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      • KCI등재

        Emulsion liquid membrane for selective extraction of bismuth from nitrate medium

        Kobra Pourabdollah,Bahram Mokhtari 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.7

        The novelty of this work is the selective extraction of bismuth ions from nitrate medium by emulsion liquid membrane. Di(2-ethylhexyl)phosphoric acid was used as extractant of bismuth ions from nitrate medium by emulsion liquid membrane, and Triton X-100 was used as the biodegradable surfactant in n-pantanol n-pentanol bulk membrane. The extraction of bismuth ions was evaluated by the yield of extraction. The experimental parameters were evaluated and were optimized. They included the ratio of di(2-ethylhexyl)phosphoric acid concentration to the concentration of /Triton X-100 concentration (1.0 : 0.5% w/w), nature of diluents (n-pentanol), nature and concentration of the stripping solution (sulfuric acid, 0.5M), stirring speed (1,800 rpm) and equilibrium time of extraction (20min), initial feed solution of bismuth (350 ppm) and the volume ratio of the internal stripping phase to the membrane phase (14 times). The experimental parameters of kinetic extraction revealed that the bismuth ions were extracted at 100% 97%.

      • KCI등재

        Structure Optimization of Di-ionizable Calixarene Nano-baskets for Competitive Solvent Extraction of Alkali and Alkaline Earth Metals

        Kobra Pourabdollah,Bahram Mokhtari 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.11

        The competitive solvent extractions of alkali and alkaline earth metals by di-ionizable calix[4]arene nanobaskets were studied using nine conformers of calix[4]arene nano-baskets. The objective of this work is to assess the variation of macrocycle conformation, orientation and position of pendant moieties upon the extraction parameters (efficiency, selectivity and pH½) of the complexes. The results revealed that alternation of ring conformation in calixarene scaffold affects the solvent extraction parameters towards alkali and alkaline earth metals, while changing the orientation of pendant moieties from ortho- to para- as well as cis- to transanalogues depicted no changes in those extraction parameters.

      • SCOPUSKCI등재

        Structure Optimization of Di-ionizable Calixarene Nano-baskets for Competitive Solvent Extraction of Alkali and Alkaline Earth Metals

        Mokhtari, Bahram,Pourabdollah, Kobra Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.11

        The competitive solvent extractions of alkali and alkaline earth metals by di-ionizable calix[4]arene nano-baskets were studied using nine conformers of calix[4]arene nano-baskets. The objective of this work is to assess the variation of macrocycle conformation, orientation and position of pendant moieties upon the extraction parameters (efficiency, selectivity and $pH_{1/2}$) of the complexes. The results revealed that alternation of ring conformation in calixarene scaffold affects the solvent extraction parameters towards alkali and alkaline earth metals, while changing the orientation of pendant moieties from ortho- to para- as well as cis- to trans-analogues depicted no changes in those extraction parameters.

      • SCOPUSKCI등재

        Inclusion Extraction of Alkali Metals by Emulsion Liquid Membranes and Nano-baskets of p-tert-Calix[4]arene Bearing Di-[N-(X)sulfonyl Carboxamide] and Di-(1-propoxy) in ortho-cone Conformation

        Mokhtari, Bahram,Pourabdollah, Kobra Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.5

        Nano-assisted inclusion separation of alkali metals from basic solutions was reported by inclusion-facilitated emulsion liquid membrane process. The novelty of this study is application of nano-baskets of calixarene in the selective and efficient separation of alkali metals as both the carrier and the surfactant. For this aim, four derivatives of $p-tert-calix$[4]arene bearing different sulfonamide moieties were synthesized and their inclusion-extraction parameters were optimized including the calixarene scaffold $\mathbf{3}$ (4 wt %) as the carrier/demulsifier, the commercial kerosene as diluent in membrane, sulphonic acid (0.2 M) and ammonium carbonate (0.4 M) as the strip and the feed phases, the phase and the treat ratios of 0.8 and 0.3, mixing speed (300 rpm), and initial solute concentration (100 mg/L). The selectivity of membrane over more than ten interfering cations was examined and the results reveled that under the optimized operating condition, the degree of inclusion-extraction of alkali metals was as high as 98-99%.

      • SCOPUSKCI등재

        Metabolic Fingerprints by Nano-baskets of 1,2-Alternate Calixarene and Emulsion Liquid Membranes

        Mokhtari, Bahram,Pourabdollah, Kobra Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.7

        A novel approach for metabolite extraction and fingerprinting was introduced based upon the nano-baskets and emulsion liquid membrane-nuclear magnetic resonance (ELM-NMR) technique. The objective of this method is optimizing the fingerprints, minimizing the metabolic variation from analysis, increasing the likelihood differences, and obtaining the maximum extraction yield. Low molecular weight metabolites in rat serum were recovered by ELMs using 12 nano-baskets of calixarene, as both emulsifier and carrier. The yields of ELMs were optimized by the method of one-at-a-time. According to NMR data, the maximum metabolic variation was achieved using scaffold 4 (4 wt %), n-decane membrane, stirring rate of 300 rpm, treat and phase ratios of 0.3 and 0.8, respectively. The results revealed that some calixarenes tend to extract non-specific macromolecules; and repeatability of fingerprints for 7-mediated ELM was maximum and for 3-mediated ELM was minimum. The yield of extractions was obtained to be higher for n-decane and lower for carbon tetrachloride. Among different membranes, the fingerprints by chlorinated liquid membranes were more repeatable than using toluene or n-decane.

      • SCOPUSKCI등재

        Effect of Crown Ring Size and Upper Moiety on the Extraction of s-Block Metals by Ionizable Calixcrown Nano-baskets

        Mokhtari, Bahram,Pourabdollah, Kobra Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.11

        Eight ionizable nano-baskets of cone 25,26-di(carboxymethoxy)calix[4]arene-crown-3,4,5,6 were synthesized and were verified by $^1H$ and $^{13}C$ NMR spectroscopy, IR spectroscopy and elemental analysis. The competitive solvent extractions of alkali and alkaline earth metal cations were studied using such nano-baskets. The novelty of this study is including three binding units of calixarene's bowl, crown ether's ring and electron-donor ionizable moieties in a unique scaffold to assess the binding tendency towards the cations. The objective of this work is to study the extraction efficiency, selectivity and $pH_{1/2}$ of such complexes. The result of solvent extraction experiments indicated that these compounds were effective extractants of alkali and alkaline earth metal cations. Their selectivities were greatly influenced by the acidity of solution and the conformations of the calixcrown. One conformer was selective to $Na^+$ in pH ${\geq}$ 4, while the other was highly selective to $Ba^{2+}$ in pH 6 and upper.

      • KCI등재

        Metabolic Fingerprints by Nano-baskets of 1,2-Alternate Calixarene and Emulsion Liquid Membranes

        Bahram Mokhtari,Kobra Pourabdollah 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.7

        A novel approach for metabolite extraction and fingerprinting was introduced based upon the nano-baskets and emulsion liquid membrane-nuclear magnetic resonance (ELM-NMR) technique. The objective of this method is optimizing the fingerprints, minimizing the metabolic variation from analysis, increasing the likelihood differences, and obtaining the maximum extraction yield. Low molecular weight metabolites in rat serum were recovered by ELMs using 12 nano-baskets of calixarene, as both emulsifier and carrier. The yields of ELMs were optimized by the method of one-at-a-time. According to NMR data, the maximum metabolic variation was achieved using scaffold 4 (4 wt %), n-decane membrane, stirring rate of 300 rpm, treat and phase ratios of 0.3 and 0.8, respectively. The results revealed that some calixarenes tend to extract non-specific macromolecules; and repeatability of fingerprints for 7-mediated ELM was maximum and for 3-mediated ELM was minimum. The yield of extractions was obtained to be higher for n-decane and lower for carbon tetrachloride. Among different membranes, the fingerprints by chlorinated liquid membranes were more repeatable than using toluene or n-decane.

      • KCI등재

        Inclusion Extraction of Alkali Metals by Emulsion Liquid Membranes and Nano-baskets of p-tert-Calix[4]arene Bearing Di-[N-(X)sulfonyl Carboxamide] and Di-(1-propoxy) in ortho-cone Conformation

        Bahram Mokhtari,Kobra Pourabdollah 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.5

        Nano-assisted inclusion separation of alkali metals from basic solutions was reported by inclusion-facilitated emulsion liquid membrane process. The novelty of this study is application of nano-baskets of calixarene in the selective and efficient separation of alkali metals as both the carrier and the surfactant. For this aim, four derivatives of p-tert-calix[4]arene bearing different sulfonamide moieties were synthesized and their inclusionextraction parameters were optimized including the calixarene scaffold 3 (4 wt %) as the carrier/demulsifier, the commercial kerosene as diluent in membrane, sulphonic acid (0.2 M) and ammonium carbonate (0.4 M) as the strip and the feed phases, the phase and the treat ratios of 0.8 and 0.3, mixing speed (300 rpm), and initial solute concentration (100 mg/L). The selectivity of membrane over more than ten interfering cations was examined and the results reveled that under the optimized operating condition, the degree of inclusionextraction of alkali metals was as high as 98-99%.

      • KCI등재

        Extraction of alkali metals using emulsion liquid membrane by nano-baskets of calix[4]crown

        Bahram Mokhtari,Kobra Pourabdollah 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.12

        Nano-assisted inclusion separation of alkali metals from basic solutions was reported by inclusion-facilitated emulsion liquid membrane process. The novelty of this study is the application of nano-baskets of calixcrown in the selective and efficient separation of alkali metals as both the carrier and the surfactant. For this aim, four derivatives of diacid calix[4]-1,2-crowns were synthesized, and their inclusion-extraction parameters were optimized including the calixcrown scaffold (13, 4 wt%) as the carrier/demulsifier, the commercial kerosene as diluent in membrane, sulphonic acid (0.2 M) and ammonium carbonate (0.4 M) as the strip and the feed phases, the phase and the treat ratios of 0.8and 0.3, mixing speed (300 rpm), and initial solute concentration (100mg/L). The selectivity of membrane over more than ten interfering cations was examined and the results revealed that under the optimized operating condition, the degree of inclusion-extraction of alkali metals was as high as 98-99%.

      • KCI등재

        Effect of Crown Ring Size and Upper Moiety on the Extraction of s-Block Metals by Ionizable Calixcrown Nano-baskets

        Bahram Mokhtari,Kobra Pourabdollah 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.11

        Eight ionizable nano-baskets of cone 25,26-di(carboxymethoxy)calix[4]arene-crown-3,4,5,6 were synthesized and were verified by ^1H and ^13C NMR spectroscopy, IR spectroscopy and elemental analysis. The competitive solvent extractions of alkali and alkaline earth metal cations were studied using such nano-baskets. The novelty of this study is including three binding units of calixarene's bowl, crown ether's ring and electron-donor ionizable moieties in a unique scaffold to assess the binding tendency towards the cations. The objective of this work is to study the extraction efficiency, selectivity and pH½ of such complexes. The result of solvent extraction experiments indicated that these compounds were effective extractants of alkali and alkaline earth metal cations. Their selectivities were greatly influenced by the acidity of solution and the conformations of the calixcrown. One conformer was selective to Na+ in pH ≥ 4, while the other was highly selective to Ba(2+) in pH 6 and upper.

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