Dinonylnaphthalene Sulfonic Acid Research Articles

Potentiometric and Laser-Acoustic Study of Aminecarboxylate Interaction of Amino Acid Molecules

This paper reports the results of studying aminecarboxylate interaction of amino acid molecules in suspensions of solvent-impregnated sulfonate ion exchangers (SISIEs) with widely variable capacities obtained by modification of the macroporous PS-DVB polymers Amberlite XAD-2 and XAD-4 with toluene solutions of dinonylnaphthalenesulfonic acid. Variation of SISIE capacities leads to modulation of their surface electrochemical properties, such as surface charge density, surface potential, and so forth, which can be easily evaluated by measuring suspension effects (ΔpH) in, for example, SISIE−HCl systems and interpretation of the results obtained within the Gouy−Chapman model of the electric double layer (EDL). The results of measuring ΔpH in SISIE−zwitterlyte systems including solutions of β-alanine and ε-aminohexanoic acid in a wide range of amino acid concentrations have shown that the behavior of SISIE suspensions in amino acid solutions differs dramatically from that of simple electrolyte (HCl) systems. Unlike SISIE−HCl systems, SISIE−zwitterlyte suspensions are characterized by the absence of the concentration compression of the diffuse part of the EDL, which can be interpreted within the framework of the aminecarboxylate interaction of amino acid molecules mechanism as the structuring of the diffuse part of EDL due to formation of amino acid chains surrounding SISIE beads. The results obtained by determination of the sound absorption coefficient in SISIE−electrolyte and SISIE−zwitterlyte systems by wide-band laser-acoustic spectroscopy are in good agreement with those obtained by a potentiometric technique.

A pyridine-based chelating solvent extraction system for selective extraction of nickel and cobalt

A novel pyridine-based chelating extractant, 2,6-bis-[5-n-nonylpyrazol-3-yl] pyridine (BNPP), has been developed and characterized. The solvent extraction of Ni and Co by a mixed system of BNPP and dinonyl naphthalene sulfonic acid (DNNSA) was studied as a function of pH, diluent, temperature, and DNNSA concentration. Stripping of Ni and Co was examined as a function of HCl and H 2SO 4 concentration. The novel system can extract Ni and/or Co selectively against Fe, Mn, Ca, Mg, and A1 from acidic sulfate solutions at a pH as low as 0.5. Separation of Ni and Co can be achieved either during loading, or during stripping stages of solvent extraction. The extractant system is stable and can be regenerated with acid. The synergistic extraction distribution diagrams and the slope analyses methods {log D vs. log[BNPP]} showed that both BNPP and DNNSA are present in the extracted Co and Ni complexes, and that two molecules of BNPP are coordinated with one metal cation.

Selective extraction of palladium from acidic nitrate solutions with thiamacrocycles-synergized dinonylnaphthalenesulfonic acid systems

Thiamacrocycles-synergized sulfonic acid extraction systems have been studied for removing traces of palladium from nitric acid solutions. The influence of the concentration of nitric acid, HDNNS, and thiamacrocycle were studied. Then different thiamacrocycles, with various cavity size and with or without substituent were evaluated. Influences on the extraction and stripping behavior is discussed.

Extraction Equilibria of Aluminum and Beryllium from Sulfate Media by Mixture of Bis(2-Ethylhexyl) Phosphoric Acid and Dinonylnaphthalene Sulfonic Acid.

The equilibria of aluminum and beryllium extraction from sulfate media are using single systems of bis(2ethylhexyl) phosphoric acid (D2EHPA) and dinonylnaphthalene sulfonic acid (DNNSA), and also the mixed system of these extractants have been studied. In the single D2EHPA system, the extraction species are found to be AIR3·HR and BeR2·2HR and separation of the two metals is satisfactory, although the extraction rate is rather slow. In the single DNNSA system, the DNNSA is found to form reverse micelles at concentrations greater than 10–5 M. Separation is poor and the extraction mechanism of the metal ions is influenced by sodium ion.The presence of D2EHPA increases the critical micelle concentration (CMC) of DNNSA. For DNNSA concentrations below the CMC, the extraction mechanism in the mixed system is identical to that for the single D2EHPA system. For DNNSA concentrations greater than the CMC in the mixed system, the distribution ratio increases and separation of the metals becomes more difficult. This type of synergistic effect appears to be caused by inclusion of D2EHPA molecules in the DNNSA micelles.

Recycling. Recovery of Nickel and Cobalt from Spent Catalyst by Means of Solvent Extraction with Synergistic Mixtures of Picolylamine in Combination with DNNSA.

The total dissolution of spent hydrodesulfurization catalyst (HDS) in sulfuric acid yields an acidic solution containing a certain amount of rare metals like molybdenum, vanadium, cobalt, nickel, and a small amount of iron as well as large excess of aluminum. In order to recover Co and Ni from the raffinate after the selective extraction of Mo and V with phosphinic acid extractants such as CYANEX 272 and PIA-8, a systematic investigation was conducted on the synergistic extraction with the mixed solvents consisting of dinonylnaphthalenesulfonic acid (DNNSA) and a series of N-alkyl-bis-picolylamine such as tri-decyl-picolylamine (TDPA), oleylpicolylamine (OLPA), and octa-decyl-picolylamine (ODPA). It was elucidated that all of these mixtures could exhibit a good synergistic effect for the extraction of Co, and Ni, while, the extraction of Al was considerably suppressed. In particular, the mixture of TDPA, or OLPA in combination with DNNSA appeared to be the most feasible and economic because it has rapid extraction rate, good phase separation, and high selectivity for Co and Ni over Al. Stripping of the loaded Ni and Co can be achieved by 0.5 and 1 M sulfuric acid and hydrochloric acid, respectively. However, smooth phase disengagement was not observed, which should be improved in future, for example by employing picolylamines with highly branched alkyl chains at tail position.

Formation of Reverse Micelles and Extraction of Aluminum and Beryllium by Mixture of Bis(2-Ethylhexyl) Phosphoric Acid and Dinonylnaphthalene Sulfonic Acid.

The formation of reverse micelles consisting of a mixture of bis(2-ethylhexyl) phosphoric acid (D2EHPA) and dinonylnaphthalene sulfonic acid (DNNSA) and its effect on the extraction of aluminum and beryllium have been studied. The total concentration of aggregates in the organic phase was measured by the vapor pressure osmometry (VPO) method. The average aggregation number for DNNSA micelle in n-hexane was found to be 16. In the D2EHPA-DNNSA mixed system, the VPO result indicates the existence of dimeric D2EHPA and mixed reverse micelles consisting of both extractants. The mean number of D2EHPA molecules included in a mixed reverse micelle was determined by the relative concentrations of D2EHPA and DNNSA. The contributions of the reverse micelles and dimeric D2EHPA molecules to the extraction of metals were also evaluated. The distribution ratio obtained by the micelles increases substantially through inclusion of D2EHPA molecules into the micelles, with this inclusion causing a synergistic extraction of the metals in the mixed system.

An Emulsion Polymerization Process for Soluble and Electrically Conductive Polyaniline

AbstractA new emulsion process has been developed for the direct synthesis of the emeraldine salt of polyaniline (PANI) that is soluble in organic solvents. The process entails forming an emulsion composed of water, a water soluble organic solvent (e.g., 2-butoxyethanol), a water insoluble organic acid (e.g., dinonylnaphthalene sulfonic acid) and aniline. Aniline is protonated by the organic acid to form a salt which partitions into the organic phase. As oxidant (ammonium peroxydisulfate) is added, PANI salt forms in the organic phase and remains soluble. As the reaction proceeds, the reaction mixture changes from an emulsion to a two phase system, the soluble PANI remaining in the organic phase. With dinonylnaphthalene sulfonic acid (DNNSA) as the organic acid, the resulting product is truly soluble in organic solvents such as xylene and toluene(not a dispersion), of high molecular weight (Mw >22,000), film forming and miscible with many polymers such as polyurethanes, epoxies and phenoxy resins. As cast, the polyaniline film is only moderately conductive, (10−5 S/cm), however treatment of the film with surfactants such as benzyltriethylammonium chloride (BTEAC) or low molecular weight alcohols and ketones such as methanol and acetone increases the conductivity 2–3 orders of magnitude.

THE SYNERGISTIC EXTRACTION OF THORIUM(IV) AND URANIUM(VI) BY 2-ETHYLHEXYL PHENYLPHOSPHONIC ACID AND MICELLES OF DINONYL NAPHTHALENE SULPHONIC ACID

ABSTRACT The extraction of thorium(IV) and uranium(VI) from nitric acid solutions into ligroine solutions of 2-ethylhexyl phenylphosphonic acid (HEHφP), micellar dinonyl naphthalene sulphonic acid (HDNNS) extractants and mixture of the two extractants is reported. A synergistic enhancement factor of 66.9 and 10.8 were observed for Th and U, respectively, when extracted from 1 M HNO3 Although HDNNS shows better separation of thorium and uranium, the mixed ligand system exhibits superior extractability for both metals ions. Slope analysis method was used to establish the extraction stoichiometry. The extraction stoichiometry varies as the concentration of the micellar HDNNS in the organic phase and the acidity of the aqueous phase changes.

THE SYNERGISTIC EXTRACTION OF BISMUTH AND ZINC BY 2-ETHYLHEXYL PHENYLPHOSPHONIC ACID AND MICELLES OF DINONYL NAPHTHALENE SULPHONIC ACID

ABSTRACT The extraction of bismuth(III) and zinc(II) from perchloric acid solutions into ligroine solutions of a mixture of 2-ethylhexyl phenylphosphonic acid (HEHφP) and micellar dinonyl naphthalene sulphonic acid (HDNNS) extractants is reported. A synergistic enhancement of extraction was observed for only Bi(III); the enhancement was by a factor of 9.5. We report an aggregation number of HDNNS for Bi(III). Slope analysis, organic phase loading and continuous variation methods were employed to ascertain the extraction stoichiometry. The extraction stoichiometry varies as the concentration of the micellar HDNNS in the organic phase and the acidity of the aqueous phase changes.

Complexation of americium(III) with a diazacrown ether

The aqueous phase complexation behaviour of trivalent americium in the presence of 1,10-diaza-4,7,13,16-tetraoxacyclooctadecane (kryptofix 22) was investigated by employing a solvent extraction tracer technique at a ligand-to-metal ratio as high as 10 5. The extraction behaviour was studied by using a liquid ion exchanger (dinonylnaphthalene sulphonic acid) both in high and low pH regions. Though no observable complexation is detected at low pH (e.g. pH 2.0), measurable complex formation was detected at higher pH values (log β L = 6.05 ± 0.30).

Squarete complexes of uranyl ions in aqueous solution

The stability constants of UO 2 2+ -squarate complexes are measured at ionic strengths of 0.05M, 0.06M, 0.075M, 0.09M, 0.1M (squaric acid-perchloric acid) using a solvent extraction method at a pH of 1.1 and a temperature of 25 °C. The extractant used is dinonylnaphthalenesulfonic acid in n-heptane. The aqueous phase was made of a mixture of squaric and perchloric acid and233U radio tracer. The stability constants of squarate complexes of UO 2 2+ is seen to decrease linearly with the square root of the ionic strength.

Regular mixtures

It is shown that Guggenheim's zeroth approximation is consistent with two kinds of solutions, one where the characteristic parameter b is independent of temperature and one dependent of temperature. The first case has tacitly been assumed to be the only one. The second one is new and is here illustrated by data on the liquid ion exchanger dinonylnaphthalene sulfonic acid.

Extraction of Eu(III) by dinonylnaphthalenesulfonic acid and synergistic effects of crown ethers and trioctylphosphine oxide

The extraction of Eu(III) by dinonylnaphthalenesulfonic acid (HDNNS) in benzene from nitrate and perchlorate solutions has been investigated. For nitrate solutions the ionic strength of the aqueous phase was kept constant at 0.1M using NaNO3−HNO3 mixtures. The Eu distribution was measured at different temperatures. The following stoichiometric formulae for the Eu species in benzene were derived: Eu(NO3) (Hn−1 (DNNS)n)2 and Eu(Hn−1 (DNNS)n)3, from the nitrate and perchlorate medium respectively (n being a small number, e.g. 1, 2 or 3). The equilibrium constants were calculated and the thermodynamic parameters of the system were determined. When adding dibenzo-24-crown-8, dicyclohexyl-18-crown-6 or trioctylphosphine oxide, no synergism, but rather antagonism was observed.

Lipophilic and immobilized anionic additives in solvent polymeric membranes of cation-selective chemical sensors

Lipophilic borate salts are frequently used as anionic additives in potentiometric and optical cation-selective sensors based on solvent polymeric membranes. The lifetime of such membranes may be limited owing to chemical decomposition and leaching of the components. Borate salts, in particular, are decomposed in the presence of acids in the membrane. Adequately substituted borate salts and sulphonic acids, such as sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, sodium tetrakis[3,5-bis(2-methoxyhexafluoro-2-propyl)phenyl]borate and dinonylnaphthalenesulphonic acid (DNSS), are shown to be sufficiently stable as membrane additives. Furthermore, lipoholic mobile or immoblizied sulphonic acids [DNNS or poly(2-acrylamido-2-methyl-1-propanesulphonic acid-co-styrene), respectively were also tested as anionic additives. Their influence on the selectivity behaviour of the sensor is attributed to their strong association with positively charged species in the membrane phase. It may be kept small by choosing ionophores that from stable complexes with the analyte.

Extraction studies of Am(III) and Eu(III) with a tris-bipyridyl macrobicyclic ligand

Complexation of Am(III) with a tris-bipyridine cryptand (L) has been carried out in a nonaqueous medium (CH3CN−CHCl3). Subsequently the complexation behaviour was investigated using the reverse extraction tracer technique with dinonyl naphthalenesulphonic acid (HD) in toluene as the organic phase and varying concentration of HCl (upto 2M) as the aqueous phase. Equilibrium is attained in the two-phase system at a rate dependent on the hydrogen ion concentration in the aqueous phase. Whereas it takes only a few minutes to attain the equilibrium state at pH 6.0, a phase contact period of 50 days was insufficient if the acidity is greater than 0.4M, presumably due to the slow dissociation of the cryptate formed. The large enhancement in the distribution ratio value in the synergistic system with 1M HCl as the aqueous phase under non-equilibrium conditions is employed for the analytical separation of Am(III) from Eu(III).

Cation exchange with reverse micelles

Experimental and modeling studies on the extraction of K + and Mg 2+ from an aqueous phase to an organic phase using a dinonylnaphthalenesulfonic acid (HD) reverse-micellar system were conducted at 25 o C. Systems containing two cations (binaries) and three cations (ternary) were investigated. Experiments for the binary systems were conducted with constant and variable total normality of cations. The system exhibited behavior similar to that of conventional ion-exchange resins.

Interfacial activity of dinonylnaphthalene sulphonic acid in the presence of modifiers possessing an hydroxyl group

The interfacial activity of dinonylnaphthalene sulphonic acid (HDNNS) and modifiers such as isodecanol or p-nonylphenol (both denoted ROH) is investigated at the n-decane/0.1 M HCl interface, at 25°C. In particular, it is shown that the addition of isodecanol or p-nonylphenol significantly decreases the interfacial activity of dinonylnaphthalene sulphonic acid. Such behaviour is quantitatively explained by the formation of non-surface-active extractant-modifier complexes; namely, (HDNNS) 3(ROH) 1 and (HDNNS) 3(ROH) 3, for isodecanol and p-nonylphenol, respectively.

THE THERMODYNAMICS OF EXTRACTION OF SOME LANTHANIDE AND OTHER IONS BY 2-ETHYLHEXYLHYDROGEN-P-PHENYLPHOSPHONATE.

ABSTRACT The thermodynamics of extraction of some lanthanide ions and bismuth, aluminium, calcium and zinc ions from perchloric acid into solutions of 2-ethylhexylhydrogen-p-phenylphosphonate have been studied. The extractions have been compared with those that employ dinonylnaphthalenesulphonic acid and factors that are responsible for the greater selectivity of the phosphonate have been elucidated. Charge density of the cation has a major influence on the mechanism of the reaction and in turn upon the thermodynamic parameters.

Effect of changing hydrodynamic conditions on the rate of processes at liquid—liquid interfaces: metal ion extraction and water solubilization by reversed micelles

Rates of water uptake by reversed micelles of a strong surface-active agent [dinonylnaphthalenesulphonic acid (HDNNS)] in n-hexane have been studied. Rates of the interfacial transfer of Ni(II) as DNNS complexes under varying hydrodynamic conditions in the phases were also investigated. The extraction took place under regimes shifting from mass transfer dominated to kinetically controlled by the interaction between reversed micelles and the adsorbed film at the interface. Comparison of experimental results with predictions by a solution to the second Fick law confirmed the previous finding that interaction between micelles and the interface is the mechanism responsible both for metal ion extraction and water dispersion as a microemulsion within the organic solvent. Molecular diffusion of metal—micelle complexes was simulated according to Higbie's penetration theory, and the renewal of fluid elements adjacent to the interface with Dankwerts' random frequencies. Using renewal frequencies estimated from water solubilization experiments, the effect of changing hydrodynamic conditions on metal ion transfer fluxes was reproduced. From the data, a micelle—interface interaction rate constant was estimated in order-of-magnitude agreement with literature values. The analysis successfully interprets the effect of varying hydrodynamic conditions on metal transfer fluxes.

Solubilization and metal complexation in a reversed micellar hydroxyoxime—sulfonic acid liquid—liquid extraction system

The solubilization of 5,8-diethyl-7-hydroxy-6-dodecanone oxime (HL, the active reagent in the commercial metal extractant LIX63) by reversed micelles of dinonylnaphthalene sulfonic acid (HDNNS) in hexane has been investigated with the vapor pressure osmometry (VPO) technique. The effect of HDNNS concentration on the solubilization of HL is compared with the corresponding effect on the distribution of nickel between an HDNNS-HL-hexane organic phase and an aqueous phase containing 1.0 mol dm −3 KNO 3 at pH 1.0. For a given total concentration of hydroxyoxime, s, the number of HL molecules solubilized per HDNNS reversed micelle (i.e., (HDNNS) 7) decreases with increase in total HDNNS concentration. The HDNNS concentration that gives s = 3 coincides approximately with the corresponding concentration that gives a maximum in nickel distribution. It is concluded that the formation of a tris metal-hydroxyoxime complex depends on the availability of HDNNS reversed micelles that contain at least three molecules of solubilized HL per reversed micelle.