Lors de ce travail nous avons étudié les modifications de HDPE, PVF, PVDF et PTFE par des plasmas O2 et N2. Nous nous sommes focalisés sur l’effet des ions et des neutres. Nous constatons dans tous les cas une modification de la composition des échantillons, cette modification de composition est accompagnée d’une modification de l’énergie de surface. Les traitements plasma greffent de nouvelles fonctions polaires (oxygénées ou azotées) à la surface des échantillons, responsables de l’augmentation de l’énergie de surface. Le PTFE traité par plasma O2 présente lui un comportement particulier. Il est possible de greffer de faibles quantités d’oxygène à sa surface et d’augmenter faiblement son énergie de surface lors de traitements de courte durée à faibles puissances. Les traitements de plus fortes puissances érodent fortement la surface du PTFE sans y greffer de fonctions oxygénées. Les surfaces obtenues sont extrêmement rugueuses et leur énergie de surface est fortement diminuée, nous obtenons des surfaces de type ultra-hydrophobes. Les résultats obtenus lors des traitements plasma ont été comparés à ceux obtenus dans le cas de traitements par des ions O2+/O+ ou N2+/N+. Ceci nous a permis de mettre en évidence une différence de réactivité des échantillons face aux différents traitements. Cette différence de réactivité nous permet de conclure que les ions ne sont pas l’espèce principale responsable de la modification de nos échantillons lors des traitements plasma. Nous avons également pu mettre en évidence une différence de réactivité entre les différents échantillons. Le HDPE, PVF et PVDF ont des réactivités semblables alors que le PTFE est beaucoup plus résistant aux modifications, nous pensons que ceci est dû à la structure entièrement fluorée du PTFE. Nous avons également étudié la résistance de nos échantillons à l’adsorption de protéines dans le cadre d’une étude sur la biocompatibilité. Nous avons pu montrer que les échantillons de PTFE rendu ultra hydrophobe, après traitement par plasma O2 de haute puissance, présentent une bonne résistance à l’adsorption de protéines. Cette caractéristique est intéressante pour la synthèse de matériaux biocompatibles.

The need for safe and functional implants has led to anincreased demand for improved biomaterials. The performance invivo depends on the interaction between the biologicalsurrounding and the surface of the material. By tailoring thesurface of a material with suitable bulk properties,biomaterials with an ability to interact with the biologicalsystem in a specific and controlled way are obtained. Siliconeelastomers have been used as biomaterials for several decades,but it is widely recognized that they are difficult to modifyby the conventional methods used for organic polymers due tothe partly inorganic structure of silicone. This thesis presents a strategy to obtain siliconebiomaterials by covalent coupling of molecules to the surfaceusing silicon chemistry. The first step is to introduce Si-Hgroups onto the surface of silicone elastomers by plasmatreatment. The second step is to react a terminal double bondof a molecule with the formed Si-H group by a catalyzedhydrosilylation reaction. The coupled molecule may eitherprovide the desired properties itself, or have a functionalitythat is able to couple another molecule with suitablecharacteristics. The influence of plasma treatment in hydrogen, argon andoxygen on the silicone elastomer was characterized by X-rayphotoelectron spectroscopy (XPS). To quantify the effect ofplasma treatment, the method of ternary XPS diagrams wasdeveloped. It was found that undesired silica-like layers wereformed under severe treatment conditions. Argon plasma at lowpower and short treatment time was the most suitable parametersetting. Subsequent hydrosilylation grafting ofallyltetrafluoroethylether, aminopropylvinylether andN-vinylformamide showed that it was possible to functionalizethe surface via a covalent link to the surface. The primaryamino groups introduced onto the surface were accessible forfurther coupling reactions. Heparin surfaces were obtained by acoupling reaction with the introduced amino groups. Keywords:Silicone elastomers, PDMS, XPS, ESCA, surfacemodification, plasma

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Quantum dots are inorganic nanocrystals of semiconductor metals that have unique light emitting properties. Due to their tunable and narrow emission profile, broad absorption spectra, resistance to photobleaching and high level of brightness they have emerged as inorganic fluorophores and numerous applicabilities for in vitro, in situ as well as in vivo studies are present. The chemical nature of the quantum dot surface needs to be altered in order to make the inorganic nanoparticles applicable to biological systems. Water soluble and biocompatible particles that limit unspecific binding to proteins can be obtained through functionalization of the surface coating with appropriate molecules.   In this pilot study, two surface modification strategies were performed upon two commercially available quantum dots in order to attach the zwitterionic molecules L-cysteine and thiolated sulfobetaine methacrylate, both shown to create non-fouling and biocompatible surfaces.   A biphasic exchange method was successfully used to perform ligand exchange of Qdot® ITK™ Organic Quantum Dots (QD-Organic) in order to exchange the structurally unknown, native lipophilic coating to one consisting of the amino acid L-cysteine (QD-Cysteine). The quantum dots transferred from the organic to the aqueous phase after the natively hydrophobic coating was changed to the hydrophilic L-cysteine. A characteristic mass fragment of protonated trioctylphosphine oxide (TOPO) was found for QD-Organic, using TOF-SIMS, suggesting TOPO is a part of the native coating. Further, the mentioned mass fragment was no longer present after the exchange. The C (1s) XPS-spectrum showed a new peak for carboxylic carbon, characteristic for L-cysteine, and expected changes in elemental composition were consistent with measured changes for all relevant elements. Large amounts of buffer remained after purification, suggesting the purification protocol needs further evaluation. Traces of the native coating were found in the C (1s) XPS-spectrum for QD-Cysteine, indicating not all ligands were exchange.      Additionally, a strategy for surface functionalization of Qdot® 655 ITK™ amino (PEG) quantum dots (QD-PEG-NH2) with L-cysteine and thiolated sulfobetaine methacrylate was outlined and performed, using Michael addition and the heterobifunctional linker 3-Maleimidobenzoic acid N-hydroxysuccinimide ester. Unfortunately, no indications of successful attachment of the linker to the quantum dot have been found, neither by TOF-SIMS nor XPS, and thus functionalization with L-cysteine and tSBMA was not achieved. In theory, the proposed coupling chemistry used during the pilot study is promising, but further experiments are needed to obtain a successful and optimized protocol for the functionalization.

The understanding of surfaces of materials is of crucial importance to all of us. Considering nanocrystals (NCs), that have a large surface to bulk ratio, the surfaces become even more important. Therefore, it is important to understand the fundamental surface properties in order to use NCs efficiently in applications. In the work reported in this thesis ZnO NCs were studied. At MAX-lab in Lund, synchrotron radiation based Spectroscopic Photoemission and Low Energy Electron Microscopy (SPELEEM) and X-ray Photoelectron Spectroscopy (XPS) were used. At Karlstad University characterization was done using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Scanning Tunnelling Microscopy (STM), Auger Electron Spectroscopy (AES), and XPS. The fundamental properties of ZnO surfaces were studied using distributions of ZnO NCs on SiO2/Si surfaces. The conditions for distribution of ZnO NCs were determined to be beneficial when using ethanol as the solvent for ultrasonically treated dispersions. Annealing at 650 °C in UHV cleaned the surfaces of the ZnO NCs enough for sharp LEEM imaging and chemical characterization while no sign of de-composition was found. A flat energy band structure for the ZnO/SiO2/Si system was proposed after 650 °C. Increasing the annealing temperature to 700 °C causes a de-composition of the ZnO that induce a downward band bending on the surfaces of ZnO NCs. Flat ZnO NCs with predominantly polar surfaces were grown using a rapid microwave assisted process. Tuning the chemistry in the growth solution the growth was restricted to only plate-shaped crystals, i.e. a very uniform growth. The surfaces of the NCs were characterized using AFM, revealing a triangular reconstruction of the ZnO(0001) surface not seen without surface treatment at ambient conditions before. Following cycles of sputtering and annealing in UHV, we observe by STM a surface reconstruction interpreted as 2x2 with 1/4 missing Zn atoms. / Baksidestext The understanding of the surfaces of materials is of crucial importance to all of us. Considering nanocrystals (NCs), that have a large surface to bulk ratio, the surfaces become even more important. In the work in this thesis ZnO NCs were studied. The fundamental properties of ZnO surfaces were studied using distributions of ZnO NCs on SiO2/Si surfaces. Annealing at 650 °C in UHV cleaned the surfaces of the ZnO NCs enough for sharp LEEM imaging and chemical characterization while no sign of de-composition was found. A flat energy band structure for the ZnO/SiO2/Si system was proposed after 650 °C. Increasing the annealing temperature to 700 °C causes a de-composition of the ZnO that induce a downward band bending on the surfaces of ZnO NCs. Flat ZnO NCs with predominantly polar surfaces were grown using a microwave assisted process. Tuning the chemistry in the growth solution the growth was restricted to only plate-shaped crystals, i.e. a very uniform growth. The surfaces of the NCs were characterized using AFM, revealing a triangular reconstruction of the ZnO(0001) surface not seen without surface treatment at ambient conditions before. Following cycles of sputtering and annealing in UHV, we observe by STM a surface reconstruction interpreted as 2x2 with 1/4 missing Zn atoms.

Nitrenes are reactive intermediates for many organic reactions, such as Curtius rearrangement. The thermo- or photochemical- decomposition of azides or isocyanates was known to generate nitrenes. We investigated the thermal chemistry of nitrene adsorbed on Cu(111) using benzyl azide (Bz-N=N=N), benzyl isocyanate (Bz-N=C=O) and phenyl isocyanate (ph-N=C=O) as precursors under ultrahigh vacuum conditions using temperature-programmed reaction/desorption (TPR/D), reflectionabsorption infrared spectroscopy (RAIRS) and X-ray photoelectron spectroscopy (XPS). Our study shows that despite of the isoelectronic functionalities (-N=N=N vs. -N=C=O) these molecules undergo different reaction pathways. For benzyl azide (Bz-N=N=N), the azido group losses N2 ,and the phenyl group migrates from nitrogen to carbon, forming surface bound H2C=N-Ph at 210 K. Eventually, H2 elimination and a carbon-to-nitrogen phenyl shift give the thermally stable ph-CN final product. XPS reveals that benzyl isocyanate (Bz-N=C=O) rearranges to form amide intermediate on the surface, which breaks into CO2, HCN and toluene at 410 K. RAIRs suggests that phenyl isocyanate (ph-N=C=O) undergoes cyclodimerization, cyclotrimerization and condensation to remove CO2 at 170 K, and phenyl group shifts from nitrogen to carbon to produce a metal bound acyl nitrene species (Ph-(C=O)-N---Cu) at 410 K.

In this thesis, the resistance switching characteristic of Zn:SiO2 -based memory was studied. The resistive memory was fabricated by sputtering to deposit the Metal/Insulator/Metal (MIM) structure. The top and bottom layers were made by Pt and TiN respectively, and the insulator was Zn:SiO2 grown by co-sputtering with SiO2 and Zinc. We found that doping Zinc into SiO2 insulator induced the resistive switching characteristic. By the treatment of supercritical carbon dioxide (SCCO2) in Zn:SiO2 -based device,the operation current would decrease. In the result of x-ray electron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) , it showed that the defects in Zn:SiO2 thin-film were reduced. And the electric conduction mechanism of low resistance state made a change from ohmic conduction to hopping conduction. To emerge spontaneous phenomenon of hopping conduction, the memory devices were fabricated with a multi-layer structure. In Auger electron spectroscopy (AES), we found the signal of zinc, split into three different kinds of peaks, which met the multi-layer structure. From I-V sweep measurement, the multi-layer structure device could be appeared the spontaneous hopping conduction mechanism. In order to find out the initial state of electric conduction mechanism .We measured the device of Pt/Zn:SiO2/TiN with constant current forming. We found the initial state of electric conduction path out successfully, and it¡¦s operation current below 10 uA.

Gold¡¦s reputation as an inactive catalyst has been changed since the discoveries made by pioneers, including Bond, Hutchings, and Haruta. Today, exploring gold¡¦s potential to catalyze a range of heterogeneous and homogeneous reactions has been a hot topic. In this dissertation, reaction of CO and hydroxyl groups and cyclotrimerization of propanal (C2H5CHO) catalyzed by gold were studied by using temperature-programmed desorption (TPD), reflection absorption infrared spectroscopy (RAIRS), X-ray photoemission spectroscopy (XPS), low energy electron diffraction (LEED) and density functional theory (DFT) calculations. keywords: LEED, XPS, RAIRS,TPD, Gold, cyclotrimerization, propanal, CO oxidation In the first topic, CO oxidation by hydroxyl groups prepared by electron beam bombardment of physisorbed water was performed on Au(110) and Au(531). The formation of hydroxyl groups was evidenced by the observation of the desorption of D2O at 175 K and D2 at 230 K in TPD, in conjunction with the O 1s peak at 531.32 eV in XPS. The adsorption of CO on the hydroxyl-covered surface resulted in CO2 desorption at 110 K and 150 K on Au(110), and 105 K, 140 K and 180 K on Au(531). In the investigation of various D2O and CO coverages, the adsorption of CO and D2O was found to be preferred on low-coordinated Au atoms. Additionally, D2O on low-coordinated Au atoms required lower dissociation energy. This site effect was correlated with the high activity of smaller gold nanoparticles. Moreover, the mechanism for reaction of CO and hydroxyl groups was suggested to be similar to the water-gas-shift reaction due to the observation of the enhancement of D2 desorption after reaction. The second topic studied the cyclotrimerization of propanal catalyzed by gold. After exposing Au(110) to propanal at 180 K, the desorption of 2,4,6-triethyl-1,3,5-trioxane ((C2H5CHO)3) was observed at 340 K. The RAIRS and XPS studies showed that the cyclotrimerization of propanal was completed at 180 K. The same results were also detected on Au(531). However, only propanal molecular desorption was found on Au(111) suggesting that the low coordination Au atoms and the trench-like structure on Au(110) and Au(531) play key roles. On Ag(110) and Cu(110), no reaction was found indicating that the intrinsic nature of gold is also an important factor for the reaction. Investigation on Pt(110) inherited with the same (1x2) missing-row structure revealed that the decarbonylation of propanal occurred due to the stronger £b2(C,O) bonding mode. The reactions observed on Au(110), Au(531), and Pt(110) strongly suggest that the activity for the reactions may result from the relativistic effect of gold. The DFT calculations further showed the interactions between hydrogen in carbonyl groups and low-coordinated Au atoms (O=C-H¡KAu) help to gather propanal molecules and preorganize them at specific surface sites while an intracomplex reaction takes place.

Semiconductor nanocrystals are expected to play an important role in the development of new generation of microelectronic and photonic devices such as light emitting diodes and memory elements. Optimization of these devices requires detailed investigations. Various spectroscopic techniques have been developed for material and devices characterization. This study covers the applications of the following techniques for the analysis of nanocrystalline materials: Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, X-Ray Diffraction (XRD) and X-Ray Photoelectron (XPS). Transmission Electron Microscopy (TEM) and Secondary Ion Mass Spectrometry (SIMS) are also used as complementary methods. Crystallinity ratio, size, physical and chemical environment of the nanostructures were probed with these methods. Si and Ge nanocrystals were formed into the oxides Al2O3 and SiO2 by ion implantation, magnetron sputtering and laser ablation methods. FTIR and XPS are two methods used to extract information on the surface of the nanocrystals. Raman and XRD are non destructive and easy-to-operate methods used widely to estimate the crystallinity to amorphous ratio and the sizes of the nanocrystals. In this study, the structural variations of SiO2 matrix during the formation of Si nanocrystals were characterized by FTIR. The shift in position and changes in intensity of the Si-O-Si asymmetric stretching band of SiOx was monitored. An indirect metrology method based on FTIR was developed to show the nanocrystal formation. Ge nanocrystals formed in SiO2 matrix were investigated using FTIR, Raman and XRD methods. FTIR spectroscopy showed that Ge atoms segregate completely from the matrix at relatively low temperatures 900 oC. The stress between the Ge nanocrystals and the matrix can vary in samples produced by magnetron sputtering if the production conditions are slightly different. Si and Ge nanocrystals were formed into Al2O3 matrix by ion implantation of Si and Ge ions into sapphire matrix. Raman, XRD, XPS and TEM methods were employed to characterize the formed nanocrystals. XRD is used to estimate the nanocrystal sizes which are in agreement with TEM observations. The stress on nanocrystals was observed by Raman and XRD methods, and a quantitative calculation was employed to the Si nanocrystals using the Raman results. XPS and SIMS depth profiles of the sample implanted with Si, and annealed at 1000 oC were measured. Precipitation of Si atoms with the heat treatment to form the nanocrystals was observed using XPS. The volume fraction of the SiOx shell to the Si core in Si nanocrystals was found to be 7.9 % at projection range of implantation.

We investigated the reactivity and bonding of perfluoroethyl groups (C2F5) on Cu(111) under ultra high vacuum conditions. Perfluoroethyl moieties bonded to the surface were generated by the dissociative adsorption of perfluoroethyl iodide. Temperature-programmed reaction/desorption (TPR/D) and reflection- adsorption infrared spectroscopy (RAIRS) revealed abounding reaction pathways, and a variety of intermediates were either identified or inferred. The major desorption products, hexafluoro-2-butyne and hexafluorocyclobutene, were detected at 360K and 440K, and some octafluorobutene was observed at 320K at higher coverages, implicating that two fluorine atoms were abstracted step-by-step from the C2F5 on Cu(111). Two sets of signature IR bands were recognized. One set (2054cm-1, 1409cm-1, 1210cm-1) was found to correlate with the surface-bound trifluorovinyl moieties which were also confirmed by directly generating this species from trifluorovinyl iodide. The other set of vibrational features (1322cm-1, 1224cm-1, 950cm-1) presumably implied the trifluoro- ethylidyne intermediate on the surface. Hence, C2F5(ad) underwent the £\-F and £]-F elimination reactions in sequence to yield trifluorovinyl which eventually led to hexafluoro-2-butyne. The alternative route was that C2F5(ad) proceeded via the £\-F elimination reaction twice to render trifluoroethylidyne which ultimately resulted in hexafluorocyclobutene. To our knowledge, the occurrence of the sequential £\-F and£]-F elimination pathway, or the double £\-F elimination reaction has never been observed in any single system.