Anionic Molecules Research Articles

The influence of photo-stimulated adsorption of polyelectrolyte molecules on electro-physical characteristics of structures based on single crystal silicon substrates

The effect of photo-stimulated adsorption of cationic (polyethylenimine, PEI) and anionic (glucose oxidase, GOx) polyelectrolyte molecules on C-V characteristics of a electrolyte/insulator/semiconductor structure was investigated. We obtained that illumination of semiconductor during the adsorption of PEI increases a shift of the flat band potential by 29% and 45% for n-Si and p-Si, respectively. Furthermore, depending on a Si conductivity type, the photo-stimulated adsorption of GOx molecules either increases (for n-Si/PEI) or decreases (for p-Si/PEI) the C-V shift, which was explained by corresponding changes of enzyme molecules on the surface, respectively. Our research is useful in fabrication of potentiometric biosensors since the growth of enzyme molecules density on the surface of the semiconductor transducer increases the threshold sensitivity of the sensor.

Anti-ICAM-1 antibody-modified nanostructured lipid carriers: a pulmonary vascular endothelium-targeted device for acute lung injury therapy

BackgroundAcute lung injury (ALI) is a life-threatening clinical syndrome without effective treatment. Targeting delivery of glucocorticoid to lung shows potential efficacy for ALI based on their anti-inflammatory and anti-fibrotic properties, breaking through their clinical application limitation due to systemic side effects. This work was aimed to establish lung-targeted dexamethasone (DEX) loaded nanostructured lipid carriers (NLCs) with opposite surface charge and investigate their therapeutic effects on lipopolysaccharide (LPS)-induced ALI mice.ResultsThe diameter of anionic anti-intercellular adhesion molecule 1 (anti-ICAM-1) antibody-conjugated DEX-loaded NLCs (ICAM/DEX/NLCs) and the cationic ones with octadecylamine (ODA) modification (ICAM/DEX/ODA-NLCs) was about 249.9 and 235.9 nm. The zeta potential of ICAM/DEX/NLCs and ICAM/DEX/ODA-NLCs was about − 30.3 and 37.4 mV, respectively. Relative to the non-targeted control and ICAM/DEX/ODA-NLCs, ICAM/DEX/NLCs exhibited higher in vitro cellular uptake in LPS-activated human vascular endothelial cell line EAhy926 after CAM-mediated endocytosis, and stronger in vivo pulmonary distribution in the ALI model mice. In vivo i.v. administration of ICAM/DEX/NLCs significantly attenuated pulmonary inflammatory cells infiltration, and the production of pro-inflammatory cytokine TNF-α and IL-6 in ALI mice. H&E stain also revealed positive histological improvements by ICAM/DEX/NLCs.ConclusionsICAM/DEX/NLCs may represent a potential pulmonary endothelium targeted device, which facilitate translation of DEX into clinical ALI treatment.

Physicochemical and Tribological Performance of Bi‐Component Supramolecular Gel Lubricants

AbstractHere, reported is a new, simple, and nonsynthetic way of in situ preparation of bi‐component supramolecular gel lubricants, which are formed by supramolecular self‐assembly of bis(2‐ethylhexyl) sulfosuccinate (AOT) and aromatic acid derivatives via the noncovalent interaction in the base lubricating oil. The formation mechanism of the gel lubricant was investigated by experimental and theoretical calculations. The results of 1H nuclear magnetic resonance, ultraviolet, and molecular dynamics simulations show that they formed a network structure through intermolecular hydrogen bonding and π–π stacking, thereby solidifying the base oil to form gel. The rheological and thermal analysis results show that these gels have shear thinning, creep recovery, and excellent thermal stability, and such characteristics make them potential as a lubricant for special mechanical working conditions. Indeed, tribological data also show that compared with commercial mineral oil 500SN, the gel lubricant has excellent lubricity, anti‐wear, and load‐carrying capacity, which is attributed to the introduction of the anionic surface active agent AOT molecules. Quartz crystal microbalance and X‐ray photoelectron spectrometer characterization proves that AOT forms an effective adsorption film and tribochemical reaction film on the contact surface in the process of friction.

Azalomycin F5a, a polyhydroxy macrolide binding to the polar head of phospholipid and targeting to lipoteichoic acid to kill methicillin-resistant Staphylococcus aureus

Azalomycin F5a was a polyhydroxy macrolide produced by streptomycete strains. Our preliminary researches indicated that it could kill methicillin-resistant Staphylococcus aureus (MRSA) likely by increasing the permeability of cell membrane, and that cell-membrane phospholipids were likely important targets. To confirm this, membrane permeability assay was performed and visualized by fluorescence staining, and then the detailed interactions between azalomycin F5a and model membranes prepared with 1,2-dihexadecanoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DPPG) were determined using attenuated total reflectance fourier transform infrared spectroscopy and 31P nuclear magnetic resonance techniques. The results indicated that there were strong interactions between azalomycin F5a and model membranes, especially between azalomycin F5a and the polar head of phospholipid. For further evidence and details, the molecular dynamics (MD) simulation of the interactions between azalomycin F5a and DPPG or lysyl-DPPG were performed using Amber16 software package. A strong interaction between the lactone ring of azalomycin F5a and the polar head of DPPG or lysyl-DPPG had been clearly observed. Moreover, a larger distribution probability out of phospholipid bilayer had been discovered for the guanidyl side chain of azalomycin F5a, especially when probable anion molecules anchoring on the cytoplasmic membrane occurred. Therefore, lipoteichoic acid (LTA), a vital component of gram-positive bacterial envelope, was investigated for its probable interactions with azalomycin F5a using broth microdilution method. The results showed that azalomycin F5a-induced MRSA lysis could be prevented by LTA. This deduced that there were some interactions between azalomycin F5a, more likely its guanidyl side chain, and LTA. Thereby, azalomycin F5a increasing the cell-membrane permeability of MRSA had likely achieved by the synergy of its lactone ring binding to the polar head of phospholipid and its guanidyl side chain targeting to LTA, and which had eventually led to the autolysis of MRSA cells.

Induced-fit expansion and contraction of a self-assembled nanocube finely responding to neutral and anionic guests

Induced-fit or conformational selection is of profound significance in biological regulation. Biological receptors alter their conformation to respond to the shape and electrostatic surfaces of guest molecules. Here we report a water-soluble artificial molecular host that can sensitively respond to the size, shape, and charged state of guest molecules. The molecular host, i.e. nanocube, is an assembled structure consisting of six gear-shaped amphiphiles (GSAs). This nanocube can expand or contract its size upon the encapsulation of neutral and anionic guest molecules with a volume ranging from 74 to 535 Å3 by induced-fit. The responding property of this nanocube, reminiscent of a feature of biological molecules, arises from the fact that the GSAs in the nanocubes are connected to each other only through the hydrophobic effect and very weak intermolecular interactions such as van der Waals and cation-π interactions.

Antiviral activity of metal chelates of caffeic acid and similar compounds towards herpes simplex, VSV-Ebola pseudotyped and vaccinia viruses

Organic compounds with a caffeoyl moiety (e.g. caffeic acid, rosmarinic acid, chicoric acid, etc.) have antiviral properties towards herpes simplex (HSV), influenza and immunodeficiency viruses (HIV). This study evaluated the HSV antiviral properties of caffeic acid when paired with a variety of metal and other inorganic ions. The results demonstrated that the antiviral activity of caffeic acid increased upwards of 100-fold by the addition of cations, such as Fe3+, and anionic molecules, such as molybdate and phosphate. Cellular toxicity tests of the caffeic acid chelates showed that they have low toxicities with selectivity indices (TD50/EC50) for Fe3+, MoO42−, and PO43− chelates being 1700, >540, and >30, respectively. Caffeic acid paired with Fe3+ was tested against eight strains of viruses, including those from different families. The caffeic acid chelates were mostly effective against HSV1 and HSV2, but they also had moderate activity against vaccinia virus and a VSV-Ebola pseudotyped virus. All the viruses that were strongly impacted by the caffeic chelates require heparan sulfate proteoglycans for cellular attachment, so it is likely that caffeic chelates target and interfere with this mechanism. Since the caffeic acid chelates target an extra-cellular process, they might be able to be combined with existing medications, such as acyclovir, that target an intracellular process to achieve greater viral control.

Carbon Nanotubes Microenvironment in Ionic Surfactant Water Solutions

The processes of aggregation of anionic (SDS) and cationic (CTAB) molecules into supramolecular formations and the effect of carbon nanotubes on the processes were investigated by conductometry and tensiometry methods. Concentration dependences of the specific electrical conductivity and surface tension of aqueous SDS and CTAB dispersions and suspensions of carbon nanotubes of the carbon nanomaterial Taunit in these dispersions were obtained. A conclusion on the change in the conformation of CTAB micelles in the presence of carbon nanotubes was drawn. A significant increase in the packing density of CTAB molecules and their ordering in the monomolecular layer at the water-air interface in the presence of carbon nanotubes was shown. In particular, this makes it possible to control the properties of the surfactant surface layer by means of carbon nanotubes.

Selective Grafting of Polyamines to Polyether Ether Ketone Surface during Molding and Its Use for Chemical Plating

We present a new approach of surface functionalization of polyether ether ketone (PEEK) that is carried out during the molding step. Thin films of polymers with different functional groups were applied to the surface of a mold and brought in close contact with a PEEK melt during injection molding. The surfaces of the produced parts were characterized after solidification. Only those PEEK surfaces that were in contact with polymers bearing primary amino groups exhibited a wettability for water. Obviously, the thin polymer film was grafted to the surface by a chemical reaction initiated by the high melt temperature. The formation of azomethine bonds between PEEK and the polyamine by coupling to the ketone groups was proposed. The other amino groups in the molecule were still in function after the molding process. They adsorbed different anionic molecules and anionic charged nanoparticles from aqueous solutions. The surfaces could be chemically plated by copper and nickel with high adhesion.

Selective Permeability of Carboxysome Shell Pores to Anionic Molecules.

Carboxysomes are closed polyhedral cellular microcompartments that increase the efficiency of carbon fixation in autotrophic bacteria. Carboxysome shells consist of small proteins that form hexameric units with semipermeable central pores containing binding sites for anions. This feature is thought to selectively allow access to RuBisCO enzymes inside the carboxysome by HCO3- (the dominant form of CO2 in the aqueous solution at pH 7.4) but not O2, which leads to a nonproductive reaction. To test this hypothesis, here we use molecular dynamics simulations to characterize the energetics and permeability of CO2, O2, and HCO3- through the central pores of two different shell proteins, namely, CsoS1A of α-carboxysome and CcmK4 of β-carboxysome shells. We find that the central pores are in fact selectively permeable to anions such as HCO3-, as predicted by the model.

Multilayer Hydrogel Capsules of Interpenetrated Network for Encapsulation of Small Molecules.

We report on a facile capsule-based platform for efficient encapsulation of a broad spectrum of hydrophilic compounds with molecular weight less than 1000 g mol-1. The encapsulated compounds extend from low-molecular-weight anionic Alexa Fluor 532 dye and cationic anticancer drug doxorubicin (DOX) to fluorescein isothiocyanate-dextrans with Mw ranging from 4000 to 40 000 g mol-1. The pH-sensitive hydrogel capsules with an interpenetrated network shell are synthesized by layer-by-layer assembly of poly(methacrylic acid) (PMAA, Mw = 150 000 g mol-1) and poly( N-vinylpyrrolidone) (PVPON, Mw = 1 300 000 g mol-1) on 5 μm silica microparticles followed by chemical cross-linking of the PMAA multilayers. Following core dissolution, the result is a hollow microcapsule with PVPON interpenetrated in the PMAA network. The capsules exhibit a reversible change in the diameter with a swelling ratio of 1.5 upon pH variation from 7.5 to 5.5. Capsules cross-linked for 4 h display high permeability toward molecules with molecular weight under 1000 g mol-1 at pH = 7.5 but exclude dextran molecules with Mw ≥ 40 000 g mol-1. Encapsulation of small molecules was achieved at pH = 7.5 followed by sealing the capsule wall with 40 000 g mol-1 dextran at pH = 5.5. This approach results in negatively charged molecules such as Alexa Fluor being entrapped within the capsule cavity, whereas positively charged molecules such as DOX are encapsulated within the negatively charged capsule shell. Considering the simple postloading approach, the ability to entrap both anionic and cationic small molecules, and the pH-responsiveness of the interpenetrated network in the physiologically relevant range, these capsules offer a versatile method for controlled delivery of multiple hydrophilic compounds.

The role of adatoms in chloride-activated colloidal silver nanoparticles for surface-enhanced Raman scattering enhancement.

Chloride-capped silver nanoparticles (Cl-AgNPs) allow for high-intensity surface-enhanced Raman scattering (SERS) spectra of cationic molecules to be obtained (even at nanomolar concentration) and may also play a key role in understanding some fundamental principles behind SERS. In this study, we describe a fast (<10 min) and simple protocol for obtaining highly SERS-active colloidal silver nanoparticles (AgNPs) with a mean diameter of 36 nm by photoconversion from AgCl precursor microparticles in the absence of any organic reducing or capping agent. The resulting AgNPs are already SERS-activated by the Cl− ions chemisorbed onto the metal surface where the chloride concentration in the colloidal solution is 10−2 M. Consequently, the enhanced SERS spectra of cationic dyes (e.g., crystal violet or 9-aminoacridine) demonstrate the advantages of Cl-AgNPs compared to the as-synthesized AgNPs obtained by standard Ag+ reduction with hydroxylamine (hya-AgNPS) or citrate (cit-AgNPs). The results of SERS experiments on anionic and cationic test molecules comparing Cl-AgNPs, hya-AgNPs and cit-AgNPs colloids activated with different amounts of Cl− and/or cations such as Ag+, Mg2+ or Ca2+ can be explained within the understanding of the adatom model – the chemisorption of cationic analytes onto the metal surface is mediated by the Cl− ions, whereas ions like Ag+, Mg2+ or Ca2+ mediate the electronic coupling of anionic species to the silver metal surface. Moreover, the SERS effect is switched on only after the electronic coupling of the adsorbate to the silver surface at SERS-active sites. The experiments presented in this study highlight the SERS-activating role played by ions such as Cl−, Ag+, Mg2+ or Ca2+, which is a process that seems to prevail over the Raman enhancement due to nanoparticle aggregation.

Role of DTAB and SDS in Bubble-Particle Attachment: AFM Force Measurement, Attachment Behaviour Visualization, and Contact Angle Study

Atomic force microscopy (AFM) and contact angle measurements were used to study the role of dodecyltrimethylammonium bromide (DTAB) and sodium dodecyl sulphate (SDS) in bubble-particle attachment. The results show that the forces between bubbles and the hydrophilic glass particle were always repulsive in the absence of DTAB and SDS. An attractive hydrophobic force was induced when the particles became hydrophobic, and the force was proportional to the water contact-angle. In the presence of DTAB and SDS, the cationic head group of DTAB adsorbed onto the negative hydrophilic glass surface as a monolayer and thus induced a hydrophobic force. However, at a high DTAB concentration, the DTAB molecules began to adsorb as a bilayer, reverting back to a hydrophilic surface. The hydrophobic force disappeared and the water film between the bubble and particle was stabilised under the repulsive double-layer force. The anionic SDS molecules could not adsorb onto the hydrophilic glass surface. The repulsive force always dominated the bubble-particle interaction. In the case of hydrophobic glass, the hydrophobic force decreased, and even disappeared, with the addition of DTAB and SDS. All the findings from the AFM force curves were consistent with the attachment behaviour and contact angle results.

Interfacial dilational rheology of fatty acid methyl ester and alkyl benzene sulfonate mixed solutions

The dilational rheological properties of aqueous solutions of anionic surfactant sodium 3,4-diheptylbenzene sulfonate (C7C7phS), nonionic surfactant oxyethylated fatty acid methyl esters (C18=E10) and their mixtures have been investigated at the kerosene-water interface by the oscillating drop method. The influences of time, dilational frequency, bulk concentration and interfacial pressure on the dilational properties have been expounded. The experimental results show that the in-film process, such as the orientation change of EO chain, controls the properties of adsorption layers formed by nonionic surfactant C18=E10 molecules. On the other hand, the diffusion-exchange process plays the crucial roles in determining the nature of film containing anionic surfactant C7C7phS molecules. The dilational rheological behaviors of C18=E10/C7C7phS mixtures in the presence of 1 × 10−5 mol·L−1 C7C7phS are close to those of C18=E10. At the same time, mixtures at mole ratio 1:1 show similar behaviors with C7C7phS. The mixed adsorption of C18=E10 and C7C7phS may lead to more compact films and result in higher interfacial elasticity.

Simultaneous double cationic and anionic molecule separation from herring milt hydrolysate and impact on resulting fraction bioactivities

Abstract The increase in fish consumption, over the last twenty years, is linked to by-product production, rich in valuable compounds such as proteins, vitamins, minerals or lipids (omega-3). Milt herring hydrolysate, containing different molecules, has been fractionated by electrodialysis with ultrafiltration membrane (EDUF) in a new configuration using four ultrafiltration membranes, allowing a simultaneous and double fractionation of anionic and cationic molecules. Four fractions were recovered, each were concentrated in compounds of low molecular weight (

Mechanistic aspects for the removal of Congo red dye from aqueous media through adsorption over N-doped graphene oxide nanoadsorbents prepared from graphite flakes and powders

This work reports the mechanistic models responsible for the adsorptive removal of Congo red (CR) dye molecules by nitrogen-doped graphene oxide nanosheets (NGO) prepared via a one-pot modified Hummer's method using either graphite powder (to form NGOp) or graphite flakes (to form NGOf) as starting materials. The microstructural properties, surface chemistry and thermal stability of the produced NGO adsorbents were ascertained using a range of characterization techniques. The effects of adsorbent dosage, CR dye initial concentration, contact time and solution pH on the removal of CR dye were studied. The NGO adsorption process was highly dependent on initial dye concentration, contact time, adsorbent dosage, pH, NGO surface area and nanosheet size. The NGOp nanoadsorbents exhibited excellent selectivity towards the removal of CR dye molecules than NGOf. NGOp adsorbents achieved maximum removal efficiency of 98–99% at a pH of 2 compared to NGOf that achieved 96–98%. The adsorption kinetics and isotherms for CR dye on the NGO adsorbents were well fitted to the pseudo second-order kinetic model. The Langmuir isotherm model indicated that the adsorption behavior occurred via chemisorption and in a homogeneous monolayer on the surface of NGO. Our findings suggest that the adsorption mechanism involved was due to electrostatic interactions between the negatively charged (oxygen-containing) and positively charged (nitrogen-containing) groups on the NGO adsorbents and the positively charged (amino and cationic azo-linkages) and negatively charged (sulfonic (SO3−)) groups on the anionic CR dye molecules. The electrostatic interactions between oxygen and nitrogen containing functional groups present on the NGO surface and functional moieties of CR molecules are necessary for the enhancement of CR adsorption over NGO surface (based on the existing pH dependence). NGOp nanosheets have shown to have higher removal potential and adsorption capacity toward CR dye compared to undoped GO and NGOf adsorbents. In particular, this work indicates that NGOp can serve as good adsorbents in the removal of anionic dyes in wastewater treatment processes.

Iron Oxide Magnetie-Polyethylene Glycol-Layered Double Hydroxide Core Shell Nanoparticles for Drug Delivery

Recently, micro- and nanoparticles with magnetic core and functional shell structures have received much attention because of their potential applications in drug delivery, biosensors catalysis, selective separation and chromatography etc. Layered double hydroxides (LDHs) nanoparticles (NPs) are an efficient cellular delivery vehicle for many negatively charged chemical species. Recently, Mg and Zn/Al-layered double hydroxide (Mg/Al-LDH) and (Zn/Al-LDH) has emerged as a promising nanocarrier for drug delivery system due to its unique properties such as low cytotoxicity, pH-controlled release, good biocompatibility, tunable particle size, and protection of drugs in the interlayer. Various anionic biofunctional molecules, including DNA, SiRNA, drugs and vitamins have been successfully intercalated into LDH interlayers, protected from enzyme degradation and delivered into the cytoplasm in mammalian cells through the clathrin-mediated endocytosis pathway. In this study, a magnetite core shell nanodrug delivery formulation was designed based on Fe3O4-PEG-Zn/Al-LHDs or Mg/Al-LDHs loaded with anticancer drug 5-Fluoro-2,4(1H,3H)-pyrimidinedione commonly called 5-fluorouracil. Designed core shell magnetite nanoparticles formulation was characterized using XRD, zeta sizer and high performance liquid chromatography (HPLC).

Multinuclear magnetic resonance investigation of cation-anion and anion-solvent interactions in carbonate electrolytes

The investigation of ion-solvent interaction in electrolytes is crucial for basic understanding of ion transport through the bulk electrolyte as well as interphase formation processes on both electrodes, which dictate performances of lithium ion batteries (LIBs). In this report, nuclear magnetic resonance (NMR) was used to study the solvation behaviors of two typical lithium salts (lithium hexafluorophosphate, or LiPF6, and lithium tetrafluoroborate, or LiBF4) dissolved in ethylene carbonate (EC)/dimethyl carbonate (DMC) mixtures. With increasing salt concentration and DMC percentage in both systems, 19F NMR experiences an upfield shift along with decreasing J31P−19F and J11B−19F, which evidence the stronger interaction between the Li+ and F− in an environment with diminishing presence of high dielectric medium. The quadrupolar relaxation of 11B dominates the 19F relaxation mechanism and demonstrates that LiBF4 mainly exists as ion pairs in solution either at high salt concentration or in a medium of low polarity. 7Li, 19F, 1H NMR diffusion measurements were conducted to characterize the relative mobility of cation, anion and solvent molecules, the results of which support the conclusion above. Salt concentration and solution polarity have a much stronger effect on cation-anion aggregation and solvation in the LiBF4 system than in the LiPF6 system.

Antimicrobial anionic polymers: the effect of cations

Development of antibacterial materials with broad spectrum activity has attracted extensive attention. Herein, anionic small molecule and their corresponding anionic polymers with various organic cations, including cyclized cations (imidazolium [Im] and piperidinium [Pi]), and linear cations (quaternary ammonium [Qa] and phosphonium [Ph]) were synthesized for the antibacterial applications. The effect of cationic structures on the antibacterial activities against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were studied systematically by determination of minimum inhibitory concentration (MIC) and molecular dynamics simulations (MDS). The antibacterial activities of the anionic small molecules against both S. aureus and E. coli are in the following order: phosphonium > imidazolium > piperidinium > quaternary ammonium. As for the anionic polymers, such a chemical cationic structure-antibacterial property relationship can also be applied to evaluate that of corresponding anionic polymers. Furthermore, the antibacterial activities of anionic polymers against S. aureus are higher than those of corresponding anionic small molecules. The synthesized anionic small molecules and anionic polymers exhibited good hemocompatibility toward human red blood, demonstrating clinical feasibility in topical applications.

Corrosion protection performance of Mo-incorporated 2-hydroxyphosphonoacetic acid-Zn2+ complex conversion layers on the cold-rolled steel substrate

A coordination-induced film-forming method was developed to construct 2-hydroxyphosphonoacetic acid (HPAA)-Zn2+ complex conversion layer (HPAA-Zn2+ layer for short) on cold-rolled steel (CRS) substrate. Moreover, the incorporation of Mo component into the HPAA-Zn2+ layer can significantly improve the uniformity and anticorrosion properties. The results showed that Mo-incorporated HPAA-Zn2+ layer displayed the best anticorrosion performance when the molar ratio of HPAA/Zn2+ was 1:1, the film-forming time was 10 min, and the concentration of molybdate was 0.1 wt%. In addition, energy dispersive spectroscopic (EDS) and X-ray photoelectron spectroscopic (XPS) results demonstrated that the Mo-incorporated HPAA-Zn2+ layer was mainly composed of ZnO and HPAA-Zn2+ complex and also confirmed that Mo-O-P bonds occurred between molybdate anion and HPAA molecule.

Studies on Interfacial Tensions of Ionic Surfactant and Alkyl Sulfobetaine Mixed Solutions

To expound the mechanisms responsible for reducing interfacial tensions (IFTs) in amphoteric and ionic surfactant mixed systems, the IFTs of mixed solutions containing alkyl sulfobetaine (ASB) and different ionic surfactants against hydrocarbons with different carbon numbers have been investigated by the spinning drop method. For cationic surfactants, the antagonistic effect for reducing IFT appears between cationic and ASB molecules because of electrostatic repulsion, which results in competitive adsorption. On the other hand, the synergistic effect will be observed in ionic and ASB mixed systems as a result of the mixed adsorption caused by the electrostatic attraction. The “chain length compatibility” between the anionic surfactant and ASB molecules leads to a stronger synergistic effect and further reduces IFT. However, “size compatibility” plays the crucial role, and only mixed solutions containing an anionic surfactant with a larger hydrophobic group can produce ultralow IFT against hydrocarbons. Th...