Surface-active Characteristics Research Articles

Synthesis of homologous series of surfactants from renewable resources, structure–properties relationship, surface active performance, evaluation of their antimicrobial and anticancer potentialities

Sugar esters display surface-active properties, wetting, emulsifying, and other physicochemical phenomena following their amphipathic nature and recognize distinct biological activity. The development of nutritional pharmaceuticals and other applications remains of great interest. Herein, three novel homologous series of several N-mono-fatty acyl amino acid glucosyl esters were synthesized, and their physicochemical properties and biological activities were evaluated. The design and preparation of these esters were chemically performed via the reaction of glucose with different fatty acyl amino acids as renewable starting materials, with the suggestion that they would acquire functional characteristics superior and competitive to certain conventional surfactants. The synthesized products are characterized using FTIR, 1H-NMR, and 13C-NMR spectroscopy. Further, their physicochemical properties, such as HLB, CMC, Γmax, γCMC, and Amin, were determined. Additionally, their antimicrobial and anticancer efficiency were assessed. The results indicate that the esters' molecular structure, including the acyl chain length and the type of amino acid, significantly influences their properties. The measured HLB ranged from 8.84 to 12.27, suggesting their use as oil/water emulsifiers, wetting, and cleansing agents. All esters demonstrate promising surface-active characteristics, with moderate to high foam production with good stability. Notably, compounds 6-O-(N-dodecanoyl, tetradecanoyl cysteine)-glucopyranose (34, 35), respectively and 6-O-(N-12-hydroxy-9-octadecenoyl cysteine)-glucopyranose (38) display superior foamability. Wetting efficiency increased with decreasing the chain length of the acyl group. The storage results reveal that increasing the fatty acyl hydrophobe length enhances the derived emulsion's stability for up to 63 days. Particularly, including cysteine in these glucosyl esters improves wetting, foaming, and emulsifying potentialities. Furthermore, the esters exhibit antibacterial activity against several tested Gram-positive and Gram-negative bacteria and fungi. On the other hand, they show significant antiproliferative effects on some liver tumor cell lines. For instance, compounds 6-O-(N-12-hydroxy-9-octadecenoylglycine)-glucopyranose (28), 6-O-(N-dodecanoyl, hexadecanoyl, 9-octadecenoyl and 12-hydroxy-9-octadecenoylvaline)- glucopyranose (29, 31, 32 and 33), respectively in addition to the dodecanoyl, hexadecanoyl, 9-octadecenoyl and 12-hydroxy-9-octadecenoyl cysteine glucopyranose (34, 36, 37 and 38), respectively significantly inhibit the examined cancer cells.

Novel bioactive petrodispersing agents based on cationic polymeric surfactant: Design, synthesis, and surface indices

Novel bioactive cationic polymeric surfactants based on fatty acid derived from natural wastes were developed with different hydrophilic head groups, which were employed for collecting the thin petroleum film from water surface and dispersing it. The preparation procedures pass through three steps, in first step lauryl methacrylate (LMA) was copolymerized with methacrylic acid (MAA) with different feed from the two monomers to obtain five copolymers of poly(LMA-co-MAA) (P1-5) of different molar ratio. In second step, carboxylic groups in copolymers (P1-5) were esterified with N,N‘-dimethyl-ethanol amine and finally the modified copolymers (PE1-5) were quaternized with Butyl-2-chloroacetate and Hexyl-2-chloroacetate to afford the bioactive PSB1-5 and PSH1-5, respectively. The structure of synthetic compounds was confirmed by FT-IR and 1H NMR. Upon examination, the surface-active characteristics of the bioactive petrodispersing agents that were synthesized exhibited significant defoaming capacity, good wettability, and foaming qualities. The synthesized PSB1-5 and PSH1-5 were applied for petro-collecting and dispersing in solid state and diluted form on three water sources. In sea water and diluted form, the results showed that PSB1-5 showed better effects than PSH1-5. Also, the antimicrobial efficiency of the synthesized PSB(1-5) and PSH(1-5) were tested. The data obtained from FT-IR and 1H NMR spectra proved the esterification of carboxylic group in copolymers due to the appearing of peak at 1738 cm−1 for carbonyl group of formed esters and the disappearing for proton of carboxylic group in 1H NMR. Also, data obtained from antimicrobial studies showed that the highest inhibition zone diameter against C. albicans, L. monocytogenes, S. aureus, Salmonella sp. and E. coli were observed for PSH(1-5). Which PSH-2 gives the highest value of inhibition zone diameter of 3.2 mm against L. monocytogenes. The results exhibited that PSH(1-5) showed the stronger antimicrobial functions than PSB(1-5).

Exploring biosurfactant from Halobacterium jilantaiense as drug against HIV and zika virus: fabrication, characterization, cytosafety property, molecular docking, and molecular dynamics simulation.

Biosurfactants are surface-active molecules with unique qualities and various uses. Many microorganisms produce secondary metabolites with surface-active characteristics that serve various antiviral functions. The HIV and Zika viruses were chosen for this study because they can spread from mother to child and result in potentially fatal infections in infants. Halophilic bacteria from the Red Sea solar saltern in Egypt were screened using drop collapse, emulsification activity, and oil displacement assays to produce biosurfactants and emulsifiers. Halobacterium jilantaiense strain JBS1 was the most effective strain of the Halobacteriaceae family. It had the best oil displacement test and emulsification activity against kerosene and crude oil, respectively. Among the ten isolates, it produced the most promising biosurfactant, also recognized by the GC-MASS library. This study evaluated biosurfactants from halophilic bacteria as potential antiviral drugs. Some of the computer methods we use are molecular docking, ADMET, and molecular dynamics. We use model organisms like the HIV reverse transcriptase (PDB: 5VZ6) and the Zika virus RNA-dependent RNA polymerase (ZV-RdRP). Molecular docking and molecular dynamics make the best complexes with 5VZ6 HIV-RT and flavone (C25) and 5wz3 ZV-RdRP and ethyl cholate (C8). Testing for ADMET toxicity on the complex revealed that it is the safest medicine conceivable. The 5VZ6-C25 and 5wz3-C8 complexes also followed the Lipinski rule. They made five hydrogen bond donors and ten hydrogen bond acceptors with 500DaMW and a 5:1 octanol/water partition coefficient. Finally, extreme settings require particular adaptations for stability, and extremophile biosurfactants may be more stable.

Amphiphilic hemicellulose based-biosurfactants for the efficient hydrocarbons separation from oily sludge

This study presents an improved sustainable approach to produce high-performance hemicellulose-based biosurfactants for environmentally friendly oily sludge remediation and oil components recovery. The amphipathic hemicellulose derivatives were prepared by hydrothermal extraction from renewable bamboo resources followed by rapid homogeneous esterification with alkenyl succinic anhydrides (C12–C18). The chemical structures of the prepared amphipathic hemicellulose derivatives were analyzed by FT-IR and NMR. The amphipathic hemicellulose derivatives with different hydrophobic chains were used to improve the separation and recovery of oil components from oily sludge in the thermal washing process. The hemicellulose modified with octadecenylsuccinic anhydride (HC-ODSA) exhibited the best oil recovery rate of 79.9%. The results of the interfacial activity, foaming, emulsification, and solubilization tests confirmed that the carbon chain length in the introduced hydrophobic groups exerted a substantial influence on the surface-active characteristics of the prepared amphipathic hemicellulose derivatives. Moreover, the results of desorption kinetics revealed that the amphiphilic hemicellulose molecules can reduce the interfacial tension between oil and water by adsorption at the interface and the petroleum hydrocarbons follow the pseudo-second-order desorption kinetic mode.

An efficient transition metal chalcogenide sensor for monitoring respiratory alkalosis

For many biomedical applications, high-precision CO2 detection with a rapid response is essential. Due to the superior surface-active characteristics, 2D materials are particularly crucial for electrochemical sensors. The liquid phase exfoliation method of 2D Co2Te3 production is used to achieve the electrochemical sensing of CO2. The Co2Te3 electrode performs better than other CO2 detectors in terms of linearity, low detection limit, and high sensitivity. The outstanding physical characteristics of the electrocatalyst, including its large specific surface area, quick electron transport, and presence of a surface charge, can be credited for its extraordinary electrocatalytic activity. More importantly, the suggested electrochemical sensor has great repeatability, strong stability, and outstanding selectivity. Additionally, the electrochemical sensor based on Co2Te3 could be used to monitor respiratory alkalosis.

Synthesis and Optimization of Rhamnolipids from Tree Borne Oils and Fats for Cosmetics Applications

Rhamnolipids are bio-surfactants with strong surface active characteristics. These are potential additives for cosmetic formulations. The production of these molecules is possible through various routes, however, their synthesis from renewable sources using bio-agents can be environment friendly and economical. Studies on bacteria are in focus for the development of rhamnolipid bio-surfactant. Pseudomonas aeruginosa is one of the bacteria being studied in depth because of its efficiency to form rhamnolipids from a range of carbon, nitrogen, substrate sources, such as tree borne oils, modified fats and blends. The rhamnolipid synthesis process was improved using response surface approach. The produced rhamnolipid has been used for preparing a cosmetic formulation. The product has shown good stability. The current study's findings indicated that the use of mathematical modeling is extremely successful in determining optimum reaction conditions and increasing the yield of a specific bio-process.

Synthesis and characterization of analogues of glycine-betaine surface-active ionic liquids

With the goal of finding sustainable solvents, novel ionic liquids (ILs) with low ecotoxicity features have been a target of research. Among these, ILs with surface-active characteristics play a significant role in the food, cosmetic, pharmaceutical, household cleaning and other detergent industries. Most surface-active ILs reported up to date are imidazolium-based, which may raise some environmental and health-related concerns. Aiming the development of ILs with surfactant properties and low ecotoxicity, in this work, novel surface-active analogues of glycine-betaine ILs (AGB-SAILs) combined with the dodecylbenzenesulfonate ([DBS]-) anion have been synthesized and characterized. The synthesized AGB-SAILs were characterized chemically by elemental analysis and spectroscopic methods. Their thermal properties, critical micellar concentration, micelle diameter and ecotoxicity against Aliivibrio fischeri were determined, being these properties compared with the commercial surfactant sodium dodecylbenzenesulfonate (SDBS). It is shown that all investigated AGB-SAILs are liquid at room temperature and thermally stable. Furthermore, most of them display a lower critical micellar concentration and lower toxicity towards Aliivibrio fischeri than SDBS, thus being good alternatives to the commercial surfactant in a wide range of applications.

Adsorption and self-assembly properties of the plant based biosurfactant, Glycyrrhizic acid

There is an increased interest in the use of natural surfactant as replacements for synthetic surfactants due to their biosustainable and biocompatible properties. A category of natural surfactants which are attracting much current interest is the triterpenoid saponins; surface active components found extensively in a wide range of plant species. A wide range of different saponin structures exist, depending upon the plant species they are extracted from; but regardless of the variation in structural details they are all highly surface active glycosides. Greater exploitation and application requires a characterisation and understanding of their basic adsorption and self-assembly properties. HypothesisGlycyrrhizic acid, extracted from Licorice root, is a monodesmosidic triterpenoid saponin. It is widely used in cosmetic and pharmaceutical applications due to its anti-inflammatory properties, and is an ingredient in foods as a sweetener additive. It has an additional attraction due to its gel forming properties at relatively low concentrations. Although it has attracted much recent attention, many of its basic surface active characteristics, adsorption and self-assembly, remain relatively unexplored. How the structure of the Glycyrrhizic acid saponin affects its surface active properties and the impact of gelation on these properties are important considerations, and to investigate these are the focus of the study. ExperimentsIn this paper the adsorption properties at the air–water interface and the self-assembly in solution have been investigated using by neutron reflectivity and small angle neutron scattering; in non-gelling and gelling conditions. FindingsThe adsorption isotherm is determined in water and in the presence of gelling additives, and compared with the adsorption behaviour of other saponins. Gelation has minimal impact on the adsorption; apart from producing a rougher surface with a surface texture on a macroscopic length scale. Globular micelles are formed in aqueous solution with modest anisotropy, and are compared with the structure of other saponin micelles. The addition of gelling agents results in only minimal micelle growth, and the solutions remain isotropic under applied shear flow.

The correlation between the surface-active characteristics of SAFOL 23 – alcohol – water systems and the length of the alkyl radical of the alcohol

The effect of isobutyl and isoamyl alcohols on the surface-active characteristics of SAFOL 23 nonionic sur-factant was studied. The surface tension isotherms (STI) of an aqueous solution of surfactant and its water-alcohol compositions are obtained. The structure of mixed micelles and the values of the surfactant interac-tion factor in the micelle, based on the STIs of SAFOL 23 – alcohol – water systems, were calculated. The dependence of surface activity on the SAFOL 23: alcohol ratio passes through a maximum, which is associat-ed with the transition of alcohol from co-surfactant to co-solvent due to the increase in its quantity. The wet-ting process of high dispersed polytetrafluoroethylene (PTFE) by SAFOL 23 – alcohol – water compositions was studied, contact angle isotherms were constructed. The PTFE surface was hydrophilized by compositions at ratios which comply with surface activity maximum. SAFOL 23 is more adsorbed on the surface of the sol-id phase than on the liquid-gas interface. The appending of alcohol into an aqueous solution of surfactant changes the ratio between hydrophilic and lipophilic groups of the composition, which affects cloud point. It significantly expands the range of application of surfactants and allows the use of SAFOL 23 as a solubilizer, emulsifier and wetting agent.

Polymeric stabilization of drilling drills with low content of solid phase

This article is devoted to identifying the relationship between the structure-forming properties of polymer stabilizers of clay suspensions (drilling fluids) and the structure of their macromolecules based on thermodynamic representations of the stability of polymer-dispersed systems. New types of polymer-micellar gels combining high structural and pseudo-plastic properties and optimal surface-active characteristics characteristic of concentrated micellar systems of the “surfactant-solubilizate” type are presented.

Pickering emulsions stabilized by sphere-spheroid mixtures

Stable oil-in-water Pickering emulsions (PEs) are prepared by using hydrophilic and oppositely charged spherical (silica) and nonspherical (hematite) nanoparticle mixture. By varying aqueous dispersion pH, the surface potentials of the particles are tuned. For fixed sizes of silica and hematite, stable emulsions are formed at low concentrations of silica when the surface potential mismatch between the particles is high. Conversely, when the latter is small, stable emulsions are found up to high concentration of silica nanoparticles. These findings are explained based on the formation of silica-hematite heteroaggregates and on their surface-active characteristics. It is found that for a given pH and particle concentration (expressed as number ratio NS-H, which is the ratio of the total number of spheres to the total number of spheroids), highly stable oil-in-water emulsions are formed only when the unstable aqueous binary mixture of colloids and the oil phase are emulsified. The result is presented as a state diagram, which shows the particle composition corresponding to the formation of stable emulsions, the composition range where the emulsions that result are unstable and the region where the emulsions do not form at all. As the formation of PE is kinetically controlled, we demonstrate that at conditions where emulsions formed via one-step emulsification for a given NS-H are unstable, following a two-step emulsification procedure yields highly stable emulsions. The work highlights the role of (i) NS-H, (ii) aqueous dispersion pH, (iii) surface potential mismatch and (iv) emulsification protocol on the formation and stability of solid particle stabilized emulsions.

Влияние изопропилового спирта на поверхностно-активные свойства SAFOL 23

The effect of isopropyl alcohol on the surface-active characteristics of SAFOL 23 nonionic surfactants was explored. The surface tension isotherms of an aqueous surfactant solution and its water-alcohol compositions were obtained. Based on a series of tension isotherms of a number of surfactant – alcohol – water systems, the compositions of mixed micelles and the values of the surfactant interaction factor in the micelle were calculated. The dependence of the surface activity of a water-alcohol composition on its composition was found and studied. The dependence of surface activity on the ratio of surfactant has the following form: alcohol is not monotonic and passes through a maximum, which is associated with a change in the function of alcohol with an increase in its content and a transition from co-surfactant to co-solvent. A feature of the adsorption process of surfactant – alcohol systems on highly dispersed PTFE was studied, namely, the free surface energy of the polymer was calculated, and isotherms of the contact angle were constructed. The cloud point of the systems was calculated and the characteristic of the hydrophilic-lipophilic balance was found. The introduction of alcohol changes the hydrophilic-lipophilic balance of SAFOL 23, which allows it to be used as a solubilizer, emulsifier.

New pyridinium bromide mono-cationic surfactant as corrosion inhibitor for carbon steel during chemical cleaning: Experimental and theoretical studies

New pyridinium bromide mono-cationic surfactant namely: 1-dodecyl-3-(hydroxymethyl) pyridin-1-ium bromide (DHPB) was prepared, 1H NMR and FTIR spectroscopy are used to confirm its chemical structure. The surface-active characteristics of DHPB were determined via surface tension measurements. The efficiency of the DHPB as corrosion inhibitors for carbon steel (CS) in 2 M HCl solution evaluated by chemical and electrochemical techniques. The high inhibition efficiencies for CS in the acidic medium have been improved by raising DHPB concentration and with raising the temperature. Quantum chemical calculations (QM) and molecular dynamics simulation (MD) show the effect of the chemical structure of the DHPB on its inhibition efficiency. Moreover, the surface morphology of CS in 2 M HCl solution before and after DHPB addition using scanning electron microscope (SEM) and atomic force microscopy (AFM) confirms the protection of CS surface via the protective layer of adsorbed DHPB.

Amphiphilic graphene quantum dots as a new class of surfactants

Graphene quantum dots (GQDs) are the latest addition to nanocarbon materials family and promise a wide spectrum of novel applications. Herein, we demonstrate amphiphilic GQDs as a new class of zero-dimensional (0D) inorganic surfactants. Amphiphilic GQDs are synthesized using a facile one-step hydrothermal process and exhibit single-layer graphene structure, high crystallinity, uniform size and bright photoluminescence. Owning to ultrasmall size and unique surface-active characteristics, amphiphilic GQDs are able to stabilize Pickering emulsion, self-assemble into self-supporting monolith, disperse hydrophobic carbon nanotubes to form ultra-light aerogel, promote fast spreading of water on superhydrophobic surface. Furthermore, GQD surfactants can mediate Pickering interfacial reactions, such as, polymerization to form hollow microspheres and chemical conversion catalyzed by acidic functional groups on GQD surface.

Helical side chain chemistry of a peptoid-based SP-C analogue: Balancing structural rigidity and biomimicry.

Surfactant protein C (SP-C) is an important constituent of lung surfactant (LS) and, along with SP-B, is included in exogenous surfactant replacement therapies for treating respiratory distress syndrome (RDS). SP-C's biophysical activity depends upon the presence of a rigid C-terminal helix, of which the secondary structure is more crucial to functionality than precise side-chain chemistry. SP-C is highly sequence-conserved, suggesting that the β-branched, aliphatic side chains of the helix are also important. Nonnatural mimics of SP-C were created using a poly-N-substituted glycine, or "peptoid," backbone. The mimics included varying amounts of α-chiral, aliphatic side chains and α-chiral, aromatic side chains in the helical region, imparting either biomimicry or structural rigidity. Biophysical studies confirmed that the peptoids mimicked SP-C's secondary structure and replicated many of its surface-active characteristics. Surface activity was optimized by incorporating both structurally rigid and biomimetic side chain chemistries in the helical region indicating that both characteristics are important for activity. By balancing these features in one mimic, a novel analogue was created that emulates SP-C's in vitro surface activity while overcoming many of the challenges related to natural SP-C. Peptoid-based analogues hold great potential for use in a synthetic, biomimetic LS formulation for treating RDS.

Dispersion Media Based on Aqueous Binary Compositions Modified by PEG-Stearox-6 for Abrasive Metalworking

Test results of the dispersive, rheological, and surface active characteristics of aqueous emulsions of the oxyethylated stearic acid derivatives (Stearox-6) and aqueous binary compositions modified by PEG–Stearox-6 are presented. Both synergism and antagonism of the dispersion effect of components being incorporated into the aqueous binary compositions (ABC) during the process of abrasive machining of steel 45 are established. The value of synergism regarding the dispersion action of ABC components is defined by the possibility to form intermolecular complexes between the molecules of amine-based oligomers of different molecular weight (MW) and Stearox-6, and antagonism is determined by their competitive adsorption at the as-formed surface of steel.

Determination of Surface-Active Characteristics of a Natural Surfactant Extracted from Sapindus Saponaria

Abstract The pulp of the fruit of Sapindus saponaria (soapnut tree) consists mainly of saponin. Surface-active characteristics of this raw saponin such as critical micelle concentration, area per molecule and, hydrophilic-lipophilic balance were investigated; this information is valuable to assess its implementation in different applications of industrial interest. By using surface tension measures and dynamic light scattering studies, the value of critical micelle concentration was found in the range of 0.03 – 0.046 g mL−1. Further increase in the concentration of crude saponin leads to a constant value of surface tension (44 mN m−1). These results were analyzed using the Gibbs adsorption isotherm yielding an estimated value of the area occupied per molecule at the air/water interface of 57.2 A2. Besides, Griffin method was used to determine the hydrophilic-lipophilic balance value (14.3). Sapindus saponaria extract properties are comparable to that of commercial surfactants, hence it could be used as an...

SURFACE-ACTIVE PROPERTIES OF THE DISTILLERS GRAINS AND THE PECTINS ISOLATED FROM THEM

Distillers grains are a huge secondary raw material resource, prospective for different fields, including pharmaceutical use, because of a rich content of biologically active compounds. The purpose of this paper was to estimate possibilities of the pharmaceutical use of distillers grains as the additive agent by means of surface-active properties of distillers grains study as well as pectins, isolated from them. We have established the surface-active properties of the liquid phase of the distillers wheat grains by means of higher pressure of air bubbles with the use of Rehbinder’s apparatus. It contained 6.67 mol/m3 pectins, and pectins isolated from a solid phase of the same distillers grains: surface activity 11.67 and 7.54, saturated surface excess amounted to 1.28×10-5 and 6.25×10-5 mol/m2, critical concentration of micelle formation amounted to 1.32 mol/m3 and 1.48 mol/m3 respectively. Surface-active characteristics of distillers grains and isolated pectins are comparable with well-known natural polysaccharides (sodium alginate, polygalacturonic acid, beet bin pectin), which are used as additive agents in technology of medicinal plants. We have determined the sizes of pectins molecules from distillers grains in the unsaturated adsorption layers, which differed from the well-known polysaccharides by lesser square (2.658 Å2), radius (0.920 Å), diameter of cross-section (1.840 Å) and the volume (2727 Å3) at the bigger mass per surface unit (1.031×10-4 кг) and a length (1026 Å). The data obtained by the sizes of pectin molecules are the favorable factor, which conduced their high biological availability.

A New Green Ionic Liquid-Based Corrosion Inhibitor for Steel in Acidic Environments.

This work examines the use of new hydrophobic ionic liquid derivatives, namely octadecylammonium tosylate (ODA-TS) and oleylammonium tosylate (OA-TS) for corrosion protection of steel in 1 M hydrochloric acid solution. Their chemical structures were determined from NMR analyses. The surface activity characteristics of the prepared ODA-TS and OA-TS were evaluated from conductance, surface tension and contact angle measurements. The data indicate the presence of a double bond in the chemical structure of OA-TS modified its surface activity parameters. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) measurements, scanning electron microscope (SEM), Energy dispersive X-rays (EDX) analysis and contact angle measurements were utilized to investigate the corrosion protection performance of ODA-TS and OA-TS on steel in acidic solution. The OA-TS and ODA-TS compounds showed good protection performance in acidic chloride solution due to formation of an inhibitive film on the steel surface.

Study of Surface Active Characteristics of Developed Detergent for Fur Treatment

Abstract The physicochemical and colloid-chemical characteristics of a developed detergent were studied. Due to synergism of surfactants of different nature the wetting and emulsifying ability as Well as the detergency of the developed detergent are very high.