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  • 1.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Azancheev, Nail
    Institute of Physics, Kazan Federal University, Kazan, Russia.
    Gibaydullin, Amal
    Institute of Physics, Kazan Federal University, Kazan, Russia.
    Bhattacharyya, Shubhankar
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Antzutkin, Oleg N.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Dynamic Properties of Imidazolium Orthoborate Ionic Liquids Mixed with Polyethylene Glycol Studied by NMR Diffusometry and Impedance Spectroscopy2018In: Magnetic Resonance in Chemistry, ISSN 0749-1581, E-ISSN 1097-458X, Vol. 56, no 2, p. 113-119Article in journal (Refereed)
    Abstract [en]

    We used 1H pulsed field gradient (PFG) NMR to study the self-diffusion of polyethylene glycol (PEG) with average molecular mass of 200 and ions in mixtures of PEG with imidazolium bis(mandelato)borate (BMB) and imidazolium bis(oxalato)borate (BOB) ionic liquids (ILs). The ionic liquid was mixed with PEG in the concentration range of 0–100 wt%. Within the temperature range of 295 to 353 K, the diffusion coefficient of BMB is slower than that of the imidazolium cation. The diffusion coefficients of PEG, as well as the imidazolium cation and BMB anions, differ under all experimental conditions tested. This demonstrates that the IL in the mixture is present in at least a partially dissociated state. Generally, increasing the concentration of PEG leads to an increase in the diffusion coefficients of PEG and both the ions, and decreases their activation energy for diffusion. NMR chemical shift alteration analysis showed that the presence of PEG changes the chemical shifts of both ions but in different directions. Impedance spectroscopy was used to measure the ionic conductivity of the ionic liquids mixed with PEG.

  • 2.
    Khan, Amir Sada
    et al.
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Man, Zakaria
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Bustam, Mohamad Azmi
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Nasrullah, Asma
    Fundamental and Applied Science Department, Universiti Teknologi PETRONAS .
    Ullah, Zahoor
    Department of Chemistry, Balochistan University of IT, Engineering and Management Sciences (BUITEMS).
    Sarwono, Ariyanti
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Muhammad, Nawshad
    Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore, Pakistan.
    Efficient Conversion of Lignocellulosic Biomass to Levulinic Acid Using Acidic Ionic Liquids2018In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 181, p. 208-214Article in journal (Refereed)
    Abstract [en]

    In the present research work, dicationic ionic liquids, containing 1,1-Bis(3-methylimidazolium-1-yl) butylene ([C4(Mim)2]) cation with counter anions [(2HSO4)(H2SO4)0], [(2HSO4)(H2SO4)2] and [(2HSO4)(H2SO4)4] were synthesised. ILs structures were confirmed using 1H NMR spectroscopy. Thermal stability, Hammett acidity, density and viscosity of ILs were determined. Various types of lignocellulosic biomass such as rubber wood, palm oil frond, bamboo and rice husk were converted into LA. Among the synthesized ionic liquids, [C4(Mim)2][(2HSO4)(H2SO4)4] showed higher % yield of LA up to 47.52 from bamboo biomass at 100 °C for 60 min, which is the better yield at low temperature and short time compared to previous reports. Surface morphology, surface functional groups and thermal stability of bamboo before and after conversion into LA were studied using SEM, FTIR and TGA analysis, respectively. This one-pot production of levulinic acid from agro-waste will open new opportunity for the conversion of sustainable biomass resources into valuable chemicals.

  • 3.
    An, Rong
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology.
    Zhou, Guobing
    School of Chemical Biological and Materials Engineering, University of Oklahoma.
    Zhu, Yudan
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University.
    Zhu, Wei
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University.
    Huang, Liangliang
    School of Chemical Biological and Materials Engineering, University of Oklahoma.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Friction of Ionic Liquid–Glycol Ether Mixtures at Titanium Interfaces: Negative Load Dependence2018In: Advanced Materials Interfaces, ISSN 2196-7350Article in journal (Refereed)
    Abstract [en]

    The atomic force microscopy experiments and nonequilibrium molecular dynamics (NEMD) simulations demonstrate a negative friction–load dependence to ionic liquid–glycol ether mixtures, that is, the friction decreases as the normal load increases. NEMD simulations reveal a structural reorientation of the studied ionic liquid (IL): as the normal load increases, the cation alkyl chains of ILs change the orientation to preferentially parallel to the tip scanning path. The flat‐oriented IL structures, similar to the “blooming lotus leaf,” produce a new sliding interface and reduce the friction. A further molecular dynamics simulation is carried out by adopting slit‐pore models to mimic the tip approaching process to confirm the dynamics of ILs. A faster diffusion of ILs in the smaller slit pore is observed. The faster diffusion of ILs in the more confined slit pore facilitates the structural reorientation of ILs. The resulted new sliding surface is responsible for the observed smaller friction at higher loads, also known as the negative friction–load dependence. These findings provide a fundamental explanation to the role of ILs in interfacial lubrications. They help to understand liquid flow properties under confinement, with implications for the development of better nanofluidic devices.

  • 4.
    Rodiouchkina, Maria
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Berglund, Kim
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Mouzon, Johanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Forsberg, Fredrik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rodushkin, Ilia
    ALS Laboratory Group, ALS Scandinavia AB.
    Larsson, Roland
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Material Characterization and Influence of Sliding Speed and Pressure on Friction and Wear Behavior of Self-Lubricating Bearing Materials for Hydropower Applications2018In: Lubricants, ISSN 2075-4442, Vol. 6, no 2, article id 39Article in journal (Refereed)
    Abstract [en]

    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.

  • 5.
    Bhattacharyya, Shubhankar
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Institute of Physics, Kazan Federal University, Russia.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    High CO2 absorption capacity by chemisorption at cations and anions in choline-based ionic liquids2017In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 19, no 46, p. 31216-31226Article in journal (Refereed)
    Abstract [en]

    The effect of CO2 absorption on the aromaticity and hydrogen bonding in ionic liquids is investigated. Five different ionic liquids with choline based cations and aprotic N-heterocyclic anions were synthesized. Purity and structures of the synthesized ionic liquids were characterized by 1H and 13C NMR spectroscopy. CO2 capture performance was studied at 20 °C and 40 °C under three different pressures (1, 3, 6 bar). The IL [N1,1,6,2OH][4-Triz] showed the highest CO2 capture capacity (28.6 wt%, 1.57 mol of CO2 per mol of the IL, 6.48 mol of CO2 per kg of the ionic liquid) at 20 °C and 1 bar. The high CO2 capture capacity of the [N1,1,6,2OH][4-Triz] IL is due to the formation of carbonic acid (–OCO2H) together with carbamate by participation of the –OH group of the [N1,1,6,2OH]+ cation in the CO2 capture process. The structure of the adduct formed by CO2 reaction with the IL [N1,1,6,2OH][4-Triz] was probed by using IR, 13C NMR and 1H–13C HMBC NMR experiments utilizing 13C labeled CO2 gas. 1H and 13C PFG NMR studies were performed before and after CO2 absorption to explore the effect of cation–anion structures on the microscopic ion dynamics in ILs. The ionic mobility was significantly increased after CO2 reaction due to lowering of aromaticity in the case of ILs with aromatic N-heterocyclic anions.

  • 6.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Oleg, Gnezdilov
    Institute of Physics, Kazan Federal University .
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Institute of Physics, Kazan Federal University.
    Ion dynamics in halogen-free phosphonium bis(salicylato)borate ionic liquid electrolytes for lithium-ion batteries2017In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 19, no 25, p. 16721-16730Article in journal (Refereed)
    Abstract [en]

    This study was focused on the investigation of ion dynamics in halogen-free, hydrophobic, and hydrolytically stable phosphonium bis(salicylato)borate [P4,4,4,8][BScB] ionic liquid electrolytes for lithium-ion batteries. The structure and purity of the synthesized ionic liquid and lithium bis(salicylato)borate Li[BScB] salt were characterized using 1H, 13C, 31P, and 11B NMR spectroscopy. The Li[BScB] salt was mixed with an ionic liquid at the concentrations ranging from 2.5 mol% to 20 mol%. The physicochemical properties of the resulting electrolytes were characterized using thermal analysis (TGA and DSC), electrical impedance spectroscopy, and pulsed-field gradient (PFG) NMR and ATR-FTIR spectroscopy. The apparent transfer numbers of the individual ions were calculated from the diffusion coefficients of the cation and anion as determined via the PFG NMR spectroscopy. NMR and ATR-FTIR spectroscopic techniques revealed dynamic interactions between the lithium cation and bis(salicylato)borate anion in the electrolytes. The ion–ion interactions were found to increase with the increasing concentration of the Li[BScB] salt, which resulted in ionic clustering at the concentrations higher than 15 mol% of Li salt in the ionic liquid.

  • 7.
    Shimpi, Manishkumar
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Pharmaceutical Crystal Engineering Using Ionic Liquid Anion–Solute Interactions2017In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 17, no 4, p. 1729-1734Article in journal (Refereed)
    Abstract [en]

    The main purpose of this work was to investigate the potential of ionic liquids (ILs) in crystal engineering. We have employed ILs with different combinations of cations and anions to study their role in directing crystal structure formation of a nicotinamide (NIC) and oxalic acid (OXA) system. A new crystal form of NIC–OXA salt (2:1) was identified and characterized using standard solid state tools such as powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and Raman and infrared spectroscopy. The crystal structure of the 2:1 salt was elucidated using single-crystal X-ray diffraction. The NIC–OXA 2:1 salt form revealed a two-dimensional layered structure, while the known 1:1 salt had a perpendicular “tape-like” structure. The 2:1 salt form could only be crystallized from the ILs possessing hydrogen bond acceptor functionality. We demonstrated that specific ILs could be selected as solvents for altering the solid-state structure of organic and inorganic materials.

  • 8.
    Geng, Shiyu
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Liu, Peng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Plasticizing and crosslinking effects of borate additives on the structure and properties of poly(vinyl acetate)2017In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 13, p. 7483-7491Article in journal (Refereed)
    Abstract [en]

    As an environmentally friendly, low-cost and widely used polymer, poly(vinyl acetate) (PVAc) is worth modifying to achieve better properties. Here, we report on the influence of borate additives on the structure and properties of partially hydrolysed PVAc. In addition to the general crosslinking function of borate additives, an extraordinary plasticizing effect was found. By controlling the pH from 4 to 11 during sample preparation, the plasticizing and crosslinking effects can be shifted. In alkaline conditions, the degree of crosslinking in the PVAc/borate sample is increased; however, this increase declines gradually with an increase in the borate additive content, which impacts the morphology of the PVAc latex particles, as well as the mechanical and thermal properties of the PVAc/borate films. In contrast, in acidic conditions, the PVAc/borate films are plasticized by borate additives; thus, their ultimate mechanical strength, elastic moduli and thermal stabilities decrease, while the water diffusivities increase.

  • 9.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Oleg I., Gnezdilov
    Institute of Physics, Kazan Federal University, 420008, Kazan, Russia.
    Rashi, Gusain
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Institute of Physics, Kazan Federal University, Russia.
    Transport and Association of Ions in Lithium Battery Electrolytes Based on Glycol Ether Mixed with Halogen-Free Orthoborate Ionic Liquid2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 16340Article in journal (Refereed)
    Abstract [en]

    Ion transport behaviour of halogen-free hybrid electrolytes for lithium-ion batteries based on phosphonium bis(salicylato)borate [P4,4,4,8][BScB] ionic liquid mixed with diethylene glycol dibutyl ether (DEGDBE) is investigated. The Li[BScB] salt is dissolved at different concentrations in the range from 0.15 mol kg−1 to 1.0 mol kg−1 in a mixture of [P4,4,4,8][BScB] and DEGDBE in 1:5 molar ratio. The ion transport properties of the resulting electrolytes are investigated using viscosity, electrical impedance spectroscopy and pulsed-Field Gradient (PFG) NMR. The apparent transfer numbers of ions are calculated from the diffusion coefficients measured by using PFG NMR. PFG NMR data suggested ion association upon addition of Li salt to the [P4,4,4,8][BScB] in DEGDBE solution. This is further confirmed by liquid state 7Li and 11B NMR, and FTIR spectroscopic techniques, which suggest strong interactions between the lithium cation and oxygen atoms of the [BScB]− anion in the hybrid electrolytes.

  • 10.
    Javed, Muhammad Asadullah
    et al.
    NMR Research Unit, University of Oulu.
    Ahola, Susanna
    NMR Research Unit, University of Oulu.
    Håkansson, Pär
    NMR Research Unit, University of Oulu.
    Mankinen, Otto
    NMR Research Unit, University of Oulu.
    Aslam, Muhammad Kamran
    NMR Research Unit, University of Oulu.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Glavatskih, Sergei
    System and Component Design, Department of Machine Design, KTH Royal Institute of Technology.
    Antzutkin, Oleg N.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Telkki, Ville-Veikko
    NMR Research Unit, University of Oulu.
    Y Structure and dynamics elucidation of ionic liquids using multidimensional Laplace NMR2017In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, no 80, p. 11056-11059Article in journal (Refereed)
    Abstract [en]

    We demonstrate the ability of multidimensional Laplace NMR (LNMR), comprising relaxation and diffusion experiments, to reveal essential information about microscopic phase structures and dynamics of ionic liquids that is not observable using conventional NMR spectroscopy or other techniques.

  • 11.
    Bhattacharyya, Shubhankar
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ether Functionalized Choline Tethered Amino Acid Ionic Liquids for Enhanced CO2 Capture2016In: A C S Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 4, no 10, p. 5441-5449Article in journal (Refereed)
    Abstract [en]

    Amino acid ionic liquids (ILs) are the most interesting and effective for CO2 capture due to their low toxicity, biodegradability and fast reactivity towards CO2. Ionic nature of amino acid ILs can raise an environmental issue if the cation counterpart becomes toxic to the aquatic ecosystems and can become potential atmospheric pollutant. In this regard, choline based ILs are known to be promising scaffolds for the development of less toxic amino acid ILs. However, the existing choline amino acid ILs are highly viscous limiting their applicability as solvents. Ether functionalized choline based amino acid ILs with novel series of less toxic green ILs were explored with reduced viscosity and high CO2 capture capacity. A simple, economic, clean and environmentally benign method was utilized for the synthesis of novel choline based amino acid ILs using a commercially available and economical starting material 2-(dimethylamino)ethanol (deanol, a human dietary food supplement). Reported ILs have low viscosity with high CO2 capture capacity (1.62 mol of CO2 /mol of IL, 4.31 mol of CO2/kg of IL, 19.02 wt.% of CO2). Mechanism of [N1,1,6,2O4][Lys]+CO2 reaction and adduct structure was proposed by means of DFT and NMR.

  • 12.
    Bhattacharyya, Shubhankar
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Functionalized Choline Based Amino Acid Ionic Liquids: Scope Of Bio-ILs2016Conference paper (Refereed)
  • 13.
    Karimi, Somayeh
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Mortazavi, Yadollah
    Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Khodadadi, Abbas Ali
    Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Sardari, Kaymar
    Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Esmaeili, Mohammad
    Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    High flux acetate functionalized silica membranes based on in-situ co-condensation for CO2/N2 separation2016In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 520, p. 574-582Article in journal (Refereed)
    Abstract [en]

    Acetate-functionalized silica membranes were prepared via co-condensation. The molar ratio of functional groups in the silica matrix was varied in the range of 0–0.6, denoted by x. The presence of functional groups bonded to the silica network was revealed by FTIR and 29Si and 13C solid-state NMR analysis. The stability of the groups was studied by TG analysis. The membranes were evaluated for CO2/N2 mixture separation in a temperature range of 253–373 K using a feed pressure of 9 bar and a sweep gas kept at atmospheric pressure on the permeate side. The membranes were found to be CO2-selective at all the conditions studied. The highest observed selectivity was 16 for x=0.4, with a CO2 permeance of 5.12×10−7 mol s−1 m−2 Pa−1. For x=0.2, a permeance of as high as 20.74×10−7 mol s−1 m−2 Pa−1 with a CO2/N2 selectivity of 7.5 was obtained. This permeance is the highest reported for CO2/N2 separation using functionalized silica membranes. It is proposed that the separation mechanism between CO2 and N2 was the preferential adsorption of CO2, which inhibited adsorption and permeation of N2 through the silica pore network. Permporometry results revealed that as the loading of functional groups increased, the He permeance decreased. It was also indicated that the quantity of micropores in the functionalized membrane was higher than that in the parent silica membrane.

  • 14.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Jamil, Maryam
    Department of Biochemistry, Quaid i Azam University, Islamabad, Pakistan.
    Aslam, Javaria
    Department of Biochemistry, Quaid i Azam University, Islamabad, Pakistan.
    Gul, Asghari
    Department of Physics, COMSATS IIT, Islamabad, Pakist.
    Akhter, Zareen
    Department of Chemistry, Quaid i Azam University, Islamabad, Pakistan.
    Mirza, Bushra
    Department of Biochemistry, Quaid i Azam University, Islamabad, Pakistan.
    Influence of Ferrocene and Transition Metals on the Biological Activities of Schiff Bases2016In: Journal of the Chemical Society of Pakistan, ISSN 0253-5106, Vol. 38, no 6, p. 1112-1120Article in journal (Refereed)
    Abstract [en]

    A series of organic and organometallic Schiff bases bearing phenylferrocene and their six transition metal complexes have been prepared and tested for their potential biological applications by using antifungal, antibacterial, antitumor activities, toxicity testing against the brine shrimp and DNA damage analysis. The copper and cobalt complexes of organic Schiff base showed significant antibacterial activity. The antifungal activities tested against six fungal strains revealed that N-(4-hydroxybenzylidene) aniline (A5) had the highest antifungal activity. Most of these compounds showed cytotoxic activity against the brine shrimp. The results of showed that these compounds had significant antitumor activity, up to 97% in the case of N-(4-chlorobenzylidene) aniline (A3). Only two compounds N-(2-hydroxy benzylidene) 4-ferrocenylaniline (F2) and Nickel (II) complex of organic Schiff base (CO2) had DNA damaging activity at 20mg/ml concentration. 

  • 15.
    Bhattacharyya, Shubhankar
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Insights into the Effect of CO2 Absorption on the Ionic Mobility of Ionic Liquids2016In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, no 41, p. 28617-28625Article in journal (Refereed)
    Abstract [en]

    We investigate a comparative effect of CO2 absorption on the ionic mobility of two choline based ionic liquids comprising two different anions such as threonine and imidazole. The synthesized ionic liquids were characterized using 1H and 13C NMR and other spectroscopic techniques. By keeping a common cation and changing the anion from threonine to imidazole both the viscosity and density reduced drastically. We found that [N1,1,6,2OH][Imi] exhibits the highest CO2 capture capacity at 20 °C of 5.27 mol of CO2 per kg of ionic liquid (1.27 mol of CO2 per mol of ionic liquid, 23.26 wt% of CO2) whereas [N1,1,6,2OH][Threo] exhibits 3.6 mol of CO2 per kg of ionic liquid (1.05 mol of CO2 per mol of ionic liquid, 15.87 wt% of CO2). The activation energy for diffusion is calculated using the Vogel-Fulcher-Tamman (VFT) equation in the form of diffusivity. It was found that the activation energy for the diffusion of [N1,1,6,2OH][Threo] is ∼10 times higher than that of [N1,1,6,2OH][Imi]. 1H diffusion NMR data revealed that the diffusivity of [N1,1,6,2OH][Imi] is increased after CO2 absorption whereas a decrease in diffusivity was observed in the case of [N1,1,6,2OH][Threo]. This anomalous behavior of [N1,1,6,2OH][Imi] was further explained by using DFT calculations.

  • 16.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Bhattacharyya, Shubhankar
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Akhtar, Farid
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Ionic Liquids As Liquid And Solid Sorbents For Post-Combustion CO2 Capture2016Conference paper (Refereed)
  • 17.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Azancheev, Nail
    Kazan (Volga Region) Federal University, Kazan.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Glavatskikh, Sergei
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Self-Diffusion of Phosphonium Bis(Salicylato)Borate Ionic Liquid in Pores of Vycor Porous Glass2016In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 230, p. 128-134Article in journal (Refereed)
    Abstract [en]

    1H NMR pulsed field gradient was used to study self-diffusion of a phosphonium bis(salicylato)borate ionic liquid ([P6,6,6,14][BScB]) in the pores of Vycor porous glass at 296 K. Confinement in pores increases diffusion coefficients of the ions by a factor of 35. However, some [P6,6,6,14][BScB] ions demonstrated apparent diffusion coefficients much lower than their mean values, which may be due to partially restricted diffusion of the ions. We suggest that this fraction corresponds to areas where ions are confined by pore ‘necks’ (micropores) and empty voids. Heating of the ionic liquid / Vycor system at 330 K led to a change in the diffusivity of the ions, because of their redistribution in the pores. The size of the bounded regions is on the order of 1 µm, as estimated from the dependence of the ion diffusivity on the diffusion time.

  • 18.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Akhtar, Farid
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Khan, Muhammad Saif Ullah
    Department of Chemistry, Quaid-i-Azam University, Islamabad.
    Akhter, Zareen
    Department of Chemistry, Quaid-i-Azam University, Islamabad.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Solid-state 13C, 15N and 29Si NMR characterization of block copolymers with CO2 capture properties2016In: Magnetic Resonance in Chemistry, ISSN 0749-1581, E-ISSN 1097-458X, Vol. 54, no 9, p. 734-739Article in journal (Refereed)
    Abstract [en]

    Natural abundance solid-state multinuclear (13C, 15N and 29Si) cross-polarization magic-angle-spinning NMR was used to study structures of three block copolymers based on polyamide and dimethylsiloxane and two polyamides, one of which including ferrocene in its structure. Assignment of most of the resonance lines in 13C, 15N and 29Si cross-polarization magic angle-spinning NMR spectra were suggested. A comparative analysis of 13C isotropic chemical shifts of polyamides with and without ferrocene has revealed a systematic shift towards higher δ -values (de-shielding) explained as the incorporation of paramagnetic ferrocene into the polyamide backbone. In addition, the 13C NMR resonance lines for ferrocene-based polyamide were significantly broadened, because of paramagnetic effects from ferrocene incorporated in the structure of this polyamide polymer. Single resonance lines with chemical shifts ranging from 88.1 to 91.5ppm were observed for 15N sites in all of studied polyamide samples. 29Si chemical shifts were found to be around 22.4ppm in polydimethylsiloxane samples that falls in the range of chemical shifts for alkylsiloxane compounds. The CO2 capture performance of polyamide-dimethylsiloxane-based block copolymers was measured as a function of temperature and pressure. The data revealed that these polymeric materials have potential to uptake CO2 (up to 9.6 cm3 g1) at ambient pressures and in the temperature interval 30–40 °C. Copyright ©2016 John Wiley & Sons, Ltd.

  • 19.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Azancheev, Nail
    Kazan (Volga Region) Federal University, Kazan.
    Taher, Mamoun
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rabét, Pauline
    Department of Organic Chemistry, School of Chemistry, Manchester University.
    Glavatskih, Sergei
    System and Component Design, KTH, Royal Institute of Technology , Machine Design, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden, Department of Physics, Warwick University, Coventry, Department of Mechanical Construction and Production, Ghent University.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Self-diffusion and interactions in mixtures of imidazolium bis(mandelato)borate ionic liquids with polyethylene glycol: 1H NMR study2015In: Magnetic Resonance in Chemistry, ISSN 0749-1581, E-ISSN 1097-458X, Vol. 53, no 7, p. 493-497Article in journal (Refereed)
    Abstract [en]

    We used 1H nuclear magnetic resonance pulsed-field gradient to study the self-diffusion of polyethylene glycol (PEG) and ions in a mixture of PEG and imidazolium bis(mandelato)borate ionic liquids (ILs) at IL concentrations from 0 to 10 wt% and temperatures from 295 to 370 K. PEG behaves as a solvent for these ILs, allowing observation of separate lines in 1H NMR spectra assigned to the cation and anion as well as to PEG. The diffusion coefficients of PEG, as well as the imidazolium cation and bis(mandelato)borate (BMB) anion, differ under all experimental conditions tested. This demonstrates that the IL in the mixture is present in at least a partially dissociated state, while the lifetimes of the associated states of the ions and ions with PEG are less than ~30 ms. Generally, increasing the concentration of the IL leads to a decrease in the diffusion coefficients of PEG and both ions. The diffusion coefficient of the anion is less than that of the cation; the molecular mass dependence of diffusion of ions can be described by the Stokes–Einstein model. NMR chemical shift alteration analysis showed that the presence of PEG changes mainly the chemical shifts of protons belonging to imidazole ring of the cation, while chemical shifts of protons of anions and PEG remain unchanged. This demonstrated that the imidazolium cation interacts mainly with PEG, which most probably occurs through the oxygen of PEG and the imidazole ring. The BMB anion does not strongly interact with PEG, but it may be indirectly affected by PEG through interaction with the cation, which directly interacts with PEG

  • 20.
    Wang, Yong-Lei
    et al.
    Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Glavatskih, Sergei
    System and Component Design, KTH, Royal Institute of Technology.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Laaksonen, Aatto
    Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University.
    Atomistic insight into orthoborate-based ionic liquids: force field development and evaluation2014In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 118, no 29, p. 8711-8723Article in journal (Refereed)
    Abstract [en]

    We have developed an all-atomistic force field for a new class of halogen-free chelated orthoboratephosphonium ionic liquids. The force field is based on an AMBER framework with determination of force field parameters for phosphorus and boron atoms, as well as refinement of several available parameters. The bond and angle force constants were adjusted to fit vibration frequency data derived from both experimental measurements and ab initio calculations. The force field parameters for several dihedral angles were obtained by fitting torsion energy profiles deduced from ab initio calculations. To validate the proposed force field parameters, atomistic simulations were performed for 12 ionic liquids consisting of tetraalkylphosphonium cations and chelated orthoborate anions. The predicted densities for neat ionic liquids and the [P6,6,6,14][BOB] sample, with a water content of approximately 2.3−2.5 wt %, are in excellent agreement with available experimental data. The potential energy components of 12 ionic liquids were discussed in detail. The radial distribution functions and spatial distribution functions were analyzed and visualized to probe the microscopic ionic structures of these ionic liquids. There are mainly four high-probability regions of chelated orthoborate anions distributed around tetraalkylphosphonium cations in the first solvation shell, and such probability distribution functions are strongly influenced by the size of anions.

  • 21.
    Taher, Mamoun
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Glavatskih, Sergei
    Machine Design, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Halogen-free ionic liquids in lubrication2014Conference paper (Refereed)
    Abstract [en]

    The use of wear-resistant non-ferrous and lightweight materials calls for novel types of lubricants including neat Ionic Liquids (ILs) and ILs as additives to base oils [1-4]. ILs are non-flammable low temperature molten salts, which have negligible volatility and a high thermal stability. However, most of previously studied ILs as promising lubricants contain BF4- or PF6- anions, which are prone to hydrolysis producing corrosive and toxic species. Here we report on the synthesis, physic-chemical and tribological characterisation of halogen-free ILs with cations belonging to different families (phosphonium, pyrrolidinium, imidazolium), combined with different orthoborate anions (bis(mandelato)borate [BMB], bis(salicylato)borate, bis(oxalato)borate, etc). It was found that these types of hf-BILs (both as neat liquids and as additives) outperform a fully formulated engine oil and a neat PEG oil as antiwear and friction reducing lubricants at steel-steel and steel-aluminium contacts.To reveal mechanisms of formation of tribofilms, the mechanochemically induced boundary films on surfaces of Al2O3, MgO and SiO2 in contact with orthoborate-based ILs were characterised using solid-state multinuclear (11B, 31P and 29Si) MAS NMR, FTIR and Raman spectroscopy. It was found that some of these ILs interact with the oxides, in particular, at elevated temperatures. We suggest that the boundary film formation between hf-BILs and -Al2O3, MgO and SiO2 surfaces is a complex process involving various chemical reactions at the solid-liquid interfaces. Self-diffusion of ionic species in orthoborate based ILs and in IL/PEG mixtures as a function of temperature was studied using pulse-field-gradient (PFG) 1H and 31P NMR [5]. It was found that [P66614][BMB] can exist in one or two different liquid “phases” with ionic species having dramatically different (by two orders of magnitude) self-diffusion coefficients: Slowly diffusing phosphonium cations with long and bulky alkyl chains form domains stabilised by hydrophobic interactions in these ILs in the temperature range 20-50 oC, while small orthoborate anions are fast diffusing species at these temperatures [5]. These domains are, however, disrupted by developed molecular motion with the cation-anion complexes having one and the same diffusion coefficient when the IL system is heated above 50oC. A similar phenomenon was also found in some other [BMB] based ILs with pyrrolidinium and imidazolium cations.

  • 22.
    Taher, Mamoun
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Baets, Patrick De
    Department of Mechanical Construction and Production, Ghent University.
    Glavatskih, Sergei
    Department of Mechanical Construction and Production, Ghent University.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Halogen-free pyrrolidinium bis(mandelato)borate ionic liquids: some physicochemical properties and lubrication performance as additives to polyethylene glycol2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 58, p. 30617-30623Article in journal (Refereed)
    Abstract [en]

    This work reports on the synthesis and physicochemical characterisation of novel halogen-free boron containing ionic liquids (hf-BILs) with dialkylpyrrolidinium cations [CnC1Pyrr]+, n ¼ 4–14, and bis(mandelato)borate anion [BMB]. All the synthesised compounds are liquids at room temperature. It was found that the thermal properties and density of these hf-BILs are affected by the length of the longest alkyl chain connected to the nitrogen atom in the pyrrolidinium cations. Differential scanning calorimetry measurements revealed that glass transition temperatures of these ionic liquids are in the temperature range from 218 to 241 K. Interestingly, the glass transition temperatures follow the “odd– even” effect related to the number of carbons (n) in one of the alkyl chains of [CnC1Pyrr]+. It was also found that hf-BILs' density decreases with an increase in the alkyl chain length of [CnC1Pyrr]+. It is suggested that the “odd–even” effect is associated with the difference in packing and specific interactions of cations and anions of this class of hf-BILs. Their lubricating properties, as 3 wt% additives in polyethylene glycol (PEG), were evaluated in steel–steel contacts. PEG with hf BILs additive provided significantly lower wear and friction compared to the neat PEG and 5W40 engine oil. It was found that shortening the length of the longest alkyl chain in the cations of [CnC1Pyrr][BMB] significantly reduces frictional losses. Antiwear properties of [CnC1Pyrr][BMB] in PEG follow the same trend.

  • 23.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Taher, Mamoun
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Glavatskih, Sergei
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    The effect of the cation alkyl chain length on density and diffusion in dialkylpyrrolidinium bis(mandelato)borate ionic liquids2014In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, no 48, p. 26798-26805Article in journal (Refereed)
    Abstract [en]

    The physicochemical properties of ionic liquids are strongly affected by the selective combination of the cations and anions comprising the ionic liquid. In particular, the length of the alkyl chains of ions has a clear influence on the ionic liquid's performance. In this paper, we study the self-diffusion of ions in a series of halogen-free boron-based ionic liquids (hf-BILs) containing bis(mandelato)borate anions and dialkylpyrrolidinium cations with long alkyl chains CnH2n+1 with n from 4 to 14 within a temperature range of 293-373 K. It was found that the hf-BILs with n = 4-7 have very similar diffusion coefficients, while hf-BILs with n = 10-14 exhibit two liquid sub-phases in almost the entire temperature range studied (293-353 K). Both liquid sub-phases differ in their diffusion coefficients, while values of the slower diffusion coefficients are close to those of hf-BILs with shorter alkyl chains. To explain the particular dependence of diffusion on the alkyl chain length, we examined the densities of the hf-BILs studied here. It was shown that the dependence of the density on the number of CH2 groups in long alkyl chains of cations can be accurately described using a "mosaic type" model, where regions of long alkyl chains of cations (named 'aliphatic' regions) and the residual chemical moieties in both cations and anions (named 'ionic' regions) give additive contributions. Changes in density due to an increase in temperature and the number of CH2 groups in the long alkyl chains of cations are determined predominantly by changes in the free volume of the 'ionic' regions, while 'aliphatic' regions are already highly compressed by van der Waals forces, which results in only infinitesimal changes in their free volumes with temperature.

  • 24.
    Hjalmarsson, Nicklas
    et al.
    Surface and Corrosion Science, School of Chemical Science and Engineering, KTH – Royal Institute of Technology.
    Asencio, Rubén Álvarez
    Surface and Corrosion Science, School of Chemical Science and Engineering, KTH – Royal Institute of Technology.
    Sweeney, James
    Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Schaufelberger, Fredrik
    Organic Chemistry, School of Chemical Science and Engineering, KTH – Royal Institute of Technology, Stockholm.
    Ramström, Olof
    Organic Chemistry, School of Chemical Science and Engineering, KTH – Royal Institute of Technology, Stockholm.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Atkin, Rob
    Surface and Corrosion Science, School of Chemical Science and Engineering, KTH – Royal Institute of Technology.
    Glavatskih, Sergei
    Department of Physics, Warwick University, Coventry.
    Rutland, Mark W.
    Surface and Corrosion Science, School of Chemical Science and Engineering, KTH – Royal Institute of Technology.
    Biodegradable ionic liquids as lubricants2013Conference paper (Refereed)
  • 25.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Glavatskih, Sergei
    Machine Design, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Boron in tribology: from borates to ionic liquids2013In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 51, no 3, p. 281-301Article in journal (Refereed)
    Abstract [en]

    Boron compounds are widely used in a range of tribological applications such as friction modifiers, antioxidants, antiwear additives, and in many cases as environmentally friendly lubricants. The chemical nature and structure of boron compounds provide multifunctionality. They are used as (1) solid lubricants such as boric acid and hexagonal boron nitride, (2) liquid lubricants such as ionic liquids, (3) lubricant additives such as borate derivatives of various organic and inorganic compounds, and (4) coatings such as cubic boron nitride and different metal borides. Boron is also one of the most favorable elements for coatings and thin films in biotribological and biomedical applications. This review outlines the growing role of boron in lubrication over the past several decades, summarizesthe main findings, and identifies future challenges related to boron chemistry.

  • 26.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Glavatskih, Sergei
    Machine Design, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Boundary films at metal oxide-ionic liquid interfaces studied by solid-state NMR spectroscopy2013Conference paper (Refereed)
    Abstract [en]

    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.

  • 27.
    Taher, Mamoun
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Glavatskih, Sergei
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Halogen free boron-based ionic liquids as novel lubricants2013Conference paper (Other academic)
    Abstract [en]

    Most of the modern lubricants and lubricant additives have been designed and optimized for ferrous materials. A growing trend towardswider use of lightweight and wear resistant non-ferrous materials calls for new efficient and environmentally friendly lubricants.In this study, halogen free boron based ionic liquids (hf-BILs) were designed, synthesized and tribologically tested for ferrous and non-ferrous materials.

  • 28.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Taher, Mamoun
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Glavatskih, Sergei
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    NMR self-diffusion study of a phosphonium bis(mandelato)borate ionic liquid2013In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 15, no 23, p. 9281-9287Article in journal (Refereed)
    Abstract [en]

    Newly synthesized halogen-free boron based ionic liquids (hf-BILs) composed of chelated orthoborate anionsand phosphonium cations have hydrolytic stability, low melting point and outstanding wear and frictionreducing properties. We report here the peculiarities of self-diffusion in one representative from this class,trihexyltetradecylphosphonium bis(mandelato)borate, [P6,6,6,14][BMB], in the temperature range of itspractical interest, 20–100 1C. NMR techniques demonstrated complicated diffusional behaviour – the ionicliquid can exist in one or two liquid ‘‘phases’’. In the low-temperature range (20–50 1C), two phases coexistwhere the cations, [P6,6,6,14], are contained mainly in the phase with slower diffusion coefficients while theanions, [BMB], are in the phase with faster diffusion coefficients. Cations have lower diffusion coefficientswith a factor of 20 as compared with the anions, an effect which is caused by aggregation of cations intodomains due to so-called ‘‘hydrophobic interaction’’ of their hydrocarbon chains. As the temperature risesabove 60 1C, the two phases merge into one where both ions have equal diffusion coefficients. This iscaused by thermal motion making the cation domains smaller in size and more easily interacting withanions. As a result, anions and cations diffuse in this high-temperature range as a pair.

  • 29.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Glavatskih, Sergei
    System and Component Design, KTH, Royal Institute of Technology.
    Dean, Pamela M.
    School of Chemistry, Monash University, Clayton, Victoria 3800, Australia.
    MacFarlane, Douglas R.
    School of Chemistry, Monash University, Clayton, Victoria 3800, Australia.
    Forsyth, Maria
    Department of Materials Engineering, Monash University.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Halogen-free chelated orthoborate ionic liquids and organic ionic plastic crystals2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 14, p. 6928-6938Article in journal (Refereed)
    Abstract [en]

    Five halogen-free orthoborate salts comprised of three different cations (cholinium, pyrrolidinium and imidazolium) and two orthoborate anions, bis(mandelato)borate and bis(salicylato)borate, were synthesised and characterised by DSC, X-ray diffraction and NMR. DSC measurements revealed that glass transition points of these orthoborate salts are in the temperature range from −18 to −2 °C. In addition, it was found that [EMPy][BScB] and [EMIm][BScB] salts have solid–solid phase transitions below their melting points, i.e. they exhibit typical features of plastic crystals. Salts of the bis(salicylato)borate anion [BScB]− have higher melting points compared with corresponding salts of the bis(mandelato)borate anion [BMB]−. Single crystal X-ray diffraction crystallography (for [Chol][BScB] crystals) and solid-state multinuclear (13C, 11B and 15N) NMR spectroscopy were employed for the structural characterisation of [Chol][BScB], [EMPy][BScB] and [EMIm][BScB], which are solids at room temperature: a strong interaction between [BScB]− anions and [Chol]+ cations was identified as (i) hydrogen bonding between OH of [Chol]+ and carbonyl groups of [BScB]− and (ii) as the inductive C–Hπ interaction. In the other salt, [EMIm][BScB], anions exhibit ππ stacking in combination with C–Hπ interactions with [EMIm]+ cations. These interactions were not identified in [EMPy][BScB] probably because of the lack of aromaticity in cations of the latter system. Our data on the formation of a lanthanum complex with bis(salicylato)borate in the liquid mixture of La3+(aq) with [Chol][BScB] suggest that this class of novel ILs can be potentially used in the extraction processes of metal ions of rare earth elements.

  • 30.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Glavatskih, Sergei
    System and Component Design, KTH, Royal Institute of Technology.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Novel alkylborate–dithiocarbamate lubricant additives: synthesis and tribophysical characterization2012In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 45, no 1, p. 67-78Article in journal (Refereed)
    Abstract [en]

    Boron-based lubricant additives have recently received significant attention, because of their wear-reducing and frictional properties and low pollution. At the same time, dithiocarbamate complexes with different metals have a long history of being used as multifunctional additives to lubricants. In this study, novel, environmentally friendly additives containing alkylborate and dithiocarbamate groups with alkyl or methylbenzyl substitutes in one molecule were studied. Tribological tests were performed with the additives admixed in a mineral oil using steel-on-steel contacts in a four-ball tribometer. Borate derivatives of different dithiocarbamate ligands were synthesized by several step reactions to investigate tribochemical properties of boron, sulfur, and nitrogen combined in one selected compound. Viscous liquid products were characterized by multinuclear 1H, 13C, and 11B NMR spectroscopy. The surface morphology and the elemental composition of the tribofilms were investigated using an optical profiler and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). It was found that some of these novel compounds provide better antiwear performance and similar frictional properties compared with a commercially available ZnDTP package. Traces of sulfur in the tribofilms formed with both 0.2 and 1.0 wt% of alkylborate–dithiocarbamate compounds in a mineral oil were detected with EDS.

  • 31.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Designed boron chemistry for tribological systems2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    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.

  • 32.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Glavatskih, Sergei
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lindberg, Mats
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Interfacial antiwear and physicochemical properties of alkylborate-dithiophosphates2011In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 3, no 4, p. 956-968Article in journal (Refereed)
    Abstract [en]

    Boron compounds have become of interest in tribology because of their unique tribochemical and tribological properties. At the same time, dialkyldithiophosphates (DTPs) of transition metals have been extensively used as multifunctional additives in lubricants to control friction and reduce wear in mechanical systems. Because of the environmental pollution and health hazards of these compounds, ashless compounds with reduced amounts of sulfur and phosphorus are desirable. This work reports on the synthesis, characterization, and tribological properties of a new class of compounds, alkylboratedithiophosphates. This class combines two high-iron-affinity surface active groups, borate and dialkyldithiophosphate, into a single molecule. The final products, viscous liquids, were characterized by FT-IR, multinuclear 1H, 13C, 31P, and 11B NMR spectroscopy and thermal analyses. Residues of one representative compound from this class, DPB-EDTP, after thermal analyses were additionally 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. Antiwear and friction properties of a mineral oil with these novel additives were evaluated in a four-ball tribometer in comparison with O,O0-di-n-butyl-dithiophosphato-zinc (II), Zn-BuDTP, as a reference lubricant additive. The surface morphology and the elemental composition of the tribofilms were characterized using scanning electron microscopy with energy-dispersive X-rays spectroscopy (SEM/EDS). The results show that alkylborate-dithiophosphates, with substantially reduced amounts of sulfur and phosphorus compared with Zn-BuDTP, have considerably better antiwear and friction performance.

  • 33.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Glavatskih, Sergei
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    MacFarlane, Douglas R.
    Monash University, Melbourne, VIC.
    Somers, Anthony
    Monash University, Melbourne, VIC.
    Forsyth, Maria
    Monash University, Melbourne, VIC.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Novel halogen-free chelated orthoborate-phosphonium ionic liquids: synthesis and tribophysical properties2011In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 13, no 28, p. 12865-12873Article in journal (Refereed)
    Abstract [en]

    We report on the synthesis, characterisation, and physical and tribological properties of halogen-free ionic liquids based on various chelated orthoborate anions with different phosphonium cations, both without halogen atoms in their structure. Important physical properties of the ILs including glass transition temperatures, density, viscosity and ionic conductivity were measured and are reported here. All of these new halogen-free orthoborate ionic liquids (hf-BILs) are hydrophobic and hydrolytically stable liquids at room temperature. As lubricants, these hf-BILs exhibit considerably better antiwear and friction reducing properties under boundary lubrication conditions for steel–aluminium contacts as compared with fully formulated (15W-50 grade) engine oil. Being halogen free these hf-BILs offer a more environmentally benign alternative to ILs being currently developed for lubricant applications.

  • 34.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Glavatskih, Sergei
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Tribochemical characterization of novel boron-dithiophosphates as additives to mineral oils2011Conference paper (Refereed)
  • 35.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Boron compounds as additives to lubricants: synthesis, characterization and tribological optimization2009Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    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.

  • 36.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Glavatskih, Sergei
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Synthesis, physicochemical, and tribological characterization of S-Di-n-octoxyboron-O,O′-di-n-octyldithiophosphate2009In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 1, no 12, p. 2835-2842Article in journal (Refereed)
    Abstract [en]

    Dialkyldithiophosphates (DTPs) of zinc(II), copper(II), and other 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 extensively used for more than 60 years. These additives form a protective film on steel surfaces and, thus, control friction and reduce wear. However, ZnDTPs contain zinc and large amounts of phosphorus and sulfur, which impair the environment, both directly and indirectly, by adversely affecting the performance of catalytic converters of various automobiles. For this reason, environmental legislation imposes limitations on concentrations of phosphorus, sulfur, and zinc in the lubricants. In this work, we report on zinc-free S-di-n-octoxyboron-O,O′-di-n-octyldithiophosphate (DOB-DTP) lubricant additive with amount of phosphorus and sulfur reduced by half in a molecule as compared with ZnDTPs. DOB-DTP was synthesized by a reaction in two steps under inert nitrogen atmosphere. The final product, a viscous liquid, was characterized by the elemental analysis, FT-IR, multinuclear 1H, 13C, 31P, and 11B NMR spectroscopy and thermal analyses. Tribological performance of a mineral oil with this new additive was evaluated in comparison with O,O′-di-n-butyl-dithiophosphato-zinc(II) (ZnDTP) using a four-ball tribometer. The surface morphology and the elemental composition of the tribofilms were characterized using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS). The results show that DOB-DTP has a considerably better antiwear performance and higher stability of the coefficient of friction with time as compared with ZnDTP. Both phosphorus and sulfur were detected by the EDS on the worn steel surfaces at all concentrations of additives in the base oil.

  • 37. Shah, Faiz Ullah
    et al.
    Thaer, Barri
    Lund University.
    Jönsson, Jan Åke
    Lund University.
    Skog, Kerstin
    Lund University.
    Determination of heterocyclic aromatic amines in human urine by usinghollow-fibre supported liquid membrane extraction and liquidchromatography-ultraviolet detection system2008In: Journal of chromatography. B, ISSN 1570-0232, E-ISSN 1873-376X, Vol. 870, no 2, p. 203-208Article in journal (Refereed)
    Abstract [en]

    A hollow-fibre supported liquid membrane (HF-SLM) extraction method has been developed for determination of 11 heterocyclic aromatic amines (HCAs) in human urine samples by using high performance liquid chromatography (HPLC) equipped with an ultraviolet (UV) absorbance detector. These compounds were extracted from an alkaline urine sample (donor phase) into the organic solvent residing in the pores of a polypropylene hollow fibre and then back extracted into an acidic solution (acceptor phase) inside the lumen of the hollow fibre. After extraction, HCAs were analyzed by injecting the analyte enriched acceptor phase into the HPLC. The analyte enrichment factors ranged between 241 and 339 obtained in a 90 min extraction time, and method detection limits (MDL) ranged between 0.1 and 0.5 μg L-1 with relative standard deviation (RSD) values between 3.4% and 11%. The extraction technique employed in this work is easy to use and rapid as it involves only a few minutes manipulation of each sample. It is the most economical sample preparation/preconcentration technique to our knowledge as compared to other microextraction techniques.

  • 38. Shah, Faiz Ullah
    et al.
    Akhter, Zareen
    Quaid-i-Azam University, Islamabad.
    Siddiqi, Humaira M.
    Quaid-i-Azam University, Islamabad.
    Parvez, Masood
    University of Calgary.
    Synthesis, structure and characterization of some Schiff bases bearing phenylferrocene2007In: Applied organometallic chemistry, ISSN 0268-2605, E-ISSN 1099-0739, Vol. 21, no 9, p. 758-762Article in journal (Refereed)
    Abstract [en]

    Some novel Schiff bases bearing phenylferrocene were synthesized by condensation reaction of 4-ferrocenylaniline with different aromatic aldehydes. The compounds prepared were characterized by spectroscopic methods (IR, UV-visible, 1H and 13C NMR) and elemental analysis. The single crystal analysis of compound F1 [monoclinic, space group, P21/c (no. 14), a = 19.858(2), b = 7.416(2), c = 12.095(5) Å, β = 106.257(14) ] indicates a trans imine bond with a bond length of 1.270(2) Å, typical of a carbon-nitrogen double bond.

  • 39.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Glavatskikh, Sergei
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Antiwear additives for lubricantsPatent (Other (popular science, discussion, etc.))
    Abstract [en]

    The additives are described by the general formula (I) with 2≤k≤20, 1≤n≤20, R1 = CmH2m+1; 1≤m≤80, and R2 = CpH2p+1; 1≤p≤80.

  • 40.
    Antzutkin, Oleg
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Glavatskikh, Sergei
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Högprestandasmörjmedel och tillsatser till smörjmedel för järnhaltiga och icke järnhaltiga materialPatent (Other (popular science, discussion, etc.))
  • 41.
    Antzutkin, Oleg
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Ullah Shah, Faiz
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Glavatskikh, Sergei
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Ionic-liquid-based lubricants and lubrication additives comprising ionsPatent (Other (popular science, discussion, etc.))
    Abstract [en]

    Anti-wear and friction-reducing lubricants and additives to lubricants for both ferrous and non-ferrous materials with/without DLC (diamiond-like-coatings) or graphene-based coatings, which are halogen free boron based ionic liqs. comprising a combination of an anion chosen from a mandelato borate anion, a salicylato borate anion, an oxalato borate anion, a malonato borate anion, a succinato borate anion, a glutarato borate anion and an adipato borate anion, with at least one cation selected from a tetraalkylphosphonium cation, a choline cation, an imidazolium cation and a pyrrolidinium cation, wherein said at least one cation has at least one alkyl group substituent with the general formula CnH2n+1 , wherein 1≤n≤80. Advantages of the invention include that it provides halogen free ionic liqs. for lubrication and that sensitivity for hydrolysis is reduced.

1 - 41 of 41
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