Critical Micelle Concentration Research Articles

Heavy metal application of response surface optimized-lipopeptide biosurfactant produced by Pseudomonas aeruginosa strain CGA-02 in low-cost substrate

Cost-effective methods of biosurfactant production with minimal environmental impact are needed as global demand continues to increase. This study evaluated lipopeptide biosurfactant production in a Pseudomonas aeruginosa strain CGA-02 using a low-cost carbon substrate. The structural properties of the biosurfactant and applicability of the biosurfactant in heavy metal removal were evaluated. Response surface methodology (RSM) involving central composite design (CCD) was used to optimize process parameters to maximize biosurfactant production. The study identified sugar cane molasses and sodium nitrate as carbon and nitrogen sources of choice for bacterial growth and biosurfactant production, with a relatively 2.64-fold increase in biosurfactant yield under optimized conditions. Analysis of the biosurfactant measured a surface tension reduction of water from 72.2 ± 0.26 to 30.5 ± 0.2 mN/m at 40 mg/L critical micelle concentration. GC–MS and FTIR analysis revealed structural properties of the lipopeptide biosurfactant, with fatty acid components predominantly 9-octadecenoic acid (oleic acid), n-hexadecanoic acid, cyclotetrasiloxane and trimyristin, and infrared peaks belonging to amine, carboxyl, nitrile, alkanol, ether and carbonyl groups. Capture of heavy metals using the biosurfactant was evaluated in soil microcosms. Removal rates of 80.47, 100, 77.57, 100, and 97.57% were recorded for As, Pb, Hg, Cd and Cr respectively after 12 weeks of incubation. There was no significant difference (p < 0.05) in the removal efficiency of the biosurfactant and an analogous chemical surfactant, sodium dodecyl sulphate. First and second-order kinetic models described heavy metal removal rates by the biosurfactant. We demonstrate the production of a useful biosurfactant using low-cost waste carbon.

Phase separation, aggregation, and complexation of triton-X100 and bovine serum albumin mixture: A combined cloud point and UV–visible spectroscopic approaches

Phase separation and aggregation behaviour of triton X-100 (TX-100) and bovine serum albumin (BSA) mixture were investigated using cloud point and UV–visible spectroscopic techniques. The effects of various hydrotropes (HYTs) - namely, sodium salicylate (SS), sodium benzoate (SB), glycerol (Glyc), and 4-aminobenzoic acid (4-ABA) - on the cloud point (CP) of TX-100 + BSA were determined. The obtained CP values for the mixed system in the presence of HYTs followed the order:CPH2O+4−ABA<CPH2O+Glyc<CPH2O+SB<CPH2O+SS. The measured critical micellization concentration (CMC) values of the TX-100 + BSA mixture were found to be significantly altered with varying amounts of BSA. The calculated free energy of clouding and micellization indicated the non-spontaneous nature of the phase transition and the spontaneous association of the TX-100 + BSA mixture. The non-spontaneity of phase separation decreased with increasing concentrations of HYTs. The enumerated values of ∆Hco and ∆Sco were consistently recorded as negative and positive magnitudes, respectively, in all aqueous HYTs media. The clouding process occurred due to a combination of hydrophobic and electrostatic interactions. The binding constant of the mixed system was determined employing the UV–vis spectroscopic method using the Benesi-Hildebrand equation.

Formulating biomolecular crowns on micelles: A potential strategy for improving micelle stability

The complex environment in blood circulation has a tremendous destabilizing effect on the micelles structure, which is a vital issue to be addressed in micelles design and application. Biomolecule crowns, quickly formed on the surface of nanocarriers in vivo, may alter the physicochemical properties of nanocarriers. In this study, bovine serum albumin (BSA) or fetal bovine serum (FBS) was formulated as the biomolecular crown of the bacterial lipase-responsive micelles encapsulating the hydrophobic antibiotics chloramphenicol (CHL) to investigate their stabilization effect on the micelles. Compared with BSA-crowned micelles (BSA/PM@CHL), FBS-crowned micelles (FBS/PM@CHL) reduced drug leakage by more than 90 % without masking their lipase responsiveness, it also inhibited 77 % of bacterial growth in in vitro antibacterial activity study and significantly increased the area under plasma concentration curve and in vivo half-life in pharmacokinetic study. Then the Förster resonance energy transfer (Fret) Effect was used to further explore the mechanisms responsible for the differences between the BSA-crown and FBS-crown. The in vitro anti-dilution tests below the critical micellar concentration showed that FBS-crown could improve the thermodynamic stability of the micelles, the micelle integrity of FBS/PM was 2 times higher than that of PM diluted with aqueous dilution and 6.5 times higher than that diluted with rat plasma dilution. In vivo optical imaging study showed that micelles with dual-labeled FBS/PM (mean value = 0.363) maintained better structural integrity than dual-labeled PM (mean value = 0.325) after 4 h of injection, explaining the ability of FBS-crowned micelles to improve pharmacokinetic parameters in terms of thermodynamic stability. Besides, the destruction of PM integrity slowed down after injection into the blood circulation for 4–8h, indicating that the baring of biomolecular-crown may be in the late cycle. Overall, the biomolecular-crowned micelles strategy presents a promising strategy for maintaining the structural and functional stability of micelles under physiological conditions.

Using Poly(N‐isopropylacrylamide) and Poly(ethyleneglycol) Grafted Polycarbodiimides as Unique Nanocarriers for Hydrophobic Form of the Doxorubicin (DOX)

Using Poly(<i>N</i>‐isopropylacrylamide) and Poly(ethyleneglycol) Grafted Polycarbodiimides as Unique Nanocarriers for Hydrophobic Form of the Doxorubicin (<scp>DOX</scp>)

Synthesis and Performanceof Bio-Based Amphoteric Surfactants.

As the global surfactant market continues to expand, there is an increasing need to develop bio-based alternatives in the shift towards a circular economy. This study focuses on the synthesis of polar, amphoteric, amine-oxide surfactants starting from biomass-derived monosaccharides and demonstrating their potential in various applications. The synthesis involved a reductive amination of the sugars with an alkylamine and formaldehyde followed by oxidation to produce N-oxide surfactants. These bio-based surfactants exhibited promising properties, including high solubility, foamability, surface tension reduction, and critical micelle concentration. In particular, N-GalA1.10 and N-GalA1.12 showed comparable performance to commercial surfactants. Furthermore, these bio-based surfactants demonstrated significantly lower skin irritation potential when compared to petrochemical-derived counterparts like sodium laureth sulfate (SLES), making them potentially suitable for personal care products. The biodegradability assessment revealed that N-GalA1.12 exhibited good biodegradation, indicating its potential environmental compatibility. In conclusion, this study highlights the potential of bio-based N-oxide surfactants derived from monosaccharides as sustainable and skin-friendly alternatives to traditional amphoteric surfactants, like cocamidopropyl betaine (CAPB).

New long tail gemini surfactant in aqueous solution: Self-assembly, rheological properties and responsiveness to hydrocarbon

Gemini surfactants are promising to replace conventional monomeric surfactants in various applications. In this paper, a new gemini surfactant with long unsaturated oleyl tails and bis(hydroxyethyl) ammonium head groups linked by butyl spacer was synthesized. Its critical micelle concentration in salt-free water (12 µM) is much lower than for its monomeric analog (220 µM). Without any additives this surfactant can form viscoelastic solutions with the viscosity of up to 1 kPa·s and elastic modulus of 15 Pa at the conditions, when the viscosity of the single-chained monomeric analog is close to that of pure water. These are one of the highest values reported so far for C18-tailed gemini surfactants without additives. The structure of the gemini surfactant solutions was studied by cryo-TEM and SAXS. Cryo-TEM revealed the presence of closed-looped micelles coexisting with linear wormlike micelles as well as the regular spacing between the micelles arising from strong electrostatic repulsion between them. The SAXS curves were well-fitted by a form-factor of core–shell cylinder, which yielded the radius of the core and the thickness of the shell equal to 1.4 nm each. Addition of n-decane induced the drop of viscosity by 6 orders of magnitude accompanied by the transformation of wormlike micelles into microemulsion droplets with 4.4 nm radius. Such gemini surfactants providing high viscoelasticity to aqueous solution that is responsive to added hydrocarbon are promising for the application in oil recovery as thickeners of fracturing fluids that can be cleaned up without any breakers at the backflow of oil.

Interaction, Surface Activity, and Application of Mixed Systems of Alcohol Ether Sulfate Anionic Surfactants with Multiple Ethylene Oxide Groups and Gemini Quaternary Ammonium Surfactant.

The surface activities and application properties for the mixtures of cationic surfactants tetramethylene-1,4-bis[N,N-bis(hydroxypropyl)-hexa/decyloxypropylammonium] bromide (GC10-P) and tetramethylene-1,4-bis[N,N-bis(hydroxyethyl)-hexa/decyloxypropylammonium] bromide (GC10-E) and anionic surfactant isomeric sodium fatty alcohol ether sulfates (iso-AE9S) were investigated using both the tensiometry and the conductometry. The interaction parameters and thermodynamic micellization parameters of GC10-P/iso-AE9S and GC10-E/iso-AE9S mixtures were evaluated by Clint-Rubingh and Motomura theoretical models. When the mole fraction of α1 for GC10-P/iso-AE9S mixed system was 0.2, the critical micelle concentration (CMC) reached a minimum of 1.61 × 10-4 mol/L, and the minimum critical micelle concentration of the GC10-E/iso-AE9S mixed system is 2.67 × 10-5 mol/L at α1 = 0.6. The CMC value of the mixed system is 1-2 orders of magnitude lower than that of any single component. The results indicate that the synergistic effects of the investigated mixed systems (evaluated by βm) are in order of GC10-P/iso-AE9S < GC10-E/iso-AE9S, with maximum βm values of -17.98 and -9.78, respectively. The change in zeta potential indicates that the poly(ethylene oxide) chain has weakened the charge density of the hydrophilic headgroup of the anionic surfactant. The interfacial tension at the oil-water interface in the mixed system of anionic/cationic surfactants is lower than that of any single component, exhibiting a higher interfacial activity. The mixed system exhibits a decreased contact angle and superior wetting ability over any single component, and it also enhances foam performance, emulsification performance, and degreasing performance.

Does the Electrical Double Layer Contribute to the Mechanism of Action of Antimicrobial Peptides?

AbstractThis concept paper elucidates the possible influence of the electrical double layer (EDL) and the polyelectrolytic nature of bacterial cell walls on the behavior of antimicrobial peptides (AMPs) and lipopeptides. It proposes that the presence of EDL adjacent to lipid membranes may play a crucial role in inducing peptide aggregation and conformational changes, thus affecting their antimicrobial activity. Furthermore, it emphasizes that the negatively charged components in both Gram‐positive and Gram‐negative bacterial cell walls may act as polyelectrolytes, effectively reducing the critical micellization concentration (CMC) of positively charged peptides and lipopeptides. This reduction is expected to facilitate their aggregation, potentially enhancing their accumulation at the bacterial membrane and increasing their effectiveness in disrupting membrane integrity and exerting antimicrobial activity. Therefore, understanding the interplay between EDL effects, polyelectrolytic properties of bacterial cell walls, and the behavior of antimicrobial peptides is essential for elucidating their mechanisms of action and optimizing their therapeutic potential.

Diffusiophoretic Transport of Charged Colloids in Ionic Surfactant Gradients Entirely below versus Entirely above the Critical Micelle Concentration.

When placed in an ionic surfactant gradient, charged colloids will undergo diffusiophoresis at a velocity, uDP = MDP∇ ln S, where MDP is the diffusiophoretic mobility and S is the surfactant concentration. The diffusiophoretic mobility depends in part on the charges and diffusivities of the surfactants and their counterions. Since micellization decreases surfactant diffusivity and alters charge distributions in a surfactant solution, MDP of charged colloids in ionic surfactant gradients may differ significantly when surfactant concentrations are above or below the critical micelle concentration (CMC). The role of micelles in driving diffusiophoresis is unclear, and a previously published model that accounts for micellization suggests the possibility of a change in the sign of MDP above the CMC [Warren, P. B.; . Soft Matter 2019, 15, 278-288]. In the current study, microfluidic channels were used to measure the transport of negatively charged polystyrene colloids in sodium dodecyl sulfate (SDS) surfactant gradients established at SDS concentrations that are either fully above or fully below the CMC. Interpretation of diffusiophoresis was aided by measurements of the colloid electrophoretic mobility as a function of SDS concentration. A numerical transport model incorporating the prior diffusiophoretic mobility model for ionic surfactant gradients was implemented to elucidate signatures of positive and negative diffusiophoretic mobilities and compare with experiments. The theoretically predicted sign of the diffusiophoretic mobility below the CMC was determined to be particularly sensitive to uncertainty in colloid and surfactant properties, while above the CMC, the mobility was consistently predicted to be positive in the SDS concentration range considered in the experiments conducted here. In contrast, experiments only showed signatures of a negative diffusiophoretic mobility for these negatively charged colloids with no change of sign. Colloid diffusiophoretic transport measured in micellar solutions was more extensive than that below the CMC with the same ∇ ln S.

Graph neural networks for surfactant multi-property prediction

Surfactants are of high importance in different industrial sectors such as cosmetics, detergents, oil recovery and drug delivery systems. Therefore, many quantitative structure–property relationship (QSPR) models have been developed for surfactants. Each predictive model typically focuses on one surfactant class, mostly nonionics. Graph Neural Networks (GNNs) have exhibited a great predictive performance for property prediction of ionic liquids, polymers and drugs in general. Specifically for surfactants, GNNs can successfully predict critical micelle concentration (CMC), a key surfactant property associated with micellization. A key factor in the predictive ability of QSPR and GNN models is the data available for training. Based on extensive literature search, we create the largest available CMC database with 429 molecules and the first large data collection for surface excess concentration (Γm), another surfactant property associated with foaming, with 164 molecules. Then, we develop GNN models to predict the CMC and Γm and we explore different learning approaches, i.e., single- and multi-task learning, as well as different training strategies, namely ensemble and transfer learning. We find that a multi-task GNN with ensemble learning trained on all Γm and CMC data performs best. Thus, our results show that the simultaneous use of data from highly correlated properties can improve the predictability of surfactant properties for which only a small amount of experimental data is available. Finally, we test the ability of our CMC model to generalize on industrial grade pure component surfactants. The GNN yields highly accurate predictions for CMC, showing great potential for future industrial applications.

Degradation of anti-rust oil film in a simulated coastal atmosphere: inhibition mechanism and in-situ monitoring

Anti-rust oils (ARO) are widely used to inhibit atmospheric corrosion of metal structures, but their degradation mechanisms are unclear, particularly in coastal environments. In this work, we first prepared a kind of ARO made of sodium petroleum sulfonate (SPS) and white oil, then coated the ARO on a mild steel plate to investigate its deterioration process beneath saline water droplets by Quartz crystal microbalance (QCM) and electrochemical mapping techniques. It shows that the SPS concentration is crucial to the ARO inhibition property. When the SPS content is lower than its critical micelle concentration (CMC), saline droplets may intrude the barrier formed by the nonpolar paraffin groups of SPS and then adsorb on the steel surface, resulting in localised corrosion. However, once the SPS content exceeds its CMC, the saline droplets will be emulsified and captured in the oil phase by the reverse micelle effect, thus inhibiting the corrosion of steel substrates. Moreover, the atmospheric corrosion rate of mild steel obeys a power decaying under ARO film. Finally, a capacitive sensor was invented to evaluate the degree of degradation of ARO in situ by dielectric constant measurement.

Surface properties, aggregation behavior and wettability of the mixed system of fluorocarbon cationic surfactant and hydrocarbon anionic surfactant in dilute solutions

Traditional perfluorooctane sulfonic acid (PFOS) fluorocarbon surfactants endangered human health and environment. Therefore, an environmentally friendly quaternary ammonium cationic fluorocarbon surfactant (PFAS-IEt) was synthesized, and surface activities, aggregation behavior, adsorption properties and wettability of PFAS-IEt/sodium n-octyl sulfate (SOS) mixtures in dilute solutions were systematically investigated. The results demonstrated that PFAS-IEt possessed excellent surface activity in aqueous solution. Surprisingly, its surface tension was only 15.33 mN/m and critical micelle concentration (CMC) was 0.002 mol/L. It could be used as a potential substitute for PFOS. In addition, PFAS-IEt had the good synergistic effect with SOS. The PTFE plate with low surface energy could be completely wetted by the binary compound solution at low concentration (0.04 mol/L) (contact angle was 0°), which was superior to the reported long chain quaternary ammonium non-ionic fluorocarbon surfactants (MN-2C9F19 and EN-2C9F19).

Novel approaches to monitoring the formation of self-assembled colloids composed of cationic surfactants and alginate polysaccharide

In actual work, the self-assembly process of alginate (Alg) polysaccharide having low molecular weight (240 kDa) with cationic surfactants from the family of trimetylammonium bromide (TAB) derivatives was investigated at wide polysaccharide/surfactant molar ratio range through the interpretation of the formation of non-aggregated colloidal complexes.On one hand, the critical micelle concentration (cmc) values of the studied TAB surfactants having C12C18 chain length were determined and published for the first time in phosphate buffer solution. In addition to the applied conventional measurement procedures like tensiometry, light scattering, calorimetry, and equilibrium dialysis-based methods, the applicability of streaming potential technique was also demonstrated for the first time for these types of systems to gain a deeper insight into the formation process of the complexes built up by biocompatible polysaccharides and cationic surfactants. Through the interpretation of the change of the streaming potential values as a function of increasing surfactant's concentration it was clearly highlighted that both the individual and cooperative binding process of the surfactants can be clearly identified followed by the aggregation of the polysaccharide-surfactant colloidal complexes and the formation of surfactant micelles in the bulk dispersion.

Zwitterionic targeting nanodrugs prepared from poly(propyleneimine) dendrimers for enhanced anti-tumor therapy

Development of targeting and high drug loading drug delivery system has been gaining great interest. Zwitterionic modification of the terminal amine groups on G2 poly(propyleneimine) (G2 PPI) dendrimers was achieved via the thiol-ene click reaction, followed by the introduction of the anti-cancer drug paclitaxel and targeting peptides c(RGDfC), then the micelles were formed through self-assembly behavior, subsequently doxorubicin was encapsulated internally, finally the targeting drug-loaded micelles PPIMPRC-DOX were synthesized. The PPIMPRC-DOX micelles were irregular spherical with good monodispersity. The average particle size from TEM image was 63.05nm and the hydrodynamic size was 93.1nm, both of which were relatively uniform. The critical micelle concentration was 48.52μg/mL, the total drug loading efficiency was 32.45%. In vitro release experiments revealed that within the mildly acidic environment of tumors, PPIMPRC-DOX micelles exhibited enhanced release efficiency and increased accumulation of DOX. The anti-nonspecific protein adsorption experiment proved that the interaction between the PPIMPRC-DOX micelles and fibrinogen was very weak, and they had good anti-nonspecific protein adsorption ability. The cytotoxicity assessments using the MTT assay on HeLa cells and A549 cells revealed obvious cytotoxic effects of PPIMPRC-DOX micelles on both cells. Hence, the utilization of zwitterionic G2 PPI dendrimers in constructing PPIMPRC-DOX micelles holds promise as a prospective nanodrug delivery system.

Laboratory study on the performance of AOS surfactant in increasing oil recovery

The decline in oil recovery in the oil and gas field is a problem that must be faced along with increasing energy needs. Efforts are made to increase oil recovery reserves with advanced methods, namely Enhanced Oil Recovery. In this study, an AOS (alpha olefin sulfonate) surfactant solution was used. Tests were conducted with varying concentrations at a salinity of 7,000 ppm. Phase behavior tests were also conducted for 7 days at 80 °C. The oil recovery value of the surfactant solution was also investigated. The testing stages carried out were density, interfacial tension, and core flooding tests. After making the surfactant solution sample, a density test was conducted at 30 and 80 °C. Finally, the core flooding test. The IFT results of the surfactant solution reached the critical micelle concentration (CMC) point so that it could reduce the interfacial tension well between oil and formation water in the reservoir with an interfacial tension value of 0.8212087 dyne/cm. Core flooding results are based on surfactants that reach the CMC point. There is a surfactant with a concentration of 1% Salinity 7,000 ppm at the CMC point with a recovery factor of 7.2727%.

Preparation and characterization of self-aggregating micelles from stearic acid-modified burdock root polysaccharide

In order to obtain amphiphilic polysaccharide self-assembly micelles, the hydrophobic modification by grafting stearic acid (SA) onto the backbone of burdock root polysaccharide (BRP) was carried out and its main physicochemical properties were characterized. The results showed that the optimal esterification conditions were as follows: reaction time of 2 h, reaction temperature of 55 ℃, system pH of 8.0 and the SA addition of 4 mmol, a maximum substitution degree (DS) of the esterification products was obtained as 0.1012. The FTIR analysis verified that the modified polysaccharide successfully introduced the ester carbonyl group. 1H NMR spectra further confirmed that the esterification reaction occurred. The SA-modified BRP micelles were roughly spherical with uniform dispersion and the particle size was in the range of 259–352 nm, which showed a negative correlation with the DS. The solubility of the esterification products also decreased. The smaller critical micelle concentration (CMC) led to easier formation of self-aggregating micelles and stronger solubilization effect. The above results indicated that SA-modified BRP as a novel carrier material possessed potential to deliver hydrophobic active substances.Graphical

The effect of fir wood SLS surfactant concentration on the characteristics of light crude oil

As time progresses, oil production will gradually depletes considering limited oil reserves. This is why, an advanced stage method known as tertiary oil recovery is required. One of these methods is known as Enhanced Oil Recovery method. In this laboratory study, one specific surfactant fluid was used, namely Fir wood sodium lignosulfonate (SLS) with varying concentrations of 0.50; 1.00; 1.50; 2.00; 2.50; and 3.00% each crude oil 39 ° API. This study aims to witness the stability of SLS surfactant fluid in chemical injection. SLS surfactant injection is carried out to increase oil production in the reservoir. In this study, there are various stages in order to test the characteristics of the SLS surfactant, so it can be declared as effective in oil sweeping, namely phase behaviour test, density testing, phase behaviour test, interfacial tension test, and adsorption test. Density test is carried out to determine the density of a fluid. Phase behaviour test is intended to see the stability of emulsion obtained from the utilization of SLS surfactant. The main objective of surfactant utilization is to reduce interfacial tension which leads to IFT test. The IFT (interfacial tension) results of the SLS surfactant fluid are determined from the results of the stable phase behaviour test which evidently shows the critical micelle concentration (CMC) point, so it can properly reduce the interfacial tension of oil and formation water in the reservoir. Interfacial tension test was carried out to determine the interfacial tension between SLS surfactant and oil. Adsorption test is carried out to witness the level of fluid adsorption onto the rock surface. On static adsorption test, the result showed for 2 % surfactant concentration is 9.526 mg/gr. Dynamic adsorption test was conducted on the same concentration show results of respectively 1.865 mg/gr.

Glycidyl methyl ether: A safer alternative to ethylene oxide for designing ethoxy-free non-ionic surfactants

Ethoxylated surfactants have recently raised alarm because small amounts of dioxane, a Substance of Very High Concern (SVHC), are formed during their synthesis and degradation, with some of it ending up as traces in drinking water. This awareness has prompted a quest for alternative non-ionic surfactants free of ethoxylates yet offering a tuneable molecular structure and amphiphilic behaviour akin to polyethoxylated alcohols, CiEj. In this perspective, we performed oligomerization of Glycidyl Methyl Ether (GME) on fatty alcohols to yield branched isomers of CiEj surfactants. The amphiphilic properties of the resulting well-defined ethoxy-free surfactants were systematically compared to their polyethylene glycol counterparts. The introduction of branching in the polar head led to decreased hydrophilicity, as quantified by PIT-slope measurements. Furthermore, these branched surfactants exhibited cloud points with a reduced dependence on the oligomerization degree and lower Critical Micelle Concentrations (CMC). Consequently, these findings position them as promising alternatives to ethoxylated non-ionic surfactants. Finally, the COSMO-RS theory was strategically applied for the first time to rigorously rationalize the amphiphilic properties exhibited by these novel surfactants by precisely quantifying hydrophilic-lipophilic tendencies.

Polymeric surfactants with high acid values for emulsion type pressure-sensitive adhesives

Low molecular weight polymers with hydrophobic-carboxyl groups have been usually used as anionic surfactants in emulsion polymerization for coatings. However, such polymeric surfactants usually have low acid values below 200, because it is difficult to make high acid-value polymeric surfactants using a normal batch reactor. In this work, we polymerized high acid value polymeric surfactant having high acid values successfully up to 380 using CSTR (continuous stirring tank reactor). The synthesized polymeric surfactant was a random copolymer of P(BA-AA) and we applied them as anionic surfactants in making emulsion-type acrylic PSAs (Pressure-Sensitive Adhesives) to investigate the effects of high acid value on the adhesive properties. This CSTR enabled effective control of the polymerization reaction because it could control the composition and molecular weight of polymeric surfactants through varying monomer ratios, retention time, and initiator concentration. The surface tension analysis and emulsion stability test indicated that the polymeric surfactants exhibited a similar level of critical micelle concentration (CMC) and emulsion stability with other conventional anionic surfactants. Also, the adhesion property analysis showed that the PSA used a high acid value polymeric surfactant resulting in superior adhesive properties and heat resistance than the PSA used both low acid value polymeric surfactant and conventional low molecular weight surfactant. It was very notable that polymeric surfactants having unusually high acid values above 300 because of their high contents of carboxylic acid groups could result in superior adhesive properties and heat resistance.

Effect of strong and weak polyelectrolytes on the properties of cationic surfactant with triallyl ammonium head group: Self-assembly and biological assessment

Comprehensive assessment of polymer-colloid systems based on cationic surfactant with triallyl ammonium head group (TAS-16) in the presence of synthetic polyelectrolytes (polyacrylic acid (PAA), sodium polyacrylate (SPA), and sodium polystyrene sulfonate (PSS)) has been carried out. The addition of weak polyelectrolyte PAA significantly reduces the critical micelle concentration of the amphiphile up to 50 times. In conrtrast, strong polyelectrolytes such as PSS and SPA have a much smaller effect on the aggregation threshold of the surfactant. Spherical aggregates with a diameter of 80-230 nm were observed in the surfactant-PAA system using transmission electron microscopy. The mixed compositions exhibited high antitumor activity against the human duodenal adenocarcinoma HuTu 80 cell line (IC50=0.6 μM). The pure polymers do not cause hemolysis and hemagglutination, while TAS-16 exhibits hemolytic activity in both pure and mixed systems. The polymer-colloid complexes containing strong polyelectrolyte SPA were more effective as nanocontainers to enhance the solubility of the hydrophobic antibiotic Amphotericin B.