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Formation of Zn-Ca-Ni tri cation's phosphate coating on steel and study that properties
, Article TMS 2009 - 138th Annual Meeting and Exhibition, San Francisco, CA, 15 February 2009 through 19 February 2009 ; Volume 1 , 2009 , Pages 615-623 ; 9780873397384 (ISBN) ; Afshar, A ; Sharif University of Technology
2009
Abstract
A new Zinc phosphating bath, which produces coatings at relatively lower temperatures within a reasonable time by using of chemical accelerators has been devised. Improvement of the bath performance by the addition of divalent cations like calcium, nickel has been studied. Bath formulation and operating conditions have been optimized by coating weight determinations. Stable samples of phosphating formulations with and without calcium and nickel salts were prepared and the structure and morphology of the phosphate coatings were determined by using X-ray diffraction (XRD) techniques, scanning electron microscopy. ASTMB117 salt spray test and electrochemical impedance spectroscopy (EIS) were...
A Dopant-free hole transporting layer for efficient and stable planar perovskite solar cells
, Article Physica Status Solidi - Rapid Research Letters ; Volume 14, Issue 7 , 2020 ; Si, H ; Yadav, P ; Prochowicz, D ; Tavakoli, R ; Sharif University of Technology
Wiley-VCH Verlag
2020
Abstract
Herein, a new dopant-free organic material, PV2000, as a stable hole transporting layer (HTL) for the fabrication of stable and efficient perovskite solar cells (PSCs) is introduced. For this purpose, planar PSCs using a triple-A cation perovskite composition are fabricated and the commonly used 2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (spiro-OMeTAD) HTL is replaced by dopant-free PV2000 polymer. The characterization results disclose that the PV2000 has a great thermal stability, good hole mobility, and suitable band alignment that matches well with the valence band of triple-A cation perovskite. After proper optimization of PV2000 film thickness, a planar PSC...
Effect of nitrogen doping on glass transition and electrical conductivity of [EMIM][PF6] ionic liquid encapsulated in a zigzag carbon nanotube
, Article Journal of Physical Chemistry C ; Volume 121, Issue 29 , 2017 , Pages 15493-15508 ; 19327447 (ISSN) ; Minofar, B ; Sharif University of Technology
Abstract
Molecular level understanding of the properties of ionic liquids inside nanopores is needed in order to use ionic liquids for many applications such as electrolytes for energy storage in electric double-layer capacitors and dye-sensitized solar cells for conversion of solar energy. In this study, classical molecular dynamics (MD) simulations have been performed to investigate the radial distribution, glass transition, ionic transfer number, and electrical conductivity of the ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate [EMIM][PF6] ionic liquid encapsulated in carbon nanotube (CNT). The effect of nitrogen as a doping element in CNT on these properties of [EMIM][PF6] was also...
Electrical conductivity of methylimidazolium hexafluorophosphate ionic liquid in the presence of colloidal silver nano particles with different sizes and temperatures
, Article Journal of Physical Chemistry C ; Volume 121, Issue 39 , 2017 ; 19327447 (ISSN) ; Kiani, S ; Sharif University of Technology
American Chemical Society
2017
Abstract
Colloidal nanoparticle could be used for recognition location of tumors and cancer tissue. A simulation of molecular dynamic for colloidal silver nanoparticles (Ag NPs) based on density functional theory (DFT) potential parametrization with different sizes in 1-ethyl-3-methylimidazolium hexafluorophosphate [EMim][PF6] ionic liquid was performed. Then, using Green Kubo formalism, diffusion coefficient for Ag NPs in IL and in the gas phase was calculated. We also calculated diffusion coefficients of anions and cations for pure IL and IL in the presence of different sizes of Ag NPs at different temperatures. The findings showed that the diffusion coefficient of anions and cations increases in...
Electrostatically defying cation-cation clusters: Can likes attract in a low-polarity environment?
, Article Journal of Physical Chemistry A ; Volume 117, Issue 38 , 2013 , Pages 9252-9258 ; 10895639 (ISSN) ; Ramezani, M ; Fattahi, A ; Kass, S. R ; Sharif University of Technology
2013
Abstract
Like-charge ion pairing is commonly observed in protein structures and plays a significant role in biochemical processes. Density functional calculations combined with the conductor-like polarizable continuum model were employed to study the formation possibilities of doubly charged noncovalently linked complexes of a series of model compounds and amino acids in the gas phase and in solution. Hydrogen bond interactions were found to offset the Coulombic repulsion such that cation-cation clusters are minima on the potential energy surfaces and neither counterions nor solvent molecules are needed to hold them together. In the gas phase the dissociation energies are exothermic, and the...
Ionic liquid based on α-amino acid anion and N7,N9-dimethylguaninium cation ([dMG][AA]): Theoretical study on the structure and electronic properties
, Article Journal of Physical Chemistry A ; Volume 116, Issue 22 , April , 2012 , Pages 5436-5444 ; 10895639 (ISSN) ; Fattahi, A ; Bayat, A ; Sharif University of Technology
2012
Abstract
The interactions between five amino acid based anions ([AA] - (AA = Gly, Phe, His, Try, and Tyr)) and N7,N9-dimethylguaninium cation ([dMG] +) have been investigated by the hybrid density functional theory method B3LYP together with the basis set 6-311++G(d,p). The calculated interaction energy was found to decrease in magnitude with increasing side-chain length in the amino acid anion. The interaction between the [dMG] + cation and [AA] - anion in the most stable configurations of ion pairs is a hydrogen bonding interaction. These hydrogen bonds (H bonds) were analyzed by the quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analysis. Finally, several correlations...
Interaction of cations with 2′-deoxythymidine nucleoside and analysis of the nature and strength of cation bonds
, Article Journal of Physical Organic Chemistry ; Volume 25, Issue 2 , JAN , 2012 , Pages 153-161 ; 08943230 (ISSN) ; Fattahi, A ; Jamshidi, Z ; Sharif University of Technology
2012
Abstract
Binding of Mg 2+, Ca 2+, Zn 2+, and Cu + metal ions with 2′-deoxythymidine (dT) nucleoside was studied using a density functional theory method and a 6-311++G(d,p) basis set. This work demonstrated that the interaction of dT with these cations is tri-coordinated · (O2, O4′, O5′). Among the four types of cations, Zn 2+ cation exhibited the most tendency to interact with the dT. Cations via their interaction with dT can affect the N-glycosidic bond length, the values of pseudorotation of the sugar ring, the orientation of the base unit with respect to the sugar ring, and the acidity of the O5′H, O3′H, and N3H groups in the dT nucleoside. Natural bond orbital analysis was performed to calculate...
Meta hybrid density functional theory study of adsorption of imidazolium and ammonium based ionic liquids on graphene sheet
, Article Journal of Physical Chemistry C ; Volume 119, Issue 13 , March , 2015 , Pages 7095-7108 ; 19327447 (ISSN) ; Jamshidi, Z ; Bayat, A ; Kamath, G ; Sharif University of Technology
American Chemical Society
2015
Abstract
In this study, two types of ionic liquids (ILs) based on 1 butyl 3 methylimidazolium [Bmim]+ and butyltrimethylammonium [Btma]+ cations, paired to tetrafluoroborate [BF4], hexafluorophosphate [PF6], dicyanamide [DCA], and bis(trifluoromethylsilfonyl)imide [Tf2N] anions, were chosen as adsorbates to investigate the influence of cation and anion type on the adsorption of ILs on the graphene surface. The adsorption process on the graphene surface (circumcoronene) was studied using M06 2X/cc pVDZ level of theory. Empirical dispersion correction (D3) was also added to the M06 2X functional to investigate the effects of dispersion on the binding energy values. The graphene···IL configurations,...
DFT study of the interaction of thymine with Cu+ and Zn 2+
, Article Scientia Iranica ; Volume 16, Issue 2 C , 2009 , Pages 75-80 ; 10263098 (ISSN) ; Fattahi, A ; Sharif University of Technology
2009
Abstract
Interaction of the DNA thymine base with Cu+ and Zn3+ was studied to explore: a) The metal binding energy (MIA) of thymine with Cu+ and Zn2+ and b) The possible correlation between charge transfer and MIAs. The gas-phase Cu+ and Zn2+ affinities of thymine, as well as the Mulliken charges, on the complexed metal cations were both determined at the same computational level, including the density functional level and employing the hybrid B3LYP exchange correlation potential in connection with the 6-311++G (d,p) basis set. All the molecular complexes were obtained by interaction between the most stable tautomer of thymine and two transition mono and divalent (Cu+, Zn2+) metal ions. To probe all...
Fabrication of a modified electrode based on Fe3 O4 NPs/MWCNT nanocomposite: Application to simultaneous determination of guanine and adenine in DNA
, Article Bioelectrochemistry ; Volume 86 , 2012 , Pages 78-86 ; 15675394 (ISSN) ; Rastgar, S ; Amini, M. K ; Adeli, M ; Sharif University of Technology
Abstract
Multi-walled carbon nanotubes decorated with Fe 3O 4 nanoparticles (Fe 3O 4NPs/MWCNT) were prepared and used to construct a novel biosensor for the simultaneous detection of adenine and guanine. The direct electro-oxidation of adenine and guanine on the modified electrode were investigated by linear sweep voltammetry. The results indicate a remarkable increase in the oxidation peak currents together with negative shift in the oxidation peak potentials for both adenine and guanine, in comparison to the bare glassy carbon electrode (GCE). The surface morphology and nature of the composite film deposited on GCE were characterized by transmission electron microscopy, atomic force microscopy,...
Cobalt salophen-modified carbon-paste electrode incorporating a cationic surfactant for simultaneous voltammetric detection of ascorbic acid and dopamine
, Article Sensors and Actuators, B: Chemical ; Volume 121, Issue 2 , 2007 , Pages 530-537 ; 09254005 (ISSN) ; Zare Mehrjardi, H. R ; Sharif University of Technology
2007
Abstract
A carbon-paste electrode (CPE) is modified by incorporating cobalt-5-nitrosalophen (CoNSal) and tetraoctylammonium bromide (TOAB). The mechanism of electrocatalytic oxidation of dopamine (DA) and ascorbic acid (AA) at the surface of the CoNSal-modified CPE containing various percents of TOAB is thoroughly investigated by cyclic and differential pulse voltammetry. In solutions of pH 5.0, in which all studies are performed, DA exists as the positively charged species whereas AA is mainly as the neutral form. Therefore, the favorable ionic interaction (electrostatic repulsion) between the cationic form of DA and the cationic surfactant (TOA+) caused increasing the overvoltage for DA and...
Detailed analysis of the brine-rock interactions during low salinity water injection by a coupled geochemical-transport model
, Article Chemical Geology ; Volume 537 , 2020 ; Zivar, D ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Enhanced Oil Recovery (EOR) methods have been widely used around the world to improve oil production from petroleum reservoirs. Recently, the injection of the low salinity/smart water has gained popularity among the EOR methods. Different mechanisms are believed to exist during low salinity/smart water injection, including dissolution, precipitation, and ion exchange at the rock surface. In this study, a coupled geochemical-transport model is presented for the detailed analysis and investigation of the interactions between brine, sandstone and carbonate rocks. The proposed model presents the coupling of a geochemical software (PHREEQC) and a species transport model. This coupled method makes...
Application of the GV-MSA model to the electrolyte solutions containing mixed salts and mixed solvents
, Article Fluid Phase Equilibria ; Volume 231, Issue 1 , 2005 , Pages 67-76 ; 03783812 (ISSN) ; Taghikhani, V ; Ghotbi, C ; Sharif University of Technology
2005
Abstract
In this work the Ghotbi-Vera mean spherical approximation (GV-MSA) model, coupled with two different expressions for the cation-hydrated diameters, was used in predicting the mean ionic activity coefficients (MIAC) of electrolytes for a number of the mixed-solvent and mixed-salt electrolyte solutions at 25 °C. In all cases the cation diameters in solutions changed with concentration of electrolyte while the anion diameters were considered to be constant and equal to the corresponding Pauling diameters. In application of the GV-MSA model to the electrolyte systems, two different expressions were used for concentration dependency of cation-hydrated diameters, i.e., the GV-MSA1 and GV-MSA2...
Adsorption of pollutant cations from their aqueous solutions on graphitic carbon nitride explored by density functional theory
, Article Journal of Molecular Liquids ; Volume 260 , 15 June , 2018 , Pages 423-435 ; 01677322 (ISSN) ; Shamkhali, A. N ; Tafazzoli, M ; Parsafar, G ; Sharif University of Technology
Elsevier B.V
2018
Abstract
In this study, adsorption of important pollutant cations on the surface of graphitic carbon nitride (g-C3N4) was investigated by density functional theory. The calculations indicated that N6 cavity surrounded by triazine units is the most probable adsorption site on this surface. The structural optimizations also predicted a planar surface for Cr3+, and Ni2+/g-C3N4 systems while the structure of the surface for other systems indicated a considerable distortion with strong dependency on the cation size. Also, g-C3N4 surface exhibited the high adsorption energies for Cr3+, As3+, and Sb3+ ions in the gas phase. However, formation energies of the metal-aquo complexes of these cations indicated...
Study of the solubility of CO2, H2S and their mixture in the ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate: Experimental and modelling
, Article Journal of Chemical Thermodynamics ; Volume 65 , 2013 , Pages 220-232 ; 00219614 (ISSN) ; Ghotbi, C ; Taghikhani, V ; Jalili, A. H ; Mehdizadeh, A ; Sharif University of Technology
2013
Abstract
New experimental results are presented for the solubility of carbon dioxide, hydrogen sulfide in the ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate ([C8mim][PF6]) at temperatures range from (303.15 to 353.15) K and pressures up to about 2 MPa. The solubility of the mixture of CO2/H2S in [C8mim][PF6] under various feed compositions were also measured at temperatures of (303.15, 323.15 and 343.15) K and the pressure up to 1 MPa. The solubility of carbon dioxide and hydrogen sulfide increased with increasing pressure and decreased with increasing temperature and the solubility of H2S is about three times that of CO2 in the particular ionic liquid studied. The measured data were...
Selection of desired bentonite and evaluating influence of different acids on preparation of special clay for removal of trace olefins from aromatics
, Article Clay Minerals ; 2021 ; 00098558 (ISSN) ; Farhadi, F ; Kenari, M. A ; Eskandari, E ; Ramakrishna, S ; Sharif University of Technology
Cambridge University Press
2021
Abstract
Activated clay is an inexpensive substance with massive utilization for removal of unsaturated compounds on an industrial scale. The performance of activated clay in removing such compounds heavily relies on the type of pristine raw clay and acids which are used during the activation process. In this work, olefins removal from aromatic streams is reported by activated clays with two different routes of clay activation. After preliminary tests of four different natural clays, the best clay was selected due to having enhanced swelling index, cation exchange capacity, higher surface area, and better suspension stability, among others. Having activated clay with hydrochloric acid and sulfuric...
Cu2ZnSnS4 as a hole-transport layer in triple-cation perovskite solar cells: Current density versus layer thickness
, Article Ceramics International ; Volume 48, Issue 1 , 2022 , Pages 711-719 ; 02728842 (ISSN) ; Heidariramsheh, M ; Taghavinia, N ; Mohammadpour, R ; Rasuli, R ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Cu2ZnSnS4 (CZTS) is a good candidate for cost-effective perovskite solar cells (PSCs) due to its direct bandgap with a value of 1.4–1.5 eV. In this study, we investigate CZTS ink as an inorganic hole-transport-layer (HTL) in CsMAFAPbIBr mixed halide PSCs. We study the cell efficiency and hole extraction from the perovskite layer for different thicknesses of HTL. The optimized device exhibits better hole selectivity, and the best efficiency of the device (12.84%) is achieved for the CZTS layer with a thickness of 159 nm. The prepared samples were also tested by open-circuit voltage decay analysis and electrochemical impedance spectroscopies. Results show that the optimized device effectively...
Green porous benzamide-like nanomembranes for hazardous cations detection, separation, and concentration adjustment
, Article Journal of Hazardous Materials ; Volume 423 , 2022 ; 03043894 (ISSN) ; Fatahi, Y ; Asadnia, M ; Daneshgar, H ; Kiani, M ; Ghadiri, A. M ; Atarod, M ; Mashhadzadeh, A. H ; Akhavan, O ; Bagherzadeh, M ; Lima, E. C ; Saeb, M. R ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Green biomaterials play a crucial role in the diagnosis and treatment of diseases as well as health-related problem-solving. Typically, biocompatibility, biodegradability, and mechanical strength are requirements centered on biomaterial engineering. However, in-hospital therapeutics require an elaborated synthesis of hybrid and complex nanomaterials capable of mimicking cellular behavior. Accumulation of hazardous cations like K+ in the inner and middle ear may permanently damage the ear system. We synthesized nanoplatforms based on Allium noeanum to take the first steps in developing biological porous nanomembranes for hazardous cation detection in biological media. The...
Engineering of perovskite materials based on formamidinium and cesium hybridization for high-efficiency solar cells
, Article Chemistry of Materials ; Volume 31, Issue 5 , 2019 , Pages 1620-1627 ; 08974756 (ISSN) ; Runjhun, R ; Tavakoli, M. M ; Yadav, P ; Saski, M ; Alanazi, A. Q ; Kubicki, D. J ; Kaszkur, Z ; Zakeeruddin, S. M ; Lewiński, J ; Grätzel, M ; Sharif University of Technology
American Chemical Society
2019
Abstract
Engineering the chemical composition of inorganic-organic hybrid perovskite materials is an effective strategy to boost the performance and operational stability of perovskite solar cells (PSCs). Among the diverse family of ABX3 perovskites, methylammonium-free mixed A-site cation CsxFA1-xPbI3 perovskites appear as attractive light-absorber materials because of their optimum band gap, superior optoelectronic property, and good thermal stability. Here, we develop a simple and very effective one-step solution method for the preparation of high-quality (Cs)x(FA)1-xPbI3 perovskite films upon the addition of excess CsCl to the FAPbI3 precursor solution. It is found that the addition of CsCl as a...
Photovoltaic performance improvement in vacuum-assisted meniscus printed triple-cation mixed-halide perovskite films by surfactant engineering
, Article ACS Applied Energy Materials ; Volume 2, Issue 9 , 2019 , Pages 6209-6217 ; 25740962 (ISSN) ; Abdollah Zadeh, A ; Dehghani, M ; Taghavinia, N ; Sharif University of Technology
American Chemical Society
2019
Abstract
Scalable coating methods have recently emerged as practical alternative deposition techniques to the conventional spin-coating despite their lower yielding power conversion efficiencies (PCEs). The most important barrier acting against the use of scalable deposition methods to get a highly absorbing (>95%) film with controlled morphology in the high crystallinity of perovskite particles is the impossibility of antisolvent dripping during the deposition. Here, we demonstrate the positive role of both the surfactant-engineering and the vacuum-annealing (<100 Pa) process in improving the device performance to overcome this limit. A detailed optimization of the vacuum-assisted meniscus printing...