Sodium Dodecyl Sulfate Micelles Research Articles

The role of presence of wormlike micelles of ionic surfactants on the sterilization efficiency of sodium hypochlorite

Abstract This paper describes an attempt to increase the sterilising efficacy of sodium hypochlorite (SH) by prolonging its shelf life in gel mode through the presence of wormlike micelles. No effect was observed on the presence of SH on the ratio of highest viscosity peak of 20:80 of 3 % (w/w) sodium dodecylsulfate (SDS) and cetyltrimethylammonium bromide (CTAB). On the other side, the presence of SH has a relatively negative effect on transformation process from spherical (three-dimensional, 3D) micelles to wormlike (one-dimensional, 1D) micelles. The gel state of the aqueous SH solution is maintained even at a ratio of 20:80 SDS:CTAB 3 % (w/w). Measurements of the biological activity of the gel using Staphylococcus aureus bacteria show that the sterilizing efficiency of SH is enhanced by the presence of 1D micelles. In contrast, the stability of SH using the kinetic method shows a sudden decrease in its stability due to the presence of 1D micelles, and the same is the case when both SDS and CTAB micelles are present. It was concluded that the increase in the biological activity of SH due to presence of micelles in gel or liquid mode resulted from their chemical interference, which acts as an antibacterial formulation.

Hydrogel Films with Impact Resistance by Sacrificial Micelle-Assisted-Alignment.

Various strategies are developed to engineer aligned hierarchical architectures in polymer hydrogels for enhanced mechanical performance. However, chain alignment remains impeded by the presence of hydrogen bonds between adjacent chains. Herein, a facile sacrificial micelle-assisted-alignment strategy is proposed, leading to well-aligned, strong and tough pure chitosan hydrogels. The sacrificial sodium dodecyl sulfate micelles electrostatically interact with the protonated chitosan chains, enabling chain sliding and alignment under uniaxial forces. Subsequently, sacrificial micelles can be easily removed via NaOH treatment, causing the reforming of H-bond in the chain networks. The strength of the pure chitosan hydrogels increases 140-fold, reaching 58.9±3.4MPa; the modulus increases 595-fold, reaching 226.4±42.8MPa. After drying-rehydration, the strength and modulus further rise to 70.3±2.4 and 403.5±76.3MPa, marking a significant advancement in high-strength pure chitosan hydrogel films. Furthermore, the designed multiscale architectures involving enhanced crystallinity, well-aligned fibers, strong interfaces, robust multilayer Bouligand assembly contribute to the exact replica of lobster underbelly with impact resistance up to 6.8±1.0kJ m-1. This work presents a promising strategy for strong, tough, stiff and impact-resistant polymer hydrogels via well-aligned hierarchical design.

Precision picric acid detection via a fluorenone-amide functionalized fluorescent micellar probe

Detection of picric acid (PA) in aqueous solutions is crucial for pollution control, extending beyond national security and military applications. Herein, a binary ensemble AM@SDS has been assembled by encapsulating a fluorenone functionalized amide-based probe (AM) within the micelles of an anionic surfactant, sodium dodecyl sulphate (SDS) in an aqueous medium. A range of spectroscopic techniques, including high-resolution transmission electron microscopy (HRTEM), dynamic light scattering (DLS), and fluorescence spectroscopy (FL), have been employed to characterize the formation of micelles of AM@SDS. A remarkable increase in fluorescence intensity was observed upon interactions of AM with the microenvironment of SDS micelles. Conversely, the fluorescence intensity at 358 nm was significantly quenched in the presence of PA compared to other nitroaromatic compounds (NACs). The detection limit for PA was found to be 368 nM. Furthermore, the binary ensemble AM@SDS has demonstrated remarkable efficacy in detecting PA in real water samples from diverse sources such as lake, river, and tap water, achieving an exceptional recovery rate of up to 99.9 %.

Controllable synthesis of monodisperse hierarchical porous carbon nanorods and their derived superstructures for supercapacitors

Monodisperse hierarchical porous carbon nanorods (HPCNs-1) are synthesized through hydrothermal carbonization and KHCO3 activation using D-xylose, sodium dodecyl sulfate (SDS) and poly (4-styrene sulfonic acid-maleic acid) sodium salt (PSSMA). PSSMA regulates morphology and the accumulation of SDS micelles through inhibition and electrostatic repulsion. SDS serves as a microreactor for hydrothermal processes and a pore-forming agent. KHCO3 generates micropore and ensures a high specific surface area. Additionally, raspberry-like and spindle-like hierarchical porous nanocarbons are obtained with sodium laurate and sodium oleate. Hierarchical porous nanocarbons exhibit controllable morphology, high pore utilization, demonstrating useful electrochemical performance. In a 6 mol·L-1 KOH electrolyte, HPCNs-1 achieves a specific capacitance of 302F·g−1 at a current density of 0.2 A·g−1 with a retention rate of 98 % after 10,000 charge–discharge cycles at 10 A·g−1. In pure 1-butyl-3-methylimidazolium tetrafluoroborate electrolyte, an assembled symmetric supercapacitor with HPCNs-1 demonstrates an energy density of 39.06 W·h·kg−1 at 0.1 A·g−1.

Structural and dynamics characterization of the Zika virus NS2B using nuclear magnetic resonance and RosettaMP: A challenge for transmembrane protein studies

Zika virus (ZIKV) is an emergent flavivirus that represents a global public health concern due to its association with severe neurological disorders. NS2B is a multifunctional viral membrane protein primarily used to regulate viral protease activity and is crucial for virus replication, making it an appealing target for antiviral drugs. This study presents the structural elucidation of full-length ZIKV NS2B in sodium dodecyl sulfate (SDS) micelles using solution nuclear magnetic resonance experimental data and RosettaMP. The protein structure has four transmembrane α-helices, two amphipathic α-helices, and a β-hairpin in the hydrophilic region. NS2B presented secondary and tertiary stability in different concentrations of SDS. Furthermore, we studied the dynamics of NS2B in SDS micelles through relaxation parameters and paramagnetic relaxation enhancement experiments. The findings were consistent with the structural calculations. Our work will be essential in understanding the role of NS2B in viral replication and screening for inhibitors against ZIKV.

Effective Detoxification of Olive Mill Wastewater Using Multi-Step Surfactant-Based Treatment: Assessment of Environmental and Health Impact.

Olive mill wastewater (OMW) poses a significant environmental challenge and health concern in olive-producing countries, including Jordan. Surfactant micelles are frequently employed as solubilizing agents to enhance the water solubility of chemical compounds. This study aims to leverage the sodium dodecyl sulfate (SDS) micelles in a multi-step process to detoxify OMW for agricultural and industrial uses and reduce its impact. The OMW was treated in multiple steps: screening, coagulation with different chemicals, and distillation with different surfactants. The treatment steps were monitored using LC-MS, GC-MS, ICP-MS, chemical oxygen demand contents, and total phenolic compounds. The detoxification of OMW was evaluated using standard germination assays, MTT assays using tissue culture, and toxicity assays using fluorescence bacteria. Following the treatment, the seed growth rate improved significantly from 0% to 100%. The GC-MS revealed a substantial decrease in pollutants. The concentration of polyphenols was reduced to 2.5%, while the COD level decreased to 35%. The toxicity in bacteria was significantly reduced in a time-dependent manner, and the toxicity in human cells decreased by 95%. Additionally, between 50% and 95% of metals in OMW were removed. The multi-step SDS-based approach successfully detoxified the OMW and enhanced water quality, which would pave the road for its direct application in industry and agriculture.

Interactions of clathrate hydrate promoters sodium dodecyl sulfate and tetrahydrofuran investigated using 1H diffusion nuclear magnetic resonance at hydrate-forming conditions.

Thermodynamic hydrate promoters and kinetic hydrate promoters can be used to reduce the P-T conditions for clathrate hydrate synthesis to decrease the nucleation induction time while increasing growth rates. Two commonly used promoters for hydrate research are tetrahydrofuran (THF) and sodium dodecyl sulfate (SDS), which can increase the overall hydrate promotion when used in tandem as compared to individually. There are several molecular theories regarding how SDS promotes hydrate growth. This study explores the micellular theory, for which hydrate formation depends on surfactant aggregates (micelles) at a critical micelle concentration (CMC) to increase the interfacial surface area. The micellular theory is the most investigated and criticized surfactant hydrate promotion theory. To address questions related to micellar behavior, this study investigates the intermolecular behavior between SDS and THF for the identification of micelles at hydrate-forming conditions. The systems explored contained THF at 3 and 5 wt. % with varying concentrations of SDS below and above the CMC. Several methods including a qualitative visual method, conductivity, interfacial tensiometry, 13C Liquid-state Nuclear Magnetic Resonance (NMR) spectroscopy, and 1H diffusion NMR spectroscopy were evaluated at temperatures below the Krafft point of SDS and above 0 °C. The presence of THF at low concentrations decreased the critical temperature for the formation of SDS micelles, where SDS is solubilized in THF/water solution at hydrate-forming temperatures without precipitation. The CMC of SDS was decreased significantly even at hydrate-forming conditions. Mixed surfactant-cosolvent micellular behavior of SDS in the presence of low concentrations of THF was confirmed at hydrate-forming conditions above 0 °C.

Steady State and Time-Resolved Fluorescence Spectroscopy of Cinchonine Dication in Sodium Dodecylsulphate Micellar System.

This paper reports the influence of surface charge of the micelles on to the photophysical properties of a cinchonine dication (C2+) fluorophore in anionic, sodium dodecylsulphate (SDS), surfactant at premicellar, micellar and post-micellar concentrations in aqueous phase at room temperature. The magnitude of edge excitation red shift (EERS) in the fluorescence maximum of C2+ in bulk water solution is 1897cm- 1 whereas, in the case of SDS it is observed to be 1984cm- 1. The fluorescence decay curve of C2+ fits with multi exponential functions in the micellar system. The increase in lifetime of C2+ in SDS has been attributed to the increase in radiative rate due to the incorporation of C2+ at the micelle -water interface. The value of dynamic quenching constant determined is 16.9 M- 1. The location of the probe molecule in micellar systems has been justified by a variety of spectral parameters such as dielectric constant, ET (30), viscosity, EERS, average fluorescence decay time, radiative and non-radiative rate constants. All experimental results suggest that the C2+ molecule binds strongly with the SDS micelles and resides at micellar-water interface. The binding constant (Kb) calculated (3.85 × 105 M- 1) for C2+ in SDS revealed that the electrostatic forces mediate charge probe-micelle association.

Kinetic features of the methylinoleate oxidation in micelles of sodium dodecyl sulfate

Kinetic features of the methylinoleate oxidation in micelles of sodium dodecyl sulfate

Moment analysis method for determination of rate constants of solute permeation across interface of spherical molecular aggregates by means of high-performance liquid chromatography

A moment analysis method was developed for the study of solute permeation at the interface of spherical molecular aggregates. At first, new moment equations were developed for determining the partition equilibrium constant (Kp) and permeation rate constants (kin and kout) of solutes from the first absolute (μ1A) and second central (μ2C) moments of elution peaks measured by using high-performance liquid chromatography (HPLC). Then, the method was applied to the analysis of mass transfer phenomena of three solutes, i.e., hydroquinone, resorcinol, and catechol, at the interface of sodium dodecylsulfate (SDS) micelles. HPLC data were measured by using an ODS column and an aqueous phosphate buffer solution (pH = 7.0) as the mobile phase solvent. Pulse response experiments were conducted while changing SDS concentration (5 - 20 mmol dm−3) in the mobile phase under the conditions that the surface of ODS stationary phase was dynamically coated by SDS monomers. In order to demonstrate the effectiveness of the moment analysis method using HPLC, the values of Kp, kin, and kout were determined for the three solutes as 35 - 69, 2.4 × 10−8 - 1.4 × 10−6 m s−1, and 7.0 × 10−10 - 2.1 × 10−8 m s−1, respectively. Their values increase with an increase in the hydrophobicity of the solutes. The method has some advantages for the study of interfacial solute permeation of molecular aggregates. For example, neither immobilization nor chemical modification of both solute molecules and molecular aggregates is required when elution peaks are measured by using HPLC. Interfacial solute permeation takes place in the mobile phase without any chemical reaction or physical action on molecular aggregates. The values of Kp, kin, and kout were analytically determined from those of μ1A and μ2C by using the moment equations. The results of this study must contribute to the dissemination of an opportunity for studying the interfacial solute permeation of molecular aggregates to many researchers because of extremely high versatility of HPLC.

Analytical quality by design-based development of a capillary electrophoresis method for Omeprazole impurity profiling

Omeprazole (OME) is a proton pump inhibitor used to treat gastroesophageal reflux disease associated conditions. The current study presents an Analytical Quality by Design-based approach for the development of a CE method for OME impurity profiling. The scouting experiments suggested the selection of solvent modified Micellar ElectroKinetic Chromatography operative mode using a pseudostationary phase composed of sodium dodecyl sulfate (SDS) micelles and n-butanol as organic modifier in borate buffer. A symmetric three-level screening matrix 37//16 was used to evaluate the effect of Critical Method Parameters, including Background Electrolyte composition and instrumental settings, on Critical Method Attributes (critical resolution values, OME peak width and analysis time). The analytical procedure was optimized using Response Surface Methodology through a Central Composite Orthogonal Design. Risk of failure maps made it possible to define the Method Operable Design Region, within which the following optimized conditions were selected: 72 mM borate buffer pH 10.0, 96 mM SDS, 1.45 %v/v n-butanol, capillary temperature 21 °C, applied voltage 25 kV. The method was validated according to ICH guidelines and robustness was evaluated using a Plackett-Burman design. The developed procedure enables the simultaneous determination of OME and seven related impurities, and has been successfully applied to the analysis of pharmaceutical formulations.

Tunable thermoresponsive hydrogels for temperature regulation and warning in fruit and vegetables preservation

Fresh fruit and vegetables usually suffer from quality deterioration when exposed to inappropriate temperatures. Common energy-input temperature regulation is widely applied but there remain challenges of increasing energy consumption. Passive temperature management regulates the heat transfer without energy consumption, showing a sustainable strategy for food preservation. Here, thermoresponsive hydrogels were constructed by incorporating NaCl and sodium dodecyl sulfate (SDS) micelles into a poly(N-isopropylacrylamide-co-acrylamide) (P(NIPAM-co-AM)) network. Due to the excellent mechanical properties and reversible thermochromism at 14 °C and 37 °C, Gel-8 wt%-NaCl could inhibit temperature rise and avoid sunburn damage to peppers under direct sunlight by blocking the input of solar energy and accelerating moisture evaporation. Additionally, hydrogels could act as a feasible sensor by providing real-time visual warnings for inappropriate temperatures during banana storage. Based on the self-adaptive thermoresponsive behaviour, the prepared hydrogels showed effective performance of temperature regulation and quality preservation of fruit and vegetables.

Sodium dodecyl sulfate micelles: Accurate analysis of small-angle X-ray scattering data through form factor and atomistic molecular dynamics modelling

The structure of micelles of sodium dodecyl sulfate (SDS) is probed via analysis of small-angle x-ray scattering (SAXS) data with the aim to fit the data over an extended wavenumber q range. This provides detailed information on the micelle shape, which can be described as a polydisperse triaxial ellipsoidal core-shell structure according to model form factor fitting. This model was necessary to fit the data over a wide q range, which is not accurately represented by simpler models such as biaxial ellipsoidal core-shell structures. Data for SDS (at fixed concentration) in a NaCl concentration series revealed increasing structure factor effects with decreasing salt concentration. This reflects decreased charge screening on the headgroups. The structure factor could be modelled using a simple hard sphere structure factor. The analysis of form factor was complemented by atomistic molecular dynamics (MD) simulations, starting from an unbiased initial configuration of a defined number of molecules in a box. The MD configurations were used to calculate the form factor using the software CRYSOL (for small-angle scattering analysis of solution scattering, traditionally for proteins, here for micelles) and accounting for the boundary layer hydration effects. Good agreement with experimental data was found for systems with association numbers close to p = 60. This association number is consistent with that obtained from analysis of the form factor (in the case where structure factor effects could be neglected) and from model-free analysis of the forward scattering intensity. It is also in agreement with prior literature and our findings in regard to form factor parameters are also compared to previous reports.

Molecular insights into fragrance release from SDS and SLES micelles

Understanding the interaction between fragrance and surfactant micelles is essential for formulators to develop performing fragrant products. The equilibrium of fragrances in micellar solution of two commonly used surfactants in home and body care industries, namely sodium dodecyl sulphate (SDS) and sodium lauryl ether sulphate (SLES), has been investigated. The difference between SDS and SLES in the release of fragrant compounds is assessed by headspace measurements and explained at a molecular level by the different solubilization sites of the perfume within the micellar systems. Diffusion-Ordered Nuclear Magnetic Resonance Spectroscopy (DOSY NMR) shows that SLES micelles solubilize less fragrance than SDS. Subsequently, a shift from fragrance positioning through the water phase from SDS to SLES system is shown with COSMOmic calculations. This study brings knowledge on fragrance/surfactant interactions and shows the interest of using a computational method to screen and compare fragranced surfactants systems allowing formulators to anticipate the performance of their products.

Insight into the interaction of quinizarin with SDS micelles - effects of additives.

Association behavior between quinizarin (1,4-dihydroxyanthraquinone), an analogue of the chromophore of anthracycline anticancer drugs and sodium dodecyl sulfate (SDS) micelles in the presence of glucose, NaCl and urea additives was studied using absorption spectroscopy and conductometric techniques. The spectral results indicate an increase of binding constant and partition coefficient values in the presence of glucose and NaCl whereas the addition of urea leads to a decrease of binding strength and quinizarin partitioning into SDS micelles. Thus, the rise of NaCl and glucose concentrations is favorable for the quinizarin distribution into SDS micelles. From electrical conductivity measurements it was found that the critical micelle concentration (CMC) of SDS/quinizarin system decreases by adding NaCl and glucose whereas urea has not influence on the micelization process at the concentrations used in the present study.Since biologically compounds like glucose, NaCl and urea are found in the human body, the attained outcomes can be important in finding of effective drug delivery systems.

Insights into the role of ionic surfactants on the morphology of gold and gold@silver nanoparticles

Cyanidin-3, 5-di-O-glycoside (anthocyanin) was extracted from the red rose flower petals in an aqueous media. Anthocyanin was used as reductant to the preparation of gold nanoparticles with cationic and anionic surfactants. UV–visible absorption spectroscope, transmission electron microscope, scanning electron microscope, and energy dispersive X-ray spectroscope were employed to determine absorption bands of anthocyanin, surface Plasmon resonance (SPR) band, and morphology of the gold and gold@silver nanoparticles. Anthocyanin exhibited two absorption peaks at 284 and 518 nm, and one shoulder at 328 nm in the UV–visible spectrum. The intensity of these peaks decreases with time after the addition of HAuCl4. The color and the position of SPR band of gold nanoparticles depend on the concentration of gold salt with and without cetyltrimethylammonium bromide (CTAB), and sodium dodecyl sulfate (SDS). The anionic and cationic head groups of SDS and CTAB micelles have significant impact of the morphology of gold nanoparticles. Seedless co-reduction method was used for the synthesis of gold@silver nanoparticles. TEM images clearly indicate the formation of bimetallic gold@silver core-shell nanoparticles. The antioxidant power of AuNPs and gold@silver nanoparticles were tested in terms of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity as a function of different concentrations of nanoparticles.

Counter-ion adsorption and electrostatic potential in sodium and choline dodecyl sulfate micelles - a molecular dynamics simulation study.

Choline-based surfactants are interesting both from the practical point of view to obtaining environmental-friendly surfactants as well as from the theoretical side since the interactions between the choline and surfactants can help to understand self-assembly phenomena in deep eutectic solvents. Although no significant change was noticed in the micelle size and shape due to the exchange of the sodium counter-ion by choline in our simulations, the adsorption of the choline cation over the micelle surface is stronger than the adsorption of the sodium, which leads to a reduction of the exposed surface area of the micelle and remarkable effects over the electrostatic potential. The choline neutralizes the surface charge of the surfactant better than sodium; however, this is partially compensated by a stronger water orientation around the SDS micelle. The balance between the contributions from the surfactant, the counter-ion, and water to the electrostatic potential leads to a complex pattern with alternate regions of positive and negative potential at the micelle/water interface which can be important to the incorporation of other charged species at the micelle surface as well as for the interaction between micelles in solution. To evaluate the effects of the counter-ion substitution, micelles of sodium dodecyl sulfate (SDS) and choline dodecyl sulfate (ChDS) were studied and compared by means of molecular dynamics simulations in aqueous solution. In both cases, the simulations started from pre-assembled micelles with 60 dodecyl sulfate ions and 240-ns simulations were performed at NPT ensemble at T = 323.15K and P = 1bar using the Gromacs software with the OPLS-AA force field to describe dodecyl sulfate and choline, Åqvist parameters for sodium, and SPC model for water molecules.

Interaction of sodium dodecyl sulfate and triton X-100 with ofloxacin drug using conductivity and UV–visible spectroscopic techniques in aqueous alcohols media at several temperatures

The current investigation explores the association and complexation of the mixture of anionic surfactant, sodium dodecyl sulfate (SDS), and antibiotic drug, ofloxacin (OFC) as well as nonionic surfactant, Triton X-100 (TRX) and OFC drug respectively in several additive solutions. The investigations were performed by applying conductivity and UV-Visible spectroscopic techniques. The impacts of drug concentration, types of solvents, and composition of aq. solutions of alcohols (methanol (MeOH), ethanol (EtOH), and 1-propanol (1-PrOH)) as well as temperature change have been investigated on the micelle formation of SDS + OFC mixture. The micellization of SDS + OFC and TRX + OFC systems has been characterized by the determination of critical micelle concentration (CMC) from conductivity vs. SDS concentration (conductivity technique) and Absorbance vs log[TRX] (UV-Visible spectroscopic technique) plots respectively. The micellization of SDS was delayed owing to the introduction of the OFC drug while the effect has been intensified as a function of OFC concentration. At a fixed OFC concentration and temperature, the CMC values were acquired to be augmented with the upsurge of alcohol concentration. The enhancement of the CMC changes has been perceived with the escalation of temperature at a definite concentration of OFC in water and 5% (w/w) aq. alcohols media. The disfavor of micellization of TRX in aq. EtOH solutions in comparison to aqueous solution also detected from UV-Visible spectroscopic technique. The binding constant (Kb) for the complexation of TRX with OFC drug was determined using the Benesi-Hildebrand plot. The Kb values were obtained to be affected by the change of solvent and temperature. The negative free energy change (∆Gmo/ ∆Gbo) of the micellization and complexation demonstrate the spontaneous occurrence of micelle formation and complex development. The enthalpy changes (∆Hmo) of micellization were negative (exothermic process) and entropy changes (∆Smo) were positive (highly disordered and entropy-dominated micellization). Other thermodynamic properties ((∆Hbo and ∆Sbo) and thermodynamics of transfer) have been evaluated and illustrated as well, for the working systems.

Micellization of sodium dodecyl sulfate in the vicinity of Krafft point: an NMR and dielectric spectroscopy study

Micellization of sodium dodecyl sulfate in the vicinity of Krafft point: an NMR and dielectric spectroscopy study

Kinetic Features of Methylinoleate Oxidation in Micelles of Sodium Dodecyl Sulfate

Kinetic Features of Methylinoleate Oxidation in Micelles of Sodium Dodecyl Sulfate