The surface functionalisation of polyethylene and polypropylene by industrial and laboratory scale corona treatments and by laboratory flame treatment was studied. The surface sensitive techniques of X-ray photoelectron spectroscopy (XPS), attenuated total reflection infra-red spectroscopy (FTIR-ATR), contact angle measurement and electron microscopy (SEM and TEM) were employed. Corona and flame treatments resulted in incorporation of oxygen only into the surfaces of both polyethylene and polypropylene, resulting in improved surface wettabilities. A variety of oxygen functional groups were introduced by the two treatments. The industrial and laboratory scale treatments of both polymers were found to be similar in terms of the oxygen concentrations incorporated and surface wettabilities achieved. The presence of significant amounts of chain scission products were indicated on corona treated surfaces, while only minimal quantities were indicted on flame treated surfaces. This was attributed to their volatilisation during flame treatment. Introduction of sulfur dioxide into the flame and corona regions during treatment resulted in significant improvements in surface wettability. Incorporation of sulfur and nitrogen resulted from the presence of sulfur dioxide. A possible mechanism involving the formation of sulfonic acid groups and ammonium sulfonate groups was suggested. An oxidation depth model developed for use with variable take-off angle XPS showed that significantly deeper oxidation occurred in the presence of sulfur dioxide. Corona treatment was more effective in improving surface wettabilities than flame treatment, this being attributed to heat induced functional group reorientation during flame . treatment for polyethylene and to differences in surface chemistry resulting from the two treatments in the case of polypropylene. The surface wettability of poly ethylene was more readily improved than the surface wettability of polypropylene after all the treatments investigated. A method for estimating functional group concentrations using chemical derivatisation and contact angle measurement was developed. Functional group estimates for flame treated polyethylene were found to be in good agreement with chemical derivatisation used in conjunction with XPS measurements.

This thesis focuses on understanding the chemistry involved in a variety of surface modification reactions, both on metal oxides and graphene. In this work, the rates of chemisorption of a prototypical phosphonic acid on ITO under several processing protocols are measured using XPS to determine the optimal procedure. UPS is used to track the dependence of the electronic structure of the system, specifically of the work function and position of the valence band maximum on coverage. Phosphonic acid monolayers with appropriate tail groups can also be used to initiate chemistry from surfaces, which has potential for building layers of organic-electronic devices, including organic solar cells and capacitors. The growth of non-conjugated polymers from BaTiO₃ nanoparticles using a facile ATRP technique is studied via solution-phase and solid-state techniques to determine its applicability to make matrix-free composites for hybrid dielectrics. In addition, the surface chemistry involved in Kumada Catalyst-Transfer to grow polythiophene derivatives from ITO is examined via XPS. Finally, the newly emerged alternative for replacement of ITO as transparent electrode, graphene, is n- and p-doped using redox-active, solution-processable metal-organics, which increased its conductivity and allowed the work function to be tuned over a range of 1.8 eV. The systems are characterized in a systematic study, and the results are promising for future applications of graphene.

Graphene is a novel two dimensional material that is revolutionizing many areas of science and it is no surprise that a significant amount of effort is dedicated to its investigation. One of the major areas of graphene research is the development of procedures for large scale production. Among many recently developed methodologies, graphene oxide reduction stands out as a straightforward and scalable procedure for producing final material with properties similar to those of graphene. Laser reduction of graphite oxide is one of the novel approaches for producing multilayer graphene, and this work describes a viable approach in detail. It is determined that a material which is comprised of a combination of laser reduced graphite oxide-coupled to an unreduced graphite oxide layers beneath it, produces a broadband photosensitive material. The efficiency of light conversion into electrical current is greatly dependent upon the oxygen content of the underlying graphite oxide. Developing novel ways for reducing graphite oxide is an ongoing effort. This work also presents a new method for achieving complete reduction of graphite oxide for producing predominantly sp2 hybridized material. This approach is based on the irradiation of graphite oxide with a high flux 3 keV Ar ion beam in vacuum. It is determined that the angle of irradiation greatly influences the final surface morphology of reduced graphite oxide. Also, multilayer epitaxial graphene growth on silicon carbide in ultra-high vacuum was investigated with quadrupole mass spectrometry (QMS). Subliming molecular and atomic species were monitored as a function of temperature and heating time. The grown films were characterized with X-ray photoelectron spectroscopy coupled with Ar ion depth profiling.

Τα οργανικά φωτοβολταϊκά (OPV) είναι συσκευές που παρουσιάζουν μια ελκυστική λύση για εφαρμογές ηλιακής ενέργειας λόγω του χαμηλού κόστους παραγωγής τους, της μηχανικής ευκαμψίας και τη δυνατότητα παραγωγής συσκευών μεγάλης έκτασης και μικρού βάρους. Οι πιο αποδοτικοί δέκτες ηλεκτρονίων μέχρι σήμερα στα OPVs βασίζονται σε τροποποιημένα φουλερένια. Ωστόσο, χρειάζονται περαιτέρω βελτιώσεις προκειμένου να επιτευχθεί πιο αποτελεσματική μεταφορά των διαχωρισμένων φορέων στα αντίστοιχα ηλεκτρόδια. Προσπάθειες προς αυτή την κατεύθυνση έχουν γίνει, είτε επηρεάζοντας την αναμειξιμότητα μεταξύ του δότη και δέκτη είτε με την ανάπτυξη πιο αποτελεσματικών δοτών ή δεκτών ηλεκτρονίων. Νέα υβριδικά υλικά με βάση το φουλλερένιο έχουν χρησιμοποιηθεί για να επηρεάσουν τις ημιαγώγιμες ιδιότητες των πολυμερών. Δεδομένου ότι οι πολυκινολίνες αποτελούν μια από τις πλέον υποσχόμενες κατηγορίες πολυμερών μεταφοράς φορτίου (οπής ή ηλεκτρονίου) για εφαρμογή σε διάφορες οπτοηλεκτρονικές εφαρμογές, ο συνδυασμός τους με C60 αναμένεται να παράσχει μια λύση για την ενίσχυση των οπτικών, μορφολογικών και ηλεκτρονικών τους ιδιοτήτων. Πρόσφατη έρευνα έχει δείξει ότι η τροποποίηση των πολυκινολινών ώστε να έχουν χαμηλότρες τιμές LUMO θα ενισχύσει τις ιδιότητες τους ως δέκτες ηλεκτρονίων. Στην εργασία αυτή μελετήθηκαν οι ηλεκτρονικές ιδιότητες διαφόρων υλικών που αντιστοιχούν στα διαδοχικά στάδια σύνθεση ενός νέου υβριδικού συμπολυμερικού δέκτη μέσω των φασματοσκοπιών φωτοηλεκτρονίων από ακτίνες-Χ και ακτινοβολία UV (XPS/UPS). Το τελικό υβριδικό πολυμερές που μελετήθηκε είναι η πολυ-πενταφθόροφενυλοκινολίνη η οποία υβριδίστηκε με C60 (P5FQ-C60). Το μονομερές πενταφθόροφενυλοκινολίνη (Ph5FQ), το καθαρό C60 και το υβριδικό μονομερές Ph5FQ-C60 έχουν επίσης μελετηθεί. Επίσης μελετήθηκαν τα υβριδικά συμπολυμερή P3OT-co-P5FQ και P3OT-co-(P5FQ-Ν-C60) με αναλογία 1:10 για χρήση ως δέκτες ηλεκτρονίων με καλύτερη αναμειξιμότητα με τον δότη. Για την φασματοσκοπική έρευνα τα δείγματα αποτέθηκαν σε υποστρώματα Si με χρήση spin coating από διαλύματα τολουολίου, THF ή χλωροφορμίου. Οι μετρήσεις πραγματοποιήθηκαν σε θάλαμο ανάλυσης υπερυψηλού κενού (βασική πίεση 5x10-9 mbar). Από τις μετρήσεις XPS η κορυφή F1s των μη υβριδικών μορίων εμφανίστηκε σε ενέργεια σύνδεσης (BE) 688.3 eV, μια τιμή που αντιστοιχεί σε άτομα φθορίου με δεσμούς C-F. Η ίδια κορυφή μετατοπίζεται σε χαμηλότερες ενέργειες σύνδεσης σε όλα τα υβριδικά υλικά, υποδεικνύοντας την επίδραση των μορίων C60 στο ηλεκτρονιακό νέφος των φθορίων της κινολίνης. Από τα φάσματα UPS μετρήθηκε το υψηλότερο κατειλημμένο μοριακό τροχιακό (HOMO) σε σχέση με το επίπεδο Fermi καθώς και το κατώφλι υψηλών ενεργειών σύνδεσης (HBE) για κάθε υλικό. Από αυτά, υπολογίστηκε το έργο εξόδου τους, ενώ από το άθροισμα του έργου εξόδου και της ενέργειας σύνδεσης του ΗΟΜΟ υπολογίστηκαν οι Ενέργειες Ιονισμού (ΙΡ). Αυτή είναι μια χρήσιμη παράμετρος για τον χαρακτηρισμό των ημιαγώγιμων πολυμερών επειδή αντιστοιχεί στην απόσταση μεταξύ του ΗΟΜΟ και του επιπέδου κενού και σε συνδυασμό με το ενεργειακό χάσμα (Eg) μπορεί να υπολογιστεί η χαμηλότερο μη κατειλημμένο μοριακό τροχιακό (LUMO). Τα αποτελέσματα δείχνουν ότι οι ιδιότητες των ημιαγώγιμων πολυμερών ή μονομερών μπορούν αποτελεσματικά να επηρεαστούν με υβριδοποίηση με χρήση νανοδομών του άνθρακα, που σε αυτή την περίπτωση είναι το C60. / Organic photovoltaic (OPV) devices present an attractive solution for solar energy applications due to their inherently low material costs, mechanical flexibility, and the potential of scalability to large area, light weight, devices. The most efficient electron accepting materials used so far in OPVs are based on modified fullerenes. However, further improvement is needed in order to achieve more efficient transport of the separated charges to the respective electrodes. Attempts to this direction have been made either by influencing the miscibility between the donor and acceptor phases or by the development of more efficient electron donor or electron acceptor materials. New hybrid materials comprising of fullerene can been used to tune the semiconducting properties of polymers. Since polyquinolines are one of the most promising classes of electron-transporting and electron-accepting polymers for use in various optoelectronic applications their combination with C60 is expected to provide a route for the modulation of their optical, morphological as well as their electronic properties. Previous work has shown that the modification of polyquinolines towards lower LUMO values will increase their electron accepting properties. In this work the electronic properties of various materials that correspond to the sequential synthesis steps of a novel hybrid copolymeric acceptor are investigated by x-ray and UV photoelectron spectroscopies (XPS/UPS). The hybrid material under investigation is the newly synthesised poly-perfluorophenylquinoline(P5FQ-C60) hybridised with C60. The perfluorophenylquinoline monomer (P5FQ, Fig1a), C60 on its own and the hybrid P5FQ-C60 are also studied. The hybrid copolymers P3OT-co-P5FQ and P3OT-co- (P5FQ-N-C60) with a ratio of 1:10 are also studied for use as electron acceptors to confer better miscibility with the donor. For the spectroscopic investigation the samples were deposited on Si substrates by spin coating from toluene,THF or chloroform solutions. The measurements were carried out in an ultrahigh vacuum analysis chamber (base pressure 5x10-9 mbar) equipped with a hemispherical electron energy analyzer, a twin anode X-ray source for XPS and a discharge UV lamp for UPS. The XPS F1s photo-peak from the non hybrid samples appeared at binding energy (BE) 688.3 eV, a value that corresponds to fluorine atoms in C-F bonds. The same peak was shifted to lower binding energy in the case of all hybrid materials. Despite the fact that the F1s peak has a measurable signal, the C1s component corresponding to C-F bonds (BE=289.4 eV) appeared to be at noise level for all the materials under investigation. This is attributed to the fact that the photoionization cross section of C1s is about four times lower than that for F1s. From the UP spectra the Highest Occupied Molecular Orbital (HOMO) with respect to the Fermi Level and the high binding energy (HBE) cut off can be measured. From the latter the work function of the material is calculated, while the sum of the work function and the binding energy of HOMO correspond to the Ionization Potential (IP). This is a useful parameter for the characterization of semiconducting polymers because it corresponds to the distance between the HOMO and the vacuum level and in combination with band gap (Eg) values can be used for the calculation of the Electron Affinity or in other words the Lowest Unoccupied Molecular Orbital (LUMO) position. The results demonstrate that the semiconducting properties of polymeric or monomeric materials can be effectively tuned by hybridization with carbon based nanostructures, in this case C60.

Les mémoires flash non volatiles - utilisées dans les ordinateurs, téléphones portables ou clés USB - peuvent être constituées de nanocristaux semiconducteurs (SC) insérées dans une matrice isolante. Elles nécessitent l'élaboration d'hétérostructures de type "oxyde/SC/oxyde/Si(00l)" et la maîtrise de chaque interface. Dans ce cadre, nous avons étudié les mécanismes de croissance initiale du Si et du Ge (SC) sur des substrats d'oxyde cristallins LaA1O3(001) à forte permittivité (high-k). Les propriétés chimiques et structurales ont été déterminées in-situ par photoémission X (XPS et XPD) et par diffraction d'électrons (RHEED et LEED) puis ex-situ par microscopies en champ proche (AFM) et en transmission (HRTEM). Le substrat LaAlO3(001) propre présente une reconstruction de surface c(2x2) attribuée à des lacunes d'O en surface. Les croissances de Si et Ge ont été réalisées par épitaxie par jet moléculaire (MBE), soit à température ambiante suivies de recuits, soit à haute température. L'épitaxie requiert des températures de dépôt supérieures à 550°C. Le mode de croissance est de type Volmer Weber caractérisé par la formation d'îlots cristallins de dimensions nanométriques et de forte densité. Ces îlots sont relaxés et présentent une interface abrupte avec le substrat. Quant aux îlots de Ge, ils ont majoritairement des orientations aléatoires avec néanmoins une relation d'épitaxie privilégiée, la même que celle du Si.

Šiame darbe panaudojant zolis-gelis technologiją, susintetinti vanadžio junginių oksidinio kserogelio ir bronzos bei molekulinio oksidinio kserogelio ir bronzos plonieji sluoksniai. Visų minėtų medžiagų cheminė sudėtis ištirta Rentgeno fotoelektronų spektroskopijos metodu, siekiant nustatyti metalų jonų valentines būsenas. Panaudojant zolis-gelis technologiją, galima gana paprastais metodais, nenaudojant sudėtingos technologinės įrangos, gaminti vanadžio oksidinių bronzų plonuosius sluoksnius. Vanadžio amonio hidratuoti oksidiniai junginiai gali būti naudojami kaip medžiagos amoniako dujų jutikliams gaminti. / The thin films of molecular oxide xerogels and bronzes as well as oxide xerogels and bronzes of vanadium compounds were synthesized by sol-gel technology method. The chemical composition of mentioned compounds was investigated using XPS method in order to determine the valence of metal ions. It is shown that it is possible to produce the thin films of vanadium oxide bronzes using simple methods. The possibility to use vanadium-ammonium oxide hydrated compounds as materials for producing the ammonium sensors is shown in the dissertation.

Electrodeposition of diamond-like carbon (DLC) films was studied on different substrates using two different electrochemical methods. The first electrochemical method using a three-electrode system was studied to successfully deposit hydrogenated DLC films on Nickel, Copper and Brass substrates. The as-deposited films were characterized by scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry (CV). A variety of experimental parameters were shown to affect the deposition process. The second electrochemical method was developed for the first time to deposit hydrogen free DLC films on Ni substrates through a two-electrode system. The as-deposited films were characterized by Raman spectroscopy and FTIR. According to Raman spectra, a high fraction of diamond nanocrystals were found to form in the films. Several possible mechanisms were discussed for each deposition method. An electrochemical method was proposed to deposit boron-doped diamond films for future work.

Structural and optical properties of ZnO nanostructures synthesized by low energy ion implantation technique were examined. ZnO molecular ions were implanted into Si/SiO2 substrates at room temperature and then furnace annealed under different temperatures and environments. In all as-implanted samples only Zn nanostructures with varying diameters distributed into the Si/SiO2 matrices were observed. No trace of ZnO was found. The distributions of Zn nanostructures in Si/SiO2 closely matched results from Stopping and Range of Ions in Matter (SRIM) simulations. During annealing at 750 oC, Zn diffused both toward and away from the surface of the substrate and combine with oxygen to form ZnO nanostructures. At higher annealing temperatures ZnO bonding started to break down and transfer to zinc silicate (Zn2SiO4), and at 900 oC the ZnO was completely converted into Zn2SiO4. The average sizes of Zn/ZnO nanostructures depended on the ion fluence. If the fluence increased the average sizes of nanostructures also increased and vice versa. For room temperature photoluminescence (RT-PL), band-edge emission in the ultraviolet (UV) region was observed from all samples annealed at 700 oC/750 oC and were slightly blue shifted as compare to bulk ZnO. Donor-bound exciton (D,X) and acceptor-bound exciton (A,X) transitions were observed in low temperature photoluminescence (PL). The lifetime of both donor-bound excitonic emission (D, X) and acceptor-bound excitonic emission (A, X) were found to be in the picosecond (ps) range.

Metal nanoparticles have received much interest for their application in catalysis due to high surface-to-volume ratios resulting in more available active sites. Ideally these catalysts are heterogeneous and allow for facile separation from the catalytic reaction mixture making them ideal for industrial application. Dispersed metal nanoparticles are explored due to their high reactivity in solution and are stabilized by surfactants and polymers. However, it is difficult to determine whether or not a catalyst is truly heterogeneous as a certain degree of leaching from the metal nanoparticle is inevitable. Determining the mechanisms involved in nanocatalysis is also a challenge. In this study, a series of dispersed palladium nanocatalysts in the Suzuki reaction with phenylboronic acid and bromobenzene were characterized before and after catalysis to determine what changes occur. Samples where characterized before and after the catalytic reaction by XPS, SEM, and EDS to monitor changes in particle size and composition. Reaction mixtures after catalysis were analyzed by ICP-MS for leached palladium species to determine if concentrations were high enough for homogeneous catalysis to take place. The dispersed palladium nanoparticles studied experienced growth during the catalytic process and a significant amount of leaching. XPS analysis indicates the presence of aromatic species on the particle surface after the catalytic reaction. The aromatic species is likely biphenyl, the product of the catalytic reaction, as the presence of boron and bromine was not found in XPS and EDS analysis.

As of 21st September 2017, industrial use of hexavalent chromium (Cr(VI)) will, due to its environmental toxicity and carcinogenicity, be restricted by REACH regulations. Saab Aeronautics is therefore shifting anticorrosion surface treatment of aluminum alloys from hexavalent chromium conversion to trivalent chromium (Cr(III)) passivation. The purpose of this thesis is to investigate the characteristics of conversion coatings formed with the passivation chemical SurTec 650V, in order to facilitate transfer to the more environmental friendly alternative. Process parameters, such as pH and immersion time in SurTec 650V passivation baths, have been investigated for passivation of three different aluminum alloys; 2024, 6061 and 7075. The characteristics of the Cr(III) conversion coatings achieved at laboratory scale in the thesis work have been compared with SurTec 650V process in production scale and with Cr(VI) containing Alodine 1200 and Alodine 1500 processes. The impact of varying process parameters have been investigated with goniometry, x-ray photoelectron spectroscopy (XPS), auger electron spectroscopy (AES), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to analyse characteristics of the conversion coatings. Differences in chemical composition on the surface and in depth profile was detected with XPS and AES, respectively and topology of coatings was found to differ for different aluminium alloys and parameter combinations. With TEM, the thickness of the conversion coating was found to be approximately 30-50 nm, which is thinner than the coatings formed with Cr(VI) passivation. Characteristics of coatings formed with Cr(III) passivation is concluded to be very dependent on parameter variation, especially for alloy 2024. Differences also occur between passivation at laboratory and production scale. Further evaluation of the production scale SurTec 650V process and corrosion testing should be performed, and an elaboration of a process control is required before the shift to an environmental friendly passivation process can be completely successful at Saab.