The main objectives for this licentiate thesis have been to study and model the reactions at the water-mineral interface of two subsystems: maghemite-H+-silicate and olivine-H+. An increased knowledge of these systems will make it possible to further extend the complexity of the aqueous phase in future experiments. This will make it possible to further approach a composition that resembles the flotation and agglomeration process water in the production of iron ore pellets. To be able to characterise and predict the influence of different species from the process water on the different mineral particle surfaces, is an important step towards optimisation of the pellet production process and increased recirculation of the process water. Both synthetic and natural minerals were used in the experiments, in which the protolytic surface exchange reactions of the subsystems were analysed by high precision potentiometric titrations. The minerals and their surfaces were characterised using XRD, XPS, SEM-EDS and BET, both before and after the experiments. The zeta potential of olivine and silicate modified maghemite particles were also determined as a function of pH. Surface complexation models were derived to describe the reactions in the systems. The Constant Capacitance Model (CCM) was used to model the experimental results.The evaluation of the potentiometric data from the studies of the maghemite-H+-silicate system indicates that soluble silicates will mainly adsorb to maghemite as monodentate surface species at the defined experimental conditions. Models including polymerisation of adsorbed silicates and/or bidentate silicate ligands were tested, but could not well be fitted to titration data. The adsorption maximum of silicates was found to be within the range pH 9.0 to 9.5. At the experimental conditions used, approximately 82 % of the added silicate was adsorbed. At higher pH, the silicate started to desorb from the maghemite surface and at pH 11.1 only 60 % was still adsorbed. Olivine ((Mg,Fe)2SiO4), one of the major rock forming silicate minerals in nature, is added in the agglomeration process to improve the performance of the iron ore pellets in the blast furnace. The results from the studies of the olivine - H+ system shows that the dissolution of olivine is essentially incongruent, with an excess of magnesium ions released in to the aqueous suspension. Studies of olivine samples equilibrated in electrolytes with magnesium ions added using XPS, SEM and zeta potential measurements have also shown that the magnesium ion release and adsorption at the surface layers is reversible, no support for surface precipitation of new phases as Mg(OH)2 could be found. Experimental potentiometric data of olivine-H+ at alkaline conditions was successfully fitted to a two pKa electrostatically corrected model. The importance of steady state conditions when acquiring titration data was illustrated by comparing the amount of active surface sites detected by steady state titrations and considerably faster titrations.

Developing new technological solutions, such as use of lightweight materials, less harmful fuels, controlled fuel combustion processes or more efficient exhaust gas after-treatment, are possible ways to reduce the environmental impact of machines. Both the reduction of wear and the friction control are key issues for decreasing of energy losses, improving efficiency and increasing of the life-span of an engine. Dialkyldithiophosphates (DTPs) of different metals have been extensively used as multifunctional additives in lubricants to control friction and reduce wear in mechanical systems. Among these DTP-compounds, zinc dialkyldithiophosphates (ZnDTPs) are the most common additives used for more than 60 years. These additives form protective films on steel surfaces and, thus, control friction and reduce wear. However, ZnDTPs contain zinc and large amounts of phosphorus and sulphur, which are human health hazards and cause environmental pollution by degrading catalytic converters in automobiles. Therefore, replacement of ZnDTPs byzinc free compounds with reduced amounts of sulphur and phosphorus are urgently needed.Boron-containing compounds are known as corrosion inhibitors, antioxidants, friction modifiers and effective anti-wear additives either dissolved in oil or as an insoluble and inorganic borate salts dispersed in oil in the nanoparticulate form. These compounds are emerging as attractive replacements for the compounds already used as additives in lubricants. The focus of the present work is on the development and tribological investigations of new boron compounds as highperformance additives in lubricants. These should be ashless with significantly reduced amounts sulphur and phosphorus, which is favourable for the environment protection. The work was carried out in the following steps: (1) Synthesis of new additives; (2) Characterization of the additives with FTIR, (1H, 13C, 31P, 11B) NMR spectroscopy, elemental analysis and thermal analysis (TG/DTG, DTA and QMS); (3) Tribological evaluation using four ball Tribometer; (4) Surface analysis using an optical profiler and Scanning Electron Microscopy coupled with X-ray Energy Dispersive Spectroscopy (SEM/EDS). It was found that the novel boroncompounds have considerably better antiwear performance and higher stability of the coefficient of friction with time as compared with ZnDTP. These novel compounds are ashless with reduced amounts of sulphur and phosphorus. They also have excellent tribological properties, high thermal stability, good miscibility with oils and positive environmental issues which make them an attractive alternative to ZnDTP.

Lubricants are used to control friction and reduce wear by preventing direct contact between surfaces in a relative motion. Most of the modern lubricants and lubricant additives have been designed and optimized for ferrous materials. A growing trend towards wider use of lightweight and wear resistant non-ferrous materials calls for new efficient and environmentally friendly Lubricants. Boron compounds are attractive alternatives for the commercially available lubricants and lubricant additives. Some boron compounds have already been proven as efficient friction modifiers, antioxidants, corrosion inhibitors and antiwear additives in lubricants.In this work we focus on design, synthesis, physicochemical characterization and tribological studies of novel boron compounds. Boron based ionic liquids (ILs) and dithiocarbamates (B-DTCs) were designed, synthesized and tribologically characterized. The work was carried out in the following steps: (i) design and synthesis of novel boron compounds; (ii) physicochemical characterization of the synthesized compounds by FTIR, liquid-state (1H, 13C, and 11B) and solid-state (13C and 11B) nuclear magnetic resonance (NMR) spectroscopy, elemental analysis, thermal analysis (TG, DTA, DSC and QMS), powder XRD, density and viscosity measurements; (iii) tribological characterization using four-ball and pin-on-disc tribometers and (iv) surface analysis using Scanning Electron Microscopy coupled with X-ray Energy Dispersive Spectroscopy (SEM/EDS), optical interferometer and stylus profilometer. Some of these new boron-based compounds revealed significantly better antiwear and friction reducing performance on steel-steel contacts compared with fully formulated engine oils. (i) Nine novel ILs of pryrrolidinium bis(salicylato)borate were synthesized and physicochemically characterized. They are solid at room temperature and some of them behave as plastic crystals. Some of these ILs were tested as lubricants at 100 ºC, i.e. above their melting points. These ILs have shown significantly better antiwear and friction reducing performance in lubrication of steel-steel contacts compared to fully formulated synthetic engine oil 5W40.(ii) Nine novel room temperature ionic liquids (RTILs) of pyrrolidinium bis(mandelato)borate were synthesized and physicochemically characterized. These ILs were tribologically tested as 3 wt % additives in polyethylene glycol (PEG) and they have shown considerably better antiwear and friction reducing properties in boundary lubrication of steel-steel contacts at room temperature compared with neat PEG and engine oil 5W40.(iii) Boron based compounds containing alkylborate and dithiocarbamate groups with alkyl substitutes in one molecule were synthesized and physicochemically characterized. The influence of alkyl chain length (butyl and/or octyl substitutes at DTC and borate groups) and heterocyclicity in boron based dithiocarbamate compounds (B-DTCs) on their tribophysical properties as additives in a mineral oil was studied for steel-steel lubricated contacts.

Decontamination of industrially polluted waters has been enclosed in REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) since 2007, when it entered into force in the European Union, which emphasized the need to search for more effective sorbents. Many studies on inorganic ion-exchangers have been carried out due to the scientific interest towards their high mechanical and thermal stabilities, high resistance to oxidation and high sorption capacity regarding transition and radioactive metal ions. Titanium phosphates (TiP) in particular, have revealed very good cation-exchange properties in relation to different transition metal ions in aqueous solutions. It has been demonstrated that their physicochemical properties as well as their structural characteristics can be altered by carefully choosing the conditions of synthesis: the temperature, acidity, Ti(IV) speciation in solution and reaction time. Since the ‘classical’ crystalline TiP ionites have been divided into two main groups: alfa type; α-TiP [α-Ti(HPO4)2•H2O] and gamma type; γ-TiP [Ti(H2PO4)(PO4)•H2O] with different functional groups (–H2PO4, –HPO4 and –PO4) present, the researchers have focused on synthesis of various metastable TiP with different functional properties. In this work, three different synthetic routes for TiP ion-exchangers were explored in order to obtain a sorbent composed solely of –H2PO4 exchange units. The ─H2PO4 groups were expected to considerably increase the pH working range of the sorbents and to nearly double the theoretical exchange capacity of TiP ion-exchangers containing mostly –HPO4 functional groups. Among the synthesized ion-exchangers (TiP1, TiP2 and TiP3), TiP1 has shown very good sorption characteristics and therefore, most of the studies were performed on it. TiP1 was synthesized at mild thermal conditions using cobalt(II) ions as a modifying agent and HCl-washes as post-synthetic treatments. This sorbent was characterized by different spectroscopic techniques and its chemical formula was established to be: TiO(OH)(H2PO4)•H2O. The sorption capacity of TiP1, estimated about 4.8 meq.g-1, is higher than the reported exchange capacity for various amorphous TiP. The sorption characteristics of TiP1 towards divalent ions such as Cu2+, Zn2+, Ni2+, Mn2+ and Co2+, were investigated in this work. The results of the sorption experiments (in the 1-20 mmol.L-1 range) were fitted to the Langmuir and Temkin models with the latter one being somewhat preferred for most of the metal ions studied. This indicates that interactions between adsorbed molecules cannot be neglected. It was also found that the kinetics of the ion-exchange process was very fast and the equilibrium was reached within 10 minutes. The kinetic data were modeled using the pseudo-second order reaction rate and the obtained curves were consistent with chemisorption being the rate limiting step of the reactions. The selectivity order of the metal ions studied towards TiP1 here was found to be: Cu2+ > Zn2+ > Mn2+ > Co2+ > Ni2+. The TiP1 sorbent has also shown to be a very good cation-exchanger when batch experiments were performed using heavy metals polluted waters from closed mines, supplied by Boliden AB. These studies delineated that TiP1 has displayed exclusive sorption capacities and imminent ion-exchange kinetics. It has been distinctly shown that a modest change in the synthesis could facilitate the fabrication of titanium phosphate ion-exchangers with improved and versatile sorption properties.

Metal-dithiocarbamate complexes find wide-ranging applications in nanomaterial and metalseparation science, and have potential use as chemotherapeutic, pesticides, and as additives tolubricants. A highly versatile dialkyldithiocarbamate (R2NCS2–) ligand can form stablecomplexes with all the transition elements and also the majority of main group, lanthanide andactinide elements. Here we present structural investigations of the molecular and electronicstructures of dialkyldithiocarbamate complexes with yttrium(III), lanthanum(III), andbismuth(III) of molecular formula [Y{S2CN(C2H5)2}3PHEN], [La{S2CN(C2H5)2}3PHEN], and[Bi2{S2CN-n(C4H9)2}6] (where PHEN=1,10-Phenanthroline) . The experimental solid-state 13Cand 15N cross polarization magic-angle-spinning (CP-MAS) NMR results are reported for allthese three complexes. We also report new single-crystal X-ray structures of heterolepticyttrium, lanthanum, and homoleptic bismuth dialkyldithiocarbamate complexes. Thecomparative analysis of powder XRD patterns and solid-state 13C and 15N CP-MAS spectra ofpolycrystalline yttrium(III) and lanthanum(III) diethyldithiocarbamato-phenanthrolinecomplexes shows the presence of significant structural differences. The diethyldithiocarbamatophenanthrolinecomplex of yttrium has a very similar structural type to a previously reported Xraydiffraction structure for [Nd{S2CN(C2H5)2}3PHEN] whereas, the crystal structure of[La{S2CN(C2H5)2}3PHEN] is considerably more complex. Our NMR and single-crystal X-raydiffraction results suggested polymorphism for bismuth di-n-butyldithiocarbamate complex.Finally, the experimental NMR results are complemented by chemical shifts obtained usingquantum chemical methods and verified the spectral assignments. Overall, our workdemonstrates how different experimental and theoretical methods can be combined that canafford insights into the solid-state structure and bonding environments of metal complexes.

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Transferring analytical methods is crucial in chemical laboratories. The need for the transfer may arise for different reasons such as sharing data between different laboratories, replacement or upgrade of analytical instrument, or limited instruments available etc. The performance and sensitivity of different instruments may vary. Three LC-MS instruments of two different manufacturers were used to identify critical parameters that might affect signal intensity. The instruments included in this study were two tandem mass spectrometers (Waters Acquity® TQD MS and Waters Xevo® TQSμ MS) and an orbitrap mass spectrometer (Thermo Scientific Q Exactive Focus). The capillary and cone voltages of selected model compounds were optimized prior to linearity study. The linearity study was performed in order to examine the dynamic range of the instruments. Limits of detection and quantitation were also evaluated. Different instrument settings were tested in order to evaluate and compare the impact of different MS parameters on the signal intensity of the selected model compounds. Thermo Scientific Q Exactive Focus was observed to be less sensitive to different settings. An existing analytical method for fluoxetine (ESI+) and bisphenol A (ESI-) was transferred from Waters Xevo® TQSμ MS to Thermo Scientific Q Exactive Focus; the performance of Waters Xevo® TQSμ MS and Waters Acquity® TQD MS was compared by using the same analytical method on both instruments. The results showed that LOD and LOQ were higher for Waters Acquity® TQD MS than for Waters Xevo® TQSμ MS. Additionally, the method transfer resulted in similar LOD and LOQ values for fluoxetine and bisphenol A on Waters Xevo® TQS micro MS and Thermo Scientific Q Exactive Focus. In case high sensitivity is not a requirement of an analysis, a set of standard settings as the ones used in this study may be sufficient during a method transfer between Waters Acquity® TQD MS and Thermo Scientific Q Exactive Focus.

Enzymes converting CO2 can be helpful with battling today’s environmental problems with global warming due to greenhouse gases. It can also contribute to make industrial processes cheaper and cleaner. During this project, enzymes have been studied to understand the process better. Two types of enzymes have been studied, formate dehydrogenases and carbonic anhydrases. Amongst these, formate dehydrogenase was chosen to continue working with, using the crystal structure PDB ID 2NAD. The protein was studied with YASARA, and molecular docking was performed, with 2NAD as the target and hydrogen carbonate as the ligand. Both automatic and manual docking was used, with manual docking being the only that yielded favorable results. The protein was mutated to enhance affinity for the hydrogen carbonate, which proved successful. It was concluded that the hydrogen carbonate was too small to yield a successful automatic docking, but that manual docking worked. It was also shown that the interactions between the hydrogen carbonate and 2NAD was affected by pH, and that the affinity was improved by mutating the protein, making the configuration more stable.

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