Cationic Gemini Surfactants Research Articles

Corrigendum: Solution Behavior of Bovine Skin Gelatin in the Presence of Cationic Gemini Surfactants

The authors declare no conflict of interest.

Adsorption Characteristics of a Cationic Gemini Surfactant on Carbonate Outcrops: Adsorption Reduction Using Methylene Blue

Surfactant adsorption has been a great challenge for surfactant-based chemically enhanced oil recovery (cEOR) techniques as it directly reflects the overall efficiency of a cEOR project. The static adsorption of an in-house-synthesized cationic Gemini surfactant (GS12) has been investigated on carbonate outcrops as a function of concentration, time, salinity, and temperature. Three different types of carbonate outcrop samples taken from the Al-Lidam area with an increasing percentage of silica and clay impurities were investigated. It was found that the higher the presence of silicate and clay minerals in the carbonate outcrops, the higher will be the surfactant adsorption. The adsorption of GS12 was found to decrease at elevated temperatures and in a highly saline environment, especially at very high concentrations of divalent salts (CaCl2 and MgCl2). In addition, a novel adsorption inhibitor─methylene blue─has been proposed in this study, which reduced the surfactant adsorption dramatically on carbonate outcrops. The GS12 adsorption on carbonate samples 1, 2, and 3 was reduced to 0.14 mg/g-rock, 0.48 mg/g-rock, and 2.31 mg/g-rock, respectively, by the addition of 500 ppm methylene blue in a 1500 ppm surfactant solution. Moreover, curve fitting was also performed to analyze the adsorption isotherm and kinetic data. Redlich–Peterson and pseudo-second-order models were found to be the best to describe the adsorption isotherm and kinetics, respectively.

Static adsorption of a novel cationic gemini surfactant: A mineralogical study

Surfactants are deemed as an advantageous chemical in enhanced oil recovery (EOR) because of their potential of lowering the interfacial tension and modifying the wettability. However, the surfactant loss by adsorption on the rock surface is one of the major shortcomings of surfactant-based flooding techniques. The static adsorption of an in-house synthesized cationic gemini surfactant (GS12) is investigated as a function of mineral type, salinity, and concentration. Both clay and non-clay minerals have been examined. Surfactant adsorption was increased continuously by the increase of concentration till 1000 ppm and then an adsorption plateau was observed in all minerals except montmorillonite and kaolinite. It was found that clay minerals may cause more detrimental effects as compared to silicate minerals and carbonate minerals showed the least adsorption. The maximum amount of surfactant adsorbed on the mineral surface was in the order of montmorillonite > kaolinite > illite > K-feldspar > quartz > dolomite > calcite. Lower adsorption of GS12 was detected because of the presence of multivalent ions (Ca2+ and Mg2+). Methylene blue (MB) has been revealed as a novel adsorption inhibitor for cationic GS12 on various minerals. MB adsorbs on the negative binding sites of both clay and non-clay minerals. Therefore, an electrostatic repulsion takes place between the cationic dye (MB) and cationic GS12, leading to the reduction of GS12 adsorption on the mineral surface. Only the addition of 100 ppm of MB in the surfactant solution at the highest concentration (1500 ppm) reduced GS12 adsorption on quartz surface to 0.67 mg/g-rock. This study will help in designing the chemical EOR process using GS12 on carbonate formation containing silica and clay minerals as impurities.

Role of Dual Nature of Ionic Liquid in Solvation Dynamics and Rotational Diffusion in Mixed Micelles: A Time‐Resolved Fluorescence and Fluorescence Anisotropy Study

AbstractThe present work demonstrates the role of the dual nature of an ionic liquid, 1‐dodecyl‐3‐methylimidazolium bromide (C12mimBr), in the solvation dynamics and rotational diffusion of Coumarin 153 (C‐153) in the aqueous mixed micellar solutions of three cationic gemini surfactants, 12‐s‐12,2Br− (where s = 4, 6 and 8) using different spectroscopic and light scattering techniques. Ionic liquid within the micelles controls the weightages of solvation components. In pure micelles of a gemini surfactant, the fast and slow solvation components are major and minor, respectively, which vary based on the concentration of the ionic liquid. The effective solvation rate enhances with increasing concentration of C12mimBr. Dual nature of C12mimBr governs the size of mixed micelles. Thus the associated time constant for rotational motion also alters accordingly. In micelle, lateral diffusion coefficient (DL) value enhances with its increasing size due to mixed micelle's increased porosity. Gemini spacer chain length effect is also discussed.

Larvicidal evaluation of two novel cationic gemini surfactants against the potential vector of West Nile virus Culex pipiens Linnaeus (Diptera: Culicidae).

The development of insecticide resistance is a serious consequence of the widespread applications of synthetic insecticides. Recent studies have provided alternatives to currently available insecticides. Here, novel cationic gemini surfactants were synthesized to assess their insecticidal activities using laboratory and field strains larvae of Culex pipiens Linnaeus (Diptera: Culicidae). The efficacy of these surfactants was compared to that of clove oil and spinosad. The two surfactants G1 and G2 showed good insecticidal activities in laboratory strain with LC50 0.013 and 0.054 ppm, respectively, relative to spinosad with LC50 0.027 ppm, 48 h posttreatment. Although spinosad showed high efficiency against lab strain, it exhibited a high resistance ratio (RR) of 15.111 and 13.111 toward the field strain at 24 and 48 h posttreatment, respectively. The two gemini surfactants have a good safety profile and low RR (RR <5), which is close to clove oil; however, G1 and G2 presented high activities with 11,043.230 and 2658.648 folds, respectively, compared to clove oil. The treated Cx. pipiens larvae showed severe morphological malformations after treatment with gemini surfactants. The results of this study are promising in terms of developing novel, effective, affordable, and safe approaches for mosquito control strategies to reduce the risk of arbovirus transmission, which remains a global public health threat.

Synergistic effects of Gemini cationic surfactants with multiple quaternary ammonium groups and anionic surfactants with long EO chains in the mixed systems

In this study, two different anionic surfactants containing long polyoxyethylene chains involving sodium fatty alcohol ether carboxylates (AE9C) as well as isomeric sodium fatty alcohol ether sulfates (iso-AE9S) are mixed with a new Gemini cationic surfactant bearing four quaternary ammonium groups (TC-GS). Then, the surface properties and aggregation behavior of the two mixed systems were investigated. The effect of the long polyoxyethylene chains on the conformation and hydration of the hydrophilic head group of AE9C and iso-AE9S weakened their negative charge density, thus hindering their excessive electrostatic adsorption with TC-GS and improving the stability of the mixed systems. The positive synergistic effects of TC-GS/AE9C and TC-GS/iso-AE9S exhibited significantly lower critical micelle concentration, faster diffusion rates, and superior wetting capability compared to single surfactants. The micellization process of both mixed systems is spontaneously enthalpy-driven, and the diffusion-adsorption process is consistent with the mixed diffusion-kinetic mechanism. Finally, both mixed systems are capable of forming complex and interesting aggregate morphologies, with TC-GS/AE9C can form multilayer spherical vesicles and TC-GS/iso-AE9S can form multicompartment concentric spherical vesicles.

Capsaicin-loaded alginate nanoparticles embedded polycaprolactone-chitosan nanofibers as a controlled drug delivery nanoplatform for anticancer activity

Nanocarrier-based drug delivery systems have been designed into various structures that can effectively prevent cancer progression and improve the therapeutic cancer index. However, most of these delivery systems are designed to be simple nanostructures with several limitations, including low stability and burst drug release features. A nano-in-nano delivery technique is explored to address the aforementioned concerns. Accordingly, this study investigated the release behavior of a novel nanoparticles-in-nanofibers delivery system composed of capsaicin-loaded alginate nanoparticles embedded in polycaprolactone-chitosan nanofiber mats. First, alginate nanoparticles were prepared with different concentrations of cationic gemini surfactant and using nanoemulsion templates. The optimized formulation of alginate nanoparticles was utilized for loading capsaicin and exhibited a diameter of 19.42 ± 1.8 nm and encapsulation efficiency of 98.7 % ± 0.6 %. Likewise, blend polycaprolactone-chitosan nanofibers were prepared with different blend ratios of their solutions (i.e., 100:0, 80:20, 60:40) by electrospinning method. After the characterization of electrospun mats, the optimal nanofibers were employed for embedding capsaicin-loaded alginate nanoparticles. Our findings revealed that embedding capsaicin-loaded alginate nanoparticles in polycaprolactone-chitosan nanofibers, prolonged capsaicin release from 120 h to more than 500 h. Furthermore, the results of in vitro analysis demonstrated that the designed nanoplatform could effectively inhibit the proliferation of MCF-7 human breast cells while being nontoxic to human dermal fibroblasts (HDF). Collectively, the prepared nanocomposite drug delivery platform might be promising for the long-term and controlled release of capsaicin for the prevention and treatment of cancer.

Physiochemical insight into the solution behavior of cationic gemini surfactant in water and ethanol–water systems

AbstractSurfactants in water and both alcohol‐water mixed solutions are used extensively in a host of industrial applications. This work presents the solution behavior and micellar transition of a cationic gemini surfactant (GS): N,N′‐dihexadecyl‐N,N,N′,N′‐tetramethyl‐N,N′‐ethanediyl‐diammonium dibromide (16‐2‐16) in water and mixed water‐ethanol media. Phase behavior for 16‐2‐16 in the ethanol–water system was investigated at ambient temperature. The rheological data obtained for these systems at varying alcohol concentrations showed that the system viscosity (η) decreased with as the ethanol concentration increased. Small‐angle neutron scattering (SANS) was used to probe the structural details of the cationic micelles as a function of ethanol concentration and temperature. The scattering data inferred a structural transition from unilamellar vesicles (ULV) through rod‐like micelles to ellipsoidal micelles occurs that is dependent on the solvent composition and temperature indicating the behavior of ethanol molecules as a cosolvent in the process of micelle breaking. The plausible physicochemical interactions in the 16‐2‐16‐ethanol mixed system were further investigated using a computational simulation study employing density functional theory (DFT)/B3LYP (Gauss View 5.0.9) utilizing a 3‐21G basis set.

Solution Behavior of Bovine Skin Gelatin in the Presence of Cationic Gemini Surfactants

AbstractThe biophysical interaction between gelatin and cationic biodegradable Cm−E2O−Cm gemini surfactants (Cm represents alkyl chain where m=12, 14 and 16; E2 and O denote two ester groups and ethylene oxide, respectively) was analyzed utilizing a multi‐technique approach. The electronic absorption spectroscopy, far‐UV CD and pyrene micropolarity data evinced the formation of a complex between the concerned geminis and the biopolymer. Interestingly, the intrinsic fluorescence spectra do not exhibit concentration dependent behavior with respect to the surfactants giving an impression of poor interaction of gelatin with the geminis. Thereafter, the bulk solution properties, viz. foaming stabilities, viscosities and emulsion stabilities were measured to analyze the effect of binding. All the results combined together led to the inference of significant interaction between gelatin and the gemini surfactants which influence their physicochemical properties.

Molecular interaction of di-ester bonded cationic Gemini surfactants with pepsin: in vitro and in silico perspectives

The implications of surfactant–enzyme/protein interactions in a variety of fields, including biotechnology, cosmetics, paints and pharmaceuticals, have attracted a lot of attention in contemporary studies. Herein, we have employed several in vitro and in silico techniques such as excitation and absorption spectroscopies, circular dichroism and FT-IR spectroscopies, density functional and molecular dynamics simulations to understand the interaction behavior of oxy-diester-based green cationic Gemini surfactants, N1,N1,N14,N14-tetramethyl-2,13-dioxo-N1,N14-dialkyl-3,6,12-tetraoxateradecane-1,14-diaminiumdichloride (abbreviated as Cm-E2O2-Cm, where ‘m’ stands for alkyl chain length, m = 12 and 14) with one of the main digestive proteins, pepsin. The spectroscopic techniques confirm the static quenching effect of surfactants on pepsin. The calculated physical parameters (Ksv , Kb and ΔG) and their order reveal the distinguished implications for the surfactants’ chain lengths. The spontaneity of interaction was also confirmed by negative Gibbs free energy change values. The extrinsic spectroscopic study with pyrene as fluorescence probe, FT-IR and CD techniques indicated a potential conformational change in pepsin induced by the Gemini surfactants. DFT, docking and MD simulations provided the theoretical understanding regarding the quantum mechanical environment, location of binding and stability of the protein–surfactant complexation in energy terms. We believe this study will be a humble addition to our existing knowledge in the field of protein–surfactant interactions. Communicated by Ramaswamy H. Sarma

Gemini cationic surfactant based 4-(dimethylamino)benzaldehyde: surface characteristics and biological activity, a straightforward one-step synthesis

Gemini cationic surfactant based 4-(dimethylamino)benzaldehyde: surface characteristics and biological activity, a straightforward one-step synthesis

Inhibition Action of Cationic Gemini Surfactants on Mild Steel Corrosion in 1 N HCl

Inhibition Action of Cationic Gemini Surfactants on Mild Steel Corrosion in 1 N HCl

Tensiometric and Fluorescence Study of Cationic Gemini Surfactant with Some Special Alcohols

Special alcohols have been used as additives to study interfacial properties of cationic Gemini surfactant pentanediyl- 1, 5-bis (dimethyldodecylammonium bromide) (12-5-12). As these branched chain alcohols (in comparison with linear chain alcohols) are playing a measure roll in creating a microemulsion with Gemini surfactants. The surface tension values were measured by using ring detachment method. During the experiments, the ring was cleaned well by heating it in alcohol flame. The critical micelle concentration (cmc) values were obtained from surface tension (γ) versus logCt plots. The γ values decreased continuously and then become constant along a wide concentration range. The point of break, when the constancy of surface tension begins, was taken as the cmc of the system. Calculated Parameters are cmc, Гmax (maximum surface excess concentration), Amin (minimum surface area per molecule), C20 (the concentration of surfactant where the surface tension of the solvent is being reduced by 20 mN.m-1), (free energy of the given air/water interface), and the standard Gibbs energy of adsorption, ΔG­­0ads. An important property of micelle formation is the mean aggregation number which provides direct information about the general size and shape of the aggregates formed by amphiphiles in solution, and how these properties are related to the molecular structure of the amphiphiles. Mixed micellization behavior has been shown by these parameters. The mean aggregation number (Nagg­) of mixed micelles has been obtained by using the steady state fluorescence quenching method. Some other concerned parameters including dielectric constant (D), binding constant (KSV) were calculated in this study by using the ratio of intensity of peaks.

Synthesis of Gemini cationic surfactants based on natural nicotinic acid and evaluation of their inhibition performance at C-steel/1 M HCl interface: Electrochemical and computational investigations

Herein, we prepare effective Gemini cationic surfactants (CSII, CSIV) and characterize them using FT-IR and 1HNMR spectroscopy. The adsorptive properties of CSII and CSIV at HCl/air and C-steel/HCl interfaces were examined with surface tension and electrochemical parameters, respectively. The critical micelle concentration (CMC) of the CSII and CSIV indicated their adsorption affinity at the HCl/air interface. Where, aliphatic chains increase surface coverage percentage and aid in surfactant adsorption. The electrochemical parameters of C-steel in 1 M HCl were studied using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) at different temperatures. The charge transfer resistance of the C-steel electrode was enhanced from 28.2 Ω.cm2 to 770.79 and 831.45 Ω.cm2 after adding 5 × 10−4 M of CSII and CSIV, respectively. Both CSII and CSIV act as mixed inhibitors with inhibition performance exceeding 97% due to their highly adsorption affinity. The chemical adsorption affinity of these compounds is suggested by the higher adsorption energy (∆G*ads) values (>−40 kJ mol−1) according to the Langmuir isotherm model. The theoretical calculations including DFT, and Monte Carlo simulation (MCs) provide insight into the relationship between corrosion inhibition and molecular structure, where the calculated parameters agree with the experimental results.

Novel Gemini Surfactant for Binding Eu(III)-Polyoxometalate into Hydrogels and Polymer Latexes.

The incorporation of rare-earth ions into polymer matrices can lead to useful materials in various fields such as biomarkers, lasers, luminescent devices, optical storage materials, and so on. Methods of incorporation are either extremely simple, such as mixing the polymer and the ion of interest in adequate solvents, or more sophisticated such as synthesizing predesigned monomers that contain the rare-earth ion or binding the ion on an already formed polymer chain. Cationic gemini surfactants represent a class of surfactants that can be used to incorporate metal-oxygen cluster compounds by means of strong electrostatic interactions. In this study, first, a novel cationic gemini surfactant having double bonds on both side chains was designed and prepared. After characterization, the surfactant was used to synthesize hydrogels with different degrees of crosslinking and also as a surfmer in emulsion polymerization of methyl methacrylate. The resulted polymer matrices were able to bind europium-polyoxometalate Na9[EuW10O36].32H2O. In case of luminescent lanthanide ions, changing the microenvironment around the metal ion also changes the intensity of some emission peaks as well as other luminescent parameters. Investigation of emission spectra of Eu3+ indicates a decrease in the symmetry of the microenvironment, when the polyanions pass from water to latex, to surfactant solution, and to hydrogel.

Interfacial properties of cationic and anionic Gemini surfactant mixtures

AbstractThe possibility and the prospect of cationic/anionic (“catanionic”) surfactant mixtures based on sulfonate Gemini surfactant (SGS) and bisquaternary ammonium salt (BQAS) in the field of enhanced oil recovery was investigated. The critical micelle concentration (CMC) of SGS/BQAS surfactant mixtures was 5.0 × 10−6 mol/L, 1–2 orders of magnitude lower than neat BQAS or SGS. A solution of either neat SGS or BQAS, could not reach an ultra‐low interfacial tension (IFT); but 1:1 mol/mol mixtures of SGS/BQAS reduced the IFT to 1.0 × 10−3 mN/m at 100 mg/L. For the studied surfactant concentrations, all mixtures exhibited the lowest IFT when the molar fraction of SGS among the surfactant equaled 0.5, indicating optimal conditions for interfacial activity. The IFT between the 1:1 mol/mol SGS/BQAS mixtures and crude oil decreased and then increased with the NaCl and CaCl2 concentrations. When the total surfactant concentration was above 50 mg/L, the IFT of SGS/BQAS mixtures was below 0.01 mN/m at the studied NaCl concentrations. Adding inorganic salt reduced the charges of hydrophilic head groups, thereby making the interfacial arrangement more compact. At the NaCl concentration was above 40,000 mg/L, surfactant molecules moved from the liquid–liquid interface to the oil phase, thus resulting in low interfacial activity. In addition, inorganic salts decreased the attractive interactions of the SGS/BQAS micelles that form in water, decreasing the apparent hydrodynamic radius (DH, app) of surfactant aggregates. When the total concentration of surfactants was above 50 mg/L, the IFT between the SGS/BQAS mixtures and crude oil decreased first and then increased with time. At different surfactant concentrations, the IFT of the SGS/BQAS mixtures attained the lowest values at different times. A high surfactant concentration helped surfactant molecules diffuse from the water phase to the interfacial layer, rapidly reducing the IFT. In conclusion, the cationic‐anionic Gemini surfactant mixtures exhibit superior interfacial activity, which may promote the application of Gemini surfactant.

Synthesis of gemini cationic surfactants-based pyridine Schiff base for steel corrosion and sulfate reducing bacteria mitigation

Three gemini cationic surfactant with different hydrophobic tails labeled GSBO, GSBD, and GSBH based azomethine and pyridine nuclei have been synthesized and confirmed spectroscopy via FTIR, 1HNMR, and mass spectroscopy. The surface and thermodynamic study were conducted via measurement the surface tension measurements at different temperatures for well examining their corrosion inhibition efficiency. The affinity of the GSBO, GSBD, and GSBH toward micelle formation and adsorption at interface were hydrophobic and temperature dependent. The C-steel corrosion suppression via the synthesized GSBO, GSBD, and GSBH in 1 M H2SO4 were evaluated using electrochemical impedance spectroscopy, weight loss and polarization techniques, demonstrating their efficient affinity to mitigate the steel corrosion. Increasing the surfactant hydrophobicity exhibit higher ability to suppress the corrosion, as confined by the higher inhibition efficiency achieved by GSBH of 94.5 % that matched with higher adsorption affinity as claimed from the surface and thermodynamic investigation. The Tafel examination clarified GSBO, GSBD, and GSBH behaves as mixed type inhibitors following modified Langmuir isotherm. The inhibitors adsorption on C-steel was confirmed by XPS and SEM surface examination. Ultimately the synthesized azomethine based pyridine nuclei showed affinity to mitigate the sulfate reducing bacteria (SRB) with cut-off point observed for GSBO.

Role of a novel cationic gemini surfactant (CGS) on a one-step sol-gel process and photocatalytic properties of TiO2 powders.

TiO2 nanoparticles were prepared using a sol-gel process in combination with a novel cationic gemini surfactant (CGS) with amide functional groups at low temperatures. Titanium (IV) isopropoxide (TIP) and CGS were used as the starting materials and as effective agents, respectively, to orient the nanoparticles during the sol-gel synthesis. To reveal both the structural and morphological properties of the nanopowders prepared in this work, they were characterized using X-ray diffraction (XRD) analysis, scanning electron microscope (SEM), and Brunauer-Emmett-Teller (BET) surface area apparatus. The pore volume and pore size were calculated using the Barrett-Joyner-Halenda (BJH) model on the desorption branch. The experimental results show that the surface area and average crystallite size of the obtained TiO2 nanopowders vary between 160-203 m2/g and 27-49 nm, respectively. It was observed that the N2 adsorption-desorption isotherms for almost all samples of TiO2-X% CGS (X: mass of CGS) show the typical Type I with a hysteresis loop of H4. The photocatalytic activities of the CGS-modified nanocomposites are evaluated not only by the photocatalytic degradation of methyl orange (MO) but also by the reduction of Cr(VI) as model pollutants in the presence of visible light.

Flotation separation of bastnaesite from calcite using a novel Gemini surfactant as the collector

The effective separation of bastnaesite from calcium-containing gangue minerals such as calcite is often difficult and the development of more environmentally-friendly and efficient collectors is imperative. A novel cationic Gemini surfactant ethane-1,2-dodecyldimethylammonium bromide (EDDA) was designed and synthesized in the laboratory, and the flotation performance of EDDA was investigated by micro-flotation and artificial mixed minerals experiments. When the EDDA concentration was 1.5 × 10−4 mol/L at pH 7, the grade of REO and the recovery with EDDA were 70.35 % and 88.45 %, respectively. While the grade of REO of NaOL and DDA were only 35.4 % and 44.15 %, indicating that EDDA has excellent selective collecting ability for bastnaesite. The contact angle test depicts that the hydrophobicity of bastnaesite surface enhances while the wettability of calcite surface almost unchanged. The adsorption mechanism was investigated by means of Fourier transform infrared spectroscopy (FTIR), zeta potential and X-ray photoelectron spectroscopy (XPS). The analysis results indicate that EDDA adsorbs on the surface of bastnaesite through electrostatic and hydrogen bonding, and strengthened the surface hydrophobicity of bastnaesite instead of calcite. The study reports the feasibility of applying EDDA for the separation of bastnaesite from calcite.

Inhibition of low carbon steel corrosion by a cationic gemini surfactant in 10wt.% H2SO4 and 15wt.% HCl under static condition and hydrodynamic flow

The corrosion inhibition potentials of a cationic gemini surfactant (CGS) on low carbon (LC) steel in highly corrosive environment of 10 wt.% H2SO4 and 15 wt.% HCl (which imitates oil well acidic environment) at elevated temperatures was studied using potentiodynamic polarization (PDP), gravimetric, and surface (XPS, SEM and EDX) analyses. Unprecedented inhibition efficiencies (IE) of 92.2% and 92.5% were repeatedly obtained at CGS concentrations of as low as 0.25 ppm and 1 ppm in 15 wt.% HCl and 10 wt.% H2SO4 at 25 °C by gravimetry, respectively. Higher inhibition efficiencies were obtained at elevated CGS concentrations. The inhibitor act as a mixed type based on the PDP data. The adsorption of CGS on the steel surface further supports a stronger tendency for he CGS adsorption onto the steel surface, thereby establishing an effective protective mechanism of the steel. The CGS performance was enhanced under hydrodynamic condition than static condition in 15 wt.% HCl while the opposite was the case in 10 wt.% H2SO4. Density Functional Theory (DFT) calculations and Monte-Carlo (MC) dynamics simulations supported the experimental findings of the CGS inhibition potentials for steel surface in the studied media. This study showcases the high potential of employing CGS for effective control of the corrosion, even at low dosage, in industrial applications involving the use of highly reactive acids at higher temperatures where economically viable operations are necessary.