Benzene Sulphonate Research Articles

Synthesis and characterization of some novel hexa-coordinated mixed-ligand complexes of lanthanides with 4-(3,5-diphenyl-2-pyrazolin-1-yl) benzenesulphonic acid

Novel mixed-ligand 1,10-phenanthroline complexes of some lanthanides of the formula [M(phen) 2(DPBS) 2]·DPBS, where phen = 1,10-phenanthroline, DPBS = 4-(3,5-diphenyl-2-pyrazolin-1-yl)benzene sulphonate ion and M = lanthanide and yttrium have been synthesized by the interaction of M(phen) 2(ClO 4) 3 with HDPBS in methanol. These complexes have been characterized by elemental analyses, molar conductances, magnetic measurements, thermogravimetric analyses, XPS, IR and UV-vis spectral studies. An octahedral structure has been proposed for all the complexes, where phen is trans to phen in the equatorial position and two DPBS ligands are trans to each other at the axial positions.

Adsorption of Cationic and Anionic Surfactants on Charged Metal Oxide Surfaces

The adsorption of cationic (alkyl pyridinium salts) and anionic (alkyl benzene sulphonates) surfactants on the mineral oxide rutile is studied as a function of surfactant concentration, surfactant chain length, solution pH, and ionic strength in solution. Experimental results are complemented with model calculations based on the self-consistent (mean) field lattice theory for adsorption and association (SCFA). In the theory no ad hoc assumptions are made with respect to the adsorbed layer structure, but local aggregates cannot be considered. Both the experiment and theory show that the adsorption isotherms, plotted as the log of the adsorption versus the log of the equilibrium concentration, can be divided into four characteristic regions. This behavior has been found previously for anionic surfactants adsorbed on metal oxides, but for cationic surfactants on metal oxides this is a novelty. The four-region isotherm vanishes at pH values close to the point of zero charge of the oxide and when the background electrolyte concentration is on the order of 0.1 M. In region I, isolated molecules adsorb. In region II, hemi-micelles, defined as aggregates of "head-on" adsorbed surfactant molecules, are formed. In region III, the hemi-micelles transform into ad-micelles, defined as aggregates of both "head-on" and "head-out" adsorbed surfactant molecules. Region IV occurs once the CMC is reached. The transition from hemi-micelles to ad-micelles is highlighted by an (approximately) common intersection point between isotherms measured at different salt concentrations. Salt concentration and pH govern the Coulombic interactions; their effect observed in praxis is also found with the model calculations. In addition to the similarity in adsorption behavior of the cationic and the anionic surfactant on oppositely charged rutile, specific differences resulting from the different head groups are discussed.

Adsorption of lauryl benzyl sulphonate on algae

The residue from the extraction of agar-agar from Gracilaria debilis was evaluated as a biosorbent for the removal of linear alkyl benzene sulphonate from aqueous solution. The adsorption was studied in batch systems at 25°C and at different pH values. A preliminary screening showed that the average size of the sorbent did not affect the adsorption characteristics. The isotherm equilibrium data were found to fit the Freundlich equation and the Freundlich constant ‘K’, which is a measure of the capacity of the sorbent, was found to decrease as the pH increased. Initial adsorption rates showed that, as the pH was increased, the initial adsorption rate decreased.

A study of the adsorption of aromatic sulphonate anions at the gold (210) single-crystal electrode

The adsorption behaviour of benzenesulphonate (BS) and p-toluenesulphonate (PTS) anions at an Au(210) single-crystal electrode was investigated employing cyclic voltammetry and capacity measurements at constant ionic strength. It was found that the charge σ i due to specifically adsorbed anions is significantly greater (in the region of saturation) for the BS anion than for the PTS anion. It was postulated that BS anions can assume two different orientations at the electrode surface. A more detailed study of the adsorption process based on the Frumkin isotherm was performed for PTS anions. The inner-layer capacity was analysed into its components. The analysis indicated that the molecular structure of a given anion determines its behaviour during the adsorption process.

Effects of Photolytic Pretreatment on Biodegradation and Detoxification of Surfactants in Anaerobic Digestion

The effects of photolytic pretreatment on the biodegradation and detoxification of surfactants in anaerobic digestion were investigated by batch experiments with anaerobic digester sludges. Experimental results revealed that the surfactants were lowly biodegradable and highly toxic to methanogenic bacteria but a photolytic pretreatment with UV irradiation using a TiO2 catalyst was very effective at enhancing the biodegradability and reducing the toxicity of the surfactants. Both anionic sodium dodecyl sulphate (SDS) and sodium dodecyl benzene sulphonate (ABS), and nonionic p-nonylphenyl poly (oxyethylene) ether (NPE) brought about 50-60% reduction and cationic tetradecyldimethylbenzyl ammonium chloride (TBC) caused 100% reduction at a 100 mg/l concentration in the production of methane from glucose. With photolytic pretreatment of the surfactants under 4 h of UV irradiation, however, methanogenic activity was greatly enhanced in TBC and 30-50% increased in methane production in the other three surfactants as compared with unpretreated systems. The results imply that a combined system of photolytic and biological processes will be applicable to the treatment of wastewater containing toxic organics such as surfactants. It is also indicated that the photolysis of such aromatic surfactants as ABS, TBC and NPE is primarily a cleavage of the benzene ring and the degradation rate is expressed as a first order reaction.

Surfactants: non-biodegradable, significant pollutants in sewage treatment plant effluents: Separation, identification and quantification by liquid chromatography, flow-injection analysis—mass spectrometry and tandem mass spectrometry

Effluents from biological waste water treatment plants contain mainly non-biodegradable polar compounds. Methods for the detection, identification and determination of these hardly or non-eliminatable polar organic compounds are described. Flow-injection analysis (FIA) and liquid chromatographic (LC) separation on an analytical column by mass spectrometric (MS) and tandem mass spectrometric (MS-MS) detection coupled by a thermospray (TSP) interface were performed. The results showed that non-ionic surfactants and their metabolites (primary degradation products) besides linear alkyl benzene sulphonates (LABS) may dominate the range of pollutants. LC-MS confirmed that retention time shifts may occur if waste water extracts are separated on analytical columns. This cannot be recognized by UV detection. The identification of a biochemical degradation product of a non-ionic surfactant was carried out by both FIA-MS-MS and LC-MS-MS. Quantification of this compound was performed by standard addition analysis using FIA-MS or LC-MS in the selected-ion monitoring (SIM) mode. The time required for quantification is 25–30 times higher using LC-MS instead of FIA-MS.

Foam and Dynamic Surface Properties of Micellar Alkyl Benzene Sulphonates

The amount of foam formed when micellar solutions of a homologous series of anionic surfactants are subjected to a fixed agitation in the presence of antifoam often exhibits a maximum at a certain chain length. Here we consider the behavior of an homologous series of alkyl benzene sulphonates in the presence of a synergistic hydrophobic particle/hydrophobic oil antifoam. The equilibrium surface tensions of micellar solutions of homologous anionic surfactant solutions decrease with increase in chain length. However the gradients of dynamic surface tensions against reciprocal time increase with increasing chain length. This implies progressive decreases in the efficiency of transport of surfactant to air-water surfaces as the chain length increases. Measurements of micellar diffusion coefficients imply that this is not due to decreasing rates of diffusion. We tentatively ascribe it to decreasing rates of micelle breakdown as the chain length increases and the CMC decreases. The combination of decreasing equilibrium surface tension and increasing gradients of dynamic surface tension with reciprocal time means that plots of dynamic surface tension (at sufficiently high reciprocal times) against chain length will reveal a minimum. Here we correlate that minimum with the maximum in foam formed in the presence of antifoam. That maximum then arises as a consequence of a compromise between increasing surface activity and decreasing efficiency of transport of surfactant to air-water surfaces during foam generation. Foam and surface tension measurements are compared with theoretical considerations concerning the mode of action of the antifoam.

The effect of plasticization and pH on film formation of acrylic latexes

AbstractThe effect of several variables relevant to film formation in 49 : 49 : 2 poly(methyl methacrylate‐co‐butyl acrylate‐co‐methacrylic acid) latexes were studied.Plasticization of the terpolymer by both an anionic [sodium dodecyl benzene sulphonate (NaDBS)] and a nonionic [nonyl phenol ethylene oxide adduct (NP40), forty ethylene oxide units on average] surfactant were investigated. Dynamic mechanical measurements indicated that NP40 plasticized the polymer, whereas NaDBS did not. This was attributed to the compatibility of the nonionic emulsifier and the polymer. The influence of the surfactants on the film formation process was studied using minimum film temperature (MFT) measurements and scanning electron microscopy (SEM). As expected, the MFT was independent of NaDBS concentration. However, the MFT was also independent of NP40 concentration. Film formation was further investigated using SEM. The series of micrographs at varying NaDBS concentrations showed no effect on the degree of film fusion. However, surface exudates were observed. The micrographs revealed that increasing NP40 content resulted in an apparently greater degree of film coalescence. That is, there was bridging of the particles in the interstitial regions. This was attributed to localized plasticization of the polymer in these regions by NP40.The effect of water plasticization of the latex polymer was studied using dynamic mechanical measurements. The physical character of the terpolymer was varied using mol wt modifiers (CBr4 chain transfer agent and ethylene glycol dimethacrylate crosslinker). It was found that all of the polymers were plasticized by water.Finally, the film forming behavior was investigated as a function of latex pH. MFT measurements indicated an independence of pH. © 1993 John Wiley & Sons, Inc.

Comparison of Bacterial Toxicity Tests Based on Growth, Dehydrogenase Activity, and Esterase Activity of Pseudomonas fluorescens

Bacterial test systems that are used to assess the environmental risk of chemicals show considerable differences in sensitivity to toxic chemicals. This variation may be caused by differences in sensitivity between species and test parameters of the test systems. In this study, the differences in sensitivity of three test parameters, growth, esterase activity, and dehydrogenase activity, using Pseudomonas fluorescens as the test organism, were studied. The effect of eight substances was tested: pentachlorophenol, 2,4-dichlorophenol, aniline, trichloroethylene, nonylphenolethoxylate, tetrapropylene benzene sulphonate, copper, and nickel. None of the three test parameters was the most sensitive to all substances, although dehydrogenase activity showed a high sensitivity in most cases. The observed differences in sensitivity among the three test parameters were of the same order of magnitude as those previously observed for different strains of bacteria. It was concluded that the choice of test parameter is just as important as the choice of test species to the sensitivity of a test system. The differences in sensitivity between test parameters and between species may account for a great deal of the observed variation between test results obtained with different methods.

Influence of sediment on the biodegradation kinetics of linear Alkylbenzene sulphonates in the marine environment

Primary degradation of a linear‐chain sodium dodecyl benzene sulphonate was studied in the laboratory by using water and sediments taken from various points in the Bay of Cádiz and the surrounding tidal lands and marshes. The degradation, carried out in a testing system quite similar to the “river‐die‐away”;, was shown to depend on the granulometric characteristics of the sediment and on the initial surfactant concentration. In most test runs, the biodegradation kinetic equations derived from the process showed good agreement with the non‐structured model of bacterial growth proposed by Velhurst and Pearld & Read1, and subsequently modified by Volterra1.

Binding studies of sodium dodecyl benzene sulphonate with poly(N-vinyl-2-pyrrolidone)

The binding of sodium dodecyl benzene sulphonate (SDBS) with poly(N-vinyl-2-pyrrolidone) (PVP) has been investigated at 303.15 and 313.15 K using equilibrium dialysis, surface tension, viscosity, ultrasound velocity and ultrasound absorption techniques. From each of these studies four distinct regions of SDBS-PVP interactions were observed. Interaction of SDBS with PVP was found to involve the binding of surfactant dimers with the polymer molecule followed by usual micellization. The binding data has been analyzed in terms of various models of polymer-surfactant interaction.

Electrophoretic studies of calcium carbonate particles dispersed in various hydrocarbon liquids

The electrophoretic mobilities for an overbased calcium additive dispersed in a variety of non-polar hydrocarbon media have been determined using phase-analysis light scattering. It is evident that a significant charge exists at the particle/ liquid interface, probably as a result of the alkyl benzene sulphonate surfactant being incorporated into the additive. It is apparent that the magnitude of the estimated surface potential when the additive is redispersed into different organic media is initially the same for a given additive. In the case of aliphatic hydrocarbons (cyclohexane and dodecane), the surface potential remains constant with time. However, when aromatic hydrocarbon media are employed, the surface potential decreases with time at a rate that correlates with the molecular size of the hydrocarbon. The effect of the presence of water has been studied and it is found that the mobility of particles dispersed into aromatic media is strongly influenced by the amount of water present. The converse is found for aliphatic media. An additive with shorter surfactant chains is found to exhibit more negative surface potentials in all media compared to an additive with longer surfactant chains. The results are explained in terms of the equilibrium between surfactant at the solid/liquid interface and in free solution.

Influence of linear alkyl benzene sulphonate on the distribution of hexachlorocyclohexane isomers among sediment-water and biota compartments

The distribution of gamma-hexachlorocyclohexane (HCH) and its conversion to the alpha-isomer from gamma-HCH-loaded sediment in the presence and absence of linear alkyl benzene sulphonate (LAS) in an experimental system with sediment, water and Lemna minor (L) were studied. The LAS facilitated conversion of gamma-isomer to the alpha-isomer. The magnitude of conversion was in the order Lemna > water > sediment. Along with the enhanced release of HCH from sediment, LAS also enhanced silica dissolution. The ecotoxicological significance of these data are discussed.

Application of QSAR to biodegradation of linear alkylbenzene sulphonate (LAS) isomers and homologues

An approach of initially testing various structure descriptors on a trial and error basis, followed by mechanistic hypothesis and simple mathematical modelling to refine the choice of descriptor, is applied to develop a quantitative structure-activity relationship (QSAR) correlating initial biodegradation relative rate constants with carbon number and substitution position for (4-sulphophenyl)-substituted alkanes (linear alkyl benzene sulphonates, LAS). The relative rate constants are found to be linearly correlated with a composite descriptor, [(0.5 + L −1) −12 + (0.5 + S −1) −12] 1 2 where L and S are the carbon numbers of the longer and shorter chains, respectively, counting from the (4-sulphophenyl) substitution position.

Biochemical alterations in fish fingerlings (Cyprinus carpio) exposed to sublethal concentration of linear alkyl benzene sulphonate

Fish fingerlings (Cyprinus carpio) were exposed to sublethal concentrations of linear alkyl benzene sulphonate (0.005 ppm) for 24, 48, and 96 h under static laboratory conditions. Alterations were noted in the levels of glycogen, lactic acid, sialic acid, and acid and alkaline phosphatases in the gill, liver, and kidney. This chemical may impair metabolic processes in fingerling carp, because increased exposure resulted in significant increases in lactic acid and decreases in glycogen and sialic acid along with inhibition of acid and alkaline phosphatase activity.

Preparation of microlatex dispersions using oil-in-water microemulsions

The preparation of microlatex dispersions from microemulsions of a monomer (styrene, methylmethacrylate or vinyl acetate) is described. A simple method for preparing the microemulsion has been devised. This consists of forming a water-in-oil (w/o) emulsion using a low (HLB) surfactant (nonylphenol with 5, 6 or 7 moles ethylene oxide) and then titrating with an aqueous solution of a high HLB surfactant (nonylphenol with 15 or 16 moles ethylene oxide). A small amount of anionic surfactant (sodium lauryl sulphate, sodium dodecyl benzene sulphonate or dioctyl sulphosuccinate) was also incorporated to enhance the stability of the w/o emulsion and facilitate the inversion to an o/w microemulsion. The droplet-size distribution of the resulting microemulsion was determined using photon-correlation spectroscopy.

Retardation of biodegradation of linear alkyl benzene sulphonate by a sublethal concentration of mercuric chloride.

Retardation of biodegradation of linear alkyl benzene sulphonate by a sublethal concentration of mercuric chloride.

Effect of additives on corrosive wear of carbon steel

The effect of additives on the tribological behaviour of 1045 steel in NaCl and H 2SO 4 solution was Investigated. Four substances (K 2Cr 2O 7, sodium dodecyl benzene sulphonate (SDBS), (CH 2) 6N 4 and IMC-5) were used in both solutions as additives to control the corrosive wear loss of specimen. A pin-on-ring wear apparatus and a rotating scratching device with a speed regulator were designed and manufactured for the investigation of steady and transient corrosive wear process. The dependences of friction coefficient and wear loss of specimen vs. load and speed in both aggressive media with or without additives were determined and the morphology of wear tracks was observed by scanning electron microscopy. In order to explain the effect of additives on corrosive wear, the re-formation rate of the passive film and the effect of additives on polarization curves were also determined for the same testing condition. The results show that the roles of additives in corrosive wear can be divided into three types in reducing material removal: 1. (a) as the lubricating additive in a heavy duty and mild corrosive medium (SDBS); 2. (b) as the corrosive inhibitor in a low duty and severe aggressive medium (K 2Cr 2O 7 and (CH 2) 6N 4); 3. (c) as the corrosive wear inhibitor in serious situations (IMC-5).

Aquatische Toxizität / Aquatic Toxicity of LAS

The aquatic toxicity of alkyl benzene sulphonates was assessed by the mortality of naturally occurring bacteria, Daphnia and the Microtox test. Generally speaking, the tested surfactants do not increase bacterial mortality except branched alkyl benzene sulphonate. The aquatic toxcity assessed by Daphnia and the Microtox test was directly proportional to the chain length in the case of linear alkyl benzene sulphonates

Asthmagenic properties of a newly developed detergent ingredient: sodium iso-nonanoyl oxybenzene sulphonate.

The suspicion that a newly developed detergent ingredient, sodium iso-nonanoyl oxybenzene sulphonate (SINOS), was inducing asthma among a workforce led to a series of inhalation challenge tests to determine the specificity and dose response characteristics of its asthma provoking properties. Three previously exposed workers, three non-exposed non-asthmatic controls, and three non-exposed asthmatic controls were challenged with SINOS 0.01-100 micrograms and another chemically similar surface active detergent ingredient, linear alkyl benzene sulphonate (LAS) 0.01-100 micrograms. Asthmatic symptoms, late falls in FEV1, and increases in non-specific bronchial responsiveness were seen after the inhalation of SINOS in all three workers, confirming SINOS as a cause of occupational asthma. No changes were seen after the inhalation of SINOS in either group of control subjects nor after LAS in any subject. These findings suggest that SINOS causes asthma through a specific hypersensitivity mechanism unrelated to its surface active properties.