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41.
Zirconium and titanium can be easily and quickly extracted from ca. 0.5 M hydrochloric, nitric or sulphuric acid by means of n-heptylarsonic acid in chloroform. The metal can be determined gravimetrically, or after some pretreatment, titrimetrically or photometrically. The extraction allows a quantitative separation from a large number of elements. The results obtained for technical products such as alloys and glass are compared with results of standard methods. 相似文献
42.
S. S. Batool S. R. Gilani M. N. Tahir A. Siddique W. T. A. Harrison 《Journal of Structural Chemistry》2016,57(6):1176-1181
A new mixed-ligand one-dimensional copper(II) coordination polymer [Cu(en)(sal)Cl] n where en = ethylenediamine(C2H8N2) and Hsal = 2-hydroxybenzoic acid (salicylic acid; C7H6O3) is synthesized and characterized by FTIR spectroscopy and single crystal X-ray diffraction. The structure contains Cu2+ ions in two different distorted octahedral coordination environments: an axially extended CuN4Cl2 moiety arising from a pair of bidentate en ligands and a CuO4Cl2 moiety arising from a pair of asymmetrically coordinated sal– anions. The chloride ions bridge the copper ions into a zigzag chain propagating in [001]. The structure is consolidated by N–H???O and N–H???Cl hydrogen bonds which generate a layered network. Crystal data: C9H13ClCuN2O3, M r = 296.20, monoclinic, P21/c, a = 13.9179(10) Å, b = 10.4900(8) Å, c = 8.5181(6) Å, β = 105.518(4)°, V = 1198.30(15) Å3, Z = 4, R(F) = 0.026, w R(F 2) = 0.068. 相似文献
43.
The synthesis of enantiopure unsymmetrical N-heterocyclic based zwitterions incorporating imidazolinium and alkylsulfonate or sulfamate groups is described. The desired compounds were prepared in good yields from 1,3-propanesultone or cyclic sulfamidates and imidazolines. The imidazolinium based zwitterions proved to be versatile chiral solvating agents for Mosher’s acid, alcohols, cyanohydrins, amino alcohols, nitro alcohols, thiols, and carboxylic acids with very high shifts in the 1H and 19F NMR. 相似文献
44.
Gilani AG Sariri R Bahrpaima K 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2001,57(1):155-161
The aggregation of Rhodamine 6G in liquid crystalline solutions was studied using polarised spectroscopy and in a guest-host system based on homogeneous-homeotropic alignment. The orientation of the dye molecules (guest) was controlled using an electric field, and this enabled the contrast ratio R of the dye to be obtained by electrically switching. The excitonic treatment of the absorption spectra suggests a coplanar structure for the dimeric aggregates. 相似文献
45.
Hamed Hamishehkar Jaber Emami Abdolhossein Rouholamini Najafabadi Kambiz Gilani Mohsen Minaiyan Hamid Mahdavi Ali Nokhodchi 《Colloids and surfaces. B, Biointerfaces》2009,74(1):340-349
Biodegradable polymeric microspheres are ideal vehicles for controlled delivery applications of drugs, peptides and proteins. Amongst them, poly(lactic-co-glycolic acid) (PLGA) has generated enormous interest due to their favorable properties and also has been approved by FDA for drug delivery. Insulin-loaded PLGA microparticles were prepared by our developed single phase oil in oil (o/o) emulsion solvent evaporation technique. Insulin, a model protein, was successfully loaded into microparticles by changing experimental variables such as polymer molecular weight, polymer concentration, surfactant concentration and stirring speed in order to optimize process variables on drug encapsulation efficiency, release rates, size and size distribution. A 24 full factorial design was employed to evaluate systematically the combined effect of variables on responses. Scanning electron microscope (SEM) confirmed spherical shapes, smooth surface morphology and microsphere structure without aggregation. FTIR and DSC results showed drug–polymer interaction. The encapsulation efficiency of insulin was mainly influenced by surfactant concentration. Moreover, polymer concentration and polymer molecular weight affected burst release of drug and size characteristics of microspheres, respectively. It was concluded that using PLGA with higher molecular weight, high surfactant and polymer concentrations led to a more appropriate encapsulation efficiency of insulin with low burst effect and desirable release pattern. 相似文献
46.
H. Ghanadzadeh A. Ghanadzadeh Gilani Kh. Bahrpaima R. Sariri 《The Journal of chemical thermodynamics》2010,42(2):267-273
Experimental tie-line results and phase diagrams were obtained for the ternary systems of {water + propionic acid + organic solvent (cyclohexane, toluene, and methylcyclohexane)} at T = 303.2 K and atmospheric pressure. The organic solvents were two cycloaliphatic hydrocarbons (i.e., cyclohexane and methylcyclohexane) and an aromatic hydrocarbon (toluene). The experimental tie-lines values were also compared with those calculated by the UNIQUAC and NRTL models. The consistency of the values of the experimental tie-lines was determined through the Othmer–Tobias and Hands plots. Distribution coefficients and separation factors were evaluated over the immiscibility regions and a comparison of the extracting capabilities of the solvents was made with respect to distribution coefficients and separation factors. The Kamlet LSER model was applied to correlate distribution coefficients and separation factors in these ternary systems. The LSER model values showed a good regression to the experimental results. 相似文献
47.
Hamid Heshmati Hossein Ghanadzadeh Gilani Amir Haidary 《Journal of Dispersion Science and Technology》2014,35(4):501-509
In this study, an amidoximated chelating ion exchange resin was prepared by poly-acrylonitrile (PAN) grafted potato starch. The adsorbent characterizations such as specific surface area, pore volume, average pore radius, and Fourier transform infrared (FTIR) spectrum of the resin were measured. The effects of pH, adsorbent dosage, contact time, initial concentration of thorium ion, and temperature on adsorption of thorium ion from aqueous solutions were investigated. Four isotherm models including Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin were applied to analyze the equilibrium isotherm data. The results showed that Langmuir and Temkin models had a good agreement with experimental data. The maximum capacity of the adsorbent using the Langmuir isotherm model was 227.27 mg · g?1. The kinetic models like pseudo-first-order, pseudo-second-order, Elovich, and intraparticle were examined to describe the adsorption process. The kinetics of the adsorption process was found to follow the pseudo-second-order kinetic model. The thermodynamic parameters (ΔG°, ΔH°, ΔS°) were also calculated using equilibrium constant values at various temperatures (25, 35, 45, 55°C) and the positive value for ΔH° showed an endothermic adsorption process. The study suggests that the prepared adsorbent has promising potential for the removal of thorium from wastewaters. 相似文献
48.
The aggregation of some aldehydes in nonpolar solvents was investigated using the static dielectric method. The molecular association of acetone and two of its derivatives (acetophenone and benzophenone) in cyclohexane solvent were also investigated by this method. Analysis of the static dielectric data for solution of these materials indicated a high molecular association. It was found that benzaldehyde and its derivatives have a strong tendency for antiparallel molecular association, whereas acetone and its derivatives have a tendency for parallel alignment. The experimental results show that there is a sensitive relationship between the molecular association and molecular structure of these materials. The influence of solvent on the molecular association of the solute molecules was studied and compared. 相似文献
49.
Asl? Gök?. ?smail K?rba?lar Hasan Uslu H. Ghanadzadeh Gilani 《Fluid Phase Equilibria》2011,303(1):71-75
Liquid-liquid equilibrium (LLE) data of the solubility (binodal) curves and tie-line end compositions were examined for mixtures of {(water (1) + butyric acid (2) + diethyl succinate or diethyl glutarate or diethyl adipate (3)} at 298.2 K and 101.3 ± 0.7 kPa. The relative mutual solubility of butyric acid is higher in the diethyl succinate or diethyl glutarate or diethyl adipate layers than water layers. The consistency of the experimental tie-lines was determined through the Othmer-Tobias correlation equation. The LLE data were correlated with NRTL model, indicating the reliability of the NRTL equations for these ternary systems. The best results were achieved with the NRTL equation, using non-randomness parameter (α = 0.3) for the correlation. Distribution coefficients and separation factors were measured to evaluate the extracting capability of the solvents. 相似文献
50.
Irfan Ijaz Ezaz Gilani Ammara Nazir Aysha Bukhari 《Green Chemistry Letters and Reviews》2020,13(3):223-245
ABSTRACT Nanotechnology is an emerging field of science. The base of nanotechnology is nanoparticles. The size of nanoparticles ranges from 1 to 100?nm. The nanoparticles are classified into different classes such as inorganic nanoparticles, organic nanoparticles, ceramic nanoparticles and carbon base nanoparticles. The inorganic nanoparticles are further classified into metal nanoparticles and metal oxide nanoparticles.similarly carbon base nanoparticles classified into Fullerene, Carbon nanotubes, Graphene, Carbon nanofiber and carbon black Nanoparticles are also classified on the basis of dimension such as one dimension nanoparticles, two-dimension nanoparticles and three-dimension nanoparticles. The nanoparticles are synthesized by using two approaches like top-down approach and bottom-up approach. In this review chemical, physical and green synthesis of nanoparticles is reported. The synthesized nanoparticles are synthesized using different qualitative and quantitative techniques. The Qualitative techniques include Fourier Transform Infrared Spectroscopy (FT-IR), UV-Vis spectrophotometry, Scanning electron microscope (SEM), X.ray diffraction (XRD) and Atomic Force Microscopy (AFM). The Quantitative techniques include Transmission Electron Microscopy (TEM), Annular Dark-Field Imaging (HAADF) and Intracranial pressure (ICP). The nanoparticles have different application which is reported in this review. 相似文献