aliquat 336
Recently Published Documents

Triglycerides of waste cooking oil reacted with methanol in refluxing toluene to yield mixtures of diglycerides, monoglycerides and fatty acid methyl esters (FAMEs) in the presence of 20% (w/w) catalyst/oil using the hydrophilic sulfonated silica (SiO2-SO3H) catalyst alone or with the addition of 10% (w/w) co-catalyst/oil [(Bun4N)](BF4) or Aliquat 336]. The addition of the ammonium salts to the catalyst lead to a decrease in the amounts of diglycerides in the products, but the concentrations of monoglycerides increased. Mixtures of [(Bun4N)](BF4)/catalyst were superior to catalyst alone or Aliquat 336/catalyst for promoting the production of mixtures with high concentrations of FAMEs. The same experiments were repeated using DMSO as the solvent. The use of the more polar solvent resulted in excellent conversion of the triglycerides to FAME esters with all three-catalyst media. A simplified mechanism is presented to account for the experimental results.

Abstract Liquid-liquid extraction is one of the most used separation methods in chemical technology for recovery and separation of metal ions, other inorganic and organic substances. It is known that for extraction of Zn(II) the most frequently used extractants are D2EHPA, Aliquat 336, etc., diluted in an organic solvent. The use of these reagents does not meet the principles of “green” chemistry. Thus, in the present work, the extraction system based on polypropylene glycol 425 and sodium chloride for the extraction of Zn(II) ions from aqueous solutions is proposed. Equilibrium values of the distribution coefficient in the proposed aqueous two-phase system have been determined. Dependence of metal distribution coefficient on time of phase contact is obtained, time to reach equilibrium was 10 minutes. The isotherm of Zn(II) extraction obtained in the proposed system is a straight line, which indicates the independence of the distribution coefficient from the initial concentration of metal in the solution. The received experimental data can be used at the creation of “green” schemes of processing of Ni-MH batteries.

Abstract To date, there are a number of methods for selective extraction of transition metal ions based on liquid-liquid extraction. One of the most interesting methods of metal ions extraction is liquid-liquid extraction with application of ionic liquids based on quaternary ammonium bases and organic acid residues, in particular, organophosphorus, diluted with organic solvent (toluene, xylene, kerosene, etc.). However, using of organic solvents does not correspond to the modern tendencies of harmful effects on the environment reducing. Thus, we propose to use Aliquat 336 and D2EHPA-based ionic liquid for extraction of transition metal ions in ecologically safe aqueous two-phase system based on polypropylene glycol 425 and sodium chloride. Di(2-ethylhexyl) phosphate trioctylmethylammonium has been shown to yield more than 80% Fe(III) and Y(III) ions.

The application of polymer inclusion membranes (PIMs) for the aquatic remediation of several heavy metals, dyes, and nutrients has been extensively studied. However, its application in treating organic compounds such as Ibuprofen, an emerging pharmaceutical contaminant that poses potential environmental problems, has not been explored satisfactorily. Therefore, graphene oxide (GO) doped PIMs were fabricated, characterized, and applied to extract aqueous Ibuprofen at varied pH conditions. The doped PIMs were synthesized using a low concentration of Aliquat 336 as carrier and 0, 0.15, 0.45, and 0.75% GO as nanoparticles in polyvinyl chloride (PVC) base polymer without adding any plasticizer. The synthesized PIM was characterized by SEM, FTIR, physical, and chemical stability. The GO doped PIM was well plasticized and had an optimal Ibuprofen extraction efficiency of about 84% at pH of 10 and 0.75% GO concentration. Furthermore, the GO doped PIM’s chemical stability indicates better stability in acidic solution than in the alkaline solution. This study demonstrates that the graphene oxide-doped PIM significantly enhanced the extraction of Ibuprofen at a low concentration. However, further research is required to improve its stability and efficiency for the remediation of the ubiquitous Ibuprofen in the aquatic environment.

Abstract The present work reports studies on the effective removal of Rhodamine-B (RhB) using Aliquat-336 modified Amberlite XAD-4 resin in the fixed-bed columns in series. The effect of flow rate (Q = 2 to 6 mL·min−1), bed height (h = 3.5 to 7 cm) and initial RhB dye concentration (Cin = 10 to 20 mg·L−1) was studied. When a single column was used, 93% RhB dye was removed in 3 h at Q = 2 mL·min−1, Cin = 10 mg·L−1, and h = 7 cm. When three columns in series were used, almost 100% dye was removed until 80 h. The maximum breakthrough time (142 h) and saturation time (244 h) were found by keeping Q = 2 mL·min−1, h = 7 cm of each column and Cin = 10 mg·L−1. Mathematical modeling of the breakthrough curves was done by using Yoon-Nelson, Clark, Wolborska, and pore diffusion models. The Clark model best fitted the experimental data. The possible interaction mechanism between Aliquat-336 and RhB dye was proposed. The column was regenerated in continuous mode using 1 M HCl solution and maintaining a flow rate of 2 mL·min−1.

Novel hybrid polymer inclusion membranes (PIMs) based on poly(vinylidene fluoride) (PVDF) (polymer matrix) and Aliquat 336 (ion carrier) and containing native sodium (Cloisite Na+ (CNa)) and organo-modified (Cloisite 30B (C30B)) Montmorillonites were elaborated and tested for the removal of toxic Cr(VI) ions from the aqueous solution. The influence of the nanoclay incorporation on the physicochemical properties of PVDF-based PIMs was studied and the resulting membrane transport properties of the Cr(VI) ions were investigated in detail. The water contact angle measurements reveal that the incorporation of the CNa nanofiller affects the membrane wettability as less hydrophilic surface is obtained in this case—~47° in the presence of CNa as compared with ~15° for PIMs with C30B. The membrane rigidity is found to be dependent on the type and size of the used Montmorillonite. The increase of Young’s modulus is higher when CNa is incorporated in comparison with C30B. The stiffness of the PIM is strongly increased with CNa amount (four times higher with 30 wt %) which is not the case for C30B (only 1.5 times). Higher Cr(VI) permeation flux is obtained for PIMs containing CNa (~2.7 µmol/(m2·s)) owing to their porous structure as compared with membranes loaded with C30B and those without filler (~2 µmol/(m2·s) in both cases). The PIM with 20 wt % of native sodium Montmorillonite revealed satisfactory stability during five cycles of the Cr(VI) transport due to the high membrane rigidity and hydrophobicity. Much lower macromolecular chain mobility in this case allows limiting the carrier loss, thus increasing the membrane stability. On the contrary, a deterioration of the transport performance is recorded for the membrane filled with C30B and that without filler. The obtained results showed the possibility to extend the PIM lifetime through the incorporation of nanoparticles that diminish the carrier loss (Aliquat 336) from the membrane into the aqueous phase by limiting its mobility within the membrane by tortuosity effect and membrane stiffening without losing its permselective properties.