Synthesis and surface activities of multi-ammonium cationics derived from n-octadecyl glycidyl

In this study, cationic surfactants having two, three or four hydroxyl groups were synthesized by the condensation reaction of n-octadecyl glycidyl ether and amine (methyl amine and dimethyl amine) followed by the quaternization with dimethyl sulfate. The structure of a resulting product was determined by ¹H NMR and FT-IR spectroscopies. Interfacial tensions measured as a function of time for n-decane drops brought into contact with 1 wt. % surfactant solutions at 25°C indicated that the interfacial tension decreased over a period of about 10–15 min to an equilibrium value. The results of contact angle measurements indicate that C18-BADM surfactant having four hydroxyl groups is the best wetting agent among others studied. Moreover, the excellent adsorption capacity of C18-BADM system suggests that it can be used as a softening agent during a laundry process. The results of foam stability measurement were consistent with those of CMC and contact angle. The percentage of foam volume decrease was found to increase with the hydrophilicity of a surfactant.     

Synthesis and properties of quaternary ammonium Gemini surfactants with hydroxyl groups

The article describes synthesis of four hydroxyethyl alkylene–double alkyl bromide through substitution of nucleophilic d iethanolamine, 1-bromododecane, and 1,4-dibromobutane. The structure of the new hydroxyl cationic surfactant (HDCS) was characterized by ¹H NMR and FTIR spectra. The aqueous solution of HDCS showed critical micelle concentration, i.e., 5.6 × 10^?2 mM, and could reduce oil/water interfacial tension to 3.28 × 10^?3 mN m^?1. The surface tension measurements provided a series of parameters, including critical micelle concentration (CMC), surface tension at the CMC (γ_CMC), adsorption efficiency (pC₂₀), and effectiveness of surface tension reduction (Π_CMC). In addition, maximum surface excess concentration (Г_max) and minimum surface area/molecule (A_min) at the air/water interface were obtained by the Gibbs adsorption isotherm. The influence of inorganic salts (sodium chloride, calcium chloride) and organic salts (sodium benzoate) on the surface tension of HDCS in aqueous solution was investigated. For wettability alteration measurement, contact angle measurement as a quantitative method was utilized. Meanwhile, foam ability, foam stability, and emulsifying property of the synthesized surfactant were also examined at different concentration. HDCS also had excellent viscosity property.     

Synthesis and properties of nonylphenol-substituted dodecyl sulfonate

Nonylphenol-substituted dodecyl sulfonate (C₁₂-NPAS) was synthesized via sulfonation-alkylation-neutralization using 1-dodecene, SO₃, and nonylphenol as raw materials. The properties such as surface tension, interfacial tension (IFT), wettability, foam properties, and salinity tolerance of C₁₂-NPAS were systematically investigated. The results show that the critical micelle concentration (CMC) of C₁₂-NPAS was 0.22?mmol?·?L^?1 and the surface tension at the CMC (γ_CMC) of C₁₂-NPAS was 29.4 mN/m. When compared with the traditional surfactants sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate (SDS), and linear alkylbenzene sulfonate (LAS), the surface properties of C₁₂-NPAS were found to be superior. The IFT between Daqing crude oil and a weak-base alkaline/surfactant/polymer (ASP) oil flooding system containing 0.1?wt% of C₁₂-NPAS can reach an ultralow level of 2.79?×?10^?3 mN/m, which was lower than that found for the traditional surfactant heavy alkylbenzene sulfonate (HABS). The salinity and hardness tolerance of C₁₂-NPAS were much stronger than those found for conventional surfactants, petroleum sulfonate, and LAS. C₁₂-NPAS also shows improved wetting performance, foamability, and foam stability.     

Synthesis and performance of a series of dual hydroxyl sulfobetaine surfactants

Five kinds of dual hydroxyl sulfobetaines with different carbon atom numbers in hydrophobic chain were synthesized by using linear saturated alcohol, epichlorohydrin and dimethylamine, and then their structures were characterized by FTIR and ¹H NMR. The stability of all synthesized betaine surfactants in hard water was at level 4, which indicated they had high tolerance on hard water. Their CMC and γ_cmc were lower than the conventional cationic surfactant dodecyltrimethylammonium bromide and anionic surfactant sodium dodecyl, so they had more excellent surface activities. With the chain length increasing from C₈ to C₁₄, the surface activities, emulsifying properties and foaming properties of these betaine surfactants improved because surfactant molecules tightly arranged in the oil-water interface, but there was abnormal phenomenon of surface activity and foam property from C₁₄ to C₁₆ due to overlong hydrophobic chain. According to the results of the experiment, C₁₄SB was the most practical in the five kinds of surfactants, which was potential candidate to enhance oil recovery in oil field. The performances of C₁₄SB were as follows: CMC?=?2.2?×?10^?4?mol/L, γ_cmc?=?30.9 mN/m and the time of bleeding 10?mL water t?=?375?s at 2?g/L the optimum emulsification concentration.     

Effect of Surfactants on the Formation,Morphology, and Surface Property of Synthesized SiO2 Nanoparticles

Abstract

This study investigated the effect of cationic, anionic (saturated and unsaturated), and nonionic surfactants on the formation, morphology, and surface properties of silica nanoparticles synthesized by the ammonium‐catalyzed hydrolysis of tetraethoxysilane in alcoholic media. Results indicate that at a relatively low surfactant concentration (1 × 10^?3–1 × 10^?6 M), cationic surfactants significantly affected the growth of silica particles as measured by dynamic light scattering and transmission electron microscopic analyses. In contrast, the anionic and nonionic surfactants showed relatively minor effects in the low concentration range. The magnitude of negative zeta potential was reduced for silica colloids that were synthesized in the presence of cationic surfactant because of charge neutralization. The presence of anionic surfactants only slightly increased the negative zeta potential while the nonionic surfactant showed no obvious effects. At high surfactant concentrations (>1 × 10^?3 M), cationic and anionic surfactants both induced colloid aggregation, while the nonionic surfactant showed no effect on particle size. Raman spectroscopic analysis suggests that molecules of cationic surfactants adsorb on silica surfaces via head groups, aided by favorable electrostatic attraction, while molecules of anionic and nonionic surfactants adsorb via their hydrophobic tails.     

Wetting properties of aqueous solutions of hydrophobically modified inulin polymeric surfactant

The contact angles of aqueous solutions of a polymeric surfactant namely hydrophobically modified inulin (INUTEC®SP1) were measured on hydrophilic and hydrophobised quartz glass surfaces using the sessile drop technique. These measurements showed a large difference (>10°) between the advancing contact angle θ ₁ (that is measured immediately after placing the drop on the surface) and the constant contact angle θ ₂ (that is measured 30 minutes after placing the drop). In all the results only the contact angle θ ₂ was subsequently measured. θ versus INUTEC®SP1 concentration C _s curves were obtained at various NaCl concentrations both on hydrophilic and hydrophobic glass surfaces. On hydrophilic glass surface the θ versus C _s curves showed a maximum at a concentration range of 10^–6 to 2?×?10^–5 mol dm^-3 INUTEC®SP1. These curves were shifted to lower values as the NaCl concentration was increased. On such hydrophilic surface the INUTEC®SP1 molecule adsorbs with the polyfructose loops and tails oriented towards the surface leaving the alkyl chains in solution. Saturation adsorption with this orientation occurs at 2?×?10^–5 mol dm^-3 INUTEC®SP1. However, the contact angles remain quite small (<18°) indicating the presence of several hydrophilic glass patches uncovered by surfactant molecules. At C _s?>?2?×?10^–5 mol dm^-3 θ decreases with further increase of the INUTEC®SP1 concentration reaching 5° at the Critical Association Concentration (CAC) of the polymer. This indicates the formation of a bilayer of INUTEC®SP1 molecules with the alkyl chains hydrophobically attached to those of the first layer. On a hydrophobic glass surface, adsorption of INUTEC®SP1 occurs by multi-point attachment with the alkyl chains on the surface leaving the hydrophilic polyfructose loops and tails dangling in solution. This results in a gradual decrease of the contact angle with increase in INUTEC®SP1 concentration, reaching a plateau value (>85°) between 2?×?10^–5 and 2?×?10^–4 mol dm^-3. The large contact angles obtained on adsorption of the polymeric surfactant on a hydrophobic surface indicate the presence of several uncovered hydrophobic patches. These results give a reasonable picture of the adsorption and orientation of the INUTEC®SP1 molecules on both hydrophilic and hydrophobic solid surfaces.     

Comparison of polymeric and ceramic membranes performance in the process of micellar enhanced ultrafiltration of cadmium(II) ions from aqueous solutions

A comparison of polymeric and ceramic membranes in the ultrafiltration process was studied and presented. This study was conducted on the separation of cadmium(II) ions, with particular reference to parameters such as hydrodynamic permeability coefficient, membrane fouling, amount of surfactant in the permeate, efficiency, and effectiveness of the process. The effect of ionic (SDS) and non-ionic (Rofam 10) surfactants or their mixture was investigated. The hydrodynamic permeability coefficient of the ceramic membrane was found to be much lower in comparison to those of the polymeric ones (1.69 × 10^?7 m³ h^?1 m^?2 Pa^?1, 5.66 × 10^?7 m³ h^?1 m^?2 Pa^?1, and 9.26 × 10^?7 m³ h^?1 m^?2 Pa^?1 for ceramic, CA, and PVDF, respectively). However, filtration of the surfactants solutions did not cause permanent blocking of pores and the surface of the ceramic membrane in contrast to the polymeric ones. No significant differences in surfactants permeation through the membranes tested were observed. Concentration of the surfactant in the permeate was lower than 1 CMC for the Rofam 10 solution and exceeded the CMC by about 40 % for the SDS solution. Better separation properties of polymer membranes for the separation of cadmium(II) ions from micellar systems were identified.     

Octadecylamine cobalt(III) dimethyl glyoximato complexes: synthesis,thermodynamics of micellization,steady-state photolysis and biological activities

A new class of surfactant–cobalt(III) complexes of the type trans-[Co(DH)₂(OA)X], where DH = dimethylglyoxime, OA = octadecylamine, X = Cl^?, Br^?, I^?, N₃ ^?, NO₂ ^?, SCN^? or OA, were synthesized and characterized by physicochemical and spectroscopic methods. The critical micelle concentration (CMC) values of these surfactant–cobalt(III) complexes in ethanol solution were obtained by measuring absorption at ~250 nm. Specific conductivity data (at 303–313 K) served for the evaluation of the temperature-dependent CMC and the thermodynamics of micellization (ΔG _m ⁰ , ΔH _m ⁰ and ΔS _m ⁰ ). Steady-state photolysis and cyclic voltammetry of the complexes were studied. The surfactant–cobalt(III) complexes were screened for their antibacterial and antifungal activities against various microorganisms.     

Properties and Extraction for [Ni(NH3)6]2+ of ATPS-a Formed by Aqueous Cationic–Anionic Surfactant Mixtures

The properties and extraction for [Ni(NH₃)₆]²⁺ of anionic aqueous two-phase systems (ATPS-a) that formed in mixtures of cetyltrimethylammonium bromide (CTAB) and excess sodium dodecyl sulfate (SDS) aqueous solutions were investigated. The results showed that the properties and extraction effects were strongly affected by the surfactant concentration, the temperature of system, and the mole fraction of surfactants. The increase of temperature induces narrower phase region and larger phase volume ratio. In addition, [Ni(NH₃)₆]²⁺ was extracted into the surfactant-rich phase with higher distribution coefficient when the liquid crystal had the birefringent properties. Moreover, the distribution coefficient can be improved through reducing the concentration of surfactant from 0.15 to 0.05 mol · L^?1 or increasing mole fraction of CTAB from 21.9% to 23.1%. The results showed that ATPS of cationic–anionic surfactants was efficient for [Ni(NH₃)₆]²⁺ extraction with distribution coefficients of 13.5 when the total surfactant concentration was 0.05 mol · L^?1, mole fraction of CTAB was 21%, and temperature was 34°C.     

Synthesis and Properties of a New Piperazine-Based Bicaudate Gemini Surfactant

A novel bicaudate gemini surfactant was synthesized with anhydrous piperazine, chloride- bian, and 1-bromo dodecane as raw materials. Its structure was verified by infrared and ¹H NMR. The surface active properties of the bicaudate gemini surfactant in water were measured at 55°C. Its critical micelle concentration (cmc) and γ cmc was 0.50 mmol · L^?1 and 28.95 mN · m^?1, respectively. Results indicate that there was not a remarkable difference in γ_cmc values between the synthesized bicaudate surfactant and conventional gemini surfactant N,N′–bis (dodecyl dimethyl ammonium bromide)-3-oxa-1,5-pentadiammonium. The sterilizing antimicrobial performance of the bicaudate gemini surfactant was examined. The bicaudate gemini surfactant show excellent inhibition against 18 types of bacteria compared with conventional monomeric surfactant and gemini surfactant at concentrations of 50 mg/L.     

Synthesis and properties of the cationic fluorocarbon emulsifier-free latex in a new micellar system

Cationic fluorocarbon emulsifier-free latex (CFEL) based on hexafluorobutyl methacrylate (FA), styrene, butyl acrylate, and methacrylatoethyl trimethyl ammonium chloride is successfully prepared in a new micellar system in which the fluorinated surface active monomer (FSM) based on isophorone diisocyanate, dodecafluoroheptanol, and allyl polyethylene glycol is used. The chemical structure of FSM is characterized by Fourier transform infrared spectroscopy, ¹H-NMR, and its surface-active properties have been investigated by surface tension determinator. Besides, effect of FSM, FA, and also the curing temperature on the latex and film properties has been investigated by the coagulation ratio (W _c ), precipitation ratio (W _p ), Nano-ZS particle sizer, contact angle, and water absorption ratio, respectively. The results show that the FSM is successfully prepared. The CMC of FSM is 2.37 g L^?1 and the γ _CMC is 26.31mN m^?1 accordingly. The more FSM content makes more stable emulsion and have only little adverse effect on its film properties. When the FSM content increases from 1.05 to 13.11 %, the W _c and W _p decrease by 83.5 and 32.1 %, respectively, and the surface free energy (γ) of CFEL film only increases by 8.3 %. The more FA content makes less stable emulsion but have favorable effect on its film properties. When the FA content increases from 0 to 25.11 %, the γ is decreased by 55.1 %. The curing temperature has much impact on film property. For example, the γ from 27.47 to 20.36 mJ?·?m^?2 when the curing temperature rises from 30 to 110 °C.     

Effect of the Presence of Surfactants and Immobilization Conditions on Catalysts’ Properties of <Emphasis Type="Italic">Rhizomucor miehei</Emphasis> Lipase onto Chitosan

Lipase from Rhizomucor miehei (RML) was immobilized onto chitosan support in the presence of some surfactants added at low levels using two different strategies. In the first approach, the enzyme was immobilized in the presence of surfactants on chitosan supports previously functionalized with glutaraldehyde. In the second one, after prior enzyme adsorption on chitosan beads in the presence of surfactants, the complex chitosan beads-enzyme was then cross-linked with glutaraldehyde. The effects of surfactant concentrations on the activities of free and immobilized RML were evaluated. Hexadecyltrimethylammonium bromide (CTAB) promoted an inhibition of enzyme activity while the nonionic surfactant Triton X-100 caused a slight increase in the catalytic activity of the free enzyme and the derivatives produced in both methods of immobilization. The best derivatives were achieved when the lipase was firstly adsorbed on chitosan beads at 4 °C for 1 h, 220 rpm followed by cross-link the complex chitosan beads-enzyme with glutaraldehyde 0.6% v.v^?1 at pH 7. The derivatives obtained under these conditions showed high catalytic activity and excellent thermal stability at 60° and 37 °C. The best derivative was also evaluated in the synthesis of two flavor esters namely methyl and ethyl butyrate. At non-optimized conditions, the maximum conversion yield for methyl butyrate was 89%, and for ethyl butyrate, the esterification yield was 92%. The results for both esterifications were similar to those obtained when the commercial enzyme Lipozyme® and free enzyme were used in the same reaction conditions and higher than the one achieved in the absence of the selected surfactant.     

Determination of Dialkyldimethylammonium Surfactants in Consumer Products and Aqueous Environmental Samples Using the Mixed Micelle-Based Methodology

Abstract

The determination of dialkyldimethylammonium surfactants (DDAS) based on the measurement of the critical micelle concentration (CMC) of mixed sodium dodecylsulphate (SDS)-DDAS aggregates in a basic medium ([NaOH]=4.8 × 10^?3 M) is proposed. The dye Coomassie Brilliant Blue G (CBBG) was used as a photometric probe for the rapid determination of CMCs. Formation of CBBG-DDAS and DDAS-SDS premicellar aggregates of well-defined stoichiometrics at cationic and anionic surfactant concentrations far below their CMCs is demonstrated. Increased SDS concentration in the titration medium results in the formation of DDAS-SDS mixed micelles. The strong interaction between the opposite charged head group of DDAS and SDS permits these cationic surfactants to be determined at the ng ml^?1 level with a nearly uniform response for all the DDAS tested (12–18 alkyl carbons). The relative standard deviation for 1.10 μg ml^?1 ditetradecyldimethylammonium bromide (DTDAB) was 1.5%. The mixed-micelle based methodology was applied to the determination of DDAS in softeners and aqueous environmental samples (river water and laundry effluents) with average recoveries ranged from 87.1 to 100.6 and from 96.3 to 104.0, respectively.     

Determining the Critical Micelle Concentration in O/W Emulsion Using the Rate Constant of Hydrolysis for Benzyl Acetate

An attempt to evaluate the kinetically effective critical micelle concentration CMC of sodium dodecyl sulfate (SDS) in micellar solutions and in O/W emulsions at 40°C and pH 9 utilizing the pseudo first order rate constant of benzyl acetate hydrolysis was implemented. The critical micelle concentration of SDS in micellar solutions was determined by both surface tension measurements utilizing Wilhelmy plate technique and by rate constant of hydrolysis. Hydrolysis reaction of benzyl acetate was monitored in surfactant solutions as well as in o/w emulsions as a function of time. Emulsion droplets were controlled using microfluidizer 110 T and oily droplets were separated from the emulsion by ultracentrifugation at (11,500 rpm or 9,800 g) prior to analysis by high performance liquid chromatography. The value of the critical micelle concentration (CMC) in micellar solutions in the presence of benzyl acetate as determined from the Wilhelmy plate technique was 7.8 × 10^?4 moles/L (CMC in micellar solution was 10 times lower than the value in literature due to use of buffer) while the CMC as determined from the kinetic study was 8.8 × 10^?4 moles/L. In emulsion systems, using 5% mineral oil, the CMC value was 8.6 × 10^?3 moles/L and at 10% oil, the value doubled to 1.73 × 10^?2 moles/L. The above results indicate that kinetics can be used to determine CMC in micellar solutions and in o/w emulsions.     

Synthesis and Micellar Behaviors of an Anionic Polymerizable Surfactant

A novel anionic polymerizable surfactant sodium (5‐acryloyl‐2‐(dodecyloxy)phenyl) methane sulfonate has been synthesized from phenol, acrylic acid and bromododecane by esterification, Frise rearrangement, sulfomethylation reaction and Williamson etherification. The parameters of the micellar behaviors are as follows: The CMC was 150 ppm at 40 °C; The surface absorption amounts Γ_m was 3.208 × 10^?6 mol m^?2; The molecular areas A_m was 0.550 × 10^?18m² at the interface of air‐water respectively; The aggregation number (N_agg) at C = CMC of this surfactant was 12.     

Kinetics and mechanism of the redox reaction between malachite green and iron(III) in aqueous and micellar media

The kinetics of the oxidation of malachite green (MG⁺) by Fe(III) were investigated spectrophotometrically by monitoring the absorbance change at 618 nm in aqueous and micellar media at a temperature range 20–40 °C; I = 0.10 mol dm^?3 for [H⁺] range (2.50–15.00) × 10^?4 mol dm^?3. The rate of reaction increases with increasing [H⁺]. The reaction was carried out under pseudo-first-order conditions by taking the [Fe(III)] (>10-fold) the [MG⁺]. A mechanism of the reaction between malachite green and Fe(III) is proposed, and the rate equation derived from the mechanism was consistent with the experimental rate law as follows: Rate = (k ₄ + K ₁ k ₅[H⁺]) [MG⁺][Fe(III)]. The effect of surfactants, such as cetyltrimethylammonium bromide (CTAB, a cationic surfactant) and sodium dodecylsulfate (SDS, an anionic surfactant), on the reaction rate has been studied. CTAB has no effect on the rate of reaction while SDS inhibits it. Also, the effect of ligands on the reaction rate has been investigated. It is proposed that electron transfer proceeds through an outer-sphere mechanism. The enthalpy and the entropy of the activation were calculated using the transition state theory equation.     

Novel Cationic Gemini Surfactants Based on Piperazine: Synthesis,Surface Activity,and Foam Ability

A series of novel Gemini surfactants C_n-pi-C_n with piperazine moiety as spacer was synthesized and characterized by IR, ¹H NMR, and mass spectra. Their surface activities were evaluated by surface tension, electrical conductivity, and steady-state fluorescence. The obtained results indicated that the synthesized Gemini surfactants exhibited lower critical micelle concentration (cmc) and surface tension (γ_cmc) compared with traditional surfactants. The steady-state fluorescence measurement and electrical conductivity were recorded to demonstrate the accuracy of cmc values. In addition, the micellization was evaluated using conductivity measurement in the temperature range of 298–308 K. The foamability and foam stability of these Gemini surfactants were also examined. In which, the Gemini surfactant with the shortest chain (C₁₂) showed the best foamability but the poorest foam stability. Hydrophile–lipophile balance and emulsifying ability were studied and a comparatively poor emulsifying ability displayed.     

Kinetics and Equilibria of Synthesized Anionic Surfactant onto Berea Sandstone

We present static adsorption studies of anionic surfactants on crushed Berea sandstone. The maximum adsorption density was 0.9604 mg/g. The kinetics of adsorption process was modeled using pseudo-first-order and pseudo-second-order rate equations at 25°C and 70°C. The equilibrium adsorption process was validated using Langmuir and Freundlich adsorption models. In addition, the effects of different parameters that govern the effectiveness of these surfactants such as pH and temperature were also investigated. The kinetic study results show that the surfactant adsorption is a time dependent process. The apparent rate constant of adsorption process determined by the first-order kinetic model at 25°C and 70°C were 0.11768 and ?0.04513, respectively. The rate constant for pseudo-second-order kinetic model was 0.0086 at 25°C and 0.0101 at 70°C. The adsorption of anionic surfactant followed pseudo-second-order kinetic model. The Freundlich and Langmuir model constant were 1.6509 × 10^?4 and ?9.775 × 10^?5, respectively. The equilibrium results showed that the adsorption of anionic surfactant onto Berea sandstone was well described by Langmuir adsorption model. It was concluded that anionic surfactants performed better at higher pH and temperature.      

Effects of Spacer Chain Length and Additives on Solution Properties of Cationic Gemini Surfactant

The critical micelle concentration (CMC) has been determined for the gemini surfactant trimethylene-1,3-bis(dodecyldimethyl ammonium bromide)12-s-12,2Br^?1 by means of electricity conductivity measurements. For the same number of carbon atoms in the hydrophobic chain per hydrophilic head group, geminis have CMC values well below those of conventional single-chain cationic surfactants. The CMC of 12-3-12 reduces with the addition of n-alcohol except ethanol and with the increase of n-alcohol chain length as well as increase of concentration of n-butanol and sodium chloride. Steady-state fluorescence quenching technology has been employed to study the aggregation number of micelle, which increases with increase in the length of n-alcohol. The Kraft temperature measurements also indicate that the stability of solid surfactant hydrate decreases along with the improvement of concentration of n-butanol and sodium chloride.     

Synthesis and Properties of a Sulfonic Acid-Containing Gemini Surfactant

A novel sulfonic acid-containing gemini surfactant, 6,6′-(butane-1,4-diylbis(oxy)) bis(3-nonylbenzenesulfonic acid), 9BA-4-9BA, was synthesized in high purity and high yield using a facile preparation pathway, and characterized by FTIR, ¹H NMR, and elemental analysis. The content of two sulfonic acid groups was measured by the acid-base titration. DSC and TGA were used to reveal the thermal properties and the product purity. The surface properties of 9BA-4-9BA were evaluated by equilibrium surface tension measurement. It shows that its CMC was 0.65 mmol/L, while the C₂₀ of 0.018 mmol/L was above two orders of magnitude lower than that of traditional monomeric surfactants such as SDS and SDBS, indicating excellent efficiency of micelle formation and reduced surface tension.