Nonionic Surfactant Research Articles

Current developments in Niosomes: Brand new extended release- An Introduction to Nonionic Stable Vesicular Systems

Vesicular systems are an innovative way to distribute drugs in a controlled way, improving bioavailability and achieving a longer-lasting therapeutic effect. When non-ionic surfactant vesicles self-assemble, niosomes are formed. The niosome formation is influenced by a number of variables, including the kind of non-ionic surfactant utilized, the preparation technique, the hydration temperature, etc. We have tried to include all the fundamental information about niosomes in this review article, including the different preparation techniques, types of niosomes, Advantages and disadvantages, niosome characterization, applications, and Drug delivery via niosomes. Lastly, the delivery system's limitations and prospects have also been covered.

FORMULATION AND EVALUATION OF Β-SITOSTEROL LOADED NIOSOMES FOR ENHANCED ANTIDIABETIC ACTIVITY: A POTENTIAL ALTERNATIVE IN TYPE 2 DIABETES MANAGEMENT

Niosomes, vesicles formed by non-ionic surfactants, offer advantages in drug delivery by enhancing solubilization and encapsulating both lipophilic and hydrophilic drugs. This study focuses on β-sitosterol-loaded niosomes designed to protect its anti-diabetic properties. Formulated with Span™ 60, Span™ 80 and cholesterol, the niosomes showed high entrapment efficiency (90%) and favorable release kinetics. Stability studies confirmed their robustness in various conditions. In vivo experiments demonstrated significant improvements in body weight and blood glucose levels in diabetic rats. The optimized formulation (NF8) exhibited controlled release and substantial antidiabetic activity, suggesting its potential as an effective treatment for type 2 diabetes mellitus.

Effect of Edge Activator Combinations in Transethosomal Formulations for Skin Delivery of Thymoquinone via Langmuir Technique

Thymoquinone (TQ), a bioactive compound found in Nigella sativa seeds, possesses diverse therapeutic properties for skin conditions. However, formulating TQ presents challenges due to its hydrophobic nature and chemical instability, which hinder its skin penetration. Transethosomes, as a formulation, offer an environment conducive to enhancing TQ’s solubility, stability, and skin permeation. To optimize TQ transethosomal formulations, we introduced a combination of ionic and nonionic surfactants, namely Tween 20 and sodium lauryl sulfate (SLS) or sodium lauroyl glutamate (SLG). Surfactants play a crucial role in stabilizing the formulation, reducing aggregation, improving biocompatibility, and minimizing potential toxicity. We fine-tuned the formulation composition and gained insights into its interfacial behavior using the Langmuir monolayer technique. This method elucidated the interfacial properties and behavior of phospholipids in ethosome and transethosome formulations. Our findings suggest that monolayer studies can serve as the initial step in selecting surfactants for nanocarrier formulations based on their interfacial dilational rheology studies. It was found that the addition of surfactant to the formulation increased the elasticity considering the capability of transethosomes to significantly decrease their radius when permeating the skin barrier. The results of the dilational rheology experiments were most relevant to drug permeation through the skin for the largest amplitude of deformation. The combination of Tween 20 and SLS efficiently modified the rheological behavior of lipids, increasing their elasticity. This conclusion was supported by in vitro studies, where formulation F2 composed of Tween 20 and SLS demonstrated the highest permeation after 24 h (300.23 µg/cm2). Furthermore, the F2 formulation showed the highest encapsulation efficiency (EE) of 94%, surpassing those of the control and ethosomal formulations. Additionally, this transethosomal formulation exhibited antimicrobial activity against S. aureus, with a zone of inhibition of 26.4 ± 0.3 mm. Importantly, we assessed the cytotoxicity of both ethosomes and transethosomes at concentrations ranging from 3.5 µM to 50 µM on HaCaT cell lines and found no cytotoxic effects compared to TQ hydroethanolic solution. These results suggest the potential safety and efficacy of TQ transethosomal formulations.

Influence of Non-Ionic Surfactant and Silver on the Photocatalytic Activity of TiO2 Films for Degradation of Dyes in Distilled and Tap Water

Influence of Non-Ionic Surfactant and Silver on the Photocatalytic Activity of TiO2 Films for Degradation of Dyes in Distilled and Tap Water

Mitigating strategy and mechanism of cement slurry contamination caused by oil-based mud: Macro-micro experiments, molecular dynamics simulation and dissipative particle dynamics simulation

During the cementing process, the oil-well cement (OWC) inevitably comes into contact with oil-based mud (OBM), which contaminates the OWC due to the incompatibility between OBM and the OWC. As a solution, hydrophilic surfactants can reduce interfacial tension and enhance the wetting compatibility of oil and water. Therefore, adding surfactants to the OWC is expected to alleviate contamination caused by OBM. In this study, a new strategy was proposed to combine non-ionic surfactants and anionic surfactants to form a composite surfactant (OP-S2), which overcomes the defect that excessive use of anionic surfactants deteriorates the performance of the OWC—showing great potential in adjusting the compatibility between OBM and the OWC and reducing cement contamination. The mechanism of contamination alleviation during the cementing process was elucidated by comparing the anticontamination properties of a single non-ionic surfactant (OP-S1) and OP-S2. In addition, molecular dynamics (MD) and dissipative particle dynamics (DPD) simulations were used to verify the mechanism of different types of surfactants in removing contamination further, providing theoretical guidance for future research on anti-contamination agents.

Microfluidic Stress Device to Decouple the Synergistic Effect of Shear and Interfaces on Antibody Aggregation

Protein denaturation and aggregation resulting from the effects of interfacial stress, often enhanced by flow and shear stress, pose significant challenges in the production of therapeutic proteins and monoclonal antibodies. The influence of flow on protein stability is closely intertwined with interfacial effects. In this study, we have developed a microfluidic device capable of exposing low volume (< 320 µL) protein solutions to highly uniform shear. To disentangle the synergistic impact of flow and interfaces on protein aggregation, we fabricated two devices composed of different materials, namely poly(methyl methacrylate) (PMMA) and stainless steel. Upon application of shear, we observed formation of protein particles in the micron-size range. Notably, The number of particles generated in the steel devices was ∼ 3.5 fold lower than in the PMMA device, hinting at an interface-mediated effect. With increasing the protein concentration from 1 to 50 mg/mL we observed a saturation in the amount of aggregates, further confirming the key role of solid-liquid interfaces in inducing particle formation. Introduction of non-ionic surfactants prevented protein aggregation, even at the highest tested protein concentration and low surfactant concentrations of 0.05 mg/mL. Overall, our findings corroborate the synergistic impact of shear and interface effects on protein aggregation. The device developed in this study offers a small-scale platform for assessing the stability of antibody formulations throughout various stages of the development and manufacturing process.

Rheology and surface active properties of sodium N-lauroyl sarcosinate in mixed surfactant system

Anionic surfactant sodium N-lauroyl sarcosinate (SNLS) forms elongated wormlike micelles with cocamide monoethanolamine (CMEA) and lauryl glucoside (LG) a nonionic surfactants in the pH range 5.5–6.0. The total surfactant concentration was examined between 10% and 20% wt/v, and the pH was lowered from 7.5 to 4.5. The presence of CMEA/LG diminishes electrostatic repulsion amid SNLS head groups and prompts micellar transition displaying moderate viscosity. The viscosity peak of each system occurred in the pH range 5.5–5.8, close to the system’s pKa. This might prove to be a novel approach for SNLS surfactant formulation which otherwise was difficult to thicken. Additionally, mixed surfactant systems of SNLS/CMEA/LG portrays high surface activity, enhanced foaming behavior and improved skin mildness. Further, this study demonstrated a cost-effective and thickener-free method for cleansing compositions with the desired viscosity.

Adsorption of spray droplets reduced adsorption of dicamba spray droplets on leaves as droplet size increases

Abstract Off-target movement of growth regulator herbicides can cause severe injury to susceptible plants. Apart from not spraying on windy days or at excessive boom heights, making herbicide applications using nozzles that produce large droplets is the preferred method for reducing herbicide drift. Although large droplets maintain a higher velocity and are more likely to reach the leaf surface in windy conditions, their ability to remain on the leaf surface is poorly understood. Upon impact with the leaf surface, droplets may shatter, bounce, roll-off, or be retained on a leaf surface. We examined how different nozzles, pressures, and adjuvants impact spray droplet adsorption on the leaf surface of common lambsquarters and soybean. Plants were grown in a greenhouse and sprayed in a spray chamber. Three nozzles (XR, AIXR, and TTI) were evaluated at 138, 259, and 379 kPa. Dicamba (0.14 kg ae ha⁻¹) was applied alone and with methylated seed oil (MSO), a non-ionic surfactant, silicone-based adjuvant, crop oil concentrate, or a drift reduction adjuvant. A 1, 3, 6, 8-pyrene tetra sulfonic acid tetra sodium salt was added as a tracer. Dicamba spray droplet adsorption when using the XR nozzle, which produced the smallest spray droplets, was 1.75 times greater than when applied with the TTI nozzle with the largest spray droplets. Applying dicamba with MSO increased adsorption on leaf surfaces nearly four times the amount achieved without an adjuvant. The lowest application pressure (138 kPa) increased dicamba spray volume adsorbed more than 10% compared to the higher pressures 259 and 379 kPa. By understanding the impacts of these application parameters on dicamba spray droplet adsorption, applicators can select application parameters, equipment, and adjuvants that will maximize the amount of dicamba spray volume retained on the target leaf surface while minimizing dicamba spray drift.

Synthesis of narrow-distributed Guerbet dodecyl alcohol ethoxylates on Ca(OAc)2 catalyst and theirs surface properties

Despite significant breakthroughs that have been made in the application performance of traditionally distributed Guerbet alcohol ethoxylates (GAEO), research on the characteristics of their narrow distribution products remains relatively limited. Herein, a series of hydrophilic and hydrophobic nonionic surfactants have been synthesized via the ethoxylation of 2-butyl-octanol with ethylene oxide. Ca(OAc)2 was employed as a narrow distribution (NRD) catalyst, while KOH served as a broad distribution (BRD) catalyst. The synthesized products were characterized using Fourier-transform infrared (FT-IR), 1H and 13C nuclear magnetic resonance (1H, 13C NMR) spectroscopy. In addition, a comprehensive assessment of the physicochemical and surface properties of the NRD GAEO surfactants was conducted through systematic investigations. The results were then compared to conventionally distributed GAEO surfactants. The study has demonstrated that NRD GAEO surfactants exhibited lower critical micelle concentration (CMC) values, which have the higher efficiency of the surfactant application. In addition, the NRD products have superior wettability performance, reduced foaming capacity in foam properties, and improved rapid defoaming capacities. In regarding their other properties, they closely mirrored the performance of BRD products. These findings will contribute to a comprehensive understanding of the properties of NRD ethoxylates and have substantial practical implications in optimizing personal care and household cleaning products.

Modulating protein unfolding and refolding via the synergistic association of an anionic and a nonionic surfactant

HypothesisNonionic surfactants can counter the deleterious effect that anionic surfactants have on proteins, where the folded states are retrieved from a previously unfolded state. However, further studies are required to refine our understanding of the underlying mechanism of the refolding process. While interactions between nonionic surfactants and tightly folded proteins are not anticipated, we hypothesized that intermediate stages of surfactant-induced unfolding could define new interaction mechanisms by which nonionic surfactants can further alter protein conformation. ExperimentsIn this work, the behavior of three model proteins (human growth hormone, bovine serum albumin, and β-lactoglobulin) was investigated in the presence of the anionic surfactant sodium dodecylsulfate, the nonionic surfactant β-dodecylmaltoside, and mixtures of both surfactants. The transitions occurring to the proteins were determined using intrinsic fluorescence spectroscopy and far-UV circular dichroism. Based on these results, we developed a detailed interaction model for human growth hormone. Using nuclear magnetic resonance and contrast-variation small-angle neutron scattering, we studied the amino acid environment and the conformational state of the protein. FindingsThe results demonstrate the key role of surfactant cooperation in defining the conformational state of the proteins, which can shift away or toward the folded state depending on the nonionic-to-ionic surfactant ratio. Dodecylmaltoside, initially a non-interacting surfactant, can unexpectedly associate with sodium dodecylsulfate-unfolded proteins to further impact their conformation at low nonionic-to-ionic surfactant ratio. When this ratio increases, the protein begins to retrieve the folded state. However, the native conformation cannot be fully recovered due to remnant surfactant molecules still adsorbed to the protein. This study demonstrates that the conformational landscape of the protein depends on a delicate interplay between the surfactants, ultimately controlled by the ratio between them, resulting in unpredictable changes in the protein conformation.

Surfactant Synergistic Effect and Interfacial Properties of Microemulsions Compounded with Anionic and Nonionic Surfactants Using Dissipative Particle Dynamics

Surfactant Synergistic Effect and Interfacial Properties of Microemulsions Compounded with Anionic and Nonionic Surfactants Using Dissipative Particle Dynamics

Influence of Surfactant on the Skin Permeation of Methylisothiazolinone and Methylchloroisothiazolinone.

Patch tests are often used in safety evaluations to identify the substance causing skin irritation, but the same substance can sometimes give positive or negative results depending on the test conditions. Here, we investigated differences in the skin penetration of two test compounds under different application conditions. We studied the effects of the anionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant polysorbate 80 (PS) on skin penetration of the preservatives methylisothiazolinone (MT) and methylchloroisothiazolinone (MCT), which are used in cosmetics such as shampoos. The skin permeation of MT was enhanced by SDS but was unchanged by PS. Skin impedance decreased in the presence of SDS whereas PS had the same effect as the control aqueous solution, suggesting that SDS reduction of the barrier function of skin affects the permeation of MT, a hydrophilic drug. Application of a mixture of MCT and MT in the presence of SDS did not affect the skin permeation of MCT whereas the permeation of MT was enhanced by SDS, indicating that the skin permeation of MCT is less affected by SDS than is MT. Thus, attention should be paid to the possible effect of co-solutes, especially hydrophilic drugs.

Development and characterization of dexamethasone nanodispersion for the effective treatment of diabetic retinopathy

Diabetic retinopathy is the most common complication of diabetes and remains the leading cause of vision loss worldwide. The potent glucocorticoid based anti-inflammatory drug dexamethasone (DEX) chosen for the present work is long-acting with half-life of 37–72 h extensively metabolized in to 6-hydroxy-dexamethasone (6-OH-DEX). The present work aimed to develop dexamethasone loaded nanodispersion (DEX-ND) by improving its solubility, half-life, and bioavailability in biological system thereby this formulation may be afforded economically. With the concept that polymeric surfactant improves the solubility of challenging water insoluble drug the present work has been hypothesized to improve its solubility using polyvinyl pyrrolidone (PVP-K30) polymer and polysorbate 80 (Tween 80) hydrophilic non-ionic surfactant, thereby the bioavailability is expected to get enhanced. By varying the PVP K30 and Tween 80 concentrations three different formulations were developed. The developed DEX-ND was further characterized for its compatibility, particle size, zeta potential, morphology, and in vitro release behavior. The results of Fourier transform infrared spectrometric analysis indicate the compatibility nature of DEX-ND along with other excipients/drug used in the formulation. The developed formulations showed spherical morphology, particle size ranging from 550.46 ± 107.82 to 3560 ± 284.29 nm, zeta potential ranging from −29.23 ± 1.09 to −7.793 ± 1.01 mV. The amount of DEX present in the DEX-NDs was found to be 0.95–3.93 mg. The in vitro release studies as performed by dialysis bag method showed a sustained release pattern. The results of ex vivo corneal permeation studies indicates that the developed DEX- NDs has some exposure to the posterior segment of the eye.

The effect of anti-agglomerant tween on the thermal and rheological properties of TBAF semi-clathrate hydrate slurry used for cold storage systems

Hydrate, as a phase change cold storage material, can form the slurry with certain fluidity, enabling convective heat transfer during both the heat absorption and heat release stages (cold storage or refrigeration), with high heat transfer efficiency. However, high viscosity and significant flow pressure losses are the principal challenges limiting its advancement. The paper selected four non-ionic surfactants as hydrate anti-agglomerants (Tween 20, 40, 60, 80) and utilized DSC to examine their effects on the thermal properties of TBAF semi-clathrate hydrate slurry at three theoretical hydrate concentrations (with mass fraction of 0.60, 0.70, and 0.80). Additionally, it measured the viscosity variation during the endothermic dissociation stage of the TBAF hydrate slurry and calculated the flow pressure losses in hydrate slurries within various pipe diameters. The results revealed that the presence of Tween increased the hydrate growth within the slurry, resulting in a higher available phase change enthalpy. Tween 80 demonstrated the most significant increase in enthalpy increasing effect, with an available phase change enthalpy ranging from 128.08 to 170.03 kJ/(kg·slurry) and an increase in enthalpy of 52.14 % to 91.62 %. For TBAF hydrate slurries with the theoretical hydrate mass fraction of 0.60, the addition of Tween 20 or Tween 80 significantly reduced viscosity, dropping to between 57.6 mPa·s and 116 mPa·s, and reducing viscosity by 43.4 % to 71.9 %. Furthermore, most flows with anti-agglomerants were in the laminar regime. The addition of Tween 20 and Tween 80 achieved the maximum reduction in flow pressure loss per unit length, with the highest reduction being 80.2 % (0.11 kPa/m) and 71.1 % (0.15 kPa/m), respectively. Both the phase change enthalpy of the hydrate and the viscosity of the hydrate slurry impacted the flow pressure drop within pipes. Increasing phase change enthalpy and reducing viscosity are effective strategies for mitigating flow pressure drop.

Effects of promoter and dedoping process on electrorheological response of polyaniline-graft-chitosan copolymer

In this study, electrorheological (ER) properties of biodegradable and conducting polyaniline-graft-chitosan (PAni-g-CS) copolymer particles were investigated. For this purpose, PAni and PAni-g-CS particles were synthesized by using in situ oxidative radicalic polymerization method. At first, PAni and PAni-g-CS/silicone oil (SO) ER suspensions (15% V/V) were subjected to external electric field and they exhibited low ER activity. When the external electric field strengths ([Formula: see text] were increased, both the suspensions showed electrical breakdown. Therefore, virgin PAni and PAni-g-CS were first subjected to dedoping process by treating with 1.0 M NaOH(aq) and non-ionic surfactant Triton X-100 (T-X) surfactant to enhance the expected ER activity and prevent the electrical breakdown. But we observed that the addition of T-X as promoter had no significant effect on the ER activity. On the other hand, electric filed-induced viscosities of both the suspensions were observed to enhance after the dedoping (DD) process and electrical breakdown prohibited. After the DD process, DD PAni-g-CS/SO ER system exhibited the highest electric field-induced viscosity by reaching 400[Formula: see text]Pa[Formula: see text]⋅[Formula: see text]s at [Formula: see text][Formula: see text]kV/mm. The highest ER efficiency was also obtained for DD PAni-g-CS/SO system at 15% (V/V) as 79. Additionally, typical shear thinning non-Newtonian viscoelastic behavior was observed under externally applied E. The conduction model of DD PAni-g-CS/SO system was determined to well fit the conduction model by showing a slope of [Formula: see text] calculated from the E vb. yield stress graph. In conclusion, conducting and biodegradable-dedoped PAni-g-CS particles would be a good candidate for potential ER applications as dry-based ER materials having high colloidal stability of 76%.

Enzyme stability with essential oils and surfactants. Growing towards green disinfectant detergents

This study investigates the stability of α-amylase and protease in disinfectant formulations incorporating essential oils (EOs), anionic surfactants (linear alkylbenzene sulfonate), non-ionic surfactants (alkylpolyglucosides and ethoxylated fatty alcohols), and mixtures of them, analysing the influence of the composition, temperature, and time using shelf-life assays. EOs reduce α-amylase activity showing first-order deactivation kinetics, and surfactants were found not to significantly affect its activity. However, protease activity increases with the presence of EOs, and it was also observed that the use of surfactants does not significantly affect protease activity either. This work represents a step forward in the development of environmentally friendly multifunctional detergents with high disinfectant and detersive capacity.

Solvent‐Free Synthesis of PMMA Particles using Tandem Acoustic Emulsification

AbstractPoly(methyl methacrylate) (PMMA) colloidal particles are nowadays extensively used in several applications and more specifically in nanotechnology. Challenges are focused on the green synthesis process leading to size‐controlled particles. In the present work, PMMA particles were successfully synthesized using tandem acoustic emulsification in water without organic solvent, and cross‐linkers. 2,2′‐azobis(2‐methylpropionamidine) dihydrochloride (AIBA) or ammonium persulfate (APS), were used as initiators. Parameters leading to size control were clearly identified. Consequently, the cooling rate of the solution after polymerization time appears dominating. Particle size distribution was monodispersed for both initiators. A nonionic surfactant, Tween 20, was also added, leading to a decrease in size particle and an increase in synthesis yield. Depending on the chemical groups provided by the initiator, PMMA particles appear negatively or positively charged. These charges located on the particle surface led to stable particle dispersion by limiting aggregation phenomena. Tunable surface charge was confirmed across the elaboration of coatings only made of PMMA particles, using conventional techniques wherein charged species are needed (Layer‐by‐Layer assembly and electrophoretic deposition). PMMA particles were also labelled using fluorescent dyes. Fluorescein and Nile Blue A were loaded during the polymerization process to ensure a homogeneous distribution of the dyes within the particles.

Identification and characterization of a promiscuous metallohydrolase in metallo-β-lactamase superfamily from a locally isolated organophosphate-degrading Bacillus sp. strain S3wahi

In this present study, characteristics and structure-function relationship of an organophosphate-degrading enzyme from Bacillus sp. S3wahi were described. S3wahi metallohydrolase, designated as S3wahi-MH (probable metallohydrolase YqjP), featured the conserved αβ/βα metallo-β-lactamase-fold (MBL-fold) domain and a zinc bimetal at its catalytic site. The metal binding site of S3wahi-MH also preserves the H-X-H-X-D-H motif, consisting of specific amino acids at Zn1 (Asp69, His70, Asp182, and His230) and Zn2 (His65, His67, and His137). The multifunctionality of S3wahi-MH was demonstrated through a steady-state kinetic study, revealing its highest binding affinity (KM) and catalytic efficiency (kcat/KM) for OP compound, paraoxon, with values of 8.09 × 10−6 M and 4.94 × 105 M−1 s−1, respectively. Using OP compound, paraoxon, as S3wahi-MH native substrate, S3wahi-MH exhibited remarkable stability over a broad temperature range, 20 °C – 60 °C and a broad pH tolerance, pH 6–10. Corresponded to S3wahi-MH thermal stability characterization, the estimated melting temperature (Tm) was found to be 72.12 °C. S3wahi-MH was also characterized with optimum catalytic activity at 30 °C and pH 8. Additionally, the activity of purified S3wahi-MH was greatly enhanced in the presence of 1 mM and 5 mM of manganese (Mn2+), showing relative activities of 1323.68 % and 2073.68 %, respectively. The activity of S3wahi-MH was also enhanced in the presence of DMSO and DMF, showing relative activities of 270.37 % and 307.41 %, respectively. The purified S3wahi-MH retained >60 % residual activity after exposure to non-ionic Tween series surfactants. Nevertheless, the catalytic activity of S3wahi-MH was severely impacted by the treatment of SDS, even at low concentrations. Considering its enzymatic properties and promiscuity, S3wahi-MH emerges as a promising candidate as a bioremediation tool in wide industrial applications, including agriculture industry.

Comparative study of nanoemulsion and micelle formed by surfactants containing benzene ring for spontaneous imbibition displacement

Nanoemulsion has a wide range of applications in oilfield chemistry due to its unique nanoscale size, excellent kinetic stability and high specific surface area. In this paper, a novel nanoemulsion oil flooding system was prepared using anionic surfactant sodium dodecyl benzene sulfonate (SDBS), the nonionic surfactant alkylphenol ethoxylates (OP-10), kerosene, n-butanol and deionized water. The particle size, Zeta potential, interfacial tension (IFT) and wettability properties were evaluated in the laboratory. The displacement performance of nanoemulsion was evaluated by the spontaneous imbibition experiment. Meanwhile, it compared with the same concentration of SDBS + OP-10 + n-butanol (SOB) system. The results showed that the particle size of the nanoemulsion was 70 ∼ 100 nm. When the concentration of nanoemulsion was 0.10 %, the oil–water IFT could reach 0.091 mN/m. The spontaneous imbibition oil recovery of the nanoemulsion (0.10 wt%) could reach 33.20 %, which was 23.02 % higher than that of SOB system. We also research the spontaneous imbibition displacement mechanism of nanoemulsion and micelle in low-permeability reservoirs. This paper will help to select the best oil displacement agent for the design of enhanced oil recovery (EOR) projects and promote the application of oil displacement agent in oilfield.

The Response Surface Methodology for Assessment of HLB Values of Mixtures of Non-Ionic Surfactants Using Parameters from Their π-A Isotherms.

The aim of the work was to determine important parameters of the course of π-A isotherms, which can determine the HLB (hydrophilic-lipophilic balance) value of surfactant mixtures with selected structural features, such as a straight or branched hydrocarbon chain and a double bond, using RSM (response surface methodology) computational methods. Mixtures of surfactants derived from fatty acids and sorbitan with specific HLB values were evaluated by Langmuir trough. The resulting elasticity modules (ELM) and molecules surfaces (SAM) were evaluated via response surface methodology and respective equations were calculated. The π-A isotherm determined in a Langmuir trough and the ELM and SAM parameters determined on the basis of this isotherm may be useful for determining the HLB of a fixed surfactant mixture. The RSM method used, in which ELM and SAM were assumed as two independent variables, can be a useful technique for tracking the influence of individual molecular characteristics on the hydrophilic-lipophilic properties of mixtures of surfactant compounds. Changes in HLB as a dependent variable can be described as a function of ELM and SAM.