Nonionic Type Research Articles

Equilibrium and dynamic surface tension of quaternary ammonium salts with different hydrocarbon chain length of counterions

Series of cationic surfactants didecyldimethylammonium carboxylate were synthesized with didecylmethylammonium, dimethyl carbonate and different carboxylic acids, also the equilibrium and dynamic surface tension of them were measured. Then the influence of the hydrocarbon chain length of anionic parts (carbon number of 2, 4, 6, 8, 10, respectively) on the surface properties was discussed. The well known Ward-Tordai equation was employed to analyze the adsorption of didecyldimethylammonium carboxylate. The parameters of dynamic surface tension and effective diffusion coefficients (Deff) were calculated and analyzed. On the basis of the experiments and dates, the plot of the logarithm of cmc against the carbon chain length for didecyldimethylammonium carboxylate show a linear decrease with an increase in the chain length. It is also found that the equilibrium surface tension parameters show some regular changes with the variation of the carbon chain length of counterions for the hydrophobicity, “shielding effect” and steric hindrance. From the conductivity, the conduction properties of didecyldimethylammonium carboxylate transform from ionic type to nonionic type when the carbon number of counterions is greater than or equal to 6. Furthermore, it is confirmed that the diffusion coefficient of adsorption at the interface increase with the carbon chain length of counterions which is different from the conventional surfactants, also, an appropriate theory that the adsorption mechanism of these surfactants is controlled by not only diffusion-controlled but also activated-diffusion can be given.

Polyacrylamide-Polydivinylbenzene Decorated Membrane for Sundry Ionic Stabilized Emulsions Separation via a Facile Solvothermal Method.

Aiming to solve the worldwide challenge of stabilized oil-in-water emulsion separation, a PAM-PDVB decorated nylon membrane is fabricated via a facile solvothermal route in our group. The main composition is PAM, while the PDVB plays a role as cross-linker in order to improve the interaction between the polymer and the substrate. By the combination of the superhydrophilic and underwater superoleophobic wettability of the PAM polymer with the micropore size of the substrate, the as-prepared material is able to achieve the separation of various stabilized oil-in-water emulsions including cationic type, nonionic type, and anionic type. Compared with previous works, the emulsions used in this case are more stable and can stay for several days. Besides, the solvothermal method is facile, cost saving, and relatively environmentally friendly in this experiment. Moreover, the PAM-PDVB modified membrane exhibits excellent pH stability, recyclability, and high separation efficiency (above 99%), which can be scaled up and used in the practical industrial field.

Studies on optimization of parameters for dewatering of ground calcite-rich ore

This paper deals with filtration of very-fine size ground brecciated calcitic limestone ore slurry using flocculant chemicals. Screening of flocculants was carried out using capillary suction time (CST). Optimization of the neutral slurry filtration behaviour was carried out using a commercial non-ionic type polyacrylamide based synthetic flocculant. Response surface methodology and central composite rotatable design was used for model development and optimization of the filtration process. Critical filtration parameters such as applied vacuum, cake thickness and flocculant dosage were optimized. A correlation coefficient of 0.97 was obtained both for filtration rate and percent cake moisture. The analysis of variance of the determined model indicated that linear effects, interaction effects, quadratic effects, linear terms of all the three variables and some interaction among them are more significant for the filtration rate and cake moisture percent. The optimum filtration rate of 742 kg/(h m2) was obtained at the optimum conditions with cake moisture of 22.3%.

Preflush Design for Oil-Wet Carbonate Formations: Key To Enhance Scale-Inhibitor-Squeeze Lifetime

Summary Scale-inhibitor-squeeze lifetime is measured by the duration for which the scale-inhibiting chemical is released at a concentration greater than the required minimum inhibitor concentration (MIC). Hence, enhancing scale-inhibitor adsorption and storage may proportionately enhance squeeze lifetime. With most oilfield squeeze scale inhibitors being aqueous-based, they are unlikely to be adsorbed on an oil-wet formation in optimal quantity. Investigations are made in this research on how to create the appropriate formation condition so that adsorption and lifespan of scale inhibitor in an oil-wet carbonate reservoir are enhanced, focusing on preflush design (formation-conditioning stage). Surfactants (of anionic and nonionic type), a cosurfactant, and alkali are deployed and results are evaluated through interfacial tension (IFT), phase-behavior analysis, coreflood studies, and inductively coupled plasma-mass spectroscopy (ICP-MS) analysis. Flow experiments are conducted in simulated reservoir condition by use of data and materials from a high-temperature and high-salinity carbonate reservoir. The results reveal that nonionic surfactant is most favorable in terms of scale-inhibitor-squeeze lifetime, which is enhanced by as much as 240% compared with conventional treatment. It is concluded that through correct preflush design and formation conditioning, scale-inhibitor-squeeze lifetime can be extended significantly.

Novel alkyd-linseed oil emulsion formulations for wood coatings

In this experiment an oil-in-water emulsion, suitable as a coating for wood surface protection, was obtained. The main components of this emulsion were linseed oil and an alkyd, mixed at a ratio of 1:2. The experiments were conducted to find a valid combination of solubilizing agents, capable of giving a stable emulsion. Several surfactants, obtained from different producers, were tested. The main factors considered were the nature of the surfactant and its hydrophilic-lipophilic balance (HLB). Our results confirmed that the most suitable surfactants were ethoxylated non-ionic types with a high HLB value, while surfactants based on the gemini technology showed a poor efficiency due to scarce solubility in water, which led to the separation of phases. Once the optimal emulsion composition was obtained, hydrothermally treated and untreated aspen wood samples were coated to evaluate the degree of coating absorption for two different substrates.

Synthesis of Clay Composites of Polyacrylamide and Poly-2-Hydroxyethylacrylate and Sorbtion Ability in the Case of Cetylpyridinium Bromide

<p>By the three-dimensional polymerization of nonionic (polyhydroxyethylacrylate and polyacrylamide) <br />polymers and bentonite clay from Manyrak deposit (East Kazakhstan Region) and with using of process <br />preliminary intercalation of monomers in an aqueous suspension of bentonite (polymerization in situ) the <br />chemically crosslinked composite gels were synthesized. Optimal conditions of synthesis and physical-chemical properties of composition gels were established. It was shown, that yield of gel fraction increases <br />with increasing contents of bentonite clay. Insignificant adding of negative charged particles of bentonite clay <br />gives to polymer gels of nonionic type polyelectrolyte character, that comes out in decreasing of swelling <br />degree of gels under effect of ionic strength. By using physical and chemical methods of research: equilibrium <br />swelling, IR spectroscopy, scanning electron microscope (SEM), sorption-desorption, etc. were shown the <br />formation of compatible, homogeneous, swelling in water polyelectrolyte gels formed via hydrogen bonds <br />between the components of the gel, stabilized by hydrophobic interactions of the organic polymer chains. <br />The possibility of the regulation of swelling ability of the composite gels through varying of the outside and <br />inside factors as: consist of the composition, conditions of intercalation, pH of the environment, temperature <br />and ionic strength was established, that is stimulus sensitivity of gels. The sorbtion capacity of polymer-clay composites in attitude surface active substance cetylpyridinium bromide were estimated. Increasing of <br />temperature of environment and content of bentonite clay in composite promotes the process of sorbtion <br />of surface-active substances. Considerably high sorption capacity of polymer clay composition based on <br />more hydrophilic polymer – polyacrylamide was established. By the results of investigations one may, that <br />synthesized polymer clay composites after suitable investigations can be recommend as sorbents of cationic <br />surface active substances.</p>

Micellization and Synergistic Effect in an Aqueous Solution of an AOS-TX100 Mixture: Before and After Equilibrium in the Presence of Clay

In this research, a novel surfactant mixture consisting of anionic (alpha olefin sulfonate [AOS]) and nonionic (TX100) type was developed. Possible synergistic effect in micelle formation in different mass ratios of the mixture (1:2, 1:1, and 2:1) was studied by surface tension measurement method. Rubingh's Regular Solution theory was used to evaluate the interaction parameters (β) and activity coefficient (f) for both binary mixture and single surfactants, before and after equilibrium in the presence of clay minerals (kaolinite and illite). The differences between experimentally obtained CMC values and ideally calculated values, showed nonideality of the mixtures. In addition, the lower CMC values of mixtures in comparison with individual surfactants were an indication of synergism. The synergistic effect was maintained before and after equilibrium with clay minerals. The β values of the mixture before equilibrium were in the range –1.5 to –2.6. However, after equilibrium with kaolinite, the values were in the range of –1.9 to –3.9 while after equilibrium with illite they were in the range –1 to –3. For the mixture, before and after equilibrium, the synergism became more severe as mole fractions of AOS increased in the mixture.

Influence of surfactants on electrodeposition of a Ni-nanoparticulate SiC composite coating

Nickel coatings containing well-dispersed, submicron (150–500 nm) silicon carbide particles were electrodeposited on copper from an agitated, modified Watts nickel electrolyte at 60°C using current densities of 10–100 mA cm− 2. Coumarin additions (0–5 g dm− 3) to a bath containing 10 g dm− 3 SiC at 6 A dm− 2 resulted in lower microhardness but considerably reduced abrasive wear in the composite coatings. Over 20 other surfactants including anionic, cationic, and non-ionic types were evaluated for their influence on the surface and tribological properties of the nanocomposite coatings. The surfactant levels (typically 0–3 g dm− 3) were chosen to give good particle dispersions in the bath while avoiding any obvious deposit quality problems. Coating microhardness (via nanoindentation measurement), surface coefficient of friction (COF) and abrasive wear performance of the coatings under three-body, water-based conditions were investigated. The surfactants affected the degree of silicon carbide nanosized particles incorporated into the coating, from 5 to 54 vol.-%, and altered the surface microstructure from a matte to a bright surface finish and from porous to nodular, compact coatings. The nickel-nanosized silicon carbide composite coatings showed improved resistance to abrasive wear compared to a plain nickel (PN) deposit by a factor of 2–20.

A comparison on core drilling of silicon carbide and alumina engineering ceramics with mono-layer brazed diamond tool using surfactant as coolant

Core drilling with diamond tool is an efficient method for machining of holes in engineering ceramics. A comparative study on core drilling of silicon carbide and alumina engineering ceramics with mono-layer brazed diamond tool was carried out. Two surfactant (anionic type 1631 and nonionic type OP10) water solutions were used as coolant in core drilling. The effect of the coolant׳s type and concentration on drilling torque and drilling efficiency were also investigated. The morphologies of machined surface of ceramics and the wear of diamond grits were examined. According to the results, the anionic surfactant 1631 water solution produces a lower drilling torque and higher drilling efficiency than that of nonionic OP10. Both silicon carbide and alumina demonstrate a ductile regime of material removal under the lower maximum undeformed chip thickness (0.08mm). The wear of brazed diamond grits for drilling of silicon carbide is much severer than that of alumina.

Effect of surfactants on the removal and acute toxicity of aqueous nC60 aggregates in water treatment process.

This work aimed to evaluate the effect of surfactants on the removal of aqueous nC60 aggregates by coagulation-filtration process and assess the acute toxicity of filtrates by Microtox test. Three surfactants including cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and Triton X-100 (TX100) were selected representing cationic, anionic, and nonionic types, respectively. Results showed that the change of physicochemical properties of nC60 associating with different types of surfactants determined nC60's removal efficiency and acute toxicity. CTAB increased the number of large particles. It also changed the zeta potential of nC60 from negative to positive, leading to the low removal rates (17.3-50.2%) when CTAB concentration was designed in the range of 0.03-1 g/L, and the filtrates showed acute toxicity to bioluminescent bacteria (inhibition rate > 80%). On the contrary, TX100 obviously increased the proportion of small particles, and it is noteworthy that even less than 1 mg/L of nC60 (20% of the initial concentration) with TX100 remaining in filtrates could evoke phototoxicity due to reactive oxygen species (ROS) generation under UV irradiation. Compared to CTAB and TX100, SDS exerted an effect on the removal process and toxicity of nC60 only when concentration was beyond the critical micelle concentration (CMC; 2.5 g/L). These findings collectively suggest that characteristics of nC60 are flexible and strongly dependent on surfactant modification, as a result of which these particles could potentially find their way through water treatment route and exert a potential toxicity risk.

PH- and concentration-induced micelle-to-vesicle transitions in pyrrolidone-based Gemini surfactants

The self-assembly of novel Gemini surfactants with pyrrolidone head groups, N,N'-dialkyl-N,N'-di(ethyl-2-pyrrolidone) ethylenediamine (Di-C (n) P, where n = 6, 8, 10, 12), was studied systematically by employing UV-vis spectroscopy, fluorescence spectroscopy, NMR, dynamic light scattering (DLS), and cryo-transmission electronic microscopy (cryo-TEM) measurements. pH-induced spherical micelle-to-vesicle transitions (MVTs) were observed in all diluted Di-C (n) P aqueous solutions. Spherical micelles were formed when solution pHs were below 7.0, in which Di-C (n) Ps were 1:2 or 1:1 type cationic surfactants, whereas vesicles were formed instead at higher pHs, e.g., pH = 11.0, when Di-C (n) Ps were nonionic type. Apart from the pH-induced MVTs, concentration-induced MVTs were also observed in the protonated Di-C (n) P aqueous solutions due to counterion binding, indicating the presence of a second critical vesicle concentration (cvc) for ionic type Di-C (n) P. Furthermore, the cvc is decreased linearly with the number of carbon atoms n in the hydrophobic tail, following the well-known Stauff-Klevens rule, in the given protonation states.

O-alkylation of disodium salt of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate with 1,2-dichloroethane catalyzed by ionic type phase transfer catalyst and potassium iodide

Diethyl 3,4-ethylenedioxythiophene-2,5-dicarboxylate was efficiently synthesized via the O-alkylation of disodium salt of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate with 1,2-dichloroethane over ionic type phase transfer catalysts, such as tetrabutyl ammonium bromide and benzyltriethyl ammonium chloride. The ionic type phase transfer catalysts showed higher catalytic activities than the nonionic type phase transfer catalysts, such as triethylamine, pyridine, 18-crown-6, and polyethylene glycol 400/600, in the O-alkylation reaction. The conversion of the disodium salt of more than 97% and the selectivity of diethyl 3,4-ethylenedioxythiophene-2,5-dicarboxylate of more than 98% were achieved when the O-alkylation reaction was synergistically catalyzed by tetrabutyl ammonium bromide and potassium iodide.

Effect of Polyoxyethylene Type Nonionic Surfactant and Polar Lipophilic Oil on Solubilization of Mixed Surfactant Microemulsion Systems

In the present report, the water solubilization capacity of water-in-oil microemulsion systems comprising mixed surfactants, that is, anionic sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and nonionic(s) [viz., polyoxyethylene (2) stearyl ether (Brij-72), polyoxyethylene (10) stearyl ether (Brij-76), polyoxyethylene (20) stearyl ether (Brij-78), polyoxyethylene (2) oleyl ether (Brij-92), polyoxyethylene (10) oleyl ether (Brij-97), and polyoxyethylene (20) oleyl ether (Brij-98)] was investigated in polar lipophilic oils [viz., ethyl myristate (EM), isopropyl myristate (IPM), and isopropyl palmitate (IPP)] with varying mole fractions of nonionic surfactant (Xnonionic) at a fixed surfactant concentration and 303 K. A maximum (i.e., synergism) in water solubilization (ω0,max) was observed at an optimal value of mole fraction of nonionic surfactant (Xnonionic,max). The solubilization efficiency parameter (SP*water) and the free energy of dissolution (ΔG0s) were evaluated for these mixed systems. All of the physicochemical parameters for solubilization (viz., ω0,max, Xnonionic,max, and SP*water) were found to be dependent on both nonionic surfactants and oils. A minimum in ΔG0s was observed at corresponding Xnonionic,max, where a maximum in SP*water was evidenced. The IPP-based system was found to be most efficient, whereas the EM-based system was least efficient. An attempt was made to correlate the interdependence of physicochemical (ω0,max or SP*water) and thermodynamic (ΔG0s) parameters.

Synthesis and characterization of emulsion‐type curing agent of water‐borne epoxy resin

ABSTRACTSelf‐emulsified water‐borne epoxy curing agent of nonionic type was prepared using triethylene tetramine (TETA) and derivative of epoxy resin as a capping agent, which was synthesized by liquid epoxy resin (E51) and polyethylene glycol (PEG), and the curing agent possessed emulsification and curing properties at the same time. The curing agent with good property of emulsifying liquid epoxy resin could be obtained under the condition of the molar ratio of PEG : E51 : TETA as 0.8 : 1 : 3.5 at 80°C for 5 h. The mean particle size of the emulsion liquid was about 220 nm with the prepared curing agent and epoxy resin at the mass ratio of 1 : 3. The structure of the emulsion‐type curing agent was confirmed by FTIR and 1H NMR spectra, and the mechanism of cured film formation was also analyzed by SEM photographs. The cured film prepared by the emulsion‐type curing agent and epoxy resin under ambient cure conditions showed good properties even at high staving temperature. This study provides useful suggestions for the application of the water‐borne epoxy resins in coating industry. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2652–2659, 2013

Rheological behavor of kaoline water suspensions in presence of surfactants

Despite the great number of works devoted to the rheological behavior of kaolin water suspensions, there are no general guidelines for regulation of coagulation interaction with the addition of an effective concentration of various surfactants to the system, which can be adsorbed on the surface of a mineral. The article presents the study of interaction of kaolin with different surface activity and surfactants of anionic and nonionic types, which is of interest from both scientific and practical point of view, since it will permit to control the viscosity of compositions. It was found that the addition of an anionic surfactant to a suspension reduces the structure strength, and it occurs with a certain concentration. When the concentration is increased or decreased, the structural strength rises again, and in case of a nonionic surfactant, one can observe a monotonic decrease in the stability of structure. In future we will study the effect of stabilization of the modified kaolin suspensions to maximize the content of solid phase in dispersion while maintaining its sedimentation stability during transportation and processing.

Formation of calcite with stepped (104) face under control of poly (ethylene glycol)-b-poly (l-leucine) at the air–solution interface

Calcite rhombohedron with stepped indentation on its (104) face attached onto the air–solution interface was easily fabricated by using a non-ionic peptide type block copolymer poly (ethylene glycol)-b-poly (L-leucine) as the structure-directing agent. The balance of gravity and pulling force coming from the surface tension of the solution in combination with the limited Ca2+ and CO32− ion transport from the mineralization solution together played a significant role in modifying the crystal morphologies. Based on the calcite particle morphologies at different aging times, the mechanism for the formation of stepped calcite in the presence of polymer was proposed. This study provides an example that it is possible to access morphogenesis of calcium carbonate by a non-ionic copolymer which may shed new light on the controlled morphogenesis of other inorganic materials.

Fully automatable two‐dimensional hydrophilic interaction liquid chromatography–reversed phase liquid chromatography with online tandem mass spectrometry for shotgun proteomics

We have developed a fully automatable two-dimensional liquid chromatography platform for shotgun proteomics analyses based on the online coupling of hydrophilic interaction liquid chromatography (HILIC) - using a nonionic type of TSKgel Amide 80 at either pH 6.8 (neutral) or 2.7 (acidic) - with conventional low-pH reversed-phase chromatography. Online coupling of the neutral-pH HILIC and reversed phase chromatography systems outperformed the acidic HILIC-reversed phase chromatography combination, resulting in 18.4% (1914 versus 1617 nonredundant proteins) and 41.6% (12,989 versus 9172 unique peptides) increases in the number of identified peptides and proteins from duplicate analyses of Rat pheochromocytoma lysates. Armed with this optimized HILIC-reversed phase liquid chromatography platform, we identified 2554 nonredundant proteins from duplicate analyses of a Saccharomyces cerevisiae lysate, with the detected protein abundances spanning from approximately 41 to 10(6) copies per cell, which contained up to approximately 2092 different validated protein species with a dynamic range of concentrations of up to approximately 10(4) . This present study establishes a fully automated platform as a promising methodology to enable online coupling of different hydrophilic HILIC and reversed phase chromatography systems, thereby expanding the repertoire of multidimensional liquid chromatography for shotgun proteomics.

Dispersion of graphene in aqueous solutions with different types of surfactants and the production of graphene films by spray or drop coating

The performances of different kinds of surfactants for dispersing hydrophobic graphene in aqueous solutions were studied. These surfactants included cationic, non-ionic, anionic, and polymer types. The results of UV–vis analysis and sedimentation test suggested that optimum dispersion was achieved with 200–300 ppm of polyoxyethylene (40) nonylphenylether (Igepal ® CO890), a non-ionic type surfactant. The aqueous graphene suspensions were used to fabricate graphene films by two economical techniques—spray and drop coating. The graphene films have a significantly lower sheet resistance than the films of commercial nanographite conductive colloid. The graphene films dispersed with CO890 showed higher electrical conductivity than those with SDS, in consistence with the analysis of dispersion performance. Our technique for preparing stable and low viscosity aqueous graphene dispersions combined with a spray coating method can produce conductive graphene films with uniform distribution, large area, and controllable thickness at low cost.

Rectal absorption of insulin suppositories in rabbits.

When insulin solutions (100 U kg-1) at various pH values were placed in the rectum of rabbits, a large decrease in blood glucose concentration was observed except at the pH close to the iso-electric point of insulin. The effect of surface-active agents on the rectal absorption of insulin was examined by measuring the blood glucose concentration after the administration of 2 or 5 U kg-1. Non-ionic ether type, anionic, cationic and amphoteric surfactants as well as bile acids increased the absorption. The optimal effect with suppositories was reached with the addition of 1% polyoxyethylene (9) lauryl alcohol ether. Insulin suppositories containing agents enhancing rectal absorption were compared with the insulin for intravenous, intramuscular and subcutaneous injection. The changes of blood glucose and plasma immuno-reactive insulin concentration after rectal administration of insulin were similar to those after intravenous injection.

Physico-chemical studies of molecular interactions between non-ionic surfactants and bovine serum albumin

Surfactants, particularly non-ionic types, are often added to prevent and/or minimize protein aggregation during fermentation, purification, freeze-drying, shipping, and/or storage. In this work we have investigated the interactions between two non-ionic surfactants (Tween 20 and Tween 80) and bovine serum albumin (BSA), as model protein, using surface tension, fluorescence measurements and computational analysis. The results showed that, in both cases, the surface tension profile of the surfactants curve is modified upon addition of the protein, and the CMC values of Tween 20 and Tween 80 in the presence of protein are higher than the CMC values of the pure surfactants. The results indicate that although Tween 20 and Tween 80 do not greatly differ in their chemical structures, their interactions with BSA are of different nature, with distinct binding sites. Measurements at different protein concentrations showed that the interactions are also dependent on the protein aggregation state in solution. It was found from fluorescence studies that changes observed in both the intensity and wavelength of the tryptophan emission are probably caused by modifications of tryptophan environment due to surfactant binding, rather than by direct interaction. Based on a computational analysis of a BSA three-dimensional model, we hypothesize about the binding mechanism of non-ionic surfactant to globular protein, which allowed us to explain surface tension profiles and fluorescence results.