Synthesis and Physico-Chemical Properties of Sodium 3-Oxo-2-(3-(4-sulphonatophenyl)triaz-2-enyl)octadecanoate Anionic Surfactant

The novel anionic surfactant sodium 3‐oxo‐2‐(3‐(4‐sulphonatophenyl)triaz‐2‐enyl)octadecanoate (SSTO) was prepared from renewable raw materials; glycine and palmitic acid. Surface and bulk properties of SSTO were investigated by surface tension and electrical conductivity techniques at 298, 308, 318 and 328 K. Surface properties including critical micelle concentration (CMC), maximum surface excess concentration (Γ_max), minimum area per molecule (A_min), surface tension at CMC (γ_CMC), effectiveness of surface tension reduction (Π_CMC), efficiency of surface adsorption (pC₂₀), and degree of counterion dissociation (α) were determined. The thermodynamic parameters of micellization (ΔG°_mic, ΔH°_mic and ΔS°_mic) and adsorption (ΔG°_ad, ΔH°_ad and ΔS°_ad) were also investigated at 298, 308, 318 and 328 K. The effect of 3 wt% n‐propanol, n‐butanol and n‐pentanol on surface tension and conductivity at 298 K was also determined.     

Synthesis and study of the surface properties of long-chain alkylnaphthalene sulfonates

Long-chain alkylnaphthalene sulfonates were synthesized by means of a Wurtz-Fittig reaction, and the basic properties were studied in water at 30°C. Through surface tension measurements, the following values were determined: the critical micelle concentration (CMC) and the surface tension at the CMC (γ_CMC). The following values were calculated: area per molecule at the CMC (A_CMC), standard free energy change of micellization (ΔG _mic ^o ), standard free energy of adsorption (ΔG _ad ^o ), and the “efficiency” of a surfactant in reducing surface tension (pC₂₀). The micelle aggregation numbers were measured through steady-state fluorescence-quenching methods. As the chain length of the hydrocarbon of n-alkylnaphthalene sulfonate increased, the Krafft temperature increased, the surface tension decreased, the value of CMC decreased, pC₂₀ increased, ΔG _ad ^o and ΔG _mic ^o became more negative, and the micelle aggregation number increased. The results showed that sodium α-(n-decyl)naphthalene sulfonate (DNS) had a high pC₂₀, low Krafft temperature, and lower CMC than other surfactants in this study. Thus, DNS and the other n-alkylnaphthalene surfactants studied exhibit desirable properties that may be of value in some fields such as detergency, oil recovery, and dyes.     

Synthesis and Surface Active Properties of 1,1,1,1-Tetra-(2-oxypropyl Sulfonate-3-alkylether-propoxy)neopentanes

Tetrameric sulfonate surfactants 1,1,1,1-tetra-(2-oxypropyl sulfonate-3-alkylether-propoxy)neopentanes were prepared with raw materials containing epichlorohydrin, pentaerythritol, long-chain alcohols, 1,3-propane sultone and sodium hydroxide by esterification, a ring opening reaction, and a sulfonation reaction. The chemical structures of the prepared compounds were confirmed by FTIR, ¹H-NMR and element analysis. With the increasing length of the carbon chain, the values of their CMC initially decreased. The longer the alkyl chain, the higher the melting point. The Krafft point of all these tetrameric sulfonate surfactants was below 0 °C and they had excellent water solubility. These compounds were superior in surface active properties to general sulfonate surfactants SDS. The efficiency of adsorption at the water/air interface (pC₂₀) of these surfactants was very high. Their foaming properties, their wetting ability of a felt chip, and their lime-soap dispersing ability was investigated.     

Semicontinuous emulsion copolymerization of 3‐O‐methacryloyl‐1,2:5,6‐di‐O‐isopropylidene‐α‐D‐glucofuranose (3‐MDG) and butyl acrylate (BA). Monomer feed addition

New polymer colloids based on the saccharide monomer, using of 3‐O‐methacryloyl‐1,2:5,6‐di‐O‐isopropylidene‐α‐D ‐glucofuranose (3‐MDG), were prepared by semicontinuous emulsion polymerization, a widely used industrial process. The copolymerization of 3‐MDG and butyl acrylate (BA), by the monomer‐addition technique, at 70°C, using sodium persulfate (Na₂S₂O₈) as an initiator, was investigated. The influence of some reaction parameters, such as the type and concentration of the surfactants as well as the monomer addition rate (R_m) on the polymerization rate (R_p), the colloidal properties, and the stability of the latexes, was studied. It was found that under starved‐feed conditions the polymerization rate and the particle size (D) increased with an increasing rate of monomer addition. The weight‐average molecular weight (M _w) also increased by enhancing R_m and a narrower molecular weight distribution was obtained. Furthermore, the type and the concentration of the surfactants strongly influenced the particle size and its distribution. The effect of the seed stage on the particle size and its distribution was also investigated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2091–2102, 2003     

Micellization of Carboxylic Acid Gemini Surfactant and Its Interaction with Amino Acid Surfactant in Aqueous Solution

The carboxylic acid-type Gemini surfactant (CGS12) was synthesized, and its micellization in aqueous solution at different pH values at 25.0 °C was investigated. The results show that the critical micelle concentration (CMC) of CGS12 at different pH values is only 10⁻⁶ order of magnitude, and the pH has little effect on the CMC. Moreover, the interaction of CGS12 with amino acid surfactant of sodium N-lauroyl sarcosinate (SLS) at 25.0 °C and pH 7.0 was investigated using surface tension, dynamic light scattering (DLS), cryogenic transmission electron microscopy (Cryo-TEM), and Ross–Miles foam measurements. The CGS12/SLS mixture shows a low CMC, and as a whole the CMC value becomes smaller with increasing molar fraction of CGS12 (X_CGS12). Under different X_CGS12, the mixtures form soluble aggregates with different hydration radii (R_h). Moreover, the mixture aggregates are mainly in the form of vesicles. The foaming height of CGS12 is worse than that of SLS, but the CGS12/SLS mixture has good foaming stability. This work reveals that the surfactant mixture has good surface activity and good foam stability.     

Corrosion inhibition by N‐(alkyloxycarbonylmethyl)‐N‐triethanol ammonium chloride with respect to the surface and thermodynamic properties

N‐[(octyloxycarbonylmethyl)‐ N‐triethanol ammonium chloride] (C₈ ), N ‐[(dodecyl‐oxycarbonylmethyl)‐ N‐triethanol ammonium chloride] (C₁₂ ) and N ‐[(hexadecyloxycarbonylmethyl)‐N ‐triethanol ammonium chloride] (C₁₆ ) were synthesized. Surface tension was measured in aqueous solution for different concentrations at 28, 38 and 48°C. Various surface properties of the synthesized surfactants were evaluated, particularly critical micelle concentration (CMC), efficiency (Π_CMC) as well as maximum surface excess (Γ_max) and minimum surface area (A_min). Micellization and adsorption in both liquid/air and liquid/solid interfaces thermodynamics were investigated. These products have pronounced surface activity and satisfactory corrosion inhibition of C‐steel in hydrochloric acid at 28, 38 and 48°C. © 1999 Society of Chemical Industry     

Synthesis and Properties of 1,1-bis{[3-(<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-Dimethylamino)propyl]amido}alkane-di-<Emphasis Type="Italic">N</Emphasis>-oxides

A homologous series of new surface-active 1,1-bis{[3-(N,N-dimethylamino)propyl]amido}alkane-di-N-oxides were synthesized in the reaction of an appropriate diethyl 2-alkylmalonate with N,N-dimethylamino-1,3-propanediamine followed by oxidation with aqueous hydrogen peroxide. The adsorption isotherms of their aqueous solutions were measured and evaluated to obtain adsorption parameters: critical micelle concentration (CMC), surface excess concentration (Γ_CMC), equilibrium surface tension at the CMC (γ_CMC), cross-sectional area of the adsorbed surfactant molecule (A _CMC), efficiency of surface adsorption (pC₂₀), standard free energies of adsorption (ΔG°_ads), and micellization (ΔG°_CMC). All investigated di-amidoamines and di-N-oxides were practically non-toxic to selected bacteria and yeasts. These compounds are readily biodegradable in the Closed Bottle Test inoculated with activated sludge. Surface and biological properties showed that this group of N-oxide-type compounds has high surface activity and fulfills requirements for environmental acceptance.

Synthesis,characterization, and surface properties of phenylalanine-glycerol ether surfactants

A novel homologous series of 1-N-l-phenylalanine-glycerol ether surfactants was synthesized in satisfactory yields via reaction of epichlorohydrin with aliphatic alcohols with alkyl chains of 10–15 carbon atoms. Structural assignment of the new compounds was made on the basis of elemental analysis and spectroscopic data. Critical micelle concentration (CMC), surface tension at the CMC (γ_CMC), surfactant concentration required to reduce the surface tension of the solvent by 20 mN/m (pC₂₀), and the interfacial area occupied by the surfactant molecules (A_min) were determined from aqueous surface tension measurements using the Wilhelmy plate technique.     

Synthesis and Surface Active Properties of tri[(N‐alkyl‐N‐ethyl‐N‐Sodium carboxymethyl)‐2‐Ammonium bromide ethylene] Amines

Trimeric betaine surfactants tri[(N‐alkyl‐N‐ethyl‐N‐sodium carboxymethyl)‐2‐ammonium bromide ethylene] amines were prepared with raw materials containing tris(2‐aminoethyl) amine, alkyloyl chloride, lithium aluminium hydride, sodium chloroacetate, and bromoethane by alkylation, Hoffman degradation reaction, carboxymethylation and quaternary amination reaction. The chemical structures of the prepared compounds were confirmed by FTIR, ¹H NMR, MS and elemental analysis. With the increasing length of the carbon chain, the values of their critical micelle concentration initially decreased. Surface active properties of these compounds were superior to general carboxylate surfactants C₁₀H₂₁CHN⁺(CH₃)₂COONa. The minimum cross‐sectional area per surfactant molecule (A_min), standard Gibbs free energy adsorption (ΔG_ads) and standard Gibbs free energy micellization (ΔG_mic) are notably influenced by the chain length n, and the trimeric betaine surfactants have greater ability to adsorb at the air/water interface than form micelles in solution. The efficiency of adsorption at the water/air interface (pC₂₀) of these surfactants increased with the increasing length of the alkyl chain. Their foaming properties, wetting ability of a felt chip, and lime‐soap dispersing ability were also investigated.     

Surface properties of N-alkanoyl-N-methyl glucamines and related materials

The surface properties [effectiveness of surface tension reduction (γ_CMC) critical micelle concentration (CMC), efficiency of surface tension reduction (pC ₂₀), maximal surface excess concentration (Γ_max), minimal area/molecule at the interface (A _min), and the (CMC/C ₂₀) ratio] of some well-purified N-alkanoyl-N-methyl glucamines and related polyol-based N-methyl amide-type surfactants, having the structural formula RC(O)N(Me)CH₂(CHOH)_xCH₂OH, where RC(O)=undecanoyl, lauroyl, tridecanoyl, myristoyl, and x=1,3, and 4, were investigated at 25°C in distilled water and 0.1 M NaCl. Water solubility of these compounds does not simply depend on the number of hydroxyl groups in the molecule but is associated with the balance between intermolecular hydrogen bonds and hydrogen bonds formed with water molecules. The fundamental interfacial properties, such as CMC and γ_CMC and two thermodynamic parameters, standard free energy of adsorption and standard free energy of micellization, were found to be significantly dependent on the hydrophobic acyl chain rather than on the number of CHOH groups in the hydrophilic moieties. By contrast, the practical performance properties were greatly dependent on the nature of the hydrophilic group. As a whole, these surfactants had desirable foaming properties and efficient wetting abilities. Furthermore, synergism in foaming and wetting abilities was observed in a binary mixture of these surfactants with an alkyloxyethylene sulfate.     

Surface properties of linear alkyl benzene sulfonates in hard river water

Surface properties of a series of highly purified linear alkyl benzene sulfonates were extensively studied in hard river water. The effects of water hardness, alkyl chain length and position of the phenyl sulfonate group in the molecule on such surface properties as pC₂₀, critical micelle concentration (CMC), γ_CMC, CMC/C₂₀ ratio, and minimum area per molecule at the interface are discussed in detail. The position of phenyl sulfonate group in the molecule was found to have a pronounced effect on the CMC, γ_CMC value, CMC/C₂₀ ratio, and, to the contrary, a relatively small effect on the pC₂₀ value. The linear relationship between pC₂₀ or-log CMC, and m, the number of carbon atoms in the alkyl chain, was found for surfactants with the phenyl sulfonate group either at the terminal position or at the more central position in the molecule. γ_CMC decreases but the CMC value increases, when the position of phenyl sulfonate group moves from the terminal toward a more central position of the molecule, reflecting the “Hartley Effect” resulting from the branched alkyl chain.     

Synthesis, Surface and Thermodynamic Properties of Substituted Polytriethanolamine Nonionic Surfactants

Three series of nonionic surfactants derived from polytriethanolamine containing 8, 10, and 12 units of triethanolamine were synthesized. Structural assignment of the different compounds was made on the basis of FTIR and ¹H‐NMR spectroscopic data. The surface parameters of these surfactants included critical micelle concentration (CMC), surface tension at the CMC (γ_CMC), surfactant concentration required to reduce the surface tension of the solvent by 20 mN m^?1 (pC₂₀), maximum surface excess (Γ_max), and the interfacial area occupied by the surfactant molecules (A_min) using surface tension measurements. The micellization and adsorption free energies were calculated at 25 °C.     

Effects of the Polypropylene Oxide Number on the Surface Properties of a Type of Extended Surfactant

The surface properties of 5 extended surfactant C_12–14P _mE₂S solutions in pure water and 0.1 M NaCl were investigated through surface tension and electrical conductivity measurements. The surface properties measured include the critical micelle concentration (CMC), critical surface tension (γ_cmc), maximum surface excess concentration (Γ_max), minimum area occupied per surfactant molecule (A_min), and efficiency in surface tension reduction (pC₂₀). The CMC values of the 5 surfactants decreased with increasing polypropylene oxide number (PON) and were higher than those obtained in 0.1 M NaCl. The Γ_max values showed a downward trend whereas the A_min values exhibited an upward trend with increasing PON without NaCl. The Γ_max values were higher and the A_min values were lower than those obtained without 0.1 M NaCl. The CMC values increased at elevated temperatures. The CMC values of C_12–14P₃E₂S, C_12–14P₅E₂S, and C_12–14P₈E₂S were similar but were markedly lower than those of C_12–14E₂S at different temperatures. When PON was less than 12, the log CMC value decreased linearly with increasing PON in the absence of salt, and the relationship between pC₂₀ and PON was linear. But in the presence of 0.1 M NaCl, the log CMC value decreased exponentially with increasing PON.     

Wetting behaviour and direct observation of thermally responsive polystyrene‐block‐poly(N‐isopropylacrylamide)‐block‐polystyrene electrospun fibres in aqueous environment

Electrospun fibres of thermally responsive triblock copolymer polystyrene‐block‐poly(N‐isopropylacrylamide)‐block‐polystyrene were prepared. Fibre morphology and swelling were studied below and above the lower critical solution temperature of poly(N‐isopropylacrylamide) (PNIPAM) using cryo‐electron microscopy. Cryo‐transmission electron microscopy showed that the fibre diameter increased up to 150% after immersion in water at 20 °C. In contrast, at 45 °C the fibre diameter increased considerably less. The sessile drop technique was used to characterize temperature‐dependent wetting of fibre mats. Contact angle (θ_CA) measurements revealed that a block copolymer fibre mat changed from hydrophobic (θ_CA > 90°) to hydrophilic (θ_CA < 90°) state within seconds after applying a water droplet on it at 20 °C. At 40 °C the initial contact angle was measured to be higher (135°) and it decreased much less than at 20 °C during the first minute of measurement. We observed using scanning electron microscopy that the electrospun fibres of the block copolymer having 77 wt% of PNIPAM lost their cylindrical shape and changed from fibres to thin sheets at both 20 and 40 °C within seconds after applying water on the fibres. Fibres having 55 wt% of PNIPAM were observed to be stable in water at both 20 and 40 °C, which resulted, surprisingly, in fibre mats with the strongest effects on thermally sensitive wetting. We discuss the surprising results and the implications that the evolution of fibre surface roughness has on the long‐term wetting behaviour, demonstrating a self‐adaptable hydrophilicity/hydrophobicity nature of the fibre mats. © 2013 Society of Chemical Industry     

Synthesis and Surface Properties of Novel Gemini Imidazolium Surfactants

Five new Gemini imidazolium surfactants were synthesized from imidazole and 1-bromoalkane (C₈, C₁₀, C₁₂, C₁₄, C₁₆) to get 1-alkylimidazole, which was further reacted with 1,3-dichloropropan-2-ol to form the surfactant molecule, 1,1′-(propane-1,3-diyl-2-ol) bis(3-alkyl-1H-imidazol-3-ium) chloride. The structures of the five new surfactants and intermediates were characterized by ¹H-NMR, ¹³C-NMR and IR spectra. Thermal properties of the five new surfactants were studied with thermogravimetric analysis and differential scanning calorimetry, the five new surfactants showed a transition from a crystalline phase to a thermotropic liquid–crystalline phase at around ca. 100 °C, which transformed to an isotropic liquid phase at around ca. 165 °C. The five new surfactants critical micelle concentrations (CMC) in the aqueous solutions were determined by surface tension and electrical conductivity methods. The surface tension measurements provided a series of parameters, including critical micelle concentration (CMC), surface tension at the CMC (γ _CMC), adsorption efficiency  (pC ₂₀), and effectiveness of surface tension reduction (π_CMC). In addition, with application of the Gibbs adsorption isotherm, maximum surface excess concentration (Γ_max) and minimum surface area/molecule (A_min) at the air–water interface were obtained. The parameters β (degree of counterion binding to micelles), ΔG _ads ^θ (Gibbs free energy of adsorption), and ΔG _mic ^θ (Gibbs free energy change of micellization) were also derived. The results indicated that the five new Gemini surfactants exhibited very low CMC and a good efficiency in lowering the surface tension of water. The foamability and foam stability of the five new surfactants were also examined at different CMC.     

A Novel Zwitterionic Imidazolium-Based Ionic Liquid Surfactant: 1-Carboxymethyl-3-Dodecylimidazolium Inner Salt

A novel zwitterionic imidazolium-based ionic liquid (IL) surfactant, 1-carboxymethyl-3-dodecylimidazolium inner salt, was synthesized. The molecule structure was confirmed by means of electrospray ionization mass spectrometry, ¹H nuclear magnetic resonance and elemental analysis. The isoelectric point (pI) is 3.8 ± 0.1 at 35 ± 0.1 °C. The other important physicochemical parameters such as the critical micelle concentration (CMC), the surface tension at CMC (γ_CMC), the adsorption efficiency (pC ₂₀), the surface pressure at CMC (Π_CMC), the maximum surface excess (Γ_m), the minimum molecular cross-sectional area (A _min), the value of CMC/C ₂₀ and the average number of aggregation (N _m) were determined by surface tension and steady-state fluorescence probe methods, respectively.     

Synthesis and Characterization of Novel Surfactants Based on 2‐Hydroxy‐4‐(Methylthio)Butanoic Acid: 1. Anionic Surfactants

2‐Hydroxy‐4‐(methylthio)butanoic acid (HMTBA) is a commonly used animal feed additive available in large quantities. In this study, anionic surfactants were synthesized utilizing HMTBA as a starting material. Specifically, a straight‐chain fatty acid containing 12 or 16 carbon atoms was attached to the hydroxyl group via esterification. After neutralization of the carboxylic acid with sodium, the molecules behave as anionic surfactants. Oxidation of the sulfur atom can be performed to further increase water solubility. The molecules exhibit critical micelle concentrations (CMCs), and lower the surface tension to 35–45 mN/m at the CMC. The derivatives have low Krafft points (<4 °C) and good wetting performance. The hardness tolerance of the ester made from dodecanoic acid is ～2.5–4 orders of magnitude higher than an analogous carboxylate surfactant, namely sodium dodecanoate. Foam created according to the Ross‐Miles foam test is substantial, but dissipates quickly as compared to other anionic surfactants.     

Structural and Physicochemical Properties of a Polymerizable Surfactant Synthesized from <Emphasis Type="Italic">N</Emphasis>-Methylol Acrylamide

A new polymerizable nonionic surfactant with reactive vinyl groups has been synthesized from N‐methylol acrylamide using a two‐step procedure. The structure of the surfactant molecule was characterized by Fourier transform infrared, ¹H nuclear magnetic resonance and mass spectroscopy. The surface active properties alongside its self‐assembly properties were investigated by surface tension, electrical conductivity, and fluorescence spectroscopy measurements. As compared with other nonionic surfactants, this study showed that this polymerizable surfactant possesses slightly a higher critical micelle concentration (CMC) value and the surface tension value at CMC. The obtained CMC values were compatible among measurements, ca. 0.02–0.038 M. The evidence of micelle formation also provided by the zeta potential measurements and the obtained zeta potential values showed that the polymerizable surfactant solutions had limited stability. The hydrolysis stability and solubility of the polymerizable surfactant were also investigated. The solubility results have shown that it was soluble in polar solvents while insoluble in nonpolar solvents both at room temperature and 40 °C. The acidic and basic hydrolysis of the surfactant increased as the temperature increased and the hydrolysis stability was 180 min (basic medium) and 55 min (acidic medium) at 80 °C.     

Carbon dioxide‐in‐water foams stabilized with nanoparticles and surfactant acting in synergy

Synergistic interactions at the interface of nanoparticles (bare colloidal silica) and surfactant (caprylamidopropyl betaine) led to the generation of viscous and stable CO₂‐in‐water (C/W) foams with fine texture at 19.4 MPa and 50°C. Interestingly, neither species generated C/W foams alone. The surfactant became cationic in the presence of CO₂ and adsorbed on the hydrophilic silica nanoparticle surfaces resulting in an increase in the carbon dioxide/water/nanoparticle contact angle. The surfactant also adsorbed at the CO₂–water interface, reducing interfacial tension to allow formation of finer bubbles. The foams were generated in a beadpack and characterized by apparent viscosity measurements both in the beadpack and in a capillary tube viscometer. In addition, the macroscopic foam stability was observed visually. The foam texture and viscosity were tunable by controlling the aqueous phase composition. Foam stability is discussed in terms of lamella drainage, disjoining pressure, interfacial viscosity, and hole formation. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3490–3501, 2013     

Comparative Investigation of Dynamic Foam Behavior of Air–Water and CO2–Water Systems

The purpose of this study was to understand and compare the dynamic foam behavior of the surfactant Tween‐20 in air–water and CO₂–water systems. The foam height in the CO₂–water system was less than that in the air–water system, but the foam stability was better in the CO₂–water system. The effect of temperature on axial dye displacement and foam bubble size was studied, where the foam generation ability of the surfactant was directly proportional to the temperature, while the foaminess was inversely proportional. The observed highest foam volume for the air–water system was 3922 ± 181 cm³ and for the CO₂–water system 3195 ± 181 cm³ at 5.0 g L^–1 of surfactant at air flow rate of 1 liter per minute (LPM) at 52 °C. The half‐life for the air–water and the CO₂–water system was 110 and 40 s, respectively, at 5.0 g L^–1 of surfactant at the air flow rate of 1 LPM and 28 °C. In wet foam, the liquid holdup range for the air–water system was 0.38–0.52% and for the CO₂–water system 0.51–0.72% in the concentration range 1.0–5.0 g L^–1 at 1 LPM gas flow rate.