Influence Of Sodium Dodecyl Sulfate Research Articles

Influence of sodium dodecyl sulfate coating on adsorption of methylene blue by biochar from aqueous solution

Biochar is regarded as a promising new class of materials due to its multifunctional character and the possibility of effectively coupling different properties. With increasing introduction into the environment, environmental chemicals such as surfactants will load onto the released biochar and change its physicochemical characteristics and adsorption behavior toward pollutants. In this study, sodium dodecyl sulfate (SDS), as one type of anionic surfactant, was coated onto biochar with different loading amounts. The influence of SDS loading onto biochar's physicochemical properties were investigated by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, zeta potential and Brunauer–Emmett–Teller (BET) surface area and pore size distribution analysis. Results showed that the pore size of the biochar decreased gradually with the increase of SDS loading because of the surface-adsorption and pore-blocking processes; the pH of the point of zero charge (pHPZC) decreased with increasing SDS loading. Although surface-coating with SDS decreased the pore size of the biochar, its adsorption capacity toward Methylene Blue (MB) significantly increased. The biochar-bound SDS introduced functional groups and negative charges to the biochar surface, which could thus enhance the adsorption of MB via hydrogen bonding and electrostatic interaction. The results can shed light on the underlying mechanism of the influence of anionic surfactants on the adsorption of MB by biochar.

The influence of aqueous sodium dodecyl sulphate solution in the photoresponsivity of nitrogen doped graphene oxide photodetector

The homogeneity and agglomeration in graphene based photodetector plays an important role in the photoconduction. The influence of sodium dodecyl sulphate (SDS) solution in nitrogen doped graphene oxide (N-GO) is studied based on the photoresponsivity behaviour. One step hydrothermal method and drop casting technique are utilized to obtain N-GO photodetectors. High photoresponsivity about 1000 folds is achieved in N-GO prepared with SDS solution (N-GO/SDS) compared to the N-GO prepared without SDS solution. Raman spectrum also revealed a high intense D and G band as well as a slightly broaden 2D band due to sp2 hybridization. The fabricated device has exhibited wide range of responsivity to infrared (IR) laser 974 nm pulse and illumination. Real time current measurement in N-GO and current–voltage (I-V) characteristics in N-GO/SDS showed a significant photoconduction due to laser 974 nm illumination. The external quantum efficiency (EQE) in the N-GO/SDS solution is about 394830% compared to N-GO prepared without SDS, which is only 272%. The evaluated fall time at frequency modulation of 0.1 and 1 Hz for direct current (dc) bias voltage of 5.0 V found to be shorter compared to that of 2.5 V, whereas the fall time at high frequency modulation at 5000 Hz exhibited similar time around 77 μs.

Response surface approach for isocratic separation of some natural anthraquinone dyes by micellar liquid chromatography

A simple multi-parameter strategy was designed for simultaneous optimization of analysis time and resolution values in micellar liquid chromatography of four natural antraquinone dyes (Alizarin, Purpurin, Danthron, and Quinizarin) in isocratic mode. In this regard, the experimental variables were arranged based on central composite design. To optimize the analysis time of the dyes with satisfactory peak resolutions, the influence of sodium dodecyl sulfate (SDS) concentration, volume percentage of acetic acid (ACA), type and volume percentage of the alcoholic modifiers (methanol, ethanol, propanol, butanol and pentanol) in the mobile phase were investigated through the use of multivariate analysis. The performed approach was validated in accordance with the guidelines of the International Conference on Harmonization (ICH) and the robustness of the method was proven by means of the effect plot. The appropriate combination of the mobile phase was 0.09molL−1 SDS, 10% (v/v %) ethanol-propanol (1:1), and 4% (v/v %) ACA. The applicability of the recommended procedure was estimated on madder root, waste and river water samples for separation and measurement of the four anthraquinone dyes.

Intensification of liquid-liquid mass transfer in a circular microchannel in the presence of sodium dodecyl sulfate

Liquid-liquid slug flow inside a circular microchannel was studied experimentally to examine the influence of the presence of sodium dodecyl sulfate (SDS) on hydrodynamics and mass transfer. The microchannel was made of polytetrafluoroethylene (PTFE), with the internal diameter of 0.6mm. The applied method for estimating mass transfer coefficients considerably increased the accuracy of the results. The findings revealed that the presence of SDS in the aqueous phase decreased the slug length of both phases due to the decrement of the interfacial tension, leading to the enhancement of the specific interfacial area. However, improved recirculations inside the slugs were mainly responsible for the enhanced mass transfer. The influence of SDS on internal circulations was remarkably greater than that on the interfacial area. Although the mass transfer coefficients were augmented with the SDS concentration, the increasing effect was levelled off at higher concentrations. Accordingly, a new correlation relating the overall volumetric mass transfer coefficient to Capillary number, Reynolds number and SDS concentration was proposed.

INFLUENCE OF SODIUM DODECYL SULFATE ON STABILITY OF BILAYER LIPID MEMBRANES

In the paper influence of Sodium dodecyl sulfate (SDS) on planar bilayer lipid membranes (BLM) was investigated. It was shown that the presence of SDS and it’s concentration increasing leads to the loss of stability of the BLM, which is associated with the decrease in the value of the linear tension of pore edge in BLM, because of positive spontaneous curvature of the SDS molecule. It is also shown that the number of lipid pores on the BLM increases as a result of increase in probability of the pore formation, with reduction of the value of linear tension.

Influence of sodium dodecyl sulfate on the phase transition of thermoresponsive hyperbranched polymer in water

The influence of sodium dodecyl sulfate (SDS) on the cloud point temperature (Tcp) of the aqueous solution of thermoresponsive hyperbranched polyethylenimine derivative HPEI-IBAm was studied systematically. When pH was below 8.5, HPEI-IBAm was positively-charged. Initially, the Tcp of HPEI-IBAm decreased significantly, followed by an obvious increase with the increase of SDS concentration. The lower the pH was, the higher the SDS concentration was required to achieve the minimum Tcp. When pH was above 8.5, HPEI-IBAm was neutral and raising the SDS concentration led to the gradual increase of Tcp. Compared to linear poly(N-isopropyl acrylamide) (PNIPAm), the Tcp of the current hyperbranched HPEI-IBAm was more sensitive to SDS. The thermoresponsive HPEI-IBAm/SDS complex was used as host to accommodate the non-polar pyrene in water. The lowest SDS concentration for effectively enhancing the solubility of pyrene in water was around 6.4 mmol·L-1. When HPEI-IBAm was present, the SDS concentration threshhold was decreased to about 0.31 mmol·L-1. Fluorescence technique with pyrene as the hydrophobic probe demonstrated that the SDS concentration of 7.2 mmol·L-1 was required to form the hydrophobic domain to accommodate pyrene guests without HPEI-IBAm, while only 0.2 mmol·L-1 of SDS was required in the presence of HPEI-IBAm.

Dynamic monitoring of cellular metabolic activity in combination with live cell imaging.

We present an automated analysis of the cellular dynamic metabolic activity in combination with live cell imaging, an essential factor for understanding the fundamental cellular physiological responses. For that purpose, we utilized the Intelligent Microplate Reader, a new analysis platform for marker-free cell-based assays in real-time. To demonstrate the benefit of the platform, we analyzed the relationship between various dynamic cell parameters (extracellular acidification, oxygen uptake, cell morphology, cell density and cell migration) of L929, a mouse fibroblast cell line, under the influence of sodium dodecyl sulfate. The dynamic kinetics of the monitored parameters are consistent and revealing much information about the activity occurring in the cells.

Interfacial Tension of the n-Hexane–Water System under the Influence of Magnetite Nanoparticles and Sodium Dodecyl Sulfate Assembly at Different Temperatures

The influence of sodium dodecyl sulfate (SDS) and magnetite nanoparticles (NPs), individually and simultaneously, on the interfacial tension of n-hexane–water was studied over the temperature range from (288.2 to 308.2) K. Results show that SDS in the range from (0 to 2.00·10–4) mol·dm–3 is adsorbed positively; while, NPs in the mass fraction range from (0 to 5.00·10–4) are adsorbed negatively and cause interfacial tension to rise. Interestingly, with the presence of both SDS and NPs, interfacial tension is reduced more than with SDS only, because the repulsive interactions between SDS molecules are weakened in the presence of positively charged NPs. An almost linear decrease in interfacial tension with temperature is also relevant in all cases. The experimental data, below the critical micelle concentration of SDS, were nicely reproduced by the Szyszkowski adsorption isotherm. Accordingly, obtained SDS saturated interface excess is reduced with NPs mass fraction, and on the other hand, adsorption tendency increases with temperature and NPs mass fraction.

Denaturation of bovine serum albumin initiated by sodium dodecyl sulfate as monitored via the intrinsic fluorescence of the protein

The tryptophan fluorescence of bovine serum albumin (BSA) is used to study the denaturation transitions in BSA under the influence of sodium dodecyl sulfate (SDS) at various pH values. The stepwise quenching of BSA tryptophan fluorescence and the gradual increase in the degree of anisotropy of BSA tryptophan fluorescence with increasing SDS concentration in solutions indicate the stepwise nature of denaturation: the first stage is a loosening of protein globules, whereas the second is a complete unfolding of the protein amino acid chain. At pH > pI of BSA, the denaturation BSA proceeds through both stages. At pH > pI of BSA, the denaturation BSA runs poorly and stops after the first stage. A more efficient BSA denaturation under the action of SDS occurs at pH < pI of BSA, with the efficiency of BSA denaturation under the influence of SDS decreasing with increasing pH.

Study on the influence of SDS and THF on hydrate-based gas separation performance

Hydrate additives can be used to mitigate hydrate formation conditions, promote hydrate growth rate and improve separation efficiency. CO2+N2 and CO2+CH4 systems with presence of sodium dodecyl sulfate (SDS) or tetrahydrofuran (THF) are studied to analyze the effect of hydrate additives on gas separation performance. The experiment results show that CO2 can be selectively enriched in the hydrate phase. SDS can speed up the hydrate growth rate by facilitating gas molecules solubilization. When SDS concentration increases, split and loss fraction increase initially and then decrease slightly, resulting in a decreased separation factor. The optimum concentration of SDS exists at the range of 100–300ppm. As THF can be easily encaged in hydrate cavities, hydrate formation condition can be mitigated greatly with its existence. Additionally, THF can also strengthen hydrate formation. The THF effect on separation performance is related to feed gas components. CO2 occupies the small cavities of type II hydrate prior to N2. But the competitiveness of CO2 and CH4 to occupy cavities are quite fair. The variations of split fraction, loss fraction and separation factor depend on the concentration of THF added. The work in this paper has a positive role in flue gas CO2 capture and natural gas de-acidification.

Effect of SDS and CTAB on Derivatives of Antimicrobial Peptides Arenicin and LL-37

Abstract The interaction of two antimicrobial peptides (AMPs) with amphiphiles was investigated. In addition, the influence of sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) solutions, both below and above the critical micelle concentration (cmc), was investigated by circular dichroism (CD) spectroscopy. The AMPs we used were from two different classes: C/S-Ar-1, from a lugworm, and LL-20, a fragment of human LL-37. Cationic CTAB did not influence the AMPs, independent of the amphiphile aggregation state. However, anionic SDS had a clear effect on the secondary structure of the peptides. In the case of C/S-Ar-1, no difference was observed in the CD spectra below or above the cmc (change to β-sheet). In contrast, SDS monomers led to an aggregation of LL-20 and SDS micelles changed the secondary structure of the peptides from unstructured to α-helical.

The effect of SDS surfactant on tensile properties of electrodeposited Ni–Co/SiC nanocomposites

Ni–Co/SiC nanocomposites were electrodeposited from modified Watts bath containing SiC particles with 50nm average size. The influence of sodium dodecyl sulphate (SDS) concentration on surface properties of nano-particles, microstructure and mechanical properties of nanocomposites were investigated. The electrodeposition mechanism and particles–cathode interactions were studied by means of cyclic voltammetry (CV) test. The mechanical properties of electrodeposits were investigated by Vickers microhardness and tensile tests. The results indicated that addition of SDS to Ni–Co electrolyte shifted onset of cathodic reactions to higher cathodic potentials and displaced the reduction curve to lower currents at similar potentials due to the adsorption of SDS molecules on cathode surface and suppressing of cathodic reactions. Moreover, addition of SDS to the electrolyte enhanced absolute surface charge and adsorption of metal ions on SiC particles, which in turn, increased the amount and improved the uniform distribution of SiC particles in the deposits. This resulted in considerable enhancement in the microhardness, yield and ultimate tensile strength (UTS) of Ni–Co/SiC deposits. Moreover, addition of SDS up to 0.25g/L significantly enhanced the elongation to failure of deposits due to impeding the agglomeration of ceramic particles and microstructure refining. Further increase in SDS concentration led to a decrease in ductility due to embrittling of Ni–Co matrix.

Mutual Influence of Sodium Dodecyl Sulphate and Calcium Propionate in Biocidal Activity and Corrosion Inhibition of Carbon Steel

The inhibition and biocidal efficiency of sodium dodecyl sulphate (SDS) and calcium propionate (CP) in controlling corrosion of carbon steel immersed in an aqueous solution has been evaluated by weight loss and biocidal efficiency method in the absence and presence of Zn2+. The formulation consisting of CP and Zn2+ has excellent inhibition efficiency (IE). The biocidal efficiency of this formulation is 46 %. To improve the biocidal efficiency a third substance SDS is added. A synergistic effect is noticed between SDS, Zn2+ and CP. The formulation consisting 50 ppm of calcium propionate, 200 ppm of SDS and 50 ppm of Zn2+ shows 99 % IE and 100 % biocidal efficiency. Addition of SDS enhances the IE of Zn2+ and CP system. Electrochemical studies were carried out to find out the nature of the corrosion inhibitor. The CP–Zn2+–SDS system functions as a mixed inhibitor. The scanning electron micrographs and atomic force micrographs reveal the formation of a protective film on the metal surface.

Platelets to rings: Influence of sodium dodecyl sulfate on Zn–Al layered double hydroxide morphology

In the current study, influence of sodium dodecyl sulfate (SDS) on the crystallization of Zn–Al layered double hydroxide (LDH) was investigated. Depending on the SDS concentration coral-like and for the first time ring-like morphologies were obtained in a urea-hydrolysis method. It was revealed that the surfactant level in the starting solution plays an important role in the morphology. Concentration of surfactant equal to or above the anion exchange capacity of the LDH is influential in creating different morphologies. Another important parameter was the critical micelle concentration (CMC) of the surfactant. Surfactant concentrations well above CMC value resulted in ring-like structures. The crystallization mechanism was discussed.

Surfactant effect on electrochemical behavior of Co–TiO2 nanocomposite coatings

The influence of sodium dodecyl sulfate (SDS) as anionic surfactant and cetyltrimethyl ammonium bromide (CTAB) as cationic surfactant on the morphology, composition, and texture and corrosion behavior of electrodeposited Co–TiO2 coatings was investigated. The polarization test revealed that the coatings deposited from SDS containing solution formed passive layer in low current densities and high positive voltages than coatings deposited in CTAB containing solution. The corrosion resistance of deposited coatings from SDS containing solution was improved in NaOH and H2SO4 solutions than CTAB one. The performed impedance test results in both corrosive media were compatible with the results of polarization test. The coatings deposited with CTAB had grains structure of 62nm whilst SDS ones showed finer grains around 45nm, which it was evaluated by XRD analysis and chronoamperometry extrapolation.

Performance of Sodium Dodecyl Sulfate in Slurry with Glycine and Hydrogen Peroxide for Copper-Chemical Mechanical Polishing

The performance of sodium dodecyl sulfate (SDS), an anion surfactant, in a slurry with glycine and hydrogen peroxide for copper-chemical mechanical polishing (Cu-CMP) was studied. The wettability and surface tension of the slurry for copper and the zeta potential of were examined. The influence of SDS on the static corrosion, material removal rate, and the surface roughness was studied. The results showed that SDS improved Cu-CMP performance by changing the physical characteristics of the slurry and protecting the copper surface from corrosion and scratches. A surface with the lowest amount of scratches and corrosion after polishing was obtained when concentration of the SDS surfactant was in the glycine– solution. The mechanism of action between the SDS and copper surface was investigated by electrochemical polarization and X-ray photoelectron spectroscopy. Finally, a physical model was developed to describe the interactions between particles, the copper surface, and SDS in the slurry.

Influence of sodium dodecyl sulfate on swelling, erosion and release behavior of HPMC matrix tablets containing a poorly water-soluble drug

The effect of sodium dodecyl sulfate (SDS) on the swelling, erosion and release behavior of HPMC matrix tablets was examined. Swelling and erosion of HPMC matrix tablets were determined by measuring the wet and subsequent dry weights of matrices. The rate of uptake of the dissolution medium by the matrix was quantified using a square root relationship whilst the erosion of the polymer was described using the cube root law. The extent of swelling decreased with increasing SDS concentrations in the dissolution medium but the rate of erosion was found to follow a reverse trend. Such phenomena might have been caused by the attractive hydrophobic interaction between HPMC and SDS as demonstrated by the cloud points of the solutions containing both the surfactant and polymer. Release profiles of nimodipine from HPMC tablets in aqueous media containing different concentrations of SDS were finally studied. Increasing SDS concentrations in the medium was shown to accelerate the release of nimodipine from the tablets, possibly due to increasing nimodipine solubility and increasing rate of erosion by increasing SDS concentrations in the dissolution medium.

Influence of Sodium Dodecyl Sulfate Presence on Esterification of Propylene Glycol with Lauric Acid

In this study, the influence of sodium dodecyl sulfate (SDS) on the direct esterification of 1,2-propanediol (propylene glycol, PG) with dodecanoic acid (lauric acid, LA) was investigated. It was stated that formation of a mixed interfacial film of the anionic surfactant and synthesized monoacylpropyleneglycol (PGML) emulsifier lowers the interfacial tension between phases to produce a transparent microemulsion. Therefore, SDS was found to be effective in increasing the contact between reagents and, as a consequence, accelerating the reaction progress. The obtained products were liquid and transparent substances at room temperature. The particle size distribution of the formed microemulsion systems range from about 25−45 nm, depending on the concentration of surfactant in the reaction mixture. The hydrophilic−lipophilic properties of synthesized products were also studied. The concentration of SDS in the reaction mixture influenced the hydrophile−lipophile balance (HLB) values of the obtained emulsifiers.

Influence of Surface Active Solute on Ultrasonic Waveform Distortion in Liquid Containing Air Bubbles

The influence of sodium dodecyl sulfate (SDS) on waveform distortion of 141 kHz ultrasonic standing waves in liquids containing air bubbles was investigated for various transducer powers. Fast Fourier transform (FFT) operations were performed on the pressure waveform to obtain the harmonic components. In addition, the intensity of sonoluminescence (SL) was measured as a function of the power. Waveform distortion was observed for water at high applied power, with the curve exhibiting a steeper gradient for positive pressures and a broadened minimum for negative pressures. This was in reasonable agreement with theoretical studies reported in the literature. Much less distortion was found for a 1 mM SDS solution as the applied power was increased than for water or a 10 mM SDS solution. This may be attributed to a lower population of large coalesced bubbles in the 1 mM solution due to electrostatic repulsion, leading to damping of the sound energy and little cavitation noise because of viscous resistance to bubble radial motion in addition to adsorption and desorption of surfactant molecules at the bubble-liquid interface. For 10 mM SDS, the power threshold for the harmonic components was lower than that for the SL. In this case, it appears that there is a range of applied powers where most bubbles are stable and cannot collapse. The influence of the addition of an electrolyte and a nonionic surfactant was also investigated.

Influence of SDS on particle size and adhesion of precipitating calcium carbonate

The effect of different amounts of sodium dodecyl sulfate (SDS) and time of their addition to the system on the properties of calcium carbonate precipitated from aqueous solutions of CaCl 2 and Na 2CO 3 were studied. From statistical evaluation it was found that average number of the particles deposited on glass surface and, average and total surface area they occupy depend on the amount of the surfactant and time of its addition. Only if the surfactant was added to the system just after the CaCl 2 and Na 2CO 3 solutions mixing up, a decrease of these parameters took place, the greatest in the presence of 0.42 μmol of SDS. On the contrary, if SDS solution was added after 3 min, it caused an increase of the average and total surface area occupied by the CaCO 3 particles, while the average number of particles changed only within standard deviation. From the obtained results it may be concluded that SDS can affect both nucleation and crystal growth of CaCO 3, but its nature depends on the surfactant amount and time of its addition to the system.