Nonionic Sugar-based Surfactants Research Articles

Enhanced solubilization of strongly adsorbed organic pollutants using synthetic and natural surfactants in soil flushing: Column experiment simulation

This study investigates the performance of two non-ionic sugar-based surfactants, belonging to the families of synthetic alkylpoliglucosides and biological rhamnolipids, for enhancing the solubilization and mass transfer of strongly adsorbed hydrophobic organic compounds (HOCs) in porous media. Using toluene and perchloroethylene (PCE) as reference pollutants, a continuous configuration test (column experiment) was performed to simulate a soil flushing process under controlled laboratory conditions. The potential applicability of the selected surfactants in remediation processes was evaluated within the context of Surfactant Enhanced Aquifer Remediation (SEAR) technology. Experimental results showed that both surfactants effectively increased the solubilization of contaminants adsorbed on porous media. Compared to H2O flushing, synthetic surfactant increased the solubilization of toluene by 52% and the solubilization of PCE by 81%, while biosurfactant increased solubilization ability by 73% and 92% for toluene and PCE, respectively. Biosurfactant exhibited the greatest solubilization ability, with 92% of adsorbed toluene and 98% of adsorbed PCE solubilized. This research highlights the potential of green surfactants as efficient candidates for remediation processes due to their excellent solubilization ability and environmentally friendly nature.

Performance of alkyl β-D-maltosides in molecular self-assembly and formation of oil-in-water nanoemulsions as drug delivery systems

Alkyl β-D-maltosides are nonionic sugar-based surfactants that can be used as excipients in lipid-based nanoparticles because of their physiological functions and biocompatibility. The self-assembly of alkyl β-D-maltosides (C8-C12) was studied to investigate the effects of alkyl chain length in the binary and ternary systems. Surface tension measurements in the binary systems revealed a synergistic effect on the stability of mixed surfactants with Tween 80 (T80) in the critical aggregation concentration (CAC). Subsequently, formulations of 10:90 wt% oil-in-water (O/W) nanoemulsions (ternary systems) containing T80/alkyl β-D-maltosides with and without cyclosporine (CsA) as the hydrophobic model drug were characterised by particle size, polydispersity index (PDI), morphology, rheology, and physical stability. The formulations of all nanoemulsion systems were found to be stable against phase separation for 28 days at room temperature. The hydrophobic effect of n-dodecyl-β-D-maltoside (DDM, C12) was stronger by enhancing the stability of T80 nanoemulsion in molecular self-assembly compared to the shorter chains of the maltosides. The in vitro drug release study showed that T80/DDM nanoemulsion improved the cumulative release of CsA in 24 h by 98.33 ± 7.72% compared to T80 nanoemulsion at 83.75 ± 4.05%. The release of CsA has the highest fit with the Korsmeyer-Peppas kinetic model (R2 > 0.9), suggesting that CsA is released slowly from the oily core of nanoemulsions to the dissolution medium due to its hydrophobic nature. The cytotoxicity study against 3T3 cells showed that all formulations had no cytotoxicity effect (IC50) up to 500 μg/mL. The findings demonstrated that T80/DDM nanoemulsion holds great promise as a drug delivery system for the treatment of psoriasis.

Foaming behavior of sugar-based surfactants: influence of molecular structure and anticipation from surface properties

Sugar-based surfactants are a class of environmentally-friendly surface-active molecules well known for their functional performances, good biodegradability and reduced ecological footprint. Many previous studies have explored the surface properties of these surfactants. However, very little research has investigated their foaming properties. The present study examines the foaming behavior of 17 nonionic sugar-based surfactants with gradual structure variation. Foaming properties such as foamability, foam stability and maximum foam density were measured using the gas-sparging method. The influence of surfactant structure and concentration on foaming properties was evaluated. The data on surface adsorption properties, determined in the previous study, and foaming properties were then analyzed using a Principal Component Analysis. It was shown that the foaming behavior of glycolipids can be correlated to concentration and interfacial properties. Predictive models are proposed to anticipate the foaming behavior and provide a useful guide for screening the foamability of bio-based surfactants in various technological applications.

Phase Studies and Efficient Recovery of Inorganic Metal Salts from the Microemulsion System Using a Sugar-Based Non-Ionic Surfactant

Abstract In the present work, the phase behaviour of the microemulsion system formulated by using water, organic solvent, and a sugar-based non-ionic surfactant was investigated in detail. We have used a sugar-based non-ionic surfactant for formulation of microemulsion, as it is a greener alternative for the formulation of a microemulsion system, owing to the following aspects: a) better physicochemical properties as compared to that of the conventional non-ionic surfactants, b) non-toxicity, and c) biodegradability. The extraction of heavy metal ions from the metal complexes as well as the recovery efficiency of heavy metal ions using a microemulsion system has been investigated. The maximum absorbance values of metal ions, after recovery from the metal complexes, were measured. Moreover, the UV-Visible spectrophotometric studies revealed that the absorbance increases with an increase in metal ion concentration in the aqueous phase while its value decreases with an increase in the concentration of potassium thiocyanate in the aqueous phase after the extraction of the metal ions from the metal complexes. Furthermore, it has also been evaluated that 4.0 mol/L potassium thiocyanate is the optimum concentration required for efficient recovery of 0.05 mol/L cobalt ion as well as nickel ions. The recovery efficiency of cobalt ions was found to be 97%, whereas that of nickel ions was determined to be 94% respectively. In addition to being an environmentally friendly approach, the present work is an economically viable option too, as it deals with the studies related to the extraction and efficient recovery of metal ions.

Gelled non-toxic bicontinuous microemulsions as promising transdermal drug carriers

Gelled non-toxic bicontinuous microemulsions have great potentials in transdermal drug delivery. The bicontinuous microemulsion provides optimum drug solubilisation and promotes skin permeation, while the gel network provides mechanical stability and an easy application. For the first time, we have formulated such a gelled non-toxic bicontinuous microemulsion consisting of H2O, isopropyl myristate (IPM), the non-ionic sugar-based surfactant Plantacare 1200 UP (C12G1.4), 1,2-octanediol, and the low molecular weight gelator 1,3:2,4-dibenzylidene-D-sorbitol (DBS). In this study, we solubilised both hydrophobic and hydrophilic model drugs in the non-toxic bicontinuous microemulsion, namely lidocaine and diclofenac sodium salt. We found that the microemulsion allows for the solubilisation of designated amounts of both model drugs in the same formulation. Interestingly, the combination of both drugs led to the unexpected stabilisation of a scattering one-phase formulation without adding the surfactant Plantacare 1200 UP. Furthermore, the drug-loaded microemulsions were gelled by DBS without altering the phase behaviour. Finally, we found the rheological behaviour of the drug-free and drug-loaded microemulsions to be quite similar. These results suggest that the drug-containing gelled bicontinuous microemulsion is an orthogonal self-assembled system with a high potential for the use in transdermal drug delivery.

Physicochemical, foaming and biological properties of lowly irritant anionic sugar-based surfactants

Surface-active compounds derived from biomass, especially sugar-based amphiphiles, have received wide attention regarding their biodegradability, low toxicity and ecological acceptability. Compared to nonionic sugar-based surfactants, the anionic ones show significantly better solubility, higher surface activity and foaming performance. Thus they are largely used in personal care formulations and many technological applications. However, anionic surfactants are well known to induce skin and eye irritation.In this study, three sugar-based anionic surfactants, bearing a lipidic chain grafted to the anomeric position of a monosaccharide (glucose or xylose) and a sulfate group on the primary hydroxyl, were synthesized: 6-O-sulfo-N-(β-d-glucopyranosyl) dodecanamide (GlcNC12S), N-dodecyl-6-O-sulfo-d-gluconamide (GlcCC12S) and N-dodecyl-6-O-sulfo-d-xylonamide (XylCC12S). These molecules were investigated in details for their self-assembling behavior, foaming properties and biological effects. All their properties were compared to those of two commercially available anionic surfactants, sodium laureth sulfate (SLES) and sodium dodecylsulfate (SDS).Results revealed that the three anionic glycolipids show surface properties and foaming behavior comparable to those of SDS. Furthermore, their cytotoxic and irritation potentials are significantly lower compared to commercial molecules, which make these renewable molecules potential candidates for replacement of petroleum-based compounds.

Dynamic interfacial properties of sugar-based surfactants: Experimental study and modeling

Careful investigation about dynamic adsorption properties of surfactant molecules has a tremendous interest for their practical applications. The intention of this article is to study the dynamic adsorption properties at air/water interface for 16 nonionic sugar-based surfactants with gradual structure variation. Based on obtained results the dynamic surface tension (DST) behaviour of glycolipids was found to depend on both hydrophobic chain length and bulk concentration of surfactant. Interestingly, the plot of the maximum rate of surface tension decrease against the surfactant bulk concentration showed a linear trend for all studied surfactants independently of their structure. Furthermore, it was confirmed that all molecules were gathered on one unique curve representing a plot of the limit elasticity versus the relative surface concentration of surfactant. The using approach provided further insight into the anticipation of the dynamic surface properties of sugar-based amphiphiles.

Phase behavior and microstructure of sugar surfactant-ionic liquid microemulsions

Microemulsions have been explored as a unique and versatile reaction media for a variety of chemical reactions, viz. nanoparticle preparation, organic synthesis, bio-organic synthesis etc. The phase behavior and microstructure of a ternary system water/1-butyl-3-methylimidazolium hexafluorophosphate/Sugar Surfactant was studied as a function of temperature and sugar surfactant mass fraction, γ. In the present study, a hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate was used to replace commonly used organic solvents (n-alkanes) as an oil/non-polar phase substitute in ternary microemulsion formulations, wherein, a sugar based alkyl polyglycoside nonionic surfactant was used instead of a conventional nonionic surfactant (i.e., alkyl polyoxyethylene ether class) to solubilize hydrophobic ionic liquid and water. The effect of alkanols of variable chain length (octanol, decanol and dodecanol) as co-surfactant on the phase behavior and microstructure of ionic liquid/sugar surfactant/water ternary microemulsion systems was also investigated. The ability of nonionic sugar-based surfactant n-decyl β-D-maltoside, and n-dodecyl β-D-maltoside, to solubilize oil (hydrophobic ionic liquid) and water, i.e., was evaluated. Moreover, phase behavior and microstructure of ternary systems, 1-butyl-3-methylimidazolium tetrafluoroborate:water (1:1)/sugar surfactant/n-alkanes (alkanes of varying chain length, i.e., octane, decane and dodecane) was also studied. Solubilization of a water insoluble dye, Sudan Red, in selected microemulsion systems was also investigated.

Water Solubility and Surface Property of Alkyl Di-/Tri-/Tetraoxyethyl β-d-Xylopyranosides.

Alkyl di-/tri-/tetraoxyethyl β-d-xylopyranosides as derivatives of alkyl xylosides are a class of non-ionic sugar-based surfactants. They were stereoselectively synthesized by the Helferich method. Their properties including hydrophilic-lipophilic balance number, water solubility, surface property, foam property, emulsifying property, and thermotropic liquid crystal property were mainly investigated. The results showed that their water solubility decreased with increasing the alkyl chain length and increasing the number of the oligooxyethyl fragment. The critical micelle concentration had a monotonous decreasing trend with increasing the alkyl chain length. Nonyl di-/tri-/tetraoxyethyl β-d-xylopyranosides [-(OCH2CH2)m-, where m = 2, 3, and 4] exhibited the most excellent foaming ability and foam stability. In the n-octane/water system, dodecyl tetraoxyethyl β-d-xylopyranosides and tetradecyl tetraoxyethyl β-d-xylopyranosides had the strongest emulsion ability. In addition, some alkyl di-/tri-/tetraoxyethyl β-d-xylopyranosides had thermotropic liquid crystal properties. Such sugar-based surfactants, alkyl di-/tri-/tetraoxyethyl β-d-xylopyranosides, will be expected to develop for a variety of practical application.

Introduction of a nonionic sugar-based surfactant to an oppositely charged hydrophobically modified polyelectrolyte and surfactant binary system

Interactions between polymer and surfactant provide the system a variety of properties that can be readily used by industries to achieve desired features for their products and formulations. Inclusion of a third component to the binary system is expected to present synergistic or antagonistic effects, and also lead to preferred advantages, such as reduced quantities of the components to present a comparable performance and improved environmental-benignity. In this study a sugar-based surfactant n-Dodecyl β-D-Maltoside (DM) is introduced into an oppositely charged hydrophobically modified polyelectrolyte-surfactant system comprised by a guar grafted with hydroxypropyl trimethyl ammonium chloride (Guar-HTAC) and Sodium Dodecylsulfate (SDS). By following the pattern curves of surface tension, polarity and turbidity profiles, it was found that DM plays a crucial role in the interaction process: DM leads to the formation of a soluble but surface active complex which has not been observed in the Guar-HTAC/SDS and SDS/DM systems; since DM cooperates with SDS to form micelles at much lower SDS concentrations, under certain conditions it is SDS/DM micelles instead of single SDS or DM molecules that interact with Guar-HTAC. Such behaviors are believed to be resulted from the structures of the complexes formed by the three components. Molecular structures of these formed complexes need to be investigated following this study.

Curvophilic-curvophobic balance of monoalkyl-mannosides determines the magnitude of disturbance promoted in synthetic bilayers

The principles governing surfactant-lipid interactions, involved in biological membrane solubilization and reconstitution processes, are a topic of great interest in the field of membrane biochemistry and biophysics.Among non-ionic surfactants, which are extensively used in purification, characterization and reconstitution of membrane proteins and for reconstitution studies, sugar-based surfactants are particularly interesting because, besides being considered “green” chemicals, they have very good physical-chemical and dermatological properties. Mixtures of non-ionic sugar-based surfactants and phospholipids can result in interesting aggregates (micelles or vesicles) with promising applications in drug delivery, as a biocompatible carrier system.In this work, we studied how the incorporation of three different monoalkyl mannoside derivatives in synthetic bilayers modify their physical-chemical properties (transition temperature, fluidity) or promotes their solubilization. Determinations were made by using fluorescence spectroscopy, colorimetry and optical density measurements. Our results showed first that the mannoside derivatives behave different from other alkyl monosaccharides previously reported, such as glucosides and galactoside. Second, the ability of mannose derivatives to solubilize membranes dependents on its structure (length of alkyl chain) and the affinity between mannose derivatives and the lipid bilayer does not only depend on their Hydrophilic Lipophilic Balance, but also on the effect of the packing capabilities of the hydrophilic sugar head.

Synthesis and surface properties of alkyl β‑d‑thioglucopyranoside

Alkyl thioglycosides are a class of nonionic sugar-based sulfur-containing surfactants and bioreagents. The surfactants 1,2‑trans alkyl β‑d‑thioglucopyranosides with different alkyl chain length (n = 6–12) were stereoselectively prepared by the Helferich method. Their properties including HLB number, logP value, water solubility, foam property, emulsifying property, surface property and thermotropic liquid crystal property were mainly investigated. The results showed that their HLB numbers and water-solubility decreased as the related logP values increased with increasing the alkyl chain length. Alkyl β‑d‑thioglucosides were already insoluble in water with n ≥ 10. Both β‑d‑thioglucopyranosides (n = 8, 9) reduced the surface tension of the related aqueous solution to nearly 29 mN·m−1 at the critical micelle concentration (CMC), they also had excellent foaming ability and foam stability. Nonyl β‑d‑thioglucopyranoside had good emulsifying properties for both n‑octane/water system and toluene/water system. Alkyl β‑d‑thioglucopyranosides (n = 6–12) were observed to have the thermotropic liquid crystal properties.

Understanding of the foam capability of sugar-based nonionic surfactant from molecular level

In this paper, the correlation of the interfacial molecular array behavior of sugar-based green surfactant dodecyl maltoside DDM, and its apparent foam properties was investigated by molecular dynamics simulation and quantum chemical calculation as well as experimental methods. A common nonionic surfactant nona-ethylene glycol dodecyl ether C12E9, which has same hydrophobic tail and similar O atom number in headgroup with DDM, was studied as a reference. It was found that, not only the array behaviors of hydrophilic groups of DDM and C12E9 at the air-water interface, but also the intermolecular interactions were quite different. The simulation finding agreed well with the experimental results, by which how the interfacial molecular array behavior of the two types of nonionic surfactants affect the foam properties was revealed, and the application potential of DDM being used as foam stabilizer under diverse harsh conditions, such as high salinity, high temperature, strong acid and alkali, was presented, which should be quite meaningful.

Micellization of Lactosylammonium Surfactants with Different Counter Ions and Their Interaction with DNA

So far, the studies about the physical chemical properties of sugar-based surfactants have been still unsystematic; most of the studies have been focused on nonionic sugar-based surfactants. In the present work, we studied the micellization of four lactose-based surfactants, with the same headgroup (lactosylammonium) and the same hydrophobic alkyl chain (dodecyl) but different counterions (malonate, adipate, propionate, and hexanoate), at 25.0 and/or 50.0 °C. We found that these four surfactants could decrease the surface tension of water to ca. 30 mN/m. When the number of carboxylate groups in the counterion was the same, the counterion having a shorter alkyl chain could lead to a smaller minimum area per surfactant molecule. Moreover, the surfactants with monocarboxylates as counterions had much lower critical micelle concentrations than those with dicarboxylates as counterions, and the micelles from the former surfactants had a lower counterion binding degree. The lactosylammonium surfactants could bin...

Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer via covalent immobilization of nonionic sugar-based Gemini surfactants

Gemini surfactants (GS) with sugar-containing head-groups and different alkyl chains were successfully prepared. Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer was grafted with glycidyl methacrylate (GMA) by means of UV-induced graft polymerization, and then the pGMA-grafted film was chemically immobilized with the GS. The surface graft polymerization was confirmed by ATR-FTIR and XPS. The wettability and hemocompatibility of the modified surface were characterized by means of water contact angle, protein adsorption, and platelet adhesion assays. The results showed that amphiphilic surfactant-containing polymer surfaces presented protein-resistant behavior and anti-platelet adhesion after functionalization with GS, GS1 and GS2. Besides, the hemocompatibility of the modified surface deteriorated as the length of hydrophobic chain of GS increased.

Surface modification of polypropylene nonwoven fabrics via covalent immobilization of nonionic sugar-based surfactants

Amphiphilic N-alkyl-1-amino-1-deoxy-D-glucitol (CnAG, n=8, 12) were successfully prepared. Polypropylene nonwoven fabrics (PPNWF) were grafted with glycidyl methacrylate (GMA) via a technique of UV-induced graft polymerization combined with plasma pre-treatment, and then PPNWF-g-GMA was used for the covalent immobilization of CnAG. The surface graft polymerization was confirmed by ATR-FTIR and XPS, respectively. Effect of grafting parameters, e.g., acetone content, monomer concentration and UV irradiation time on the grafting density of GMA was investigated. And the hemocompatibility of the modified PPNWF was evaluated by protein adsorption and platelet adhesion. It was founded that the CnAG-modified substrates greatly suppressed protein adsorption and platelet adhesion compared with the native and pGMA-grafted PPNWF.

Molecular interactions of cationic gemini surfactants (m-s-m) with an environmental friendly nonionic sugar-based surfactant (β-C12G): Interfacial, micellar and aggregation behavior

In the present study, mixtures of cationic gemini surfactants with a non-ionic sugar-based surfactant in aqueous solutions containing electrolyte (NaBr) have been studied. The experimental results were evaluated using the Regular Solution Theory. The strength of interaction of all the surfactants is attributed to the sterical and electrical factors on mixed monolayer and micelle formation and of surfactant–surfactant interactions. The results show stronger interaction at the air/water interface and greater preference for adsorbing at the air/water interface relative to mixed micelle formation in the solution phase. The alkyl chain length and spacer of gemini govern the aggregation behavior of the mixed micelles.

Self-Aggregation of MEGA-9 (N-Nonanoyl-N-methyl-d-glucamine) in Aqueous Medium: Physicochemistry of Interfacial and Solution Behaviors with Special Reference to Formation Energetics and Micelle Microenvironment

Self-aggregation of MEGA-9 (N-nonanoyl-N-methyl-D-glucamine), a nonionic sugar-based surfactant, was studied with respect to the effect of salt (NaCl) and ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) on its critical micelle concentration (cmc), aggregation number, hydrodynamic dimensions, energetics of micellization, and micellar microenvironment. Fluorimetry (both steady state and time resolved) was used to understand the microenvironments under the influence of additives. NaCl was found to decrease cmc, increase aggregation number (N), increase micellar size, and decrease enthalpy of micelle formation; the IL effect on the parameters was mostly opposite. The microscopic properties of micelles were probed using two fluorophores: one nonpolar C-153 (2,3,5,6-1H,4H-tetrahydro-8-trifluormethylquinolizino-(9,9a,1-gh)coumarin) and the other fairly polar ANS (8-anilinonaphthalene-1-sulfonate); they delivered information on the palisade layer and the peripheral region of the micelle interface, respectively. Energy of activation and entropy of activation of the dynamics of the probes were evaluated from their decay time, lifetime, and rotational movements in the regions of residency in the micelles. Density functional theory (DFT) calculations showed that the ternary combination MEGA-9/IL/H2O had the maximum interaction energy compared to any of the binary combinations. Thus, the ionic liquid reduced MEGA-9 self-association to a large extent.

Interfacing Multistage Mass Spectrometry with Liquid Chromatography or Ion Mobility Separation for Synthetic Polymer Analysis

Synthetic polymers are naturally mixtures of homologs, even in pure form. More complexity is introduced by the presence of different comonomers, end groups and/or macromolecular architectures. The analysis of such systems is substantially facilitated by interfacing mass spectrometry (MS), which disperses based on mass, with an additional level of separation involving either interactive liquid chromatography (LC) or ion mobility (IM) spectrometry, both of which are readily coupled online with electrospray ionization and MS detection. IM-MS separates in the gas phase, post-ionization and, therefore, is ideally suitable for labile and reactive polymers. Its usefulness is illustrated with the characterization of non-covalent siloxane-saccharide complexes, metallosupramolecular assemblies and an air- and moisture-sensitive inorganic polymer, poly(dichlorophosphazene). Conversely, LC-MS which separates in solution phase, before ionization, is most effective for the analysis of polymeric mixtures whose components differ in polarity. Interactive LC conditions can be optimized to disperse by the content of hydrophobic units, as is demonstrated for amphiphilic polyether copolymers and sugar-based nonionic surfactant blends. Both LC-MS and IM-MS can be extended into a third dimension by tandem mass spectrometry (MS(2)) studies on select oligomers, in order to obtain insight into individual end groups and isomeric architectures, comonomer sequences and degree of substitution, for example, by hydrophobic functionalities.

1H NMR study of micelles formed by mixture of nonionic n-dodecyl- β- d-maltoside and cationic gemini surfactants

The relative arrangement and interaction of the cationic butane-1,4 bis(dodecyl dimethyl ammonium chloride) gemini (12–4–12) with nonionic sugar-based surfactant n-dodecyl- β- d-maltoside (DM) was studied by NMR techniques. It is shown that the methylene group next to the ammonium head in the gemini is close to the penultimate sugar ring of DM in their mixed micelles, and the hydrophobic chain of DM molecule and the two hydrophobic chains of 12–4–12 gemini are side by side in the interior of the micellar core. The size of the mixed micelles is largely dependent on the DM composition at fixed total surfactant concentrations. At fixed DM concentration, the interaction between DM and 12–4–12 gemini increases gradually with decrease in DM/12–4–12 ratio from 1:1 to 1:4. At higher 12–4–12 gemini ratios of 1:6 and 1:8.5, the intermolecular interaction starts to decrease gradually, implying the intramolecular interaction is more dominant than intermolecular interactions in the mixed micelles. NMR results suggest that relatively strongest intermolecular interactions in the mixed micelles of DM and 12–4–12 gemini exist at DM/12–4–12 mixing ratio of 1:4.