New amphoteric surfactants containing a phosphoric acid group: I. syntheses and physicochemical properties of sodium 2-(n-2-hydroxyalkyl-n-methylamino)ethyl hydrogen phosphate

A series of new amphoteric surfactants having a phosphoric acid group, a tertiary amino group and a 2-hydroxyalkyl group, sodium 2-(N-2-hydroxyalkyl-N-methyl-amino)ethyl hydrogen phosphates (alkyl: n-tetradecyl, n-hexadecyl, n-octadecyl), were prepared by an addition reaction of 1,2-epoxyalkanes to N-methylaminoethanol, followed by the introduction of a phosphoric acid group and neutralization with sodium hydroxide. The structures of these compounds were confirmed by spectroscopy and elemental analysis. The solubility in solvents, Krafft point, surface tension, critical micelle concentration (CMC), occupation area of the molecule at the surface of aqueous solutions and foaming power were measured. It was shown that a 2-hydroxyethyl group in a long alkyl chain seemed to behave as a hydrophobic part.     

Surface active hydroxamic acids. I. Preparation and properties of long-chain alkyl[oligo(oxyethylene)] oxymethylenehydroxamic acids

For the development of surfactants having an ability to interact with metal ions, hydroxamic acids containing a long-chain alkyl[oligo(oxyethylene)] group were prepared. Any hydroxamic acid with an octyl, decyl or dodecyl group was made readily soluble in water by introducing four oxyethylene units into the molecule. These water-soluble hydroxamic acids had a micelleforming ability and acted as polyoxyethylene-type nonionic surfactants under acidic and neutral conditions. Additionally, those compounds were found to form a water-soluble complex with ferric ion at pH 2, and these complexes also showed surface active properties.     

Physicochemical Properties of Novel Phosphobetaine Zwitterionic Surfactants and Mixed Systems with an Anionic Surfactant

A series of novel zwitterionic phosphobetaine (PPBT) surfactants were synthesized using long chain fatty alcohol, epichlorohydrin, dimethylamine and sodium dihydrogen phosphate as raw materials. The physicochemical properties of the phosphobetaine surfactants such as isoelectric point, foaming, surface tension, critical micelle concentration (CMC) and Krafft point were measured. Low CMC and surface tension values indicated the surface activities of the phosphobetaine surfactants were quite excellent. The CMC and surface tension values of PPBT/SDS mixed systems were determined. It was found both of CMC and surface tension values decreased compared with single surfactant system because of the association between dodecyl sulfate anions and cationic groups in phosphobetaine by electrostatic attraction.     

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.     

Preparation,surface-active properties and acid decomposition profiles of a new “soap” bearing a 1,3-dioxolane ring

New soap-type surfactants bearing a 1,3-dioxolane ring were prepared in good yields by the acid-catalyzed condensation of 1-O-alkylglycerols (alkyl: decyl, dodecyl, tetradecyl, heptadecyl, octadecyl, orcis-9-octadecenyl) with oxocarboxylic acid esters, followed by alkaline hydrolysis without any expensive reagent and special equipment. These surfactants were soluble in alkaline water at room temperature. Their critical micelle concentrations were much smaller than that of sodium dodecanoate. An alkaline solution of the octadecyl homologue was nonfoaming, but the other homologues, including thecis-9-octadecenyl derivative, showed high foaming ability in alkaline solutions. The structural effect of these compounds on the area per molecule at the surface is also discussed. Because these surfactants contain a 1,3-dioxolane ring, they can be utilized as a new acid-decomposable type of cleavable surfactant. At pH 1, they decompose almost completely into nonsurface-active species after 80 min.     

Bulk and interfacial physical properties of aqueous solutions of sodium lauryl sulphate and lauryl alcohol with air and benzene systems: Part II — mixed aqueous solutions of sodium lauryl sulphate and lauryl alcohol

The pH, density, bulk viscosity and electrical conductivity of aqueous solutions of mixtures of sodium lauryl sulphate and lauryl alcohol were measured for a range of concentrations at 25°C. The influence of interface age on the interfacial tension of mutually saturated benzene/aqueous solution surfaces is also reported. The effect of impurities on various physical properties was illustrated using an impure lauryl sulphate system. A detailed comparison of these data with those reported in the literature shows satisfactory agreement above the critical micelle concentration of the sodium lauryl sulphate in water. Current data in the premicellar concentration range reveal anomalous behavior. Data reported in the literature are summarized for the pH, density, bulk viscosity, electrical conductivity, surface tension, interfacial tension with benzene, surface excess concentration, surface shear viscosity, critical micelle concentration and molecular complex formation of the sodium lauryl sulphate/lauryl alcohol aqueous solutions. The interactions of the anionic-nonionic surfactants at fluid/fluid surfaces and their influence on the physical properties are examined. The use of such systems in the stabilization of dispersions is also discussed. Eighty-five references are cited.     

Synthesis,Characterization, and Surface-Active Properties of Carboxylbetaine and Sulfobetaine Surfactants based on Vegetable Oil

A novel series of carboxylbetaine-type and sulfobetaine-type zwitterionic surfactants (castor oil amidoethyl betaine, castor oil amidoethyl sulfobetaine [CAAS], cottonseed oil amidoethyl betaine, and cottonseed oil amidoethyl sulfobetaine [COAS]) were synthesized via the reactions of nonedible vegetable oils (castor oil and cottonseed oil) with dimethylaminoethylamine, followed by the reaction with sodium chloroacetate and sodium 2-hydroxy-3-chloropropane sulfonate, respectively. Their chemical structures were confirmed using the electrospray ionization mass spectrum (ESI-MS) and infrared (IR) spectra. The surface activities of the prepared compounds were measured by surface tension. It was noticed that the sulfobetaine-type surfactants in aqueous solution performed slightly better at reducing surface tension than the carboxylbetaine-type surfactants. Meanwhile, the synthesized surfactants possess a broad range of isoelectric points, superior foam properties, and exhibit some antibacterial activity on Gram-positive and Gram-negative bacteria.     

Properties and applications of amphoteric surfactant: A concise review

Amphoteric surfactants have long hydrophobic hydrocarbon chain and hydrophilic positive as well as negative charged center connected with each other by a spacer group. Thus, this type of surfactant maintains overall charged neutrality. The properties of amphoteric surfactants depend primarily on the length of the hydrophobic hydrocarbon chain, the number of methylene segments in the spacer, the positive and negative charged groups, and their relative position. The ionic activity of amphoteric surfactants is influenced according to the pH value of the solvent. They display cationic behavior below the isoelectric points and anionic behavior at a higher pH. They take the shape of zwitterions in the area of the isoelectric point. In fact, amphoteric surfactants can be parted into pH-sensitive and pH-insensitive surfactants. The pH-insensitive surfactants stay as zwitterionic form irrespective of the pH of the solution. This surfactant has some unique features because of its precise molecular structure as follows: high water solubility, high surface activities, a wide isoelectric range, low critical micelle concentration (CMC), high foam stability, low toxicity, low irritating, excellent biodegradability, bioactivity, interface change, and so on. Because of these special characteristics, amphoteric surfactants have been immensely interested in many applications in the scientific community, including cosmetics, chromatography, enhanced oil recovery, electrochemistry, nanoscience, polymer chemistry, and waste water treatment. This review aims to study about amphoteric surfactants, which have only one hydrophobic hydrocarbon tail and two oppositely charged hydrophilic headgroups connected with each other by a spacer group and its properties, applications in various academics and industrial fields.     

Syntheses of 2-(N-alkyl-N,N-dimethylammonio)ethyl hydrogen phosphates and their physicochemical properties

A series of new amphoteric surfactants, having a quaternary ammonium group and a phosphoric acid group, 2-(N-alkyl-N,N-dimethylammonio)ethyl hydrogen phosphates (alkyl: dodecyl, tetradecyl, hexadecyl), were prepared by introducing a phosphoric acid group into N-alkyl-N,N-dimethyl-(N-2-hydroxyethyl) ammoniumiodide, followed by neutralization with sodium hydroxide and removal of inorganic salts. By the evaluation of the physicochemical properties, it was found that the phosphobetaines behave like “nonionic” surfactant in the zwitterionic region, having very small CMC values in comparison with sodium 2-(N-alkyl-N-methylamino)ethyl hydrogen phosphates. Additionally, similar trends were also observed in the experiments from the point of the effect of electrolyte and temperature on CMC, respectively. It should be considered that the hydrophobicity of the surfactant molecule is increased by the electronic interaction between the quaternary ammonium group and a phosphoric acid group. On the other hand, the phosphobetaines gave the smaller values of the occupied area per molecule at the air/water interface than sodium 2-(N-alkyl-N-methylamino)ethyl hydrogen phosphates. Therefore, it is clear that the phosphobetaines have higher surface-active properties than the amphoteric surfactants.     

蛋白质水力学半径的测定及用于蛋白质变性过程的实时监控

采用纳米粒度分析仪Zetasizer Nano测定了牛血清白蛋白（BSA）的水力学半径,考察了pH、离子强度、表面活性剂等的影响,并用于BSA热变性和脲变性过程的实时跟踪。随pH增大,BSA水力学半径呈“U”形变化趋势;酸性条件下,分子膨胀,随着盐浓度升高,BSA分子先小幅减小后显著增大;中性pH范围,离子强度对蛋白质分子尺寸影响很小,蛋白质性质相对稳定。离子型表面活性剂在蛋白质表面吸附,从而影响BSA水力学半径。通过水力学半径的测量实时跟踪蛋白质变性过程的分子变化,发现增加热变性中离子强度可加快变性速率,SDS加入增大了BSA变性温度Tm。脲在促使BSA分子扩张的同时,对链伸展有抑制作用;在DTT存在下,BSA的水力学半径随着时间变化逐渐增大。结果表明,简便的水力学半径测量可以用于蛋白质大小的表征,并可实时跟踪蛋白变性过程的分子尺度变化。     

Hydrotropic and surfactant properties of novel diisopropyl naphthalene sulfonates

A novel surfactant and hydrotrope, sodium diisopropylnaphthalene sulfonate (SDIPNS) has been developed. It contains about 92% diisopropylnaphthalene sulfonate, compared to other materials which are less than 50% diisopropylnaphthalene sulfonate. Aqueous solutions of 34–36% active SDIPNS have dual functionality. They have excellent surface properties and are compatible with conventional anionic, nonionic, and amphoteric surfactants. They demonstrate good laundering detergency in combination with sodium lauryl ethoxy sulfate, with or without builder. They maintain surface activity in 150 ppm hard water (Ca²⁺/Mg²⁺=2∶1), 5% NaCl, pH 2, and pH 12. They are effective hydrotropes. They enhance surfactant solubility, raise the cloud point of nonionic surfactants, and modify the viscosity of surfactant formulations. They are light in color and are low-foaming. Presented as a Poster Session at the American Oil Chemists' Society Annual Meeting, May 9–12, 1999, Orlando, Florida.     

Surfactants from glucamines and ω‐epoxy fatty acid esters

The ring‐opening reaction of ω‐epoxy fatty acid methyl esters (9,10‐epoxy decanoic acid methyl ester, 10,11‐epoxy undecanoic acid methyl ester and 13,14‐epoxy tetradecanoic acid methyl ester) with N‐methyl glucamine or glucamine was studied. A new method (in methanol under reflux) leads to products, which are surfactants of linear‐ or γ‐type‐structure, in fair yields and purities. In a following step the ring‐opening products were saponificated by enzymatic catalysis or by conversion with sodium hydroxide leading to amphoteric surfactants. The surface‐active properties of the methyl esters and their corresponding acids or salts were studied at various pH‐values by measurement of surface tension of aqueous solutions and by examination of foaming properties. Depending on the chain length of the used epoxides, the structure of the obtained sugar‐based surfactant and the pH‐values, different surface‐active properties were observed. Several of the achieved products reduce the surface tension of aqueous solution down to 26—40 mN/m. Examination of foaming properties of the latter show rather poor or good foamers, depending on the surfactant used or the pH‐value of the solution.     

Photosulfochlorination Synthesis and Physicochemical Properties of Methyl Ester Sulfonates Derived from Lauric and Myristic Acids

The photosulfochlorination process has been used in earlier works to produce n-alkane sulfonates. In this work, this process was applied for the first time on lauric and myristic fatty acids, leading to methyl ester sulfonates (MESs). The operating conditions were optimized and the isolation method described. Apart from the known advantages of this reaction, namely the use of sulfuryl chloride, the visible light and short reaction time, this process led to a clear mono-sulfonate products and thus allowed avoiding the bleaching step. The chemical composition of these surfactants was determined and their structures characterized by Fourier transform infrared spectroscopy, liquid chromatography-electrospray ionization tandem mass spectrometry and proton nuclear magnetic resonance. The physicochemical properties of these surfactants such as surface tension, critical micelle concentration, maximum surface excess and minimum area per molecule of surfactant at the air/water interface were determined. The Krafft point was determined experimentally and compared to the MES literature data. The experimental and calculated hydrophilic–lipophilic balance values obtained compared well. The foaming power using Bartsch’s method was presented and the results obtained compared to those of similar structures and those of sodium dodecyl sulfate.     

Sodium dialkyl phosphates: Surfactant properties and use in heavy duty detergents

A study of the physical and surface active properties of the sodium salts of dialkyl phosphates has been made. These compounds have been evaluated for use as surfactants in built detergents and their performance has been compared with commercial surfactants. The dialkyl hydrogen phosphates contained from 16–26 carbon atoms per molecule and were prepared from both straight chain alcohols and commercially available branched chain alcohols. In general, the surface active properties of the branched chain compounds are better than their corresponding straight chain compounds. Good detergency performance is obtained when the number of carbon atoms per molecule is between 17 and 23. Optimum performance is obtained with the symmetrical didecyl hydrogen phosphate salts made from commercial decyl alcohol produced by the oxo-process.     

Synthesis and Some Surface Properties of Glycine-Based Surfactants

A new group of anionic surfactants, namely sodium salts of secondary alkanesulfonamidoacetic acid, were synthesized using n-alkanesulfonyl chlorides as starting materials. These surfactants, having the formula: R–SO₂–NH–CH₂–COONa, with R = C₁₂, C₁₄, C₁₆ and C₁₈, were obtained in a simple way with quantitative yields. Different chain lengths and positional isomers of this new type of surfactants are expected to present differences in surface properties and foamability. The surface properties including critical micelle concentrations and minimal surface tensions γ_min were determined for each prepared surfactant using surface tension measurements with a Wilhelmy plate. Surface excess and minimum area per molecule at the air–water interface were determined for different concentrations at 25 and 50 °C using the Gibbs equation. The foaming power was also determined by the Bartsch method, and the results obtained were compared to those of a commercial surfactant, the linear alkylbenzenesulfonate. The stability of the foam formed was also evaluated. As expected, these surfactants exhibit good surface properties and show good foaming power.     

Synthesis and Properties of pH-Dependent Gemini Surfactants Containing Multiple Carboxyl Groups

A series of Gemini surfactants N,N″-dialkyl-N,N′,N″-tripropionate diethylenetriamine (referred as DTPDT-n, where n is the length of the hydrocarbon chain, n = 10, 12, 14) were synthesized, which have three carboxylic head-groups and two hydrophobic alkane chains. The products were characterized by means of nuclear magnetic resonance and mass spectrometry. The physicochemical properties of DTPDT-n surfactants with different hydrocarbon chain lengths were studied such as isoelectric point, surface activities, emulsifying properties, and foam properties. It is showed that these compounds exhibit pH-dependent protonation-deprotonation behavior. The isoelectric points of DTPDT-n surfactants are between 3.40 and 10.90. The critical micellar concentration (cmc) of all three surfactants are lower than the corresponding monomeric surfactants (single head group, single-chain), especially DTPDT-14, whose cmc can reach 2.29 × 10⁻⁵ mol/L. With an increase in the length of the alkyl chain, the solubility of the surfactants decreases and the surface tension of the three surfactants at cmc increases. In consideration of pH, all of three surfactants appear better emulsifying capacity and foaming property under weak alkaline conditions. DTPDT-14 has the best performance of emulsifying capacity among the three surfactants. DTPDT-10 has excellent foaming ability and foam stability.     

Sugar Surfactant-Based Shampoos

Naturally derived surfactants in hair care products are a trend in cosmetic technology. This study aimed to formulate and fully characterize the performance of shampoos with sugar-derived surfactants, namely, the alkyl polyglucosides decyl glucoside and coco-glucoside. In addition, different thickeners and conditioning ingredients were added to improve the formulation properties. A sodium laureth sulfate (SLES) formulation was used as control. Rheology, pH, foaming, contact angles on a keratin surface, and surface tensions were determined. The safety of the formulations was evaluated by in vitro cytotoxicity studies using the human keratinocyte HaCaT cell line and human retinal pigment epithelial cells ARPE-19. The efficacies were studied by in vitro hair combing force assays and in vivo sensorial analysis. The formulated sugar surfactant-based shampoos showed the following properties: (i) pH values higher than those of SLES (which were posteriorly lowered with lactic acid); (ii) higher foamability than SLES, and high wettability; (iii) Newtonian behavior and predominance of liquid state with a suitable viscosity; (iv) low cytotoxicity in both human keratinocytes and retinal cell lines (in contrast to SLES); (v) easier hair combing than SLES, when Polyquaternium-7 was used as conditioner; (vi) efficient and gentle hair washing; and (vii) favorable sensorial analysis confirming the previous washing properties. In conclusion, the sugar surfactants had a considerable impact in the properties of the shampoo formulations, in terms of both hair cleansing properties and efficacy, as demonstrated here. These favorable outcomes clearly support the use of these ingredients in shampoo formulation design.     

Mechanism of Selective Flotation of Sodium-Calcium Borates with Anionic and Cationic Collectors

Abstract

The major boron minerals, colemanite and ulexite, are frequently found together in boron deposits. Similarities in their chemical compositions create problems in the selective flotation of these minerals. The surface properties of the above boron minerals have been determined by solubility, microflotation, and zeta potential measurements using typical anionic and cationic surfactants. The isoelectric point (iep) of colemanite is 10.5, while ulexite exhibits no iep in a practical pH. Anionic surfactants thus easily float colemanite but fail to float ulexite at a natural pH. This knowledge is used to find the optimum conditions for the selective separation of colemanite from ulexite at a natural pH of 9.3. Cationic surfactants work well but are adversely affected by the presence of clay-type minerals in the boron ore which hinder the floatability of borates by the formation of a slime coating. The mechanism of slime coating onto boron minerals is also elucidated.     

Synthesis,Surface Properties and Effect of an Amino Acid Head Group of 11-(2-Methoxy-4-vinylphenoxy)undecanoicacid-Based Anionic Surfactants

Our present research describes the surface properties of three biobased anionic surfactant synthesized from vinylguaiacol and 11-bromo undecanoic acid. To further improve its hydrophobicity and bioavailability, amino acid head group incorporation was carried out. All these synthesized compounds were thoroughly characterized using NMR and mass spectroscopy. The performance properties such as foaming, wetting, emulsification value and calcium tolerance were evaluated. The studied surfactants possess excellent emulsion stability and moderate calcium tolerance as compared to commercially available surfactant sodium lauryl sulfate (SLS). The micelle formation and the thermodynamics involved at the air–water interface were estimated from surface tension measurements. These surfactants showed a higher tendency towards adsorption at the air–water interface than micellization. Dynamic light scattering and steady state fluorescence anisotropy study were carried out to shed light on the bulk micellization properties of the synthesized surfactant. Along with spherical micelles of <5 nm size, larger aggregates (35–84 nm) were observed with higher anisotropy values. FESEM images further confirmed the larger spherical micelles formed by these surfactants. The surfactants formed chiral aggregates above the critical micelle concentration as indicated by circular dichroism spectra. These surfactants may be suitable candidates for additives to detergents to improve their calcium tolerance especially in the case of hard water. Furthermore, a low foaming ability along with high emulsion stability may find these surfactants to be better replacement of the conventional surfactant used as emulsifiers in many industrial applications.     

Synthesis and properties of novel alkyl sulfate gemini surfactants

Four anionic gemini surfactants of the sulfate type C₁₂C_nC₁₂, where n is the spacer chain length (n = 3, 4, 6, and 10) were synthesized. The structures of these surfactants were confirmed by FT‐IR, ¹H NMR, ESI mass spectra (ESI‐MS), and elemental analysis. The surface‐active properties of these compounds were investigated by means of surface tension, electrical conductivity, and fluorescence measurements. Premicellar aggregations were found for the four gemini surfactants, as revealed by the conductivity measurement. The formation of premicellar aggregates may account for the discrepancy between the critical micelle concentration (cmc) obtained by the surface tension and conductivity measurement. The cmc values of these gemini surfactants were much lower than that of sodium dodecylsulfate (SDS) and decreased monotonously with the increase of spacer chain length from 3 to 10. The effect of spacer chain length on the performance properties like foaming, emulsion stability, and lime soap dispersing ability were also studied and discussed. Practical applications : Alkyl sulfate surfactants are one of the most widely used surfactants. The new alkyl sulfate gemini surfactants synthesized in our study are more surface‐active than sodium dodecylsulfate. These gemini surfactants possess low critical micelle concentrations, high emulsion stability, and excellent lime soap dispersing ability. They have potential applications in the fields of cosmetics, detergents, etc.