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Ion transport measures and details as well as physico-chemical and electrochemical properties are presented for a small set of structurally flexible pyrrolidinium (Pyrr) and morpholinium (Morph) cation-based ionic liquids (ILs), all with oligoether phosphate-based anions. All have high thermal stabilities, low glass transition temperatures, and wide electrochemical stability windows, but rather moderate ionic conductivities, whereas both the anions and the cations of the Pyrr-based ILs diffuse faster than those of the Morph-based ILs. Overall the former ILs have significantly more promise as high-temperature supercapacitor electrolytes, rendering a specific capacitance of 164 F g−1 at 1 mV s−1, a power density of 241 W kg−1 and a specific energy density of 30 Wh kg−1 at 90 °C in a symmetric graphite supercapacitor.

The formation of crosslinked bonds between wood constituents is believed to be an effective way to stabilize wood against wet conditions. The possibility to use maleic anhydride (MA) combined with sodium hypophosphite (SHP) as crosslinking agents was studied, using Scots pine sapwood and a model compound. The modified wood showed weight gain and bulking effect after treatment and subsequent Soxhlet extractions, which indicated penetration into the wood cell wall and reaction of the chemicals with the wood constituents. The FTIR spectra confirmed the formation of an ester bond between the wood and MA. Furthermore, a decrease of intensity of band at 1635 cm-1 indicated a reduction of the double bond between carbons in MA after further treatment with SHP, especially at 170 ̊C. Such reactions were studied using monomethyl maleate (MMM) and SHP. The 13C NMR spectra of the reaction product confirmed a reduction of the double bond between carbons. This paper outlines studies undertaken to date, along with outlining aims of ongoing and future work.

The corrosion inhibitive capabilities of some ferrocene-based Schiff bases on aluminium alloy AA2219-T6 in acidic medium were investigated using Tafel polarization, electrochemical impedance spectroscopy (EIS), weight loss measurement, FT-IR spectroscopy and scanning electron microscopic (SEM) techniques. The influence of molecular configuration on the corrosion inhibition behavior has been explored by quantum chemical calculation. Ferrocenyl Schiff bases 4,4′-((((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcua), 4,4′-((((ethane-1,2-diylbis(oxy))bis(2-methoxy-1,4-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcub) and 4,4′-((((ethane-1,2-diylbis(oxy))bis(2-ethoxy-1,4-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcuc) have been synthesized and characterized by FT-IR, 1H and 13C NMR spectroscopic studies. These compounds showed a substantial corrosion inhibition against aluminium alloy in 0.1 M of HCl at 298 K. Fcub and Fcuc showed better anticorrosion efficiency as compared with Fcua due to the electron donating methoxy and ethoxy group substitutions, respectively. Polarization curves also indicated that the studied biferrocenyl Schiff bases were mixed type anticorrosive materials. The inhibition of the aluminium alloy surface by biferrocenyl Schiff bases was evidenced through scanning electron microscopy (SEM) studies. Semi-empirical quantum mechanical studies revealed a correlation between corrosion inhibition efficiency and structural functionalities. Validerad;2020;Nivå 2;2020-02-24 (johcin)

Bis-aldehyde monomers 4-(4&prime, formyl-phenoxy)benzaldehyde (3a), 3-methoxy-4-(4&prime, formyl-phenoxy)benzaldehyde (3b), and 3-ethoxy-4-(4&prime, formyl-phenoxy)benzaldehyde (3c) were synthesized by etherification of 4-fluorobenzaldehyde (1) with 4-hydroxybenzaldehyde (2a), 3-methoxy-4-hydroxybenzaldehyde (2b), and 3-ethoxy-4-hydroxybenzaldehyde (2c), respectively. Each monomer was polymerized with p-phenylenediamine and 4,4&prime, diaminodiphenyl ether to yield six poly(azomethine)s. Single crystal X-ray diffraction structures of 3b and 3c were determined. The structural characterization of the monomers and poly(azomethine)s was performed by FT-IR and NMR spectroscopic techniques and elemental analysis. Physicochemical properties of polymers were investigated by powder X-ray diffraction, thermogravimetric analysis (TGA), viscometry, UV&ndash, vis, spectroscopy and photoluminescence. These polymers were subjected to electrical conductivity measurements by the four-probe method, and their conductivities were found to be in the range 4.0 &times, 10&minus, 5 to 6.4 &times, 5 Scm&minus, 1, which was significantly higher than the values reported so far.

PEGylated tetra(aniline) ABA triblock structure PEG-TANI-PEG (2) consisting of tetra(aniline) (TANI) and polyethylene glycol (PEG) was synthesized by coupling the tosylated-PEG to boc-protected NH2/NH2 TANI (1) through a simple nucleophilic substitution reaction. Deprotection of 2 resulted in a leucoemeraldine base state of TANI (2-LEB), which was oxidized to stable emeraldine base (2-EB) state. 2-EB was doped with 1 M HCl to emeraldine salt (2-ES) state. FTIR, 1H and 13C NMR and UV-Vis-NIR spectroscopy, and MS (ESI) was used for structural characterization. The synthesized triblock structure exhibited good electroactivity as confirmed by CV and UV-Vis-NIR spectroscopy. Self-assembling of the triblock structure in aqueous medium was assessed by DLS, TEM, and SEM. Spherical aggregates were observed with variable sizes depicting the effect of concentration and oxidation of 2-LEB. Further, the aggregates showed acid/base sensitivity as evaluated by doping and dedoping of 2-EB with 1 M HCl and 1 M NH4OH, respectively. Future applications in drug delivery and sensors are envisaged for such tunable self-assembled nanostructures in aqueous media. Validerad;2019;Nivå 2;2019-08-06 (johcin)

Nowadays, hydropower plants are forced to have more frequent power control and the self-lubricated bearings used in the applications are one of the most critical components affected by the continuously changing operating conditions. In this study, microstructure and composition of two commercially available bearing materials (Orkot TXM Marine and Thordon ThorPlas) used in hydropower turbines were studied. In addition, the influence of sliding speed and applied pressure on the friction and wear behavior of the materials was investigated systematically for dry sliding conditions. The bearing materials were characterized using X-ray microtomography, Nuclear Magnetic Resonance (NMR) spectroscopy and Inductively Coupled Plasma–Sector Field Mass Spectrometry (ICP-SFMS) techniques. Friction and wear tests were carried out with a polymer pin sliding against a stainless steel (SS2333) plate with a linear reciprocating motion. Test conditions were: room temperature, 9–28 MPa pressure and 10–40 mm/s sliding speed ranges. Surface analysis of the polymer pins and the wear tracks were performed by optical profilometry, Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) techniques. Test results show that, for both materials, the coefficient of friction (COF) is decreasing at higher pressures. Surface analysis reveals higher concentrations of solid lubricants in the transfer layers formed at higher pressures, explaining the decrease in COF. Furthermore, the specific wear rate coefficients are increasing at higher sliding speeds, especially at lower pressures. Results of this study demonstrate that, under dry sliding conditions, changes in sliding speed and pressure have a significant influence on the tribological behavior of these bearing materials. Validerad;2018;Nivå 2;2018-05-02 (andbra)

Godkänd; 2016; 20160717 (faisha)

Godkänd; 2016; 20160717 (faisha)

Solid-state NMR spectroscopy is a useful method for elucidating mechanisms of formation of boundary films at solid-liquid interfaces of different metal oxides in contact with different ionic liquids having halogenated anions, such as NTF2- and PF6- [1,2]. However, these halogen-based ionic liquids are susceptible to hydrolysis and generate HF that erode the surface and pollute the environment. In this study, we employed a similar NMR approach to understand the mechanism of film formation by halogen-free orthoborate ionic liquids (hf-BILs) on the metal oxide surfaces.Samples were prepared by grinding the inorganic oxide and 10 wt% of hf-BIL using mortar and pestle. The boundary films on inorganic metal oxides (Al2O3, MgO and SiO2) surfaces in contact with hf-BILs have been characterized using solid-state MAS (11B, 31P and 29Si) NMR spectroscopy. The single pulse 11B NMR data indicate that bis(mandelato)borate anion, [BMB]-, in [P6,6,6,14][BMB] BIL strongly interacts with these metal oxides, in particular, at elevated temperatures (100 °C). In contrast, no products of decomposition were detected for surface of these oxides exposed to [trihexyltetradecylphosphonium][bis(salicylato)borate] ILs at different temperatures. Therefore, it was suggested that the [BScB]- anion is weakly interacting with these oxides. 31P NMR data on the same IL/metal oxide systems revealed strong interactions of the [P6,6,6,14]+ with these oxides. We suggest that [P6,6,6,14]+ cations are also present in immobile surface layers of ILs on particles of these oxides, because 31P resonance lines of ILs were detected using 1H-31P cross polarization MAS NMR giving rise to NMR signals of solid phases with a low molecular mobility only. The existence of strongly adhered surface layers of ILs on particles of metal oxides was further confirmed by 1H-29Si CP/MAS NMR. This study suggests that the boundary film formation between hf-BILs and metal oxide surfaces is a complex process involving various chemical reactions at the interfaces. These findings can be important for understanding of mechanisms of formation and structure of tribofilms in the process of lubrication of nonferrous metal surfaces by hf-BILs. Godkänd; 2013; 20130418 (faisha)

Boron compounds can be environmentally friendly alternatives for commercially available lubricant additives. Some boron compounds are already used as friction modifiers, corrosion inhibitors, antioxidants and antiwear additives in lubricants. The focus of the present work is on the development and tribological investigations of new boron compounds for these applications. In this work, boron compounds based on dithiophosphates (DTPs), dithiocarbamates (DTCs) and ionic liquids (ILs) were designed, synthesized and tribologically optimized. The work was carried out in the following steps: (1) Synthesis of novel boron based compounds and ionic liquids; (2) Characterization of the compounds with FTIR, liquid-state (1H, 13C, 31P, 11B) and solid-state magic-angle-spinning (MAS) NMR spectroscopy, electrospray ionization mass spectrometery (ESI-MS), elemental analysis, thermal analyses (TG/DTG, DTA, DSC and QMS), viscosity, density and conductivity; (3) Tribological evaluation using four ball and pin-on-disc tribometers; (4) Surface analysis using an optical profiler and Scanning Electron Microscopy coupled with X-ray Energy Dispersive Spectroscopy (SEM/EDS). (i) Antiwear performance of S-di-n-octoxyboron-O,O’-di-n-octyldithiophosphate (DOB-DTP) was found considerably better in comparison with O,O’-di-n-butyl-dithiophosphato-zinc(II) (ZnDTP). However, since DOB-DTP contains B─S bond, which is sensitive to moisture and may be hydrolyzed by water, a novel class of alkylborate-ethyl-dithiophosphates was synthesized, in which boron is covalently bonded to the dialkyldithiophosphate group through the ethyl linker in order to avoid hydrolysis. (ii) Antiwear performance of an alkylborate-ethyl-dithiophosphate with decyl substitutes at both DTP and the borate groups of the molecule (DDB-EDTP) was superior compared with that of the octyl (DOB-EDTP) and the pentyl (DDB-EDTP) analogues. Residues of one representative compound from this class, DPB-EDTP, after thermal analyses were characterized by multinuclear 13C, 31P and 11B MAS and 31P CP/MAS NMR spectroscopy. Solid-state NMR data suggest that a dominant part of the solid residue of DPB-EDTP consists of borophosphates. (iii) It was found that a novel class of compounds containing alkylborate and dithiocarbamate groups with alkyl or methylbenzyl- substitutes in one molecule provide better antiwear performance compared with commercially available packages of ZnDTPs. (iv) Eight compounds belonging to a novel class of halogen-free chelated orthoborate ionic liquids (hf-BILs) with different phosphonium cations were synthesized. Important physical properties of the ILs including glass transition temperatures, density, viscosity and ionic conductivity were measured. As lubricants, these hf-BILs exhibit considerably better antiwear and friction reducing properties under boundary lubrication conditions for steel-aluminum contacts as compared with fully formulated (15W-50 grade) engine oil. (v) Five compounds belonging to another class of hf-BILs comprised of two chelated orthoborate anions, bis(mandelato)borate and bis(salicylato)borate, and three different nitrile cations (cholinium, pyrrolidinium and imidazolium) were prepared. Solid-state NMR spectroscopy was employed to probe interactions between cations and anions in the salts, which are solid at room temperature. Solid-state NMR data suggested a strong interaction between BScB anions and cholinium cations [Chol]+. This interaction was further confirmed by the X-ray diffraction single crystal structure of this salt as hydrogen bonding between OH of [Chol]+ and the carbonyl group of [BScB]-. The [BScB]- exhibited a strong interaction with imidazolium cation [EMIm]+, whereas a weaker interaction was suggested between pyrrolidinium cation [EMPy]+ and [BScB]-. It was found that the novel boron based DTPs and DTCs have considerably better antiwear performance and higher stability of the coefficient of friction with time as compared with ZnDTP. They also have a high thermal stability, good miscibility with oils and positive environmental issues all that make them an attractive alternative to ZnDTPs and other commercial additives to lubricants. It was found that novel halogen-free boron based ionic liquids may be also potentially used as alternative lubricants for ferrous and non-ferrous contact. Godkänd; 2011; 20110512 (faisha); DISPUTATION Ämnesområde: Gränsytors kemi/Chemistry of Interfaces Opponent: Professor Jean Michel Martin, Ecole Centrale de Lyon, Frankrike Ordförande: Professor Oleg N. Antzutkin, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Onsdag den 15 juni 2011, kl 10.00 Plats: C305, Luleå tekniska universitet

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. Godkänd; 2009; 20091027 (faisha); LICENTIATSEMINARIUM Namn: Faiz Ullah Shah Ämnesområde: Gränsytors kemi/Chemistry of Interfaces Examinator: Professor Oleg N Antzutkin, Luleå tekniska universitet Tid: Onsdag den 25 november 2009 kl 13.00 Plats: F 341, Luleå tekniska universitet