Preparation of stable magnetic nanofluids containing Fe3O4@PPy nanoparticles by a novel one-pot route

Stable magnetic nanofluids containing Fe3O4@Polypyrrole (PPy) nanoparticles (NPs) were prepared by using a facile and novel method, in which one-pot route was used. FeCl3·6H2O was applied as the iron source, and the oxidizing agent to produce PPy. Trisodium citrate (Na3cit) was used as the reducing reagent to form Fe3O4 NPs. The as-prepared nanofluid can keep long-term stability. The Fe3O4@PPy NPs can still keep dispersing well after the nanofluid has been standing for 1 month and no sedimentation is found. The polymerization reaction of the pyrrole monomers took place with Fe3+ ions as the initiator, in which these Fe3+ ions remained in the solution adsorbed on the surface of the Fe3O4 NPs. Thus, the core-shell NPs of Fe3O4@PPy were obtained. The particle size of the as-prepared Fe3O4@PPy can be easily controlled from 7 to 30 nm by the polymerization reaction of the pyrrole monomers. The steric stabilization and weight of the NPs affect the stability of the nanofluids. The as-prepared Fe3O4@PPy NPs exhibit superparamagnetic behavior

Measurement of mono ethylene glycol volume fraction at varying ionic strengths and temperatures

The estimation of Mono Ethylene Glycol (MEG) concentration is an essential criterion during the industrial regeneration of MEG to evaluate the efficiency of regeneration process and to control the concentration of MEG reinjected at the wellhead. Although many laboratory methods to determine MEG concentration exist, their application may be costly in terms of the time required to perform sampling and laboratory analysis. For this reason, an alternative method for determination of MEG concentrations has been proposed. This method can be performed on-site utilizing physical properties that can be readily measured using portable measurement devices including refractive index (n D ), electrical conductivity (EC) and total dissolved solids (TDS). The volume fraction (F vm ), n D , EC, and TDS of MEG solutions have been measured at (283.15, 298.15, and 323.15) K, (10–100) vol. %, and at (0, 0.125, 0.25, 0.5, 1.0) M NaCl total volume of solution) ionic strength (IS). The experimental results were then correlated to develop a simplistic model capable of estimating the volume fraction of MEG mixtures at varying ionic strengths. The proposed models will therefore allow a quick and convenient method for the determination of MEG concentrations in the field to quickly identify undesirable changes in produced lean MEG concentration

Removal of lead from aqueous solution using superparamagnetic palygorskite nanocomposite: Material characterization and regeneration studies

A palygorskite-iron oxide nanocomposite (Pal-IO) was synthesized in situ by embedding magnetite into the palygorskite structure through co-precipitation method. The physico-chemical characteristics of Pal-IO and their pristine components were examined through various spectroscopic and micro-analytical techniques. Batch adsorption experiments were conducted to evaluate the performance of Pal-IO in removing Pb(II) from aqueous solution. The surface morphology, magnetic recyclability and adsorption efficiency of regenerated Pal-IO using desorbing agents HCl (Pal-IO-HCl) and ethylenediaminetetraacetic acid disodium salt (EDTA-Na2) (Pal-IO-EDTA) were compared. The nanocomposite showed a superparamagnetic property (magnetic susceptibility: 20.2 emu g−1) with higher specific surface area (99.8 m2 g−1) than the pristine palygorskite (49.4 m2 g−1) and iron oxide (72.6 m2 g−1). Pal-IO showed a maximum Pb(II) adsorption capacity of 26.6 mg g−1 (experimental condition: 5 g L−1 adsorbent loading, 150 agitations min−1, initial Pb(II) concentration from 20 to 500 mg L−1, at 25 °C) with easy separation of the spent adsorbent. The adsorption data best fitted to the Langmuir isotherm model (R2 = 0.9995) and pseudo-second order kinetic model (R2 = 0.9945). Pb(II) desorption using EDTA as the complexing agent produced no disaggregation of Pal-IO crystal bundles, and was able to preserve the composite's magnetic recyclability. Pal-IO-EDTA exhibited almost 64% removal capacity after three cycles of regeneration and preserved the nanocomposite's structural integrity and magnetic properties (15.6 emu g−1). The nanocomposite holds advantages as a sustainable material (easily separable and recyclable) for potential application in purifying heavy metal contaminated wastewaters

Magnetic carrier for radionuclide removal from aqueous wastes: Parameters investigated in the development of nanoscale magnetite based carbamoyl methyl phosphine oxide

A study on superparamagnetic magnetite polymer composite development was undertaken for application to magnetically assisted chemical separation. Tetramethyl ammonium hydroxide as an alternative to ammonia was used as a precipitation agent to obtain nanoscale magnetite particles. Investigation on stoichiometry control of Fe(III) and Fe(II) ions suggested a correlation between alkalinity and initial Fe(III): Fe(II) ratio for precipitation of magnetite. Studies on polymerization conditions suggested that polymers setting at ambient conditions enable retention of superparamagnetic property of substrate magnetite. Vaporization method for impregnation of solvent extractant CMPO, yielded product that had a high sorption capability for radionuclide europium as compared to wet impregnation method

Application of magnetite hexacyanoferrate composites in magnetically assisted chemical separation of cesium

Potassium nickel hexacyanoferrate composite with magnetite finds application in the recovery of cesium from low-level liquid waste using magnetic assistance. The apparent sorption capability of hexacyanoferrate-magnetite composite and potassium nickel(II) hexacyanoferrate(II) matched indicating no loss in sorption capability as a consequence of coating to nanoscale magnetite substrate. Selectivity for cesium in a broad pH range, selectivity in the presence of high concentration of sodium nitrate, and fast exchange kinetics are additional features of the nanocomposites

Nano-aggregates of hexacyanoferrate (II)-loaded magnetite for removal of cesium from radioactive wastes

Nano-sized magnetic sorbents can be promising candidate materials for treatment of low-level effluents resulting in effective decontamination and very high volume reduction of radioactive wastes. Preparation of magnetite-hexacyanoferrate composite was based upon wet-dispersion and in situ precipitation for synthesizing coatings on magnetite. Superior magnetic properties were rendered to potassium nickel (II) hexacyanoferrate (II), a sorbent with high specificity for cesium uptake, by loading to magnetite. The magnetic complex showed same apparent sorption capability for cesium as potassium nickel (II) hexacyanoferrate (II). Transmission electron microscope revealed a particle size distribution of 8-30 nm for these magnetic particles. Large moment possessed by particles was responsible for high uptake of magnetic separator column at low background magnetic field. Low residual magnetism favored magnetic filter regeneration parameter requirement. (C) 200