Micelle Formation In Solutions Research Articles

Coarse-Grained Model Incorporating Short- and Long-Range Effective Potentials for the Fast Simulation of Micelle Formation in Solutions of Ionic Surfactants.

A coarse-grained model comprising short- and long-range effective potentials, parametrized with the iterative Boltzmann inversion (IBI) method, is presented for capturing micelle formation in aqueous solutions of ionic surfactants using as a model system sodium dodecyl sulfate (SDS). In the coarse-grained (CG) model, each SDS molecule is represented as a sequence of four beads while each water molecule is modeled as a single bead. The proposed CG scheme involves ten potential energy functions: four of them describe bonded interactions and control the distribution functions of intramolecular degrees of freedom (bond lengths, valence angles, and dihedrals) along an SDS molecule while the other six account for intermolecular interactions between pairs of SDS and water beads and control the radial distribution functions. The nonbonded effective potentials between coarse-grained SDS molecules extend up to about 12 nm and capture structural and morphological features of the micellar solution both at short and long distances. The long-range component of these potentials, in particular, captures correlations between surfactant molecules belonging to different micelles and is essential to describe ordering associated with micelle formation. A new strategy is introduced for determining the effective potentials through IBI by using information (target distribution functions) extracted from independent atomistic simulations of a micellar reference system (a salt-free SDS solution at total surfactant concentration cT equal to 103 mM, temperature T equal to 300 K, and pressure P equal to 1 atm) obtained through a multiscale approach described in an earlier study. It employs several optimization steps for bonded and nonbonded interactions and a gradual parametrization of the short- and long-range components of the latter, followed by reparametrization of the bonded ones. The proposed CG model can reproduce remarkably accurately the microstructure and morphology of the reference system within only a few hours of computational time. It is therefore very promising for future studies of structural and morphological behavior of various liquid surfactant formulations.

Tracking Wormlike Micelle Formation in Solution: Unique Insight through Fluorescence Correlation Spectroscopic Study.

Although worm-like micelles were invented 35 years ago, its formation pathway remains unclear. Inspired by the fact that a single molecular level experiment could provide meaningful and additional information, especially in a heterogeneous subpopulation, herein, we present a single molecular level study on the formation of wormlike micelles by cetyltrimethylammonium bromide (CTAB) and sodium salicylate (NaSal) in water. Our results indicated a coexistence of normal spherical micelles along with a big wormlike micelle in its formation path. More interestingly, we have two unique insights into the formation mechanism, which are inaccessible in ensemble averaged experiments: (i) at extremely low concentrations of the surfactant, [CTAB]/[NaSal] ∼ 0.06, the wormlike micelle attains the highest size; and (ii) the relative concentration of wormlike micelles is highest when [CTAB]/[NaSal] ∼ 2.

Rheology study of wormlike micellar solution formed by 1-hexadecyl-3-methylimidazolium tetrafluoroborate ionic liquids in present of sodium salicylate

The micellar solution of a surface active ionic liquid, 1-hexadecyl-3-methylimidazolium tetrafluoroborate (C16mimBF4), with the presence of organic salt sodium salicylate (NaSal) was investigated by rheological measurements and 1HNMR. According to steady-shear viscosity curves, with the increase of NaSal concentration, the zero-shear viscosity η0 firstly showed an increase which meant the gradual formation of wormlike micelles in solutions (the most optimal concentration of NaSal was 4.5 mM), then η0 decreased to the previous value which indicated the wormlike micelles were destroyed. And the results of 1HNMR were further verified the structure transformation. The C16mimBF4/NaSal solution showed special viscoelastic property with the increase of NaSal concentration. When the linear wormlike micelles formed, the mixture solutions had viscosity (G′<G″). When the branched wormlike micelles formed, the elastic property was prominent (G′>G″). In the frequency sweep rheological measurements, the curves of G′ and G″ showed two intersections, which indicates the structure of long wormlike micelles is weak and may be cut into short ones at higher shear frequency.

Adsorption and Aggregation Properties of Gemini-Type Amphiphilic Dendrimers.

Gemini-type amphiphilic dendrimers featuring two dodecyl chains and two poly(amidoamine) dendrons (2C12-2denGn, where n is the dendron (den) generation (G) number (1, 2, 3, 4, or 5)) were synthesized using ethylenediamine, alkyl bromide, and methyl acrylate. These gemini-type dendrimers were characterized by surface tension, pyrene fluorescence, static light scattering, and small-angle X-ray scattering. The results showed clear breakpoints in the surface tension versus concentration plots, which indicated adsorption at the air/water interface and micelle formation in solution despite the bulky dendron structure (e.g., generations 3 to 5), contrasting the behavior of conventional surfactants. The 2C12-2denGn dendrimers could be densely packed at the air/water interface owing to enhanced interaction between the dendrons and between the alkyl chains. Furthermore, these dendrimers formed spherical micelles at a concentration of 5.0 mmol dm-3 in solution (pH 9); the overall micelle size was not dependent on the generation number of the dendron, while as the generation number increased, the core radius of the micelle decreased, and the shell thickness of the micelle increased.

Kinetics and thermodynamics of thermal degradation and antimicrobial activity of zinc phenothiazine oleate complex

The role of metals in organic synthesis has been well known from the beginning of the development of synthetic procedure in organic Chemistry. Heterocyclic complexes have attracted increasing interest because of their role in the understanding of molecular process occurring in biochemistry and coordination chemistry. The Nitrogen donor aromatic ligand constitutes an important and interesting class of drugs/dyes not only for synthetic investigation but also for their usefulness to resist diseases. Colloidal systems are extremely wide spread in nature and are of great practical importance in our daily life. Surfactants are very useful in modern engineering and pharmaceuticals due to formation of micelles in solutions and high surface activity. Present work has been initiated with a view to obtain a profile as to the nature and structure of complex of phenothiazine with zinc oleate in different non-aqueous solvents that are of great significance in explaining their characteristics under different conditions. The present work reveals synthesis of zinc soap and its complex with phenothiazine ligand. For this synthesis the para substituted aniline was selected as the most suitable initial compound. An analytical and spectral study (IR, NMR) of this complex has been done. In order to know their thermal stability, thermogravimetric analysis has been done. A biocidal activity of complex has been carried to access their comparative toxicity.

Fungicidal Activities and Characterization of Novel Biodegradable Cu (II) Surfactants Derived from Lauric Acid

Introduction: Colloidal systems are extremely widespread in nature and are of great practical importance in our daily life. Surfactants are very important in modern engineering and pharmaceutical soap and the complexes of soaps with different ligands are used in almost all sectors of national economy due to the formation of micelles in solutions and high surface activity i.e. the ability of their molecules to form surface adsorption layers. For this purpose, first time we thought about the synthesis of copper surfactants/soaps and their complexation by N/S donor ligands. Methods and Materials: In this paper, we report the synthesis of copper laurate thiourea by conventional methods and its characterization by elemental analysis, IR, NMR, ESR spectral studies. In order to understand their biological aspects and application of these surfactants/complexes as antifungal agents, astudy has also been conducted in the field of biochemistry. In order to understand their biological aspects with special reference to fungicidal activities, three different fungi namely Aspergillus alternaria, Aspergillus Fumigatus and Aspergillus niger were taken and tested by different concentrations of copper laurate soap and its thiourea complex by P.D.A. (Potato dextrose agar) technique. Conclusion: Biological studies of these compounds will also provide an important account of information about their industrial utilization.

Study on Critical Micelle Concentration Influence in Green Synthesis of Silver Nanoparticles Assisted by Sapindus mukorossi Aqueous Extract

Silver nanoparticles synthesis mediated by plant extracts involves the colloidal stability of generated metallic particles in solutions. Formation of micelles in solutions influences the nanoparticle synthesis process and consequently, the surface plasmonic response (SPR) of the formed silver nanoparticles. Critical micelle concentration (CMC) of Sapindus mukorossi aqueous extract has been determined with ultraviolet-visible spectroscopy, two methods were used: dye micellization method, and correlation of silver nanoparticles SPR with the variation of surfactant concentration. Results obtained for CMC determination by the two methods were highly reproducible and in good correlation indicating that micelles formed by saponins present in the Sapindus mukorossi aqueous extract are useful as effective structure-driving agents to synthesize colloidal metallic nanoparticles, offering them proper growth conditions. Silver nanoparticles synthesis mixtures were studied, with Sapindus mukorossi aqueous extract and silver nitrates as precursors, in acidic and basic media, at room temperature to establish correlations between saponins structure modifications and surface plasmonic response of metallic nanoparticles. Light absorption spectrometric techniques (ultraviolet-visible and infrared), X-ray diffraction and scanning electron microscopy were used to characterize the synthesis process.

Tadpole-type amphiphilic dendrimers with bulky dendrons: Adsorption and aggregation properties

Tadpole-type amphiphilic dendrimers featuring a hexadecyl chain and two or three poly(amidoamine) dendrons (C16-mdenGn, where m is the number of dendron scaffolds (2 or 3) and n is the dendron (den) generation (G) number (1, 2, 3, 4, or 5)) were synthesized using hexadecylamine or N-hexadecylethylenediamine as central scaffolds. These dendrimers were characterized by acid-base titration, surface tension, pyrene fluorescence, static light scattering (SLS), and small-angle neutron scattering (SANS), and showed clear breakpoints in their surface tension vs. concentration plots. This behavior was indicative of adsorption at the air/water interface and micelle formation in solution despite the bulky dendron structure (e.g., generations 3–5), contrasting the behavior of conventional surfactants. Contrary to our expectation, the C16-mdenGn dendrimers could be densely packed at the air/water interface owing to enhanced hydrogen bonding between amide groups in the case of higher generation numbers. Furthermore, the above dendrimers formed spherical micelles in solution at a concentration of 5.00mmoldm−3 (pH 9), regardless of the dendron generation number. As the generation number was increased to 4 for C16-2denGn and 3 for C16-3denGn, aggregates of spherical micelles were observed. The radius of gyration of C16-mdenGn dendrimers was estimated as 2.0–2.5nm, being almost independent of the hydrophilic dendron size.

Synthesis and Solution Properties of Hydrophobically Modified Polysaccharides

Hydrophobically modified polymers are amphiphilic macromolecules mainly constituted of a hydrophilic backbone and hydrophobic side groups. In aqueous solutions these polymers undergo inter- or intra-molecular hydrophobic association, which results in unusual properties useful for a number of practical applications. The areas of application of these polymers include associative thickeners for enhanced oil recovery, pharmaceuticals, personal care formulations, coatings, adhesives, surfactants, emulsifiers, etc. This review presents the analysis of a literature data on preparation of hydrophobically modified polysaccharides (HMP) and their properties in aqueous solutions. Some of the synthetic methods used for hydrophobic modification of non-ionic (cellulose ethers, starch, dextran, pullulan, etc.), anionic (carboxymethylcellulose, hyaluronic&lt;br /&gt;acid, pectic acid, alginic acid, heparin) and cationic olysaccharides (chitosan) are presented. The methodology used for the investigation of solution properties of hydrophobically modified polysaccharides is discussed. Special attention is paid to aggregate and micelle formation in solutions of hydrophobically&lt;br /&gt;modified polysaccharides, solubilization of hydrophobic compounds, their rheological properties and surface activity. The effects of polymer architecture (level of hydrophobic substitution, nature of hydrophobic groups, molecular weight of a hydrophilic backbone, etc.), concentration, temperature, presence of inorganic salts and organic solvents on solution properties of hydrophobically modified polysaccharides are discussed. Some applications of hydrophobically modified polysaccharides are briefly highlighted.

Synthesis and Surface Active Properties of tri[(N‐alkyl‐N‐ethyl‐N‐Sodium carboxymethyl)‐2‐Ammonium bromide ethylene] Amines

AbstractTrimeric betaine surfactants tri[(N‐alkyl‐N‐ethyl‐N‐sodium carboxymethyl)‐2‐ammonium bromide ethylene] amines were prepared with raw materials containing tris(2‐aminoethyl) amine, alkyloyl chloride, lithium aluminium hydride, sodium chloroacetate, and bromoethane by alkylation, Hoffman degradation reaction, carboxymethylation and quaternary amination reaction. The chemical structures of the prepared compounds were confirmed by FTIR, 1H NMR, MS and elemental analysis. With the increasing length of the carbon chain, the values of their critical micelle concentration initially decreased. Surface active properties of these compounds were superior to general carboxylate surfactants C10H21CHN+(CH3)2COONa. The minimum cross‐sectional area per surfactant molecule (Amin), standard Gibbs free energy adsorption (ΔGads) and standard Gibbs free energy micellization (ΔGmic) are notably influenced by the chain length n, and the trimeric betaine surfactants have greater ability to adsorb at the air/water interface than form micelles in solution. The efficiency of adsorption at the water/air interface (pC20) of these surfactants increased with the increasing length of the alkyl chain. Their foaming properties, wetting ability of a felt chip, and lime‐soap dispersing ability were also investigated.

PH-responsive non-surface-active/surface-active transition of weakly ionic amphiphilic diblock copolymers

The weakly ionic amphiphilic diblock copolymer polystyrene-b-poly(acrylic acid) was synthesized by nitroxy radical-mediated living radical polymerization with precise control of block length, block ratio, and polydispersity. Systematical surface tension experiments and foam formation observations revealed that this polymer was non-surface active under neutral and alkaline (pH 10) conditions, while it was surface active under an acidic condition (pH 3). This result supports our proposed origin of non-surface activity; the image charge repulsion at the air/water interface is essential in addition to very stable micelle formation in the bulk solution. At a higher pH (pH 12), the polymer showed slight surface activity since the added NaOH played a role as an added salt. The critical micelle concentration (cmc) was estimated by static light scattering. Cmc increased with increasing added salt (NaCl) concentration as was observed for other strongly ionic non-surface-active polymers. Hence, this trend is characteristic for non-surface-active polymers. The pH dependence of cmc was minimum at pH 8–10. Since the acrylic acid block is fully ionized under this condition, the strong image charge repulsion at this condition accelerated micelle formation at a low polymer concentration, which consequently decreased cmc. Micelles in bulk solution were confirmed by dynamic light scattering, and the salt concentration and pH dependencies of the hydrodynamic radius of the micelles were also estimated. The pH-responsive non-surface-active/surface-active transition observed in this study strongly supports the fact that the image charge repulsion is an essential factor for non-surface activity in addition to stable micelle formation in solution.

Small-Angle Neutron Scattering Study on Aggregation of 1-Alkyl-3-methylimidazolium Based Ionic Liquids in Aqueous Solution

Aggregation structures of 1-alkyl-3-methylimidazolium based ionic liquids (ILs) in aqueous solution were investigated by small-angle neutron scattering (SANS) from the viewpoint of alkyl chain length, n, and anions (Cl−, Br− and trifluoromethanesulfonate, $$ {\text{CF}}_{3} {\text{SO}}_{3}^{ - } $$ ). In [C4mIm+]-based IL systems, no noticeable SANS intensity was observed for all of the systems examined here, although aqueous [C4mIm+][ $$ {\text{BF}}_{4}^{ - } $$ ] solutions show a significant SANS profile originating from concentration fluctuations in the solution (Almasy et al. J Phys Chem B 112:2382–2387, 2008). This suggests that [C4mIm+][Cl−], [C4mIm+][Br−] and [C4mIm+][ $$ {\text{CF}}_{3} {\text{SO}}_{3}^{ - } $$ ] homogeneously mix with water, unlike the [C4mIm+][ $$ {\text{BF}}_{4}^{ - } $$ ] system, due to preferential hydration of the ions. In the case of the C n mIm cations with longer alkyl chain lengths (n = 8 and 12), SANS profiles were clearly observed in the aqueous solutions at IL concentrations of C IL > 230 and 20.0 mmol·dm−3, respectively. For aqueous [C8mIm+][Br−] solutions, the asymptotic behavior of the scattering function varied largely from I(q) ~ q −2 to ~q −4 with increasing C IL, indicating that the solution changes from an inhomogeneous mixing state to a nano-scale micelle state. Aqueous [C12mIm+][Br−] solutions show a typical SANS profile for micelle formation in solution. It was found from a model-fitting analysis that the structure of the [C12mIm+][Br−] micelle is ellipsoidal, not spherical, in solutions over the C IL range examined here.

Complexation-Tailored Morphology of Asymmetric Block Copolymer Membranes

Hydrogen-bond formation between polystyrene-b-poly (4-vinylpyridine) (PS-b-P4VP) block copolymer (BCP) and -OH/-COOH functionalized organic molecules was used to tune morphology of asymmetric nanoporous membranes prepared by simultaneous self-assembly and nonsolvent induced phase separation. The morphologies were characterized by field emmision scanning electron microscopy (FESEM) and atomic force microscopy (AFM). Hydrogen bonds were confirmed by infrared (IR), and the results were correlated to rheology characterization. The OH-functionalized organic molecules direct the morphology into hexagonal order. COOH-functionalized molecules led to both lamellar and hexagonal structures. Micelle formation in solutions and their sizes were determined using dynamic light scattering (DLS) measurements and water fluxes of 600-3200 L/m(2)·h·bar were obtained. The pore size of the plain BCP membrane was smaller than with additives. The following series of additives led to pores with hexagonal order with increasing pore size: terephthalic acid (COOH-bifunctionalized) < rutin (OH-multifunctionalized) < 9-anthracenemethanol (OH-monofunctionalized) < 3,5-dihydroxybenzyl alcohol (OH-trifunctionalized).

Formation and dissociation processes of gas-phase detergent micelles.

Growing interest in micelles to protect membrane complexes during the transition from solution to gas phase prompts a better understanding of their properties. We have used ion mobility mass spectrometry to separate and assign detergent clusters formed from the n-trimethylammonium bromide series of detergents. We show that cluster size is independent of detergent concentration in solution, increases with charge state, but surprisingly decreases with alkyl chain length. This relationship contradicts the thermodynamics of micelle formation in solution. However, the liquid drop model, which considers both the surface energy and charge, correlates extremely well with the experimental cluster size. To explore further the properties of gas-phase micelles, we have performed collision-induced dissociation on them during tandem mass spectrometry. We observed both sequential asymmetric charge separation and neutral evaporation from the precursor ion cluster. Interestingly, however, we also found markedly different dissociation pathways for the longer alkyl chain detergents, with significantly fewer intermediate ions formed than for those with a shorter alkyl chain. These experiments provide an essential foundation for understanding the process of the gas-phase analysis of membrane protein complexes. Moreover they imply valuable mechanistic details of the protection afforded to protein complexes by detergent clusters during gas-phase activation processes.

Potent inhibition of ice recrystallization by low molecular weight carbohydrate-based surfactants and hydrogelators

Ice recrystallization inhibition (IRI) activity is a very desirable property for an effective cryoprotectant. This property was first observed in biological antifreezes (BAs), which cannot be utilized in cryopreservation due to their ability to bind to ice. To date, potent IRI active compounds have been limited to BAs or synthetic C-linked AFGP analogues (1 and 2), all of which are large peptide-based molecules. This paper describes the first example of low molecular weight carbohydrate-based derivatives that exhibit potent IRI activity. Non-ionic surfactant n-octyl-β-D-galactopyranoside (4) exhibited potent IRI activity at a concentration of 22 mM, whereas hydrogelator N-octyl-D-gluconamide (5) exhibited potent IRI activity at a low concentration of 0.5 mM. Thermal hysteresis measurements and solid-state NMR experiments indicated that these derivatives are not exhibiting IRI activity by binding to ice. For non-ionic surfactant derivatives (3 and 4), we demonstrated that carbohydrate hydration is important for IRI activity and that the formation of micelles in solution is not a prerequisite for IRI activity. Furthermore, using solid-state NMR and rheology we demonstrated that the ability of hydrogelators 5 and 6 to form a hydrogel is not relevant to IRI activity. Structure–function studies indicated that the amide bond in 5 is an essential structural feature required for potent IRI activity.

In situ photogelation kinetics of Laponite nanoparticle-based photorheological dispersions

In situ photorheology experiments were conducted to investigate the kinetics of UV-triggered photogelation of aqueous Laponite nanoparticle dispersions formulated with less than 10 wt% of a triblock copolymer (Pluronic F127) and diphenyliodonium-2-carboxylate monohydrate, a photoacid generator (PAG). We show that gelation kinetics depend strongly on solution composition and intensity of UV light used during in situ photorheology experiments. A decrease in gelation rate was observed with increasing Pluronic F127 concentrations while higher PAG and Laponite concentrations result in higher gelation rates. Changing the intensity of UV light from 100 mW cm−2 to 150 mW cm−2 at a constant composition reduced the exposure time required prior to onset of gelation by half. Finally, the effect of Laponite and PAG on the micellization of F127 was probed using differential scanning calorimetry (DSC). The results show that the presence of Laponite particles and PAG suppresses the enthalpic endotherm associated with micelle formation in solutions containing up to 7.2 wt% Pluronic F127. Using these results, we present a detailed mechanism for the photogelation phenomenon as well as the parameters surrounding intelligent design and formulation of these systems.

Matrix-assisted laser desorption/ionization mass spectrometry with re-engineered 2,5-dihydroxybenzoic acid derivative.

Dihydroxybenzoic acid was modified to three analogues (M2, M4 and M6). The analogues exhibited specific properties that resulted in enhancement of analyte signal intensity with or without addition of iodine compared to the underivatized parent. Addition of iodine to M2, an ester of dihydroxybenzoic acid that had a terminal double bond in the alkyl chain, resulted in peak intensities comparable to the parent, indicating that iodine interaction across the double bond resulted in enhancement although the exact mechanism is not fully understood. No enhancement on addition of iodine was observed for M4, which had a long alkyl chain that contained no double bonds. The alkyl chain allowed micelle formation in solution, which in turn allowed more uniform analyte-to-matrix mixing. The final analogue combined the long alkyl chain of M4 with the double bond of M2 and exhibited either similar peak intensities to that of dihydroxybenzoic acid or better. Micelle formation in solution was examined using spectroscopy and in the solid by reflective microscopy. The standard deviation from spot to spot was considerably lower relative to dihydroxybenzoic acid (RSD 3.4%vs. 14.2%). Unlike dihydroxybenzoic acid, the novel matrix M6 was able to yield characteristic peaks for analytes such as ubiquitin.

Physicochemical Study of the Complexation of Nortriptyline and Human Serum Albumin

The complexes formed by the interaction of the cationic amphiphilic drug nortriptyline hydrochloride and human serum albumin (HSA) were investigated at 25 °C in aqueous solution at pH 3.2, where interaction is by hydrophobic binding, and at the isoelectric point of the protein (pH 4.9), where binding is both hydrophobic and electrostatic. A variety of techniques have been used to determine changes in the physicochemical properties of the drug/protein systems as a function of drug concentration, including conductivity, ζ-potential, static and dynamic light scattering methods, and UV−vis spectroscopy. Measurements of the solution conductivity of the complexes have shown increasing adsorption of the amphiphilic drug onto the protein surface with an increase of drug concentration, leading to surface saturation and the formation of micelles in solution at a drug concentration of approximately 0.035 mol kg-1. The number of adsorption sites was determined from the observed increases of the ζ-potential as a function of drug concentration. The Gibbs energies of adsorption of the drug onto the protein showed an exponential increase with an increase of drug concentration as a consequence of the hydrophobic interaction. Measurements of the molar mass and hydrodynamic radius of the HSA/nortriptyline complexes as a function of drug concentration by static and dynamic light scattering techniques have shown a gradual increase of size typical of a saturation rather than a denaturation process. Plots of hydrodynamic radius against nortriptyline concentration and changes in the UV−vis spectra have been interpreted by comparison with typical binding isotherms.

Self-assembly of the amphipathic helix (VHLPPP)8. A mechanism for zein protein body formation

γ-Zein, a maize storage protein with an N-terminal proline-rich repetitive domain (γ-ZNPRD), is located at the periphery of protein bodies. This domain appears to be indispensable for the aggregation of the protein on the surface of the organelle. The peptide (VHLPPP)8, spanning the γ-ZNPRD, adopts a polyproline II (PPII) conformation that gives an amphipathic helix different from the α-helix. We used atomic force microscopy to study the surface organisation of the octamer, and transmission electron microscopy to visualise aggregates of the peptide in aqueous solution. We consider two self-assembly patterns that take account of the observed features. The micellar one fits best with the experimental results presented. Moreover, we found that this peptide has properties associated with surfactants, and form micelles in solution. This spontaneous amphipathic arrangement of the γ-ZNPRD suggests a mechanism of γ-zein deposition inside maize protein bodies.

Micelle formation in water solutions of polyelectrolytes for electrodeposition

The structure of aqueous solutions of polymerized (rubber oligomer) and polycondensed (alkyd and alkydepoxide oligomers) film-forming substances that are used as binders for anodic electrodeposition has been studied by conductometric and viscometric methods. A wide concentration range of these polyelectrolytes including concentrations used for electrodeposition has been investigated. The concentration dependencies of specific electric conductivity and kinematic viscosity under a certain solution concentration are characterized by four inflection points for all three oligomers. The availability of four critical micelle concentrations (CMCs) in aqueous solutions of polyelectrolytes is associated with the formation of micelles, the change of their shape, and intermicellar interaction. The micelle formation in solutions of carboxyl-containing film-forming agents has been studied by a differential spectrophotometry method. The solubilizing ability of the systems in question has been estimated.