Decrease In Critical Micelle Concentration Research Articles

Piperidinium surfactants functionalized with carbamate fragment: Aggregation, antimicrobial activity and cytotoxicity

The biomimetic nature of supramolecular systems, the structural similarity of synthetic surfactants to biomolecules (lipids, proteins), provide them with high membranotropy, the ability to overcome biological barriers, and affinity towards biosubstances. Despite rather high toxicity cationic surfactants are of importance as antimicrobial agents, gene nanocarriers and mitochondria targeted ligands. To minimize this limitation, cationic amphiphilic matrix undergoes modification with various functional groups. In this work, new piperidinium cationic surfactants containing one or two carbamate fragments were prepared; their aggregation behavior was systematically studied by tensiometery, spectrophotometry and fluorimetry. The presence of a carbamate fragment leads to a 2–3-fold decrease in critical micelle concentration and to a significant increase in solubilization capacity compared to unsubstituted analogue. Evaluation of the antimicrobial effect showed that all compounds exhibit high bactericidal and fungicidal activity against a wide range of pathogenic microorganisms, including their resistant forms. Importantly, the introducing carbamate moiety allows of decreasing hemolytic activity of cationic surfactants. The data obtained make it possible to recommend carbamate piperidinium surfactants as effective biocompatible and biodegradable nanocontainers for hydrophobic probes with high antimicrobial effect and moderate hemolytic activity.

Green Synthesis, Surface Activity, Micellar Aggregation, and Foam Properties of Amide Quaternary Ammonium Surfactants.

A series of amide quaternary ammonium surfactants with the formula C n H2n+1CONH(CH2)2N+(CH3)3·CH3CO3 - (n = 9, 11, 13, 15) were synthesized using a fatty acid, N,N-dimethylethylenediamine, and a green reagent dimethyl carbonate. A comparative study of the four surfactants in terms of surface activity, aggregation characteristics, and foam properties was conducted. The results show that these amide quaternary ammonium surfactants reduce the surface tension of water to a minimum value of 23.69 mN·m-1 at a concentration of 1.55 × 10-4 mol·L-1 and self-assemble spontaneously into aggregates, which are mostly vesicles. Furthermore, with increasing the alkyl chain length, their critical micelle concentration (CMC) values and surface tension values at the CMC (γCMC) decrease and then increase, and the degree of counterion binding (β) decreases. It is also found that these amide quaternary ammonium surfactants exhibit excellent foam ability and foam stability.

Effect of Gemini surfactant structure on water/oil interfacial properties: A dissipative particle dynamics study

Understanding the structural effects of Gemini surfactants on interfacial properties is pivotal towards the rational design of efficient Gemini surfactants. Herein, a series of alkylbenzene sulfonate Gemini surfactants have been constructed, and their influences on the interfacial properties of dodecane/water systems are systematically explored by using dissipative particle dynamics simulation. The Gemini surfactants are modeled as ‘π-shaped’ coarse-grained molecules, and their spacer lengths and hydrophobic chain lengths are varied for examining the properties including radial distribution functions, interfacial tension and thickness, and self-assembly morphologies. We find that when increasing the hydrophobic chain length, the critical micelle concentration decreases, and the oil molecules tend to penetrate into the space between two hydrophobic chains, causing nano-mixing phenomenon. This phenomenon is further enhanced when increasing the spacer length, and consequently, the oil–water interface gradually becomes curved and blurred due to the enhanced surfactant efficiency, and the system evolves from the lamellar interface state to micelle state. This work provides a theoretical basis for rational designing efficient Gemini surfactants.

Experimental study on the foam performance and fire extinguishing performance of aqueous foam stabilized by alkyl polyglucoside and urea

Foam extinguishing agents are the most effective extinguishing agents for liquid fires. The search of relevant domestic and foreign commercial foam fire extinguishing agent patents found that most commercial foam fire extinguishing agent formulations contain urea. In order to understand the mechanism of urea’s influence and clarify the application parameters of urea-added aqueous foam in the fire extinguishing process, this research investigated the surface tension, foaming ability, foam stability, and fire extinguishing performance for alkyl polyglucoside and alkyl polyglucoside/urea foams. It is found that the addition of urea promotes the formation of surfactant micelles, resulting in a decrease in critical micelle concentration, while the surface tension and foaming ability of the alkyl polyglucoside solution are only moderately affected by the urea. Besides, urea significantly improves the fire extinguishing performance of alkyl polyglucoside foam and the influence of urea concentration on fire extinguishing time is remarkable. On the one hand, the enhanced extinguishing performance can be explained by the increase of foam stability. On the other hand, urea produces incombustible gases such as NH3 and CO2 under the action of the high temperature of the fire, which may improve the fire extinguishing performance by cooling effect and asphyxiation effect. The increase in expansion ratio and the foam flow rate are beneficial to shorten the extinguishing time. The research results can guide the design of foam extinguishing agents.

The adsorption mechanism of synergic reagents and its effect on apatite flotation in oleamide-sodium dodecyl benzene sulfonate (SDBS) system

The usage of synergic reagents plays vital role in the effective flotation of phosphate ore. In this paper, the adsorption mechanism of synergic reagents and its effect on apatite flotation in oleamide-sodium dodecyl benzene sulfonate (SDBS) system were investigated via micro-flotation experiment, Zeta-potential determination, X-ray photo-electron spectroscopy (XPS), and Time-of-flight secondary ion mass spectrometry (ToF-SIMS). Experimental research represented that a highest recovery rate of 97.09% could be obtained when a mixed collector dosage of 4 × 10−4 mol/L was used with a molar ratio of oleamide to SDBS of 2:1 at pH = 9.0, and the recovery could be improved by ~4.87% comparing with the theoretical recovery rate of single collector. Results of Zeta potential and XPS indicated that the chemisorptions of C17H33CONH−, (C17H33CONH2)m and sulfonate species originated from the mixed collector onto apatite surfaces occurred. More importantly, the adsorption of amide could be reinforced in the presence of SDBS, and the N atomic concentration increased from 1.23% to 1.66%. The results of ToF-SIMS further confirmed that the normalized peak intensities of C4H5+ and C4H7+ for apatite-oleamide-SDBS sample showed a statistically increase comparing with corresponding results of apatite-oleamide sample, while the normalized peak intensities of C6H4+ presented an opposite trend comparing with that of apatite-SDBS sample. The whole thickness of the formed hydrophobic species on the apatite surfaces was approximately 40.29 nm. The synergistic effects of mixed collector were mainly attributed to the improvement of solubility and dispersion and the decrease in critical micelle concentration of oleamide in the presence of SDBS, which provided easy access to the interaction between C17H33CONH−, (C17H33CONH2)m and apatite surfaces. The results provided a new path for apatite flotation, and reinforced the theoretical basis for flotation technique of phosphate ore.

Prospects for the use of mixed micellar structures as a template in synthesis of MCM-41-type silicas

Formation of mixed micelles assisted by cetyltrimethylammonium bromide and methyl red was studied by means of conductometric and spectrophotometric methods. It follows from the analysis of conductometric dependences that the addition of azo dye leads to a decrease in critical micelle concentration of a long-chain quaternary ammonium salt. The respective thermodynamic parameters were calculated. The process of mixed micelles formation was stated to be spontaneous and the solubilization of azo dye by micelles of cetyltrimethylammonium bromide is profitable in terms of energy and accompanied by an increase in degrees of freedom of the system. Based on the data of spectrophotometric study of methyl red solutions in the presence of cetyltrimethylammonium bromide, the values of stability constant, partition coefficient and change in the standard free energy of methyl red distribution between aqueous and micellar medium were calculated. It was found that electrostatic and hydrophobic interactions arising between azo dye and cetyltrimethylammonium bromide molecules cause the orientation of methyl red from the shell towards the center of the micelles. It was shown that mixed micelles can be used as a template in sol-gel synthesis of mesoporous aminosilica of MSM-41 type. The results of low-temperature nitrogen adsorption-desorption and X-ray analysis revealed that the introduction of methyl red as a part of mixed micelles into the reaction medium of sol-gel synthesis causes substantial increase in specific surface area and total pore volume, noticeable reduction of pore diameter, thereby contributing to the formation of silica material with a pronounced long-range ordered mesoporous structure.

Synthesis and Determination of Critical Micelle Concentration of Betainthioates Surfactants

AbstractTwo series of monotailed and bolaphiles surfactants having quaternary ammonium bromide polar head have been synthesized and characterized. The critical micelle concentration (CMC) of the synthesized cationic surfactants was determined by conductimetric method. According to CMC values, the increase in alkyl chain length leads to a decrease in CMC and the bola‐type exhibits a higher CMC than their counterpart's monotailed.

Biocompatible supramolecular systems based on novel cationic imidazolium- and urethane-containing amphiphiles: Self-assembly and antimicrobial properties

In the framework of this investigation novel cationic amphiphiles of N-(2-butylaminocarbonyloxyethyl)-N-alkylimidazolium bromides series have been synthesized and characterized in terms of their aggregation capacity in aqueous solutions, antimicrobial properties and solubilization action toward hydrophobic dye. Using tensiometry, conductometry and fluorescence spectroscopy techniques it has been demonstrated, that the presence of urethane fragment with butyl moiety is responsible for the one order of magnitude decrease of critical micelle concentration of amphiphiles in comparison with unsubstituted analogs. Fabrication of aggregates with hydrodynamic diameter in the range of 4–10 nm has been exhibited for all amphiphiles. Transmission electron microscopy technique allows to establish the spherical shape of aggregates formed. These amphiphiles were shown as effective solubilizers of hydrophobic azodye, which efficacy could be 2.5-fold increased by elongation of the length of hydrophobic tail by four methylene units. Estimation of interaction of amphiphiles with biological objects has revealed, that all compounds exhibit high bacteriostatic and bactericide properties preferably toward gram-positive strains, as well as they have low hemolytic activity at active concentrations. Antibacterial properties of tetradecyl amphiphilic derivative have surpassed norfloxacin by 5 and 8.5 times in relation to Staphylococcus aureus and Bacillus cereus, respectively.

The Interaction of Hemoglobin With Sodium Dodecyl Sulfate in Presence of Ascorbic Acid

Background: Hemoglobin (Hb), oxygen, carbon dioxide, and electron transporter of the body, may enter to an oxidation process that can convert oxyhemoglobin (oxyHb) to methemoglobin (metHb) and hemichrome. Surfactants can facilitate oxidation process that may accumulate hemichrome in red blood cells. Methods: In the present study, the interaction of purified Hb with sodium dodecyl sulfate (SDS, 0-5 mM) and ascorbic acid (AA, 0-5 mM) was evaluated by UV-Vis spectroscopy and multivariate curve resolution techniques. Results: Reconstructed spectral and concentration profiles showed three forms of Hb name as oxyHb, metHb, and hemichrome with lack of fit values less than 1.85%. AA hindered the oxidation process of Hb. Conclusion: A decrease in critical micelle concentration of SDS in the presence of AA and interaction of AA with hydrogen peroxide, which is produced during the interaction of Hb with SDS, are two reasons for diminution in the oxidation process of Hb when accompanied with AA.

Effect of additives on the aggregation phenomena of amphiphilic drug and hydrotrope mixtures

Association behavior between the cationic antidepressant drug imipramine hydrochloride (IPH) and anionic hydrotrope - sodium benzoate (NaBez) mixtures in aqueous solutions, along with the electrolytes NaCl (50 mmol·kg−1) and NaBr (50 mmol·kg−1) were studied using a conductometric technique at four different temperatures. The results showed a decrease in critical micelle concentration (cmc) of IPH (drug) in combination with NaBez, viewing a remarkable interaction amongst studied constituents along with cmc values of IPH drug further lessens through raised in mole fraction (α1) of NaBez. The electrolytes NaCl and NaBr reduced the cmc of IPH, NaBez together with their mixture (IPH-NaBez) in diverse ratio and NaBr was additionally effectual in reducing the cmc of the system in comparison to NaCl. Moreover, the cmc values of IPH and NaBez mixtures showed a lower than ideal cmc (cmcid) value characterizing the non-ideality in system. Additional parameters of the conductometric method such as the micellar mole fraction employing the Rubingh and Rodenas models, interaction parameter (β), activity coefficients of the mixed micelles, and excess Gibbs free energy using the Rubingh and Rodenas models and so on were evaluated. The activity coefficients values were lessened in electrolyte solvent in the entire systems showing the enhanced non-ideality of mixed system in electrolyte solution. At various temperatures, thermodynamic parameters were also evaluated in aqueous along with electrolyte solutions. The interactions amongst the studied constituents in the aqueous system were also evaluated by fluorescence and FT-IR studies and explored in detail.

Synthesis and properties of a novel asymmetric gemini surfactant based on siloxane skeleton

The paper introduced a kind of hydrogen-containing epoxy polysiloxane skeleton of different chain lengths with a defined molecular weight. Based on the skeleton, a novel asymmetric gemini siloxane surfactant (AGSS) was synthesized by reacting with maleic anhydride monoester and taurine. The chemical structure of AGSS was characterized by 1H NMR and FT-IR. At the same time, the physical and chemical properties of the three oil displacants were systematically studied. The results show that the minimum surface tension of the series of oil displacing agents is 29.02 mN/m, and the corresponding critical micelle concentration (cmc) is 0.416 mmol/L. As the silica chain in the polysiloxane backbone increases from n = 0 to n = 8, the surface tension corresponding to the critical micelle concentration decreases, much lower than conventional hydrocarbon surfactants. Besides, the study results show that the AGSS have good temperature resistance, salt resistance and resistance to divalent ions (Ca2+, Mg2+), and the above properties meet the needs of oil displacement applications.

Novel self-assembling systems based on imidazolium amphiphiles with cleavable urethane fragment for construction of soft nanocontainers for biomedicine application

In the framework of this report the bottom-up strategy has been used for the development of novel soft nanocontainers through self-assembly of homologous series of newly synthesized amphiphilic compounds of N-(2-ethylaminocarbonyloxyethyl)-N-alkylimidazolium bromides. Their aggregation properties, solubilization capacity, antimicrobial activity, membranotropic properties and capability to form lipoplexes have been investigated. Using various physico-chemical techniques it has been demonstrated that introduction of urethane moiety into amphiphile structure results in the 2-3-fold decrease of critical micelle concentration in comparison with their unsubstituted counterparts. It has been suggested, that interaction of amphiphiles with DNA decamer is predominantly driven by cooperative electrostatic interactions. Membranotropic properties of novel amphiphiles could be regulated by the change of the length of hydrophobic tail; with these properties being the more markedly expressed in the case of the lower homologue. Estimation of antimicrobial activity against several strains of microorganisms has revealed, that these amphiphiles were by several-fold more active toward Staphylococcus aureus, Bacillus cereus bacteria and Candida albicans fungi in comparison with reference compounds – norfloxacin and ketoconazole. Hemolytic activity of these amphiphiles has not exceeded 0.9% under bactericide and bacteriostatic concentrations. The combination of advanced characteristics allows us to recommend these amphiphiles for fabrication of soft materials with the wide spectrum of practically useful properties like effective nanocontainers for drug and gene delivery, capable of crossing the cell membrane, and harmless for human agents against pathogenic microorganisms.

Self-assembled systems based on novel hydroxyethylated imidazolium-containing amphiphiles: Interaction with DNA decamer, protein and lipid.

The study on aggregation capacity of novel imidazolium-containing amphiphiles of 1-(2-hydroxyethyl)alkylimidazolium bromide series and their interaction with bio-objects (DNA decamer, bovine serum albumin, phospholipid) was performed. It was revealed that introduction of hydroxyethyl moiety into the surfactant molecule resulted in 1.5-2-fold decrease of critical micelle concentration. These modified amphiphiles quantitatively bind DNA decamer due to intercalation and hydrophobic interactions with lipoplex formation. The evaluation of membranotropic properties of these surfactants exhibited that initiation of disordering and compression of the model cell wall consisting of dipalmitoyl phosphocholine (regulation of permeability for various compounds) could be achieved by variation of the length of hydrophobic tail of imidazolium-containing amphiphiles. Transition from individual surfactants solutions to their mixtures with protein (bovine serum albumin) is accompanied by 8-fold decrease of aggregation thresholds and characterized by the presence of two critical points. The binding of components of surfactant/BSA binary systems took place through tryptophan amino acid residue of peptide macromolecule.

Removal of sodium oleate from synthetic manganese leaching solution by coagulation-dissolved air flotation

The coagulation-dissolved air flotation for removal of sodium oleate (NaOL) from synthetic manganese leaching solution was focused in this study. It indicates that partially hydrolyzed polyacrylamide (HPAM), NaOL dosage and pH have a multiple effect on the removal efficiency of NaOL. The results represents a significant removal efficiency of 97.6% NaOL was achieved under the optimal conditions of coagulation-dissolved air flotation by dosage of 20 mg/L HPAM and 30 mg/L NaOL, pH 8.0. Solution pH has a significant effect on the distribution of oleate species and Mn2+ species. The addition of HPAM facilitates the formation of OL− micelle and the decrease of critical micelle concentration (CMC). Oleate species primarily exist, containing Mn(OL)2(s), OL− and HOL(aq). HPAM could cause the Zeta potential of NaOL to shift negatively. HPAM could decrease CMC of NaOL and lead to a transition from three dimensional network structure to lamellar structure. NaOL can be removed by coagulation-dissolved air flotation through the adsorption and bridge effect of HPAM chains on the floating bubble surface.

Supramolecular systems based on cationic imidazole-containing amphiphiles bearing hydroxyethyl fragment: Aggregation properties and functional activity

In the framework of this report, investigation of aggregation behavior, solubilization activity and antimicrobial properties of novel cationic amphiphiles of 1-(2-hydroxyethyl)alkylimidazolium bromide homologous series were carried out. Using conductometry and fluorescence spectroscopy it was shown that introduction of hydroxyethyl fragment into headgroup resulted in 1.5–2-fold decrease of critical micelle concentration in comparison with unsubstituted analogues. The aggregate size of amphiphile bearing tetradecyl tail was close to conventional micelles (hydrodynamic diameter DH 2–4 nm). However, the formation of aggregates with DH ~ 100 nm was demonstrated for amphiphile with octadecyl chain. TEM images for the latter showed the presence of worm-like particles. Solubilization capacity of these amphiphiles was 1.5-fold higher than that without hydroxyethyl fragment and 2-fold higher than in the case of conventional ammonium surfactants with the same length of hydrophobic tail. The investigation of antimicrobial activity revealed that all amphiphiles exhibit more pronounced effect against some strains of microorganisms in comparison with reference drugs (norfloxacin and ketoconazole).

Synthesis of Novel Ethoxylated Quaternary Ammonium Gemini Surfactants for Enhanced Oil Recovery Application

Two aspects are always considered in the design and development of new surfactants for oilfield application. One of them is that surfactant must be sufficiently stable at reservoir temperature and the other is the solubility of the surfactant in the injection water (usually seawater) and the formation brine. Most industrially applied surfactants undergo hydrolysis at elevated temperature and the presence of reservoir ions causes surfactant precipitation. In relevance to this, a novel series of quaternary ammonium gemini surfactants with different length of spacer group (C8, C10, and C12) was synthesized and characterized using FT-IR, 13C NMR, 1H NMR, and MALDI-TOF MS. The gemini surfactants were prepared by solvent-free amidation of glycolic acid ethoxylate lauryl ether with 3-(dimethylamino)-1-propylamine followed by reaction with dibromoalkane to obtain quaternary ammonium gemini surfactants. The gemini surfactants were examined by means of surface properties and thermal stabilities. The synthesized gemini surfactants showed excellent solubility in the formation brine, seawater, and deionized water without any precipitation for up to three months at 90 °C. Thermal gravimetric data revealed that all the gemini surfactants were decomposed above 227 °C, which is higher than the oilfield temperature (≥90 °C). The decrease in critical micelle concentration (CMC) and surface tension at CMC (γcmc) was detected by enhancing spacer length in the order C8 ˃ C10 ˃ C12 which suggested that the larger the spacer, the better the surface properties. Moreover, a further decrease in CMC and γcmc was noticed by enhancing temperature (30 °C ˃ 60 °C) and salinity (deionized water ˃ seawater). The current study provides a comprehensive investigation of quaternary ammonium gemini surfactants that can be further extended potentially to use as a suitable material for oilfield application.

Counterion-coupled gemini (Cocogem) surfactants based on dodecylisopropylol amine and dicarboxylic acids: synthesis, characterization and evaluation as biocide against SRB

New cocogem surfactants were synthesized by interaction of dodecylisopropylol amine with dicarboxylic (oxalic, succinic, adipic, sebacic, tartaric, maleic, fumaric, isophthalic) acids. By tensiometric method, the surface activity of aqueous solutions of the synthesized cocogem surfactants at the border with air was studied and, by conductometric method, the specific electrical conductivity of these solutions was determined. The degree of counterion binding (β), critical micelle concentration (CMC), effectiveness of surface tension reduction (πCMC), surface excess concentration (Γmax), area per molecule at the interface (Amin), changes of Gibbs free energies of adsorption (ΔGad) and micellization (ΔGmic) have been calculated. The character of change of the colloidal-chemical indices depending on spacer-group nature and length has been clarified. So, with an elongation of the spacer group and when passing from cis-form to trans-form, the value of CMC decreases. The obtained cocogem surfactants exhibit a considerable bactericidal effectiveness against sulfate-reducing bacteria. The bactericide properties of the cocogem surfactants containing in the spacer chain a saturated hydrocarbon fragment and benzene ring are stronger than for the others.

Surface properties ofperfluorodecalin–containing liquid/liquid systems: The influence of Pluronic F-68 dissolved in the aqueous phase

Perfluorodecalin (PFD) is extensively applied as liquid carrier of gaseous metabolites in systems for in vitro cultures of various types of cells. The influence of Pluronic F-68 on modification of the surface properties of few liquid/liquid system containing PFD was discussed. Static surface and interfacial tensions (σ) of water/PFD, culture medium/PFD, as well as air/water (referentially) two-phases systems with the aqueous phase contained nonionic 3-block copolymer Pluronic F-68, were measured by the du Noüy ring method at 25 °C and 37 °C. Values of critical micelle concentration (CMC) for Pluronic F-68 dissolved in water/PFD and air/water systems were similar at constant temperature. Smaller value of maximum surface excess (Γ∞) and higher value of minimum surface area per adsorbed molecule (Amin) were obtained for water/PFD, than for water/air system. Increase of temperature from 25 °C to 37 °C resulted in significant decrease of CMC, decrease of Γ∞ and increase of Amin. Calculated value of the standard Gibbs free energy of micellization was negative and became more negative for higher temperature, what indicated that micelles were formed spontaneously and the tendency for micelle formation increased with temperature increase. The Frumkin model fits well the experimentally obtained values of σ, what has been proved by the coefficient of determination equaled to 0.994–0.996.

Lactobionic/Folate Dual-Targeted Amphiphilic Maltodextrin-Based Micelles for Targeted Codelivery of Sulfasalazine and Resveratrol to Hepatocellular Carcinoma.

In this study, promising approaches of dual-targeted micelles and drug-polymer conjugation were combined to enable injection of poorly soluble anticancer drugs together with site-specific drug release. Ursodeoxycholic acid (UDCA) as a hepatoprotective agent was grafted to maltodextrin (MD) via carbodiimide coupling to develop amphiphilic maltodextrin-ursodeoxycholic acid (MDCA)-based micelles. Sulfasalazine (SSZ), as a novel anticancer agent, was conjugated via a tumor-cleavable ester bond to MD backbone to obtain tumor-specific release, whereas resveratrol (RSV) was physically entrapped within the hydrophobic micellar core. For maximal tumor-targeting, both folic acid (FA) and lactobionic acid (LA) were coupled to the surface of micelles to obtain dual-targeted micelles. The decrease of critical micelle concentration (CMC) from 0.012 to 0.006 mg/mL declares the significance of a dual hydrophobicized core of micelles by both UDCA and SSZ. The dual-targeted micelles showed a great hemocompatibility, as well as enhanced cytotoxicity and internalization into HepG-2 liver cancer cells via binding to overexpressed folate and asialoglycoprotein receptors. In vivo, the micelles demonstrated superior antitumor effects revealed as reduction in the liver/body weight ratio, inhibition of angiogenesis, and enhanced apoptosis. Overall, combined strategies of dual active targeted micelles with bioresponsive drug conjugation could be utilized as a promising approach for tumor-targeted drug delivery.

Evaluation of micellar properties of sodium dodecylbenzene sulphonate in the presence of some salts

The influence of some salts (NaCl, KCl, $$\hbox {NH}_{4}$$ Cl and $$\hbox {MgCl}_{2})$$ on the critical micelle concentration (CMC) and fraction of counterion dissociation ( $$\alpha $$ ) of sodium dodecylbenzene sulphonate (SDBS) have been determined by conductometric and dynamic light scattering (DLS) methods at 298.15 K. The CMC determination involves fitting of experimental conductivity-surfactant concentration data into the integral form of Boltzmann-type sigmoidal equation. The procedure provides much better results compared to the conventional and differential methods for surfactant such as SDBS that exhibits a gradual transition from pre-micellar to the post-micellar region. The decrease in CMC of SDBS was found to be the highest in the presence of $$\hbox {MgCl}_{2}$$ and least in the case of NaCl among the studied salts. The fraction of counter ion dissociation decreases sharply at lower concentrations of the salts (except NaCl) which have been discussed in terms of effective ionic charge on the micelles. Using CMC and $$\alpha $$ value, the aggregation number of the micelle, micellar surface area and packing parameter has been calculated and were seen to agree well with the corresponding literature values obtained by using fluorescence and surface tension measurements. The effect of salts on the change in micellar size and the surface charge has also been evaluated with the help of DLS experiments and transmission electron microscopy (TEM) images. Synopsis:Precise and iterative procedure was used to calculate the critical micelle concentration and fraction of counter ion dissociation of SDBS micelles in the presence of salts.