to increase the film conductivity without seriously decreasing its light transmission. ITO precurse solutions were prepared from indium chloride and tin chloride (as a dopant). Quartz substrates were first spin coated with silver nitrate solution and reduced in air at 500℃ to obtain dispersed silver particles. Then, ITO precurse solutions were spin-coated on the quartz substrate with dispersed silver particles to from Ag-ITO composite films. The results showed that with 5mol% silver nitrate solution coating, the composite film would have the lowest sheet resistance 1.22 KΩ/sq, which was 52% decrease from the ITO film without disposed Ag particles. The light transmission was 85%, a decrease of 8.6% from ITO film. In the case of coating with 0.1 mol% copper nitrate solution, the Cu-ITO composite film had sheet resistance of 2.283 KΩ/sq and light transmission of 90%, which were 11% and 3.2% decrease from ITO film, respectively.

M. Tech. Chemical Engineering
The lack of clean and fresh water has become a worldwide problem because of water pollution caused by industrialization. Contamination of natural water sources by heavy metal is a worldwide public health problem, leading to waterborne outbreaks of infectious hepatitis, viral gastroenteritis, and cancer. Therefore it very important to remove these toxic metal ions from municipal and industrial effluents in order to protect plants, animals and human beings from their adverse effect before discharging into natural water bodies. Although, several separation methods such as filtration, reverse osmosis and membrane technology have been developed to remove these toxic heavy metal ions from wastewater, however these conventional treatments technologies were found to be expensive on a sustainable basis. Adsorption process was identified as the most effective, and extensively used essential process in wastewater treatment, and in order for adsorption process to feasibly remove pollutants from wastewater, there should be a need for a suitable adsorbent which will have a large porous surface area, and a controllable porous structure. Through the application of nanotechnology, nano adsorbents can be developed as effective adsorbents to treat wastewater. The main objective of this project was to apply magnetic metal doped iron oxides as an efficient adsorption media for the removing of Cr(VI), Cd(II) and V(V) ions from wastewater.

碩士
國防醫學院
微生物及免疫學研究所
100
Nano-sized metal has been widely applied in various fields. Previous studies have confirmed that the inhaled nano-particles may be distributed at nasal, pharyngeal, laryngeal, and alveolar in the respiratory systems , and penetrate into systemic circulation. Many papers and literatures indicated that nano-size particles may induce inflammation, thrombosis, pulmonary fibrosis and cardiovascular diseases, etc. In vitro, long time exposure exhibited the synthesis of cytokine was elevated, especially by ZnO. This study used BEAS2B cell line to study the effects by stimulation with nanoparticles, including Fe, Fe2O3, Al, Al2O3, and ZnO. The cytokines related to allergy and fibrosis stimulated by those nano-particulates were measured, such as TNF-α, IFN- γ, IL-6, IL-4, TGF- β, VEGF. Furthermore, the suspected signal pathway through the activation of Mitogen-Activated Protein Kinase (MAPK) and Phosphatidylinositol 3-kinase (PI3K)/Akt pathways were analyzed. Otherwise, we also survyed those cytokines in the sera of nanometal particle exposed workers. The results showed that both the stimulation effects on gene level or protein level were observed by nano-metal particles on BEAS2B cell line, in the production of IFN-γ, TGF-β, IL-6, and TNF-α. Through the analysis of MAPK factors p38, ERK1 / 2 and JNK, obvious manifestations were observed on Fe and Fe2O3 stimulation. Nano-metal particles activate the inflammatory MAPK pathway.Higher level of IL-4, IL-13, TGF-β, VEGF, IL-6, and TNF-α in the sera of exposed were also measured. We concluded that in vitro cell experiments and exposed workers’ sera, cytokines production have similar results.

碩士
南台科技大學
電機工程系
92
This article demonstrates that the nano-scale metal particles were synthesized via electrochemical technique with two kind surfactants (CTABr、D12TABr). Metal atoms are usually wrapped by surfactant micelles in order to form metal nano-particles. The auxiliary surfactant (D12TABr) concentration, applied voltage and growth temperature are playing important roles in formation of metal nano-particle. Also, we found that the auxiliary surfactants added into growth solution are resulted in increasing aggregation number of micelles and surfactant colloid condensation. The surfactant colloid condensation is increased with decreasing the size of the micelles when auxiliary surfactant concentration is increased from 1 to 30 mg. The size of metal nano-particle is found to increase linearly with the growth temperature due to increasing space available for solubilization in the micelle. Furthermore slow transport depended on applied voltage for gold ion is conducive to formation of metal nano-particle in growth solution; typically we find that that applied voltage in our study can be obtained at 2.5 V. An average particle size about 6.4 nm is obtained in primary surfactant (CTABr) with 3 ml (0.08M), auxiliary surfactant (C48H100BrN) with 30 mg, electrolysis time with 25 minutes, and acetone with 10 μl. Finally, we can successfully synthesis compound nano-particles.

碩士
臺灣大學
電子工程學研究所
98
In this work, Metal-Oxide-Semiconductor structure with Au nanocrystals formed by chemical redundant method for charge storage is fabricated. Scanning Electron Microscope is utilized to calculate the density of nanocrystals. In the characterization of memory performance, we use high frequency capacitance-voltage (C-V) measurement to measure the memory window size for comparing the storage capacity and charging efficiency. On the other hand, through the time dependent variation of device capacitance measured under fixed voltage, the effective charge loss rate can be calculated to compare the retention regarding the stored charge of devices. In the study of device, we compared the impacts between different structural parameters at first, include using gold nanoparticles and silver nanoparticles, and the variance of different diameters of gold nanoparticles, such as 10 nanometer and 20 nanometer. When the density of the gold nanoparticles increased also has influence that charge retention dropping while causing the memory window size increasing. Further, we want to improve the performance of device in addition, using excimer laser annealing to fix the defects in oxide layer, but we find the gold nanoparticles would be melted after heated by laser, and diffused into oxide layer then break down under the bias voltage.

碩士
國立清華大學
工程與系統科學系
102
Surface plasmon polariton (SPP) has attracted considerable attention owing to the property to confine light in sub-wavelength. For instance, the surface plasmon polariton takes place on the metal nanoparticles interface. In this system, due to localizing near tiny metal structure, it has been called localized surface plasmon resonance (LSPR). According to the effect of localized surface plasmon resonance, it can be used to improve absorption in photovoltaic equipment, permitting a considerable reduction in the physical thickness of solar photovoltaic absorber layers. The first purpose of this thesis is to present a new geometry metal nanoparticles structure for increasing scattering by the localized surface plasmon resonance effect. First we analyze basic sphere and cylinder metal nanoparticle in different pitch and at different wavelength. Then we present the new plasmonic structure devices to increase the scattering on metal nanoparticle by adding bullet shape metal nanoparticles. We realize that the relative better rates (bullet nanoparticle and sphere nanoparticle) become stable and relative better rates (bullet nanoparticle and cylinder nanoparticle) decrease when increasing nanoparticle radius. With radio frequency (RF) module solver in COMSOL, the optical structures are simulated and enhancement factor, improving factor, total enhancement factor are extracted. Second, we change the pitch and bullet nanoparticles radius and make that the pitch is six times of the bullet nanoparticles radius. For the smaller pitch, the enhancement factor is better at 700 nm. For the larger pitch, the enhancement factor becomes unstable. The total enhancement factor has an upper value 8.35 % when using the case without bullet nanoparticles as benchmark. Different from some prior works, this thesis is the first to study the change of the enhancement factor between different angles of incident (AOI) at different wavelength. When the wavelength is smaller than 600 nm, the enhancement factor becomes unstable between different AOI. Because the fano effect which is the destructive interference between scattered and unscattered light that occurs below resonance would affect at short wavelength. When the wavelength is larger than 600 nm, the influence of AOI effect becomes small. In addition, the total enhancement factor would be 0.94%, 1.46% and 1.50% and 5.80% which AOI are 0, 30, 45 and 60 degree when using the case without bullet nanoparticles as benchmark. And the enhancement over band gap factor would be 0.49%, 0.91% and 0.89% and 5.51% which AOI are 0, 30, 45 and 60 degree when using the case without bullet nanoparticles as benchmark. In the case that AOI is 45 degree, TE mode offers a distinct advantage over TM mode about 11.82 % when using the case without nanoparticles as benchmark. Therefore, we would just analyze TE mode between different AOI.

碩士
國立成功大學
化學工程學系碩博士班
93
The gold and silver nanoparticles were synthesized using the polymerizable surfactants of 4-(6-acryloyloxyhexyloxy)benzoic acid (AHBA) and 4-(11-acryloxy-undecyloxy)benzoic acid (AUBA). Gradient Refractive Index (GRIN) rods were fabricated by centrifugal diffusing polymerization which was developed in our lab. In order to fabricate Gradient Refractive Index (GRIN) plastic rods with a high acceptance angle, nanoparticles were used as high refractive index materials and methyl methacrylate (MMA) was used as a reactive low refractive index monomer. The nanoparticles were prepared in a surfmer/MMA/H2O reverse micellar system. The dependence of the feed molar ratio of surfmer/MMA/H2O and nanoparticles on the optical properties of GRIN plastic rods was investigated and it was found that the polymerizable surfactant with a long chain length could improve the excellent results for the preparation of nanoparticles and plastic rods. The existence of silver nanoparticles in the optical fiber was found to increase the refractive index of the plastic rods. The polymerizable surfactant with a high refractive index was found to further increase the refractive index of the GRIN plastic rods. Due to the increase of numerical aperture (NA) of the GRIN plastic rods containing nanoparticles, the brightness and optical properties of the rods were increased obviously. Image transmission and lens characteristics of GRIN plastic rods were all evaluated in this work.

碩士
國立臺灣大學
光電工程學研究所
100
In this thesis, a parallelized three-dimensional (3D) finite-difference time-domain (FDTD) method numerical simulator is developed by using the message passing interface (MPI) library coded in C++ language. The capabilities of the simulator are than demonstrated by studying two topics in metamaterials and plasmonics, respectively. The transmission/reflection spectra of metamaterial magnetic resonators with different parameters are calculated and a right-angled triangular prism is numerically designed to observe the negative-refractive-index properties of fishnet structure. For plasmonics, the spectra of total cross sections and the near fields of silver nano particles of different shapes including cubes, sphere-pairs, and nano plates, are investigated. It is shown that the phasor amplitude is larger when the wavelength is at the absorption-cross-section peak rather than the scattering-cross-section peak for the case of cubes. The FDTD obtained results are compared with those based on the pseudospectral time-domain (PSTD) method calculation. For the nano-plates, plate length along the incident electric polarization direction is found to be strongly correlated with the resonant wavelength for waves normally incident on the parallel plates.

碩士
國立臺灣大學
光電工程學研究所
96
In this research, we fabricate anodic alumina oxide (AAO) on GaN and InGaN/GaN quantum well (QW) structure. With the AAO technique, we can fabricate a thin aluminum oxide film with nano-pore array on the nitride structure, which is used as a mask to deposit metal nano-particle arrays on to study the surface plasmon (SP) characteristics, or to release the strain in the QW. Our first study is about the SP characteristics of a silver or gold nano-particle array on GaN template. We change the AAO process condition to control the hole diameter and interpore distance such that we can vary the particle size and density of the metal nano-particle array. We observe the SP absorption spectra and its resonance frequencies of different particle sizes and densities. The second study is about the strain relaxation phenomenon by fabricating nano-hole array patterns with the AAO technique on an InGaN/GaN QW structure. The effective strain relaxation, leading to the significant enhancement of emission efficiency and reduction of quantum-confined Stark effect (QCSE), in a high-indium InGaN/GaN QW structure via nano-pore fabrication on the sample surface with the anodic aluminum oxide technique is demonstrated. By generating nano-pores of 60 nm in size, 4.71 x 109 cm-2 in pore density, and a depth several nm above the QW, the internal quantum efficiency (IQE) can be increased by about three times and the QCSE is reduced by 2.5 times while the emission spectrum is blue-shifted by 14 nm in the green range. With this approach, it is possible to achieve a higher IQE and a smaller QCSE by relaxing the built-in strain of a higher-indium QW structure and blue-shifting its emission, when compared with a lower-indium sample of the same emission spectrum as the blue-shifted one.

Semiconducting polymer nanomaterials draw the attention of modern science as alternative luminescent nanomaterials over normal inorganic quantum dots and fluorescent dye molecules due to their several advantages, e.g- easy synthetic procedure, less cytotoxicity as well as more bio-compatibility, tunable optoelectronic properties and so on. The fundamental spectroscopic properties of semiconducting polymer nanomaterials strongly depends on the extent of intra/ inter molecular interactions of semiconducting polymer molecules. Eventally, it also strongly influenced by the surface Plasmon band of metal nanoparticles as well as electronic band alignment of interfacial inorganic quantum dots. Energy/ Charge transfer based photophysics of semiconducting polymer nanomaterials in presence of inorganic nanoparticles should be very much effective for the generation of efficient optoelectronic and solar cell devices. Furthermore, fluorescent dye doped semiconducting polymer nanoparticles can act as a bright, photostable luminescent source for long term imaging devices. But the fundamental photophysics of encapsulated dye molecules need to be clarified by different spectroscopic methods for the fabrication of more efficient nanoprobe. Considering these, current thesis is devoted to the advancement of efficient nanomaterials based on semiconducting polymer for different applications in photonics, optoelectronics, imaging and sensory devices.
Research was conducted under the supervision of Prof. Amitava Patra of the Materials Science division under the SPS [School of Physical Sciences]
Research was carried out under CSIR fellowship

Alla luce del recente allarmante tasso di esaurimento delle riserve di combustibili fossili e al contemporaneo drastico aumento dei livelli di CO2 nell'atmosfera, principale gas serra responsabile del riscaldamento globale e di cambiamenti climatici molto gravi, una delle priorità assolute nella ricerca a livello mondiale è quella di sfruttare il più possibile le fonti di energia rinnovabile. Una possibilità molto interessante è quella di realizzare un processo di riduzione della CO2 a combustibili liquidi che sfrutti energie rinnovabili, quale quella solare, mediante dispositivi più comunemente noti come celle fotosintetiche artificiali o foglie artificiali o celle foto-elettro-catalitiche (PEC). L'obiettivo principale di questo lavoro, è stato pertanto quello di condurre uno studio approfondito su due diversi sistemi elettrocatalitici di riduzione della CO2 a prodotti liquidi con un più alto valore aggiunto, uno operante in fase gassosa (cioè in assenza di elettrolita al catodo) e uno operante in fase liquida. In particolare, è stata progettata e utilizzata nel processo di conversione della CO2, un’innovativa cella in fase liquida operante su scala di laboratorio, sulla falsariga della cella in fase gas precedentemente sviluppata all’Università di Messina. Il lavoro è stato svolto principalmente presso il laboratorio CASPE/INSTM dell’Università degli Studi di Messina (Dipartimento di Ingegneria Elettronica, Chimica e Ingegneria Industriale). Un periodo di sei mesi è stato svolto invece, nel corso del secondo anno di dottorato, presso l’École supérieure de chimie, physique, électronique de Lyon (CPE Lyon). In tale periodo sono stati sintetizzati, mediante innovative tecniche di sintesi organometallica, materiali compositi da utilizzare come elettrocatalizzatori nel processo di riduzione della CO2. Sono state effettuate molteplici prove sperimentali utilizzando svariate tipologie di catalizzatori, sia in fase gas che in fase liquida, al fine di indagare la differente selettività, produttività e varietà di prodotti ottenuti. Il processo in fase liquida è infatti quello maggiormente studiato in letteratura, ma esistono alcune problematiche che devono essere superate per consentire un successivo semplice scale up. quali ad esempio, la scarsa solubilità della CO2 e la tipologia di prodotti ottenuti (principalmente acido formico). Lo scopo principale di questo lavoro è stato quello di preparare nuovi materiali a base di carboni dopati con metalli, catalizzatori questi molto diversi da quelli comunemente utilizzati nel processo di riduzione della CO2 (generalmente metalli in bulk), e di testarli sia in fase gas (per sfruttare i vantaggi di questa condizione, quali ad esempio facile recupero dei prodotti e alta qualità dei prodotti stessi) sia in fase liquida (per avere un miglior confronto con i dati ampiamente presenti in letteratura). Per gli studi sulla riduzione elettrocatalitica della CO2 nella cella operante in fase gassosa, sono stati preparati una serie di elettrodi (basati su nano particelle –NP- di Cu, Fe, Pt e Cu/Fe depositate su nanotubi di carbonio o carbon black e successivamente poste all'interfaccia tra una membrana di Nafion e uno strato a diffusione di gas –GDL-). I risultati ottenuti sono stati molto promettenti, sia in termini di tipologia di prodotti formati che di produttività. In fase gas (senza elettrolita) è stata osservata la formazione di prodotti ≥C1 quali etanolo, acetone e isopropanolo, in particolare utilizzando il Fe (seguito dal Pt), evidenziando che anche metalli non nobili possono essere usati in maniera efficiente in questo processo. Per migliorare la produttività nella reazione di riduzione della CO2, sono stati preparati elettrodi differenti, basati su coating con sostituti zeolitici imidazolici (SIM-1) tipo MOF. In particolare, i catalizzatori testati sono stati MOF modificati con Fe-CNT, Pt-CNT, e CuFe-CNT. E’ stato osservato un cambiamento significativo in termini di produttività e anche di selettività verso i prodotti finali. Nel dettaglio, in particolare per il catalizzatore a base di MOF modificato con Pt, è stato osservato un aumento nei prodotti carboniosi e anche una selettività più alta verso prodotti con un più elevato numero di atomi di C. Per quanto riguarda lo studio del processo di riduzione elettrocatalitica della CO2 utilizzando la cella operante in fase liquida, sono state preparate tipologie di elettrodi simili ai precedenti. Inizialmente infatti, sono stati studiati elettrodi a base di nanoparticelle metalliche (Cu, Fe, Pt, Ru, Co) depositate su nanotubi di carbonio o carbon black. L'ordine relativo della produttività nella riduzione elettrocatalitica della CO2 in questa serie di elettrodi, è però risultato essere diverso rispetto alla fase gassosa, indicando quindi un differente percorso di reazione. In termini di produttività totale, gli elettrodi a base di Pt hanno consentito di ottenere le migliori performance, seguiti da Ru e Cu, mentre il Fe ha dato risultati peggiori. Sulla base dei risultati sperimentali ottenuti, è stato inoltre ipotizzato un possibile meccanismo di reazione. Successivamente, per cercare di migliorare ulteriormente le prestazioni nel processo di riduzione della CO2 in fase liquida, è stato effettuato uno studio approfondito, volto ad indagare la dipendenza di tale processo dalle dimensioni delle nanoparticelle metalliche. A tale scopo sono stati utilizzati elettrodi a base di nanoparticelle metalliche (Ru, Fe, Pt e Cu) su nanotubi di carbonio (CNT) depositati su GDL. Sono state sintetizzate nanoparticelle metalliche di diverse dimensioni utilizzando molteplici tecniche di sintesi: (i) impregnazione che ha consentito di ottenere NP di dimensioni comprese tra 10-50 nm; (ii) sintesi organometallica che ha consentito di ottenere NP uniformi e ultrafine con dimensioni comprese tra 1-5 nm. (ad esempio sono state sintetizzate NP di Fe di 1-3 P nm) (iii) sintesi mediante nanowires che ha consentito di ottenere NP di rame ultrafine con dimensioni comprese tra 2-3,8 nm. In particolare, la novità dell’approccio mediante nanowires sta nella possibilità di ottenere particelle di dimensioni molto piccole sintetizzando inizialmente i Cu NWs, mettendoli poi a contatto con il supporto carbonioso e facilitandone il suo trasferimento, ciò grazie alle forze intermolecolari di attrazione dei gruppi funzionali presenti sui CNT parzialmente ossidati. Inoltre, a differenza della sintesi organometallica, tale approccio permette di condurre le reazioni in aria e non in atmosfera inerte. I valori di produttività ottenuti sono stati 5-30 volte più alti utilizzando nanoparticelle metalliche più piccole (ottenute via nanowires o mediante sintesi organometallica) rispetto alle nanoparticelle metalliche più grandi (ottenute per impregnazione). I risultati sperimentali indicano pertanto che le NP di dimensioni più piccole hanno un ruolo fondamentale nelle performance catalitiche. Inoltre, il carico di NP metalliche è stato significativamente ridotto dal 10% al 1-2% in peso consentendo di ottenere, per le NP più piccole, una produttività equivalente o addirittura superiore rispetto alle nanoparticelle più grandi. In seguito, è stato effettuato anche uno studio sul possibile riutilizzo degli elettrodi di lavoro e sulla disattivazione per tempi di reazione più lunghi. E’ stata infine preparata una diversa tipologia di elettrodi a base di nano-foams su lastrine metalliche, al fine di ottenere un ulteriore miglioramento nel processo di riduzione elettrocatalitica della CO2. Le nano-foams o dendriti, sono state preparate mediante la tecnica di deposizione elettrochimica ed è stato effettuato uno studio preliminare di ottimizzazione, al fine di determinare le condizioni di sintesi più adatte. In aggiunta, è stato eseguito uno studio specifico per ottimizzare il valore di Voltaggio da utilizzare nelle prove catalitiche, mediante sia test di voltammetria ciclica che test completi di riduzione della CO2. Sono stati testati nano-foams a base di Cu e Fe depositati su fogli di Cu Fe, Al, di Inconel e su una griglia di Al. L’aumento nella produttività usando queste tipologie di elettrodi, è stata nell’ordine di 2-10 volte rispetto alla massima produttività ottenuta utilizzando NP metalliche su materiali carboniosi. Svariate tecniche analitiche sono state poi utilizzate per caratterizzare in modo approfondito i materiali preparati tra cui, microscopia elettronica a trasmissione (TEM), microscopia elettronica a scansione (SEM), spettroscopia ad assorbimento atomico (AAS), diffrazione a raggi X (XRD), spettroscopia fotoelettronica a raggi X (XPS), determinazione dell’area superficiale mediante metodo Brunauer-Emmett-Teller (BET). La determinazione dei prodotti di reazione è stata effettuata invece mediante cromatografia ionica (IC), gas cromatografia con rivelatore a spettrometria di massa (GC-MS), gas cromatografia (GC) con rivelatore a termo conducibilità (TCD).
In view of the recent alarming rate of depletion of fossil fuel reserves and the drastic rise in the CO2 levels in the atmosphere leading to global warming and severe climate changes, tapping into all kinds of renewable energy sources has been among the top priorities in the research fields across the globe. One of the many such pathways is CO2 reduction to fuels using renewable energies, more commonly referred as artificial photosynthetic cells or artificial leaves or photo-electro-catalytic (PEC) cells. The key objective of the present PhD work was to conduct in-depth studies on two different electro-catalytic CO2 reduction systems: electrolyte-less cell (gas phase) and electrolytic cell (liquid phase). In particular, a novel lab scale liquid phase cell, on the similar lines of the previously realized gas phase cell at the University of Messina, was developed and used to convert electro-catalytically CO2 to more value-added products. The work was carried out at the Laboratory CASPE/INSTM of the University of Messina (Department of Electronic Engineering, Industrial Chemistry and Engineering). During the second year, a six-month period was spent at the École supérieure de chimie, physique, électronique de Lyon (CPE Lyon), where organometallic routes were explored for the synthesis of novel composite materials to be used as electrocatalysts in the CO2 reduction process. Experimental tests were carried out on various types of catalysts in both the gas and liquid phase cells to understand the different selectivity, productivity and the reaction products obtained. Liquid phase, in fact, has been the most studied process in literature, but some issues mainly related to CO2 solubility and types of products formed (i.e. mainly formic acid), have never be allowed to pass the lab scale stage. The general aim of this PhD was to prepare novel metal doped nanocarbon substrates, which are very different with respect to the conventional metal bulk layers used as electrocatalysts in CO2 reduction, and test them both in gas phase (to take advantage of these conditions, i.e easy recovery and improved quality of the products) and in liquid phase (to have a better comparison with conditions typically adopted in literature). For the studies on the electro-catalytic reduction of CO2 in gas phase cell, a series of electrodes (based on Cu, Fe, Pt and Cu/Fe metal nanoparticles – NPs - deposited on carbon nanotubes – CNTs - or carbon black and then placed at the interface between a Nafion membrane and a gas diffusion-layer) were prepared. The results, evidencing the various types of products formed and their different productivities, are very promising. Under electrolyte-less conditions, the formation of ≥C1 products (such as ethanol, acetone and isopropanol) were observed, the highest being for Fe and closely followed by Pt, evidencing that also non-noble metals can be used as efficient catalysts under these conditions. To enhance the productivities of the CO2 reduction, a different set of electrodes were also prepared based on substituted Zeolitic Imidazolate (SIM-1) type MOF coatings during a stay at CPE Lyon and Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON). Particularly, the catalysts tested were MOF-based Fe-CNTs, Pt-CNTs and Cu/Fe-CNTs. There was a significant change in the reaction products and in the selectivity towards the end-products. Particularly, especially for the MOF modified Pt based catalyst, there was an increase in the C-products and also a better selectivity towards higher C-products. Moving to the studies on the electro-catalytic reduction of CO2 in liquid phase cell, a similar set of electrodes were prepared. Initially, electrodes based on metal NPs of Cu, Fe, Pt, Ru and Co deposited on CNTs or carbon black were studied for their CO2 reduction capability. The relative order of productivity in CO2 electro-catalytic reduction in these series of electrodes was found to be different between the gas and liquid phase cells indicating the different reaction pathways. For liquid phase conditions, in terms of net C-products, catalytic electrodes based on Pt topped the class, closely followed by Ru and Cu, while Fe got the lowest position. The probable underlying reaction mechanism was also provided. In order to improve further the performances of the CO2 reduction in liquid phase conditions, a metal NPs size dependant study on the electro-catalytic reduction of CO2 to fuels was carried out. This study was performed using electrodes based on metal NPs of Ru, Fe, Pt and Cu loaded on CNTs and then transferred on a gas diffusion layers (GDL). Varied sized metal NPs have been synthesized using different techniques: (i) impregnation route to achieve NPs in the size range of 10-50 nm; (ii) organometallic approach to synthesize uniform and ultrafine NPs in the size range of 1-5 nm (i.e., Fe NPs were synthesized through a novel synthesis route to attain 13 nm NPs);(iii) Nanowire (NW) top-down approach to obtain ultrafine copper metal NPs in the size range of 2-3.8 nm. Particularly, the novelty of nanowire approach is the ability to obtain very small metal NPs starting from the synthesis of Cu NWs and then transferring the Cu onto the carbon surface, taking advantage of the different inter-forces of between Cu NWs and the functional groups present on the partially oxidized CNT surface. Furthermore, unlike the case of organo-metallic approach, this approach allows a preparation under air avoiding the use of potentially demanding inert atmospheric conditions. The enhancements in the fuel productivity were found to be 5-30 times higher for the smaller metal NPs obtained via organo-metallic route or nanowire route as compared to the larger metal NPs obtained via impregnation route. The results signify that the smaller sized metal NPs loading on the CNTs have a prevailing role in the catalytic performance and the selectivity towards different products. Moreover, the percentage of metal NPs loading was significantly reduced from 10 to 1-2 wt. % producing higher or equivalent fuels for small NPs as compared to the larger NPs. The reusability of the working electrodes and long reaction times (until 24 hours) were also probed. A different set of electrodes based on nano-foams on metal foils, were also investigated to achieve further improvements in the electro-reduction of CO2 to fuels. These nano-foams or dendrites were prepared by electrochemical deposition technique. Optimization studies on the deposition of these foams were performed initially to fix the set of preparation conditions. Moreover, voltage optimization study was performed using cyclic voltammetry and full CO2 reduction tests to find the optimum voltage for the process. The nano-foam electrodes tested include Cu and Fe foams on Cu foil, Fe foil, Al foil, Inconel foil and Al grid/mesh. The enhancements in the fuel productivity for various foams were in the range of 2-10 times greater as compared to the highest net fuel productivity achieved using metal NPs doped carbon catalytic electrodes, from all the previous studies. Various characterizations and analysis tools were used to analyse the catalysts qualitatively and quantitatively, which include Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Atomic Absorption Spectroscopy (AAS), X-ray diffraction (XRD), X-ray Photo-electron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET). To determine the fuel productivities, Ion Chromatography (IC), Gas Chromatography-Mass Spectrometer (GC-MS), Gas Chromatography (GC) were used.
Compte tenu du récent taux alarmant d'épuisement des réserves de combustibles fossiles et de l'augmentation drastique des niveaux de CO2 dans l'atmosphère qui a conduit au réchauffement de la planète et à des changements climatiques sévères, l'exploitation de toutes sortes d'énergies renouvelables a été la Parmi les principales priorités de la recherche Champs à travers le monde. L'une des nombreuses voies de ce genre est la réduction du CO2 aux combustibles utilisant des énergies renouvelables, plus communément appelées cellules photosynthétiques artificielles ou feuilles artificielles ou cellules photoélectro-catalytiques (PEC). L'objectif principal de ce travail était de réaliser des études approfondies sur les différents systèmes de réduction électro-catalytique du CO2, à savoir les cellules sans électrolyte (phase gazeuse) et les cellules électrolytiques (phase liquide). Dans ce processus, nous avons conçu une nouvelle cellule en phase liquide à échelle de laboratoire sur les lignes similaires de la cellule de phase gazeuse de modèle précédemment modélisée. Des essais expérimentaux sur la réduction du CO2 ont été réalisés sur différents types de catalyseurs dans les deux cellules afin de comprendre la sélectivité, la productivité et les produits de réaction obtenus. L'obtention de résultats de test dans les deux cellules nous a permis d'effectuer une comparaison décente avec les résultats de réduction électro-catalytique de CO2 existants dans la littérature. Des essais expérimentaux ont été réalisés sur différents types de catalyseurs à la fois dans les cellules en phase gazeuse et en phase liquide pour comprendre la sélectivité, la productivité et les produits de réaction obtenus. La phase liquide, en fait, a été le processus le plus étudié dans la littérature, mais certaines questions liées principalement à la solubilité du CO2 et aux types de produits formés (c'est-à-dire principalement l'acide formique) n'ont jamais été autorisées à franchir le stade de l'échelle du laboratoire. L'objectif général de ce doctorat était de préparer de nouveaux substrats de nanocarbone dopés par des métaux, qui sont très différents par rapport aux couches en vrac métalliques conventionnelles utilisées comme électrocatalyseurs dans la réduction de CO2, et de les tester en phase gazeuse (pour profiter de ces conditions, Une récupération facile et une qualité améliorée des produits) et en phase liquide (pour une meilleure comparaison avec les conditions typiquement adoptées dans la littérature). Pour les études sur la réduction électro-catalytique du CO2 en phase gazeuse, une série d'électrodes (à base de nanoparticules de Cu, Fe, Pt et CuFe déposées sur des nanotubes de carbone ou de noir de carbone puis placées à l'interface entre une membrane Nafion et Une électrode à couche de diffusion de gaz). Les résultats démontrent le type divers de produits formés et leurs productivités. Dans des conditions sans électrolyte, la formation de produits ≥C1 tels que l'éthanol, l'acétone et l'isopropanol a été observée la plus élevée étant pour Fe et suivie de près par Pt. Pour améliorer les productivités de la réduction du CO2, un ensemble différent d'électrodes a été préparé sur la base de revêtements MOF de type imidazolate de type zéolitique substitué (SIM-1) lors d'un séjour au CPE Lyon et à l'Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON). Les catalyseurs testés étaient Fe-CNT, Pt-CNT et CuFe-CNT basés sur MOF. Il y a eu un changement significatif dans les produits de réaction et aussi, la sélectivité vis-à-vis des produits finaux. Pour le catalyseur à base de Pt modifié, MOF, il y avait une augmentation des produits C et également une sélectivité différente tandis que pour le catalyseur à base de Fe, il y avait une légère diminution des produits C. En se reportant aux études sur la réduction électro-catalytique du CO2 dans une cellule en phase liquide, un ensemble similaire d'électrodes a été préparé afin d'obtenir une bonne comparaison des résultats dans les expériences en phase gazeuse. Initialement, des électrodes à base de nanoparticules métalliques (Cu, Fe, Pt, Ru, Co) déposées sur des nanotubes de carbone ou du noir de carbone ont été étudiées pour leur capacité de réduction du CO2. L'ordre relatif de productivité dans la réduction électrocatalytique de CO2 dans ces séries d'électrodes a été trouvé différent entre les cellules en phase gazeuse et en phase liquide indiquant les différentes voies de réaction. Pour les conditions de phase liquide, en termes de produits C nets, les électrodes catalytiques à base de Pt sont en tête de la catégorie, suivies de près par Ru et Cu, tandis que Fe a obtenu la position la plus basse. Le mécanisme réactionnel sous-jacent probable a également été fourni. Afin d'améliorer encore les performances de la réduction du CO2 dans les conditions de phase liquide, une étude de la nanoparticules métalliques (NPs) dépendant de la taille de la réduction électro-catalytique du CO2 aux combustibles a été réalisée. Ceci a été réalisé à l'aide d'électrodes à base de nanoparticules métalliques (Ru, Fe, Pt et Cu) chargées sur les nanotubes de carbone (CNT) transférés sur les couches de diffusion gazeuse (GDL). On a synthétisé des nanoparticules de métal de différentes tailles en utilisant différentes techniques de synthèse: (i) l'itinéraire d'imprégnation pour obtenir des NP dans la plage de tailles de 10 à 50 nm; (Ii) Approche organométallique pour synthétiser des NPs uniformes et ultrafines dans la plage de tailles de 1-5 nm. Fe ont été synthétisés par une nouvelle voie de synthèse et des conditions pour atteindre des NP de 1 à 3 nm. (Iii) Approche de haut en bas de Nanowire pour obtenir des NP métalliques de cuivre ultrafin dans la plage de taille de 2-3,8 nm. En particulier, la nouveauté de l'aide de nanofils est la capacité à obtenir des particules de très petite taille d'abord la synthèse du Cu NFs, puis de les mettre en contact avec le support carboné et de faciliter son transfert, cela grâce à des forces d'attraction intermoléculaires des groupes fonctionnels présent sur le CNT partiellement oxydée. En outre, contrairement à la synthèse organométallique, cette approche permet d'effectuer les réactions dans l'air et non pas dans une atmosphère inerte. Les améliorations de la productivité du combustible ont été trouvées être au moins 5 à 30 fois plus élevées pour les NP métalliques de plus petite taille obtenus par voie organo-métallique ou par nanofil, par rapport aux NP métalliques plus grands obtenus par voie d'imprégnation. Les résultats indiquent que les NP métalliques de plus petite taille chargés sur les CNT jouent un rôle prédominant dans la performance catalytique et la sélectivité vis-à-vis de différents produits. En outre, le pourcentage de charge de NP métalliques a été réduit de façon significative de 10% à 1-2% en poids, produisant des carburants plus élevés ou équivalents pour de petites NP en comparaison avec les NP plus grandes. De plus, comme on a observé clairement la productivité en H2 qui a augmenté de nombreux facteurs pour les NP plus petits sur les plus grandes NP. La réutilisabilité des électrodes de travail et les longs temps de réaction ont également été sondés. Un ensemble différent d'électrodes à base de nano-mousses sur des feuilles métalliques a également été étudié afin d'obtenir des améliorations beaucoup plus importantes de l'électro-réduction de CO2 aux carburants. Ces nano-mousses ou dendrites ont été préparées par une technique de dépôt électrochimique. Des études d'optimisation sur le dépôt de ces mousses ont été effectuées initialement pour fixer l'ensemble des conditions de préparation. De plus, une étude d'optimisation de la tension a été réalisée en utilisant la voltamétrie cyclique et des tests de réduction de CO2 complets pour fixer une tension optimale pour les réactions. Les électrodes nano-mousses testées incluent (mousses Cu, Fe sur feuille Cu, feuille Fe, feuille Al, feuille Inconel et grille Al). Les améliorations de la productivité du combustible pour diverses mousses se situaient dans la plage de 2 à 10 fois par rapport à la productivité nette de combustible la plus élevée obtenue en utilisant des électrodes catalytiques en carbone dopé par des NP métalliques. Différentes caractérisations et outils d'analyse ont été utilisés pour analyser les catalyseurs qualitativement et quantitativement qui incluent la microscopie électronique à transmission (TEM), la microscopie électronique à balayage (SEM), la spectroscopie d'absorption atomique (AAS), la diffraction des rayons X (XRD) La spectroscopie électronique (XPS) et Brunauer-Emmett-Teller (BET) et pour déterminer les productivités des combustibles, chromatographie ionique (IC), chromatographie gazeuse-spectromètre de masse (GC-MS), chromatographie gazeuse.