Conventional Surfactants Research Articles

Study the solute-solvent molecular interactions of L-Glutamine and conventional surfactants

The micellar characteristics of the three conventional surfactants such as sodium dodecyl sulfate (SDS), Hexadecyltrimethylammonium bromide (CTAB), and Triton X-100 (TX-100) are changed by the addition biologically active L-Glutamine (Glu) (i.e., 0.005, 0.01 and 0.02 M) were determined from stalagmometric, UV–visible spectroscopy, viscometric, FTIR and fluorescence methods using pyrene as probe. An observed decrease in I1/I3 in all micellar systems confirms the relative hydrophobicity of L-Glu. The CMCs values are reduced with the addition of L-Glu were determined by stalagmometric and it is confirmed by UV–visible and fluorescence methods and differs in the following order: SDS > CTAB > TX-100. The estimation of numerous interfacial parameters have also been done by using stalagmometric measurements including the (ϒCMC), (πCMC), (pC20), (Amin), and (Гmax). The concentration of L-Glu (M) rises, Amin values rise while the Гmax value falls and a significant rise in the surface tension of CMC (ϒCMC) values, with the values being in the range of 0.02 M > 0.01 M > 0.005 M > water. Hydrogen bonds, electrostatic interactions, hydrophobic interactions, and van der Waal interactions are only a few of the diverse types of interactions that were examined using FTIR in the pure surfactants and L-Glutamine mixed systems. To stabilize proteins and prevent protein aggregation, the findings presented here may be applied in pharmaceutical formulations.

Microbial biosurfactant based nanoemulsions and their applications: A review

AbstractNanoemulsions exhibit a wide range of practical applications owing to their smaller particle size, stability, and enhanced bioavailability. Conventional surfactants widely used in nanoemulsion formulations namely, polysorbate 80, macrogolglycerol ricinoleate, and 4‐octylphenol polyethoxylate have been associated with anaphylactoid responses, alterations in normal flora, cytotoxicity and tissue damage. The use of less toxic, environment‐friendly microbial biosurfactants in the formulation of nanoemulsions have been demonstrated to manifest stability, slow drug release, enhanced skin permeability, and bioactivity. The type and composition of mixed microbial biosurfactants used in nanoemulsions can decrease the droplet size and synergistically increase the stability. Moreover, a lower concentration of drug‐loaded surfactin‐based nanoemulsion synergistically inhibited the proliferation of cancer cells by 50% (IC50). The scope of the current review is to focus on the prospect of substituting conventional surfactants with biosurfactants obtained from microbial origin for nanoemulsion formulations. It also aims to draw attention to the paucity of research in the combinatorial study of biosurfactants and functional drugs used in nanoemulsions. The review emphasizes the bioactivity of microbial biosurfactant‐based nanoemulsions and their applications in diverse sectors. The differences in emulsion stability and size of microbial biosurfactant and conventional surfactant‐based nanoemulsions have been highlighted. The study intends to promote comparative research between nanoemulsions prepared using conventional surfactants and microbial biosurfactants.

Investigating the Vapor-Phase Adsorption of Aroma Molecules on the Water-Vapor Interface using Molecular Dynamics Simulations.

Surfactants are amphiphilic additives primarily used to reduce the surface tension of water and manipulate its wettability on various surfaces. Recent reports suggest that volatile surfactants, such as aroma molecules, diffuse more quickly to the interface from the vapor-phase than conventional surfactants typically used in the aqueous phase. The ability to adsorb from the vapor phase, in addition to their use as cosurfactants, expands the potential applications of volatile surfactants, particularly in situations where adding surfactants from the liquid phase is difficult. Here, we present a molecular level understanding of the adsorption kinetics of linalool, a common aroma molecule, on the water interface using molecular dynamics simulations. We note that the value of surface tension while adsorption from vapor and liquid phases is dependent only on the surface coverage. A minimum surface tension of 32 ± 1.8 mN/m is obtained in both cases at a maximum surface coverage of 4.88 μmol/m2 at 300 K. We observe the extent of decrease of the H-bonds between linalool-water and linalool-linalool molecules at various surface coverages to explain the mechanism of surface tension reduction. We solve Gibb's adsorption equation to establish a correlation between the surface coverage of linalool and the corresponding bulk concentration in experiments. We investigate the free energy profile of linalool's adsorption behavior at different surface coverages and temperatures. Our report suggests that linalool adsorption onto the water interface is an enthalpy-driven process primarily dependent on the strength of the interaction between the hydroxyl group of linalool and water molecules. These insights are crucial for selecting a suitable aroma molecule for various applications that target the vapor-phase adsorption mechanism.

Modular Toolbox as Snap Jewelry for Biomimetic Synthesis of Multifunctional Amino Acid Surfactants Inspired by Melanin.

Amino acid surfactants have gained significant importance in overcoming the limitations of conventional surfactants, notably, their low biocompatibility and biodegradability. However, the current amino acid surfactants lack multifunctional properties due to the nonreactivity of their aliphatic chains, necessitating the development of a new type of amino acid surfactant. A novel melanin-like amino acid surfactant and a biomimetic synthesis route were devised by mimicking the biosynthesis of melanin. Renewable natural polyphenol compounds with catechol moieties were utilized as building blocks for the hydrophobic group. In a proof-of-concept experiment, ethyl protocatechuate was oxidized to o-quinone and subsequently covalently linked to the amino group of lysine via Michael addition. The chemical structure was verified using liquid chromatography-tandem mass spectroscopy. The melanin-like amino acid surfactant exhibited excellent surface-active properties, with a critical micelle concentration of 1.59 mN m-1. Furthermore, it demonstrated remarkable emulsifying, foaming, solubilizing, dispersing, and wetting capabilities. Notably, it also possessed multifunctionality, including antibacterial activity, antioxidant activity, robustness, and mildness. These outstanding properties indicate significant potential for various applications. This strategy offers innovative insights and a versatile, modular toolbox for synthesizing multifunctional amino acid surfactants that mimic melanin. The approach allows for the easy interchange of o-quinone building blocks, which is akin to snap jewelry.

Synthesis and Aggregation Behavior of Hexameric Quaternary Ammonium Salt Surfactant Tz-6C12QC.

A hexameric quaternary ammonium salt surfactant Tz-6C12QC featuring a rigid triazine spacer and six ammonium groups was synthesized. The molecular structure and aggregation behavior of Tz-6C12QC were characterized by nuclear magnetic resonance spectroscopy, surface tension, conductivity, dynamic light scattering, and transmission electron microscopy, etc. Dissipative particle dynamics (DPD) simulation was employed to investigate the self-assembly behavior of Tz-6C12QC at different concentrations. The rheological behavior of the polyacrylamide/Tz-6C12QC system was characterized by shear rheology. The results indicated that Tz-6C12QC exhibited superior surface activity and lower surface tension compared to conventional surfactants. Rheology analysis revealed that Tz-6C12QC had a significant viscosity reduction effect on polyacrylamide. DLS and TEM indicated that, as the concentration of Tz-6C12QC increased, monomer associations, spherical aggregations, vesicles, tubular micelles, and bilayer vesicles were sequentially formed in the solution. This study presents a synthetic approach for polysurfactants with a rigid spacer and sheds light on the self-assembly process of micelles.

A novel erucic acid derived surfactant: Experimental and theoretical study

Erucic acid is still a difficulty to utilize efficiently as a byproduct of grease processing. An effective strategy is to develop novel surfactants derived from erucic acid. Adamantyl trimethyl ammonium erucate, (AdEr) is an ionic liquid anionic surfactant derived from erucic acid. In this study, a combination of experimental and theoretical calculations was used to compare its physical characteristics and aggregation behaviors with the previously reported choline erucate (ChEr). The physical chemical properties were evaluated by differential scanning calorimetry (DSC), thermogravimetric analysis, surface tension and dynamic light scattering (DLS). The introduction of adamantane enhanced thermal stability and increased the melting point, while maintaining the excellent water-solubility. In comparison with ChEr, AdEr has a lower critical micelle concentration (CMC) and lager micellar aggregation sizes, exhibiting better micellization ability. Density functional theory (DFT) calculations suggests that AdEr has less intramolecular activity and a more stable molecular structure. Molecular dynamic (MD) simulations verified that AdEr preferred to aggregate to form micelles and had a larger aggregation size than ChEr using parameters such as conformation snapshots, radius of gyration (Rg) and mean square displacement (MSD). According to radial distribution function (RDF) analysis, this is owing to the smaller occupied area due to lower hydration of COO− groups of AdEr, and the difference hydration extent of the cations (Ad+ and Cho+). These findings clearly suggest that AdEr can be used as a potential alternative to conventional surfactant derived from erucic acid for various applications.

Enhanced oil recovery using a novel non-ionic surfactant synthesized from olive oil: Performance and synergistic effects

In recent years, there has been increasing focus on the application of natural surfactants in enhanced oil recovery (EOR) due to the environmental concerns associated with conventional surfactants. This study presents a systematic approach in this field by introducing a novel non-ionic surfactant synthesized from olive oil through a two-step synthesis process. The synthesis of olive oil alkanolamide (OOAA) surfactant was confirmed using FTIR and characterized by GC–MS analysis. The synthesized OOAA surfactant showcased favorable attributes including effective emulsification, wettability modification, interfacial tension reduction, limited adsorption losses, and efficient oil displacement. Critical micelle concentration (CMC) of OOAA surfactant was found to be very low, 50 ppm at 303 K. At CMC, the interfacial tension (IFT) of synthesized OOAA surfactant was found to be 18.75 mN/m, which further decreased by 26 % at the optimal salinity of the NaCl solution. The contact angle study revealed significant wettability alteration for the optimized salt concentration. Adsorption of the surfactant onto rock surfaces was analyzed by using two adsorption isotherms. The Langmuir adsorption isotherm emerged as the best fitting model, yielding an R2 value of 0.899. The formulation of OOAA surfactant/PHPA/NaCl solution showed shear thinning behavior and also exhibited viscoelastic properties. The synergism of OOAA surfactant with PHPA polymer led to a substantial tertiary recovery of 31 % OOIP over the conventional water flooding. These comprehensive findings underline the potential of the synthesized OOAA surfactant for enhancing oil recovery in sandstone reservoirs.

Synergism in mixtures of nano benzimidazolium Gemini ionic liquid and sodium dodecyl sulfate surfactants in tuning interfacial properties of crude oil−water system

The high price of newly explored surfactants is a concern in applications, but their mixture with conventional surfactants can bring about desired outcomes. Gemini surface active ionic liquids (GSAILs) have emerged as unique materials in tuning interface properties. Surfactants like sodium dodecyl sulfate (SDS), on the other hand, are known effective and commercially available. This study investigates the simultaneous effects of a benzimidazolium cationic GSAIL, [C4benzim-C6-benzimC4][Br2], and SDS surfactants on the interfacial tension (IFT), emulsification, and wettability alteration of the crude oil−water system. The results demonstrate amazing synergies up to 97.6 % in the IFT reduction. An ultra-low IFT of 0.16 mN·m−1 was achieved with an optimum GSAIL mole fraction of 0.4, attributed to the attractive interaction between the cationic GSAIL and the anionic SDS. Mixtures also give 54.3 and 72.8 % synergies in emulsification and wettability alteration, respectively. The adsorption of individual and mixture of surfactants were theoretically analyzed using the Frumkin adsorption isotherm and the non-ideal interactions of the binary mixtures (NIBM) theory. The corresponding determined parameters were consistent. To have a more comprehensive analysis, the results were compared with those obtained with an analogous structure imidazolium GSAIL.

Synergistic performance of a Gemini nano ionic liquid and sodium dodecyl sulfate surfactants at the crude oil–water interface

Gemini surface active ionic liquids (GSAILs) are known as effective and environmentally friendly materials. Conventional anionic surfactants like sodium dodecyl sulfate (SDS), on the other hand, can establish desired properties in solutions. This study reports investigation on the influence of the mixtures of an imidazolium cationic GSAIL, [C4im-C6-C4im][Br]2, and the SDS anionic surfactant on the interfacial tension (IFT), emulsification, and wettability alteration of the crude oil–water system. Results demonstrate amazing synergistic effects, resulting in 97.1 % more IFT reductions compared to what could be achieved with the linear contribution of surfactants. Under the GSAIL mole fraction of 0.4 and the mixture concentration of 0.25 molˑdm−3 in aqueous phase, a low IFT of 0.18 mNˑm−1 was attained. This is attributed to the attractive interaction between the involved surfactants. Synergisms of 52.0 and 59.8 % were also achieved in emulsification and wettability alteration with the mixture of surfactants under the optimum GSAIL mole fraction of 0.4. The obtained data for the individual and the mixture of surfactants were analyzed based on, respectively, Frumkin adsorption isotherm and the “non-ideal interactions in binary mixtures” theory. Corresponding consistent parameters were determined and discussed.

Synergistic effects between anionic surfactant SDS and hydrophilic silica nanoparticles in improving foam performance for foam flooding

In foam flooding, foams stabilized by conventional anionic surfactants are usually raptured in contacting with crude oil, which behaves as a strong defoamer. In this article the synergistic effects between anionic surfactant SDS and negatively charged hydrophilic silica nanoparticles in stabilization of aqueous foams were examined. The results show that in either deionized (DI) water at 25 °C or Daqing simulated connate (SC) water with a total salinity of 6,778 mg/L at 45 °C, in absence of oil adding low concentration of silica nanoparticles into the SDS aqueous solutions can improve the foam performance of SDS mainly by increasing foam stability, as indicated by a synergistic effect index Se(d/s) (ratio of the composite foaming index of dispersion to that of solution) of 2.7 to 2.8. In presence of oil the foam performance of SDS in SC water at 45 °C can still be improved as indicated by an increased Se(d/s) of 3.7, but the maximum composite forming index is catastrophically reduced from 3222 Ls in absence of oil to 470 Ls in presence of oil. As similarly charged nanoparticles the silica nanoparticles do not adsorb at gas/liquid or oil/water interface to stabilize Pickering foams or Pickering emulsions but can improve emulsification of the oil, and the emulsified oil droplets together with the silica nanoparticles distribute in aqueous lamellae enhancing liquid viscosity and slowing down the liquid drainage in the foams. However, this effect weakens at high surfactant concentration, and addition of silica nanoparticles does not significantly reduce the interfacial tensions involved. The Enter (E), Spreading (S) and Bridging (B) coefficients of the oil in the foam systems are therefore still positive. The defoaming action of the oil in this system is not eliminated by only partially inhibited by addition of silica nanoparticles.

Tailoring the Self-Assembly of Steviol Glycoside Nanocarriers with Steroidal Amphiphiles.

Bile salts are biosurfactants that can induce structure transformations in supramolecular nanoassemblies with conventional surfactants owing to their unique, planar amphiphilic character and the rigidity of their hydrophobic steroid skeleton. However, structural information about the association of bile salts and amphiphilic glycosides is lacking. In this work, we investigated the micelle structure of two anionic di- and trihydroxy bile salts [sodium deoxycholate (SDC) and sodium cholate (SC)] and a conventional anionic surfactant [sodium dodecyl sulfate (SDS)] in mixtures with a nonionic steviol glycoside [α-glucosyl stevia (Stevia-G)] and studied their potential as a nanocarrier system for two poorly water-soluble drugs (clotrimazole and ketoconazole). Decreased critical micelle concentrations determined from surface tension measurements demonstrate synergistic interactions between Stevia-G and SDS/SDC/SC in a decreasing order. Small-angle X-ray and neutron scattering, interpreted by a core-shell ellipsoid model, indicate that SDS and bile salts act differently on the mixed micelle structure. Compared with SDS/Stevia-G, bile salt/Stevia-G had a core-shell structure more similar to that of pure Stevia-G micelles. SDC and SDS had an increasing and decreasing influence, respectively, on the available molecular surface area in mixtures with Stevia-G on the micelle core but a similar influence on the micelle shell solvation number relative to that of their pure micellar structures. The number of bile salt hydroxyl groups was influential in determining the micelle stoichiometry: an increasing number of hydroxyl groups corresponded to decreasing bile salt aggregation numbers and a smaller hydrophobic micellar core. The core volume was the most important structural factor in explaining the drug solubilization capacity of the nanocarrier systems. Therefore, bile salt-steviol glycoside mixed micellar assemblies exhibit structure control mechanisms allowing the fine-tuning of their interior hydrophobic domains important for nanocarrier applications toward solubilization of poorly water-soluble drugs.

Bio-based surfactants derived from pectin

Surfactants derived from renewable resources and synthesized using renewable feedstock and sustainable methods have become a major research focus over the past decade in the surfactant industry. This research presents an approach for rapidly converting readily available polysaccharides, like pectin derived from fruit waste, into safely biodegradable surface-active polymers. Commercially available pectin was modified with n-alkyl amines having different alkyl chain lengths using potassium carbonate as a catalyst. The effect of pectin molecular weight, alkyl chain length and degree of substitution (DS) on surface-active properties of the modified pectin derivatives was studied. Surface tension decreased slightly with lowering molecular weight, whereas interfacial tension decreased dramatically. Cytotoxicity evaluations using human dermal fibroblast, HepG2 and Jurkat cells demonstrated that these polysaccharide-based surfactants exhibit lower cytotoxicity compared to the conventional surfactants such as octyl phenol ethoxylates (i.e., Triton™ X-100), and therefore are more environmentally friendly. Biodegradation studies show that all modified pectins are “ultimately biodegradable” except for Pectin-amide C8 (1:10).

Compaction of Calf Thymus DNA by a Potential One-Head-Two-Tail Surfactant: Properties of Nanomaterials and Biological Testing for Gene Delivery.

A one-head-two-tail cationic surfactant, Dilauryldimethylammonium bromide (DDAB) has shown a great extent of calf thymus DNA (ct-DNA) compaction being adsorbed on the surfaces of negatively charged SiO2 nanoparticles (NPs). DDAB molecules show high adsorption efficiency and induce many positive surface charges per-unit surface area of the SiO2 NPs compared to cationic Gemini (12-6-12) and conventional (DTAB) surfactants in an aqueous medium at pH 7.4, as evident from zeta potential and EDAX data. Transmission electron microscopy and field emission scanning electron microscopy images, along with ethidium bromide exclusion assay and DLS data support the compaction of ct-DNA. Fluorescence microscopic images show that in the presence of SiO2 NPs, DDAB can perform 50% compaction of ct-DNA at a concentration ∼58% and ∼99% lower than that of 12-6-12 and DTAB, respectively. Better ct-DNA compaction by DDAB is evident compared to other Gemini surfactants (12-4-12 and 12-8-12) as well reported before. Time-correlated single photon counting fluorescence intensity decay measurements of a probe DAPI in ct-DNA have revealed the average lifetime value that is decreased by ∼61% at 2.5 μM of DDAB in the presence of SiO2 NPs as compared to a decrease by only ∼29% in its absence, supporting NPs-induced stronger surfactant binding with ct-DNA. Fluorescence lifetime data have also demonstrated the crowding effect of NPs. At 2.5 μM of DDAB, both fast and slow rotational relaxation components of DAPI contribute almost equally to depolarization with the absence of NPs; however, with the presence of NPs, ∼96% weightage of the anisotropy decay is for the fast component. The present DDAB-SiO2 NPs combination has proved to be an excellent gene delivery system based on the cell viability in the mouse mammary gland adenocarcinoma cells (4T1) and human embryonic kidney (HEK) 293 cell lines, and in vitro and in vivo studies.

Synthesis and properties study of alkali soluble resin fortified polyacrylate latex

AbstractLatex films with high heat resistance tend to have higher Tg and the emulsion minimum film formation temperature (MFFT) is higher. Higher MFFT latexes do not produce continuous coherent films at low temperatures during application. Consequently, in order to solve the paradoxical problem of obtaining latex films with high Tg at low emulsion MFFT, a series of alkali soluble resin (ASR) stabilized latexes were synthesized in this study using a semi‐continuous pre‐emulsification polymerization process. The microstructure of latex particles, polymerization stability, composition and properties of latex films were characterized and tested by ATR‐FTIR, TEM, ZETA potential analyzer, DSC, orthomorphic metallographic microscope, and gloss tester. The results show that the addition of ASR reduces the content of coagulum during polymerization and significantly increases the number of latex particles. The high Tg ASR also induces the formation of a microphase separation structure with a dual glass transition in the latex film, which improves heat resistance. Additionally, hydroplasticized ASR reduces emulsion MFFT, improves latex film flatness, and enhances its glossiness. The introduction of ASR acts as a dual role of synergy with conventional ionic surfactants during synthesis to increase the stability of composite latexes and with polyacrylate (PA) in application to enhance its properties.

Investigation of process variable effects on palm kernelamidopropyl betaine production

Abstract Cocamidopropyl betaine is a coconut oil-based surfactant that is widely used in cosmetics and personal care products due to its milder and less irritating properties compared to conventional petroleum-based surfactants. Palm kernel oil can be used for the synthesis of betaine (palm kernel amidopropyl betaine), following the same route as for the synthesis with coconut oil via two reaction steps. However, there was little information on the optimal operating conditions for each process. The method for the production of betaine and its operating conditions were studied in order to obtain a compatible betaine product with better properties than those of the commercial product. The studied method and operating conditions allowed the production of low viscosity betaine with a higher surfactant content (31.55 wt%) than that of the commercial betaine products (25.10 wt%). In addition, other feedstocks such as coconut oil, split palm kernel oil and coconut oil-based fatty acid methyl ester were used in this study to produce betaine from low-cost production.

Deciphering the role of sugars on aggregation and interfacial behavior of Gemini surfactant

The current study describes the mechanism of micellization and physical as well as chemical characteristics of ethylene-1, 2-bis (N, N-dimethyl-N-tetradecylammonium bromide) (14−2−14) in an aqueous solution of saccharides/sugars/carbohydrates (D-mannose, sucrose and raffinose) with concentrations 0.05, 0.1 and 0.2 mol/kg at different temperatures between 298.15 and 328.15 K. Conductometric and tensiometric measurements were applied to examine micellar modulation of 14–2–14 in terms of critical micelle concentration (CMC). The values of CMC from conductivity measurements are validated by the outcomes of surface tension measurements. Moreover, dependency of CMC over temperature has been used for computing thermodynamic parameters of micellization so as to acquire an enhanced insight into 14–2–14 behavior and occurrence of intermolecular interactions in the system. Since Gemini surfactants have lower CMC as well as greater surface activity in comparison to conventional surfactants, they result in the better formulation of saccharides-emulsifier (surfactant) combination in various food as well as cosmetic products.

Study on Pickering emulsions co-stabilized by multiple particles for building MXene-based multifunctional composite foam

Pickering emulsion, an emulsion prepared by replacing conventional surfactants with solid particles, has been extensively used to construct a variety of functional materials especially 3D porous foams or aerogels. Ti3C2Tx MXene have recently garnered tremendous attention and considered as a promising candidate for the construction of functional nanomaterials due to their fascinating properties. However, it remains a challenge to construct MXene-based composite porous materials. Herein, the Pickering emulsion co-stabilized by multiple kinds of particles and the subsequent MXene-based multifunctional composite foam were studied. The formation mechanism of Pickering emulsions stabilized by cellulose nanofibrils (CNF), nickel nanowires (Ni NW), and Ti3C2Tx MXene was investigated along with their stabilization mechanism in a complex water-oil environment. The final Pickering emulsions exhibited excellent stability over a wide pH range (5−11) and ionic strength (0–400 mM). Further, the CNF/MXene/Ni (CMN) composite foam was prepared by freeze-drying the emulsion gel. The as-prepared foam exhibited a minimum reflection loss of −30.2 dB at 2.8 GHz frequency. Moreover, the foam also exhibited promising photothermal conversion behavior, maintaining a temperature of up to approximately 80.9 °C for 200 s of exposure to 1 Sun. Therefore, this work affords a new and universal method to prepare MXene-based multifunctional porous materials for their potential applications in many areas.

Molecular design and applications of a nanostructure green Tripodal surface active ionic liquid in enhanced oil recovery: Interfacial tension reduction, wettability alteration, and emulsification

Surface active ionic liquids (SAILs) are considered as prominent materials in enhanced oil recovery thanks to their high interfacial activity. This study reports the preparation and applications of a nanostructure Tripodal imidazolium SAIL as an environmentally-friendly substitute to the conventional surfactants. The product has a star-like molecular structure centered by a triazine spacer, namely [(C4im)3TA][Cl3], prepared by a one-step synthesis method and characterized with FT-IR, NMR, XRD, and SEM analysis methods. The interfacial tension of the system was decreased to about 78% at critical micelle concentration of less than 0.08 mol·dm−3. Increasing temperature, from 298.2 to 323.2 K, improved this capability. The solid surface wettability was changed from oil-wet to water-wet and 80% and 77% stable emulsions of crude oil–aqueous solutions were created after one day and one week, respectively. Compared to the Gemini kind homologous SAILs, the superior effects of the Tripodal SAIL were revealed and attributed to the strong hydrophobic branches in the molecule. The Frumkin adsorption isotherm precisely reproduced the generated IFT data, and accordingly, the adsorption and thermodynamic parameters were determined.

Corn Oil-Water Separation: Interfacial Behavior of Extended Surfactant and Glutelin.

The purification and collection of various products from oil/water mixtures are routine procedures. However, the presence of emulsifiers that can displace other surface active components in the mixtures can significantly influence the efficiency of such procedures. Previously, we investigated interfacial mechanisms of zein protein-induced emulsification and the opposing surfactant-induced demulsification related to corn oil refinement. In this paper, we further investigated a different class of protein, glutelin, inside corn and proved that glutelin acts as an oil/water emulsifier in an acidic water environment. Furthermore, an extended surfactant's protein disordering and removal ability was tested and compared with a conventional surfactant. An extended surfactant contains a poly(propylene oxide) or poly(propylene oxide)-poly(ethylene oxide) chain inserted between the hydrophilic head and the hydrophobic tail. In this study, a nonlinear optical spectroscopic technique, sum frequency generation (SFG) vibration spectroscopy, was used to study the behavior of glutelin and extended as well as regular surfactants at the corn oil/water or aqueous solution interface. In most cases, the conventional surfactant shows better protein disordering or removal ability than the extended surfactant. However, with the addition of heat and salt to an extended surfactant solution, the experiment resulted in a substantial increase in the extended surfactant's protein disorder or removal ability.

Analyzing the modulations induced in the mixed micellar behavior of 1-alkyl-3-butylimidazolium based surface-active ionic liquids with an antibiotic drug in aqueous media

Abstract The study aims to scrutinize the mixed micellization and interfacial behavior of two 1-alkyl-3-butylimidazolium based surface-active ionic liquids (SAILs) i.e., 1-decyl-3-butylimidazolium bromide [C10bim][Br] and 1-tetradecyl-3-butylimidazolium bromide [C14bim][Br] under the influence of streptomycin sulphate (SS) drug in 5 mM concentration in aqueous media. Imidazolium-based SAILs have unique physicochemical properties and greater surface activity than conventional surfactants, which allows them to increase drug permeability, making them better drug carriers than currently available formulations. To fully utilize [C14bim][Br] and [C10bim][Br] in drug delivery applications, deep insight into the interactions occurring in the mixed micellar [C10bim][Br]/[C14bim][Br] systems in the drug’s presence are necessary to be examined. Thus, the study is conducted using conductivity and surface tension measurement techniques to fully exploit the self-assembly, micellization behavior and interactions occurring in the pure and mixed micellar system of [C10bim][Br]/[C14bim][Br] in water and 5 mM of SS solution in aqueous media. For this, various thermodynamic, surface-active and mixed micellar parameters of micellization have been calculated and analyzed with respect to change in mole fraction, temperature and addition of SS in solution.