Presence Of Nonionic Surfactant Research Articles

Effect of ethoxylated nonyl-phenols on interfacial rheological properties of oil/water systems

Interfacial rheological properties of different Hungarian crude oil/water systems were determined in wide temperature and shear rate range and in presence of ethoxylated nonyl-phenols with ethoxy group number between 10 and 40. The fundamental conclusion of the experimental results is that the interfacial viscosity, the non-Newtonian flow behavior and the activation energy of the viscous flow drastically decrease in presence of non-ionic surfactants. Modification of these interfacial rheological properties increase with decreasing ethoxy group number and increasing tenside concentration and temperature. The most radical change was observed in presence of NPEO10. As a summary it was evidenced that the interfacial rheology is an efficient and powerful detection technique, which may enhance our knowledge on formation, structure, properties and behavior of interfacial layers formed in oil/water systems. Thus, similar studies will probably accelerate the progress significantly not only in oil recovery but also in all areas of colloid science and technology.

Nitrogen Carrier and Surfactant Increase Foliar Herbicide Injury in Winter Wheat (Triticum aestivum)

A three-year field study in west-central Kansas investigated the effects of combinations of spray carrier, nonionic surfactant (NIS), triasulfuron, and/or 2,4-D on winter wheat foliar injury and grain yield. Herbicides applied in water without NIS caused little or no foliar injury in two of three years. Urea-ammonium nitrate (UAN) at 112 L/ha (40 kg N/ha) alone or as a carrier for herbicides caused moderate to severe foliar injury in all three years. Adding NIS to UAN spray solutions increased foliar injury, especially with the tank mixture of triasulfuron + 2,4-D. Effects of triasulfuron + NIS or 2,4-D applied in UAN were additive. Foliar injury was related inversely to temperature following application. Foliar injury was most evident 4 to 7 d after application and disappeared within 2 to 3 wk. Diluting UAN 50% with water lessened foliar injury in two of three years, especially in the presence of NIS, regardless of whether herbicides were in the spray solution. Treatments did not reduce wheat grain yield in any year despite estimates of up to 53% foliar injury one year.

Forces Between Emulsion Droplets: Role of Surface Charges and Excess Surfactant

We report direct measurements of the force distance profiles between emulsion droplets in surfactant solutions of various nature. We probe the evolution of double layer repulsive forces in mixture of ionic and non ionic surfactants. In the absence of any micelles, the force intensity is shown to be significantly enhanced by the presence of non ionic surfactant. Then, by varying the ratio of ionic over non ionic surfactant well above the critical micellar concentration, we investigate the behavior of forces in the presence of micelles of various charge densities. The double layer repulsive force-distance profile is not affected by the presence of neutral non ionic micelles. However, as soon as they get partially charged, a deviation from the classical electrostatic profile is observed. In that case, we establish that the repulsive force can be described by the sum of two contributions : one is the repulsive double layer repulsive force while the other is attractive and arises from the depletion of charged micelles. Because micelles and droplets are identically charged, they repel each other and this repulsion enhances the depletion force. This effect is accounted by considering an effective larger droplet diameter. We present the empirical relation between this extra thickness and the Debye length. The simple addition of the two contributions is shown to successfully describe the force-distance profiles measured in mixed ionic-non ionic as well as in purely ionic micellar solutions.

Wechselwirkungen zwischen Oligomeren des Polyethylenterephthalats und nichtionogenen Tensiden / Interactions between the oligomers of the Polyethyleneterephthalate and non-ionic surfactants

Producers and finishers of polyester fibers and filaments know well the problems involved with the existence of oligomers of ethylene terephthalate, like deposition on fibers or filaments after wet or dry heat treatments or on thread guide elements. Only few attention, however, has been paid to the question how surfactants which are in contact with the fiber for a certain time as detergents or as components of lubricants affect the systems. This work gives results of such investigations. In presence of nonionic surfactants, the following processes take place: An adsorbed surfactant layer on the surface of the oligomer crystals is established. The water solubility and also dispersion of the crystallites increase slightly as a result of the surface activity of the surfactants. Due to thermal or hydrothermal effects the composition of the oligomeric mixture is modified which is enhanced by the presence of surfactants. The formation of chemical compounds consisting of surfactants and polymers or the destruction of the high molecular PETP in presence of surfactants, however, could not be verified.

Coadsorption of Cationic–Nonionic Surfactant Mixtures on Polytetra Fluoroethylene (PTFE) Surface

Adsorption from aqueous solutions of mixtures of surfactants of cetyl trimethyl ammonium bromide (CTAB) and nonyl phenyl ethoxylates (NP −n) (n= 13, 20, 30) on PTFE was studied in a wide concentration range. The adsorption of CTAB was enhanced by the presence of nonionic surfactants and vice versa in the pre-CMC region due to chain–chain interactions. The decrease in adsorption level of CTAB with an increase in mole fraction of nonionic surfactants in the region above the CMC has been attributed to the decrease in monomer concentration due to mixed micellization with nonionic surfactants. In the case of adsorption of nonionic surfactants from the mixtures, adsorption increases in the presence of CTAB. It was also observed that among the various binary systems, maximum adsorption was observed with CTAB and NP-13 system. This was attributed to the formation of the most compact arrangement of surfactants in the clusters formed at the solid/liquid interface. Zeta potential studies carried out on these systems compliment the adsorption results.

Kinetics of Phenanthrene Dissolution into Water in the Presence of Nonionic Surfactants

The apparent liquid saturation concentration of phenanthrene and the observed mass transfer coefficient in a completely mixed batch system were quantified as a function of surfactant concentration for four commercially available nonionic surfactants and two synthetic, nonionic glycolipids under development for possible commercial application. A mathematical model was developed to describe the dissolution process in the presence of these nonionic surfactants. The model accounts for diffusional transport of phenanthrene in the aqueous phase and transport of phenanthrene-saturated micelles across the hydrodynamic boundary layer. For the surfactants investigated and the experimental apparatus used, the observed mass transfer coefficients for phenanthrene dissolution into water were in the range of 0.01-0.025 cm/min in the presence of surfactant micelles as compared to 0.1 cm/min without surfactant. Although surfactants decrease the observed mass transfer coefficient relative to water alone, the influence of surfactants on phenanthrene solubilization results in an overall increase in phenanthrene dissolution rates.

Solvent free telomerization of butadiene with water into octadienols in the presence of nonionic surfactant: efficient micellar catalysis

Telomerization of butadiene with water into 2,7-octadien-1-ol using a palladiumhydrosoluble phosphine system was investigated. The reaction was carried out without solvent in the presence of carbon dioxide and a nonionic surfactant. Promoted effect of neutral surfactant appeared above the critical micelle concentration and the conversion and the selectivity depended on the structure of nonionic surfactant hydrophilic part. The role of the nonionic surfactant is discussed.

Increased activity of Chromobacterium viscosum lipase in aerosol OT reverse micelles in the presence of nonionic surfactants.

Modification of AOT reverse micellar systems with various alkyl glucosides and nonionic surfactants was attempted in order to improve the activity to Chromobacterium viscosum lipase. Tweens and Tritons, having the poly(oxyethylene) chain, have been shown to be solubilized at the oil-water interface of AOT micelles. Alkyl glucosides were also solubilized at the interface. These additives form mixed micelles with AOT and increase the concentration of the micelles. In contrast, Spans were found to be solubilized in the micro water pool of AOT micelles. Addition of nonionic surfactants decreased the hydrophobicity of the reverse micellar systems. Improvement of the lipase activity was achieved by the addition of nonionic surfactants, because of suppression of the hydrophobic and electrostatic interaction between AOT and lipase. The addition of nonionic surfactant having a poly(oxyethylene) chain has been shown to effectively increase the activity of the lipase in reverse micelles.

Fluorescence Reaction of 5- (p-Methoxyphenylazo)-8-(p-tolylsulfonamido)quinoline with Cobalt(II) and Its Analytical Application

Abstract 5-(p-Methoxyphenylazo)-8-(p-tolylsulfonamido) quinoline(MTAQ) has been synthesized. The product was checked by IR, theroograviae-try, NMR and elemental analysis. A highly sensitive spectrofluorim-etric method has been developed for the determination of cobalt(II) based on the formation of a complex with MTAQ in slightly basic medium aqueous solution and In the presence of nonionic surfactant, tween-80. The complex shows two excitation maxima at 304 nm and 338 nm, its emission maximum is centred at 402 nm. The fluorescence intensity is proportional to cobalt(II) concentration in the range of 0-85 ppb. The method has good selectivity and has been applied to the direct fluorimetric determination of trace cobalt(II) in pig's liver, Dianchi shrimp and celery.

Substantivity of Various Anionic Surfactants Applied to Wool

Wool samples containing various anionic surfactants (alkylbenzene sulphonates, primary and secondary alkane sulphonates, and an olefin sulphonate) lose some of the surfactant to the treatment liquor when subjected to typical dyeing conditions. At the boil, equilibrium is set up within 15 minutes between the concentration of surfactant in the liquor and that on the fiber. The extent of extraction is influenced by the alkyl chain length of the surfactant, the pH of the liquor, and the bath volume. For many surfactants, less than 5% is extracted at a 20:1 liquor/wool ratio in the pH range 5–6. The presence of nonionic surfactant in the treatment liquors results in slightly higher levels of extraction. Exhaustion of anionic surfactants onto wool gives distributions of surfactant between the wool and liquor similar to those obtained when treated wools are extracted under the same conditions of temperature, pH, and liquor/wool ratio.

Spectrophotometric determination of cationic and anionic surfactants with anionic dyes in the presence of nonionic surfactants, part II: Development of batch and flow injection methods

On the basis of the changes in absorption spectra of azo dyes on the addition of an organic onium ion, spectrophotometric methods for the determination of organic onium salts and anionic surfactants were developed, and applied to flow injection method. Propyl orange (PO−) was used for the determination of organic onium ions. Pairs of PO− and Zeph+ (tetradecyldimethyl-benzylammonium ion) or PO− and nC18TMA+ (n-octadecyltrimethylammonium ion) were used for the determination of anionic surfactants. The determination range of organic onium ions were (0–3) × 10−5 M by a batch method and were (0–2) × 10−5 M by a flow injection method. The determination ranges of anionic surfactants were (0–2) × 10−5 M by the batch method, and were (0–5) × 10−5 M by the flow injection method, and the detection limit corresponding toS/N = 3 was 3 × 10−7 M by the flow injection method. By the proposed flow injection method, anionic surfactants in water samples were determined.

Spectrophotometric determination of cationic and anionic surfactants with anionic dyes in the presence of nonionic surfactants, part I: A general aspect

The behavior of color development of anionic azo dyes, methyl orange and its analogues, was examined in aqueous media by changing the microenvironment of the dyes. The addition of alcohols, organic onium ions, anionic surfactants and nonionic surfactants brought about a decrease of the band at wavelengths near 480 nm and an increase of the band at wavelengths near 420 nm. Such a shift toward the shorter wavelengths in spectra was attributed to the change of the micro-environment around the dyes from a polar field to a less polar field; that is, the shift is caused by the change of the contribution of the following resonance forms, On the basis of the color change phenomena, the spectrophotometric methods for the determination of organic onium ions and anionic surfactants were proposed.

Fluorometric determination of carbaryl in micellar Media

A new method is proposed for the fluorometric determination of carbaryl, based on the basic hydrolysis of the pesticide to 1-naphtholate at pH 12 and enhancement of the relative quantum yield of this latter compound by the presence of non-ionic surfactants. The procedure is quick and easy and presents a limit of detection of 1.4 ng/ml. The interaction of carbaryl with non-ionic surfactants has been studied both spectrophotometrically and fluorometrically, in different media. To determine carbaryl in real samples prior extraction into xylene and back-extraction with 1 M sodium hydroxide is necessary to avoid the strong quenching effect of the matrix.

The formation of pyrene:cyclomalto-oligosaccharide complexes in the presence of non-ionic surfactants

Examination of the interactions of pyrene, cyclomalto-oligosaccharides (cyclodextrins), and selected non-ionic surfactants by measurements of fluorescence life-times indicates that ternary complexes are formed. Studies of surface tensiometry indicate that binary complexes occur between cyclodextrins and non-ionic surfactants.

Liquid detergents from cationic, anionic and nonionic surfactants. adsorption, detergency and antistatic properties

AbstractThe adsorption of a mixture of cationic (c) and anionic (a) surfactants on cellulose fibers is highly dependent on the molar ratio a/c with a maximum at a/c = 0.9. When a/c is > 1.1 the adsorption is negligible. The presence of nonionic surfactants in the solution impairs the adsorption of the ionic species; this effect is stronger for nonionic surfactants with long alkyl and polyglycol ether chains. The detergency—measured on WFK cotton cloth—is highest when a/c > 1 and decreases sharply when a/c goes below 0.8. The antistatic effect for a formulated liquid detergent based on these principles was compared to one commercial liquid detergent with softening and antistatic properties and one commercial detergent powder, and the test detergent was shown to be a better antistatic agent on polyester, polyacrylonitrile and polyamide. The detergency was about the same for the two liquid detergents.

Percutaneous absorption of 4 organic solvents in the guinea pig (II). Effect of surfactants.

Percutaneous absorption of 4 organic solvents (1,1,1-trichloroethane, 1,1,2-trichloroethane, toluene and butanol) from various colloidal preparations in a surfactant-water-organic solvent system was studied in vivo in guinea pigs. The preparations examined were binary solutions of organic solvents and surfactants, o/w emulsions and microemulsions. Phase diagram, birefringence microscopy and droplet size distribution analysis were used for characterization of the preparations. It was found that skin absorption of the solvents depends on the type of surfactant, type of preparation and also on phase equilibria in the systems studied. The presence of nonionic surfactants in the solvents and in a microemulsion with butanol caused skin absorption to decrease. A reduced uptake of solvents from o/w emulsions was observed. The absorption of butanol from a microemulsion with anionic surfactant was greater than from the pure solvent.

Fluorometric determination of uranium and tungsten with o-hydroxyhydroquinonephthalein in the presence of non-ionic surfactant

Complex formation between uranium or tungsten and o-hydroxyhydroquinonephthalein (Qnph) in various micellar surfactant media has been investigated fluorometrically, and determination of uranium and tungsten based on the difference between the relative fluorescence intensities of Qnph and the metal complex at 535 nm, with excitation at 400 nm in the presence of poly(vinyl) alcohol as a non-ionic surfactant. The calibration curves were linear up to 1.0 μ/ml uranium and 0.9, μ/ml tungsten. The relative standard deviations (5 replicates) were 2.6% for tungsten and 3.0% for uranium, and recovery tests gave relatively good results (97–104%).

Decrease in the solubility product of hydroxyapatite by the adsorption of surface-active ion.

The solubility product (Ksp) of hydroxyapatite (HAP) in ionic surfactant solutions decreased with an increase in the adsorbed amount of the surface-active ions (dodecylammonium and dodecyl sulfate ions). In the presence of nonionic surfactant (polyoxyethylene(10) octylphenyl ether), Ksp was almost constant within the limit of experimental error. It was concluded that the decrease in Ksp is due to the decrease in the chemical potential of HAP through the adsorption of the surface-active ion on HAP, and due to the spontaneous change in the constituent ions of the HAP surface (i.e., surface complex formation) by ion-exchange with the surface-active ion.

Color Reaction Between 4-(2-Pyridylazo)Resorcinol and Mercury (II) in the Presence of Surfactant, and Improved Spectrophotometric Determinations of Mercury(II) and Cyanide Ion with its Coloring

Abstract The reactions among 4-(2-pyridylazo)resorcinol (PAR), mercury(II) and/or cyanide ion in the presence of water soluble surfactants alone or combination were systematically investigated at about pH 9. The spectrophotometric determinations of mercury(II) and cyanide ion were investigated by using the PAR-mercury(II)-HPC complex (3:2:2 molar ratio) in the presence of N-hexadecylpyridinium chloride (HPC) alone; calibration graphs were rectilinear in the ranges of 0 – 40 μg mercury(II) and 0 –10 μg cyanide ion in a final 10 ml with the apparent molar absorptivities of 5.9 × 104 for mercury(II) and 2.5 × 104 1 mol−1 cm−1 for cyanide ion at 590 nm. The proposed method had advantages—rapidity, simplicity without solvent extraction, and sensitivity in comparison with reported solvent extraction methods. The interference of foreign ions decreased 1/2–l//4-fold compared with that in the presence of non-ionic surfactant alone.

Preparation and characterization of indomethacin magnetic nanoparticles.

Nanoparticles of polymethylmethacrylate were prepared by the emulsion polymerization technique. The drug was embedded in the nanoparticles. The controlled growth of ferric hydroxide particles in the presence of non-ionic surfactant was effected to obtain nano-size particles and these were subsequently heated to obtain ferroso-ferric oxide (magnetite). The effect of various parameters, i.e. monomer concentration and magnetite concentration, as well as the stirring rate were studied to characterize the particle size and its distribution. Similarly, the factors which affect the total drug payload were assessed. The magno-responsive indomethacin nanoparticles were successfully prepared.