Effect Of Sodium Dodecyl Sulfate Research Articles

Inhibition Effect of Surfactants on CO2 Enclathration with Cyclopentane in an Unstirred Batch Reactor

The effect of sodium dodecyl sulfate (SDS), cetyl trimethylammonium bromide (CTAB), and fatty alcohol EO/PO derivative (LS54) on unsteady-state CO2 absorption in the metastable region of CO2 hydrates and CO2 enclathration with cyclopentane (CP) was investigated in an unstirred batch reactor. These surfactants have no measurable effect on the mass transfer of CO2 across the gas−liquid interface into water. However, they retard CO2 enclathration, and this inhibition effect becomes significant at 200 ppm of SDS and 100 ppm of LS54 or CTAB. A layer of clathrate hydrates is visually observed if charging CO2 and CP sequentially. Even though this layer cannot be macroscopically detected when swapping the order of CO2 and CP charge, the existence of this layer can be inferred from the unchanged pressure profile. This layer prevents CO2 from contacting with water and thus delays CO2 enclathration. The habit of clathrate hydrates growing along the reactor wall without agitation is discussed based on the magnitude o...

On studying the hazards of pollution of the biosphere: Effects of sodium dodecylsulfate (SDS) on planktonic filter-feeders

Many species of planktonic and benthic invertebrates are active filter-feeders. The filtration activity of aquatic organisms is of great importance for the functioning of ecosystems [1‐3]. It was shown earlier that surfactant sodium dodecylsulfate (SDS) inhibits the filtration activity of Mytilus edulis, M. galloprovincialis , and some other aquatic filter-feeders [4‐15], which is manifested in a decreased removal of suspensions from water by these organisms. Similarly to other water pollutants, surfactants have a strong anthropogenic impact on ecosystems [14]. The goal of this study was to test whether SDS has an inhibitory effect on the ability of planktonic filterfeeders Daphnia magna to remove phytoplankton from water during their filtration activity. Experiments were performed with five-day-old D. magna approximately 1 mm in size at an age of five days. Before the beginning of the experiment, daphnia were kept under laboratory conditions in vessels and fed with phytoplankton (green algae Scenedesmus quadricauda (Turp.) Breb.) at a low concentration (at most 50 thousand cells/ml). At the beginning of the experiment, S. quadricauda cells were added at a higher concentration (400 thousand cells/ml). In the control variant, daphnia were incubated in an SDS-free medium. In the experimental variants, the incubation medium contained SDS at preliminarily selected concentrations (0.1, 0.5, 1, 5, and 10 mg/l). The concentration of S. quadricauda cells was determined in a Nageotte counting chamber at a depth of 0.5 mm 3, 6, 9, 12, and 24 h after the beginning of the experiment. Each vessel contained 50 ml of water medium and 25 daphnia. Incubation was performed at 24 ± 1.5°e . Each variant was performed in duplicate. The rate of food consumption (algae removal from water) by one daphnia ( R ) was calculated by conventional formula

Pronounced Catalytic Effect of a Micellar Solution of Sodium Dodecyl Sulfate (SDS) on the Efficient C‐S Bond Formationviaan Odorless Thia‐Michael Addition Reaction through thein situGeneration ofS‐Alkylisothiouronium Salts

Abstractmagnified imageA pronounced catalytic effect of sodium dodecyl sulfate (SDS) was observed on thein situproduction ofS‐alkylisothiouronium saltsviathe reaction of primary, allyl and benzyl halides with thiourea in SDS droplets .Hydrolysis of the generatedS‐alkylisothiouronium salts in the palisade layer of the droplets produces the corresponding thiol moieties which are immediately added to the electron‐deficient olefins that are present in the micellar core to produce the thia‐Michael adducts. The entire route is an almost odorless process. The yields of the products are good to excellent and the method is applicable to large‐scale operation without any problem.

Acute effects of sodium dodecyl sulphate on the survival and on morpho-histochemical characteristics of the trunk kidney of juvenile turbot Scophthalmus maximus L.

The present article reports the effect on survival as well as on the morpho-histochemical changes in the trunk kidney of juvenile turbot Scophthalmus maximus, L. induced by acute action of the anionic surfactant, sodium dodecyl sulphate (SDS). The LC50 of SDS at 96 hours was found to be 7.5 mg/l. Lots of 20 juvenile turbots were exposed to SDS concentrations of 3, 5, 7 and 10 mg/l: the exposure time required for 50% mortality of the specimens was 384,190,12 and 4 hours and surface tension values were 60.2, 56, 54.9, and 53.3 mN/m, respectively. It should be mentioned that there was a relatively high resistance to SDS of turbot compared to other teleost species, which may be related to its benthic habit. Histopathological lesions and histochemical changes that appeared in the trunk kidney of specimens exposed to the concentrations mentioned were examined. The abnormalities observed in this organ included vacuolation and desquamation of epithelial cells and degeneration of glomeruli and tubules. At the histochemical level, we appreciated some changes in the normal distribution of carbohydrates and proteins. Although the precise mechanism by which the renal tissue injury occurs is unknown, the function of this vital organ was seriously affected and this fact may ultimately play an important role in the mortality of turbots exposed to SDS.

B122 セミクラスレートハイドレート結晶成長に与える添加剤の影響(固液相変化を伴う伝熱現象I)

Gas hydrates such as hydrogen and carbon dioxide can be produced in more moderate condition with tetra n-butyl ammonium fluoride (TBAF). But few reliable data such as the crystal growth rate and the induction time of TBAF semi-clathrate has been obtained. Therefore, in order to measure and estimate the crystal growth rate and an effect of supercooling on it of TBAF semi-clathrate, the temperature increase and its rate were measured in bulk scale. The crystal growth rate in a small channel was directly observed using a microscope. In addition, the effect of sodium dodecyl sulfate (SDS), a kind of surfactants, was investigated.

Structural Analysis and Inhibitory Kinetics of Brain Type Creatine Kinase by Sodium Dodecyl Sulfate

The studies regarding the effect of sodium dodecyl sulfate (SDS) on enzyme activities and structures can provide a valuable insight into public health. We have predicted the 3D structure of the brain creatine kinase (CK-BB) with a high resolution and simulated the docking between CK-BB and SDS. The predicted structure had a root mean square deviation of 0.51 A. The docking between CK-BB and SDS was successful with significant scores (-4.67 kcal/mol, AutoDock4 and -48.32 kcal/mol, DOCK6). We have also investigated the inactivation by using SDS to study CK-BB's folding behaviors. The two-phase rate constants as a first-order reaction were measured during inactivation. SDS strongly inhibited the CK-BB activity in a noncompetitive inhibition manner (K (i) = 1.22 mM). The tertiary structural change was induced by SDS binding with the exposure of hydrophobic surface. The methyl-beta-cyclodextrin was used to strip SDS from the enzyme molecule to reactivate. The changes of thermodynamic parameters for the SDS ligand binding such as enthalpy, Gibbs free energy, and entropy were obtained as -13 + or - 7.0 MJ/mol, 8.39 kJ/mol, and -42.754 kJ/(K mol), respectively. Our study provides important structural information for CK-BB and its interaction with SDS with an insight on its folding and inhibition kinetics.

Secondary Structural Change of Bovine Serum Albumin in Thermal Denaturation up to 130 °C and Protective Effect of Sodium Dodecyl Sulfate on the Change

The secondary structure of bovine serum albumin (BSA) was first examined in the thermal denaturation up to 130 degrees C. The helicity (66%) of the protein decreased with rise of temperature. Half of the original helicity was lost at 80 degrees C, but the helicity of 16% was still maintained even at 130 degrees C. When the BSA solution was cooled down to 25 degrees C after heating at temperatures above 50 degrees C, the helicity was not completely recovered. The higher the thermal denaturation temperature was, the lower was the recovered helicity. On the other hand, upon the addition of sodium dodecyl sulfate (SDS), the secondary structure of BSA was partially protected against the thermal denaturation above 50 degrees C where the structural change became irreversible. A particular protective effect was observed below 85 degrees C upon the coexistence of SDS of extremely low concentrations. For example, the helicity was 34% at 80 degrees C in the absence of SDS, but it was maintained at 58% at the same temperature upon the coexistence of 0.75 mM SDS. Upon cooling down from 80 to 25 degrees C, the helicity of BSA was recovered to 62% in the presence of 0.75 mM SDS. Such a protective effect of SDS was not observed above 95 degrees C. In the interaction with the surfactant, this protein structure appeared likely to have a critical temperature between 90 and 100 degrees C in addition to the critical temperature in the vicinity of 50 degrees C. This protective effect of SDS, characterized by the specific amphiphilic nature of this anionic surfactant, is considered to be attained by building cross-linking bridges between particular nonpolar residues and particular positively charged residues in the protein molecule.

Micellar catalysis in the systems arylamine-diphenylamine-NO 2 −

By methods of UV and IR spectroscopy and thermogravimetry reactions of diazotizaion and azo coupling were studied in the systems of primary arylamine (p-nitro-, p-carboxy- and p-sulfoaniline)- diphenylamine -nitrite ion in water and micellar media on the basis of surfactants. The micellar catalysis effect of sodium dodecylsulfate in the micellar media was revealed. Rate of diazotization was shown to be independent of the surfactants of various types. Formation of ionic associates of azo dyes with dodecylsulfate anions in premicellar region was established and physicochemical characteristics of the associates were estimated.

Aggregation Behavior of Pluronic-L64 in Presence of Sodium Dodecyl Sulphate in Water

The effect of sodium dodecyl sulfate (SDS) on the micellization and aggregation behavior of a poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-PPO-PEO) amphiphilic copolymer (Pluronic L64: EO13 PO30 EO13) have been investigated by various techniques like, cloud point, viscosity, isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC), fluorescence spectroscopy, room temperature phosphorescence (RTP), and small angle neutron scattering (SANS). Addition of SDS in L64 solutions shows mark alteration of different properties. We observed synergistic interaction between SDS and Pluronic L64. The changes in the critical micelle concentration (CMC), critical micelle temperature (CMT), cloud point (CP), micelle size, and shape has been correlated and reported in terms of structure dynamics and mechanics. The ITC titrations have been used to explore the different stages of binding and interactions of SDS with L64. The enthalpies of aggregation for copolymer-SDS aggregates binding, organizational change of bound aggregates, and the threshold concentrations of SDS in the presence of copolymer were estimated directly from ITC titration curves. The effect of temperature on enthalpy values has been reported in terms of different aggregation state. Fluorescence and RTP for L64 were used to investigate the change in micellar environment on the addition of SDS at different temperature. Appearance and shifting of SANS peaks have been used to monitor the size and inter micellar interaction on addition of SDS in L64 solution. Cloud point and viscosity elaborate the penetration of SDS molecule in L64 micelle and hence changing the micellar architect.

Optimization of Interactions between a Cationic Conjugated Polymer and Chromophore-Labeled DNA for Optical Amplification of Fluorescent Sensors

Cationic conjugated polymers (CCPs) have been widely utilized as signal amplifiers in biosensors to improve the detection sensitivity through fluorescence resonance energy transfer (FRET) from CCPs to dye-labeled probes or targets. This paper investigates the effect of sodium dodecyl sulfate (SDS) on energy transfer between a cationic polyfluoreneethynylene copolymer (P1) and Texas Red labeled single-stranded DNA (ssDNA-TR). The presence of SDS in solution affects both the optical properties of P1 and TR emission within P1/ssDNA-TR complexes, which provides basic information on the role of SDS in FRET between P1 and ssDNA-TR. Although the quantum yield of P1 decreases in the presence of low concentrations of SDS, the presence of SDS reduces TR fluorescence quenching within P1/ssDNA-TR complexes and increases the number of optically active polymer repeat units within the proximity of TR, which are beneficial to P1-sensitized TR emission. In the absence of SDS, FRET from P1 to ssDNA-TR provides a 2.6-fold enhancement in TR emission intensity as compared to that upon direct excitation of TR at 595 nm. At the optimum SDS concentration (5 microM), P1-sensitized TR signal output increases to 11.3-fold relative to direct excitation of TR. This study highlights the importance of modulation of the CCP/ssDNA-dye interaction in improving the signal output of dye-labeled DNA by CCP through FRET.

Sodium dodecyl sulfate‐insoluble oligomers are involved in polyglutamine degeneration

In polyglutamine (polyQ) degeneration, disease protein that carries an expanded polyQ tract is neurotoxic. Expanded polyQ protein exists in different conformations that display distinct solubility properties. In this study, an inducible transgenic Drosophila model is established to define the pathogenic form of polyQ protein at an early stage of degeneration in vivo. We show that microscopic polyQ aggregates are neither pathogenic nor protective. Further, no toxic effect of sodium dodecyl sulfate (SDS) -soluble polyQ protein is observed in our model. By means of filtration, 2 forms of SDS-insoluble protein species are identified according to their size. Coexpression of an ATPase-defective form of the molecular chaperone Hsc70 (Hsc70-K71S) selectively reduces the abundance of the large SDS-insoluble polyQ species, but such modulation has no modifying effects on degeneration. Notably, we detect a distinct Hsc70-K71S-resistant, small, SDS-insoluble polyQ oligomeric species that is closely correlated with degeneration. Our data highlight the toxic role of SDS-insoluble oligomers in polyQ degeneration in vivo.

Effects of surfactant, salt and solvent on the structure and activity of adenosine deaminase: Molecular dynamic and spectrophotometric studies

Effects of sodium dodecyl sulfate, dodecyltrimethylammonium bromide, sodium chloride, sodium sulfate, methanol and ethanol, on the structure and activity of adenosine deaminase (ADA) were investigated by UV–Vis, circular dichroism spectrophotometry and molecular dynamics (MDs) studies. Relative activity, experimental and computational helix content, total accessible surface area (ASA) and exposed charged surface area (ECSA) were obtained. The relative activity of ADA in the absence and the presence of denaturants were compared with structural results. It was shown that an increase in the surface area and a decrease in the amount of helicity are associated with a decrease in the activity of ADA.

Spectrophotometric study of the effects of surfactants and ethanol on the acidity constants of fluorescein

In the present paper, a sensitive, fast and suitable method for the calculation of p K a values of fluorescein is proposed. The effects of sodium dodecyl sulfate (SDS) and Triton X-100 (TX-100) as a surface-active agent on the acidic and basic forms, and the spectral properties of fluorescein were studied by the spectrophotometric method. The study was performed in sub-micelle surfactant concentration, and absorption spectra at 300–550 nm intervals were recorded. Stepwise acidity constants of fluorescein at pH range 1.50–10.00 and at constant ionic strength 0.1 M and 25 °C were determined using DATAN program using pH-spectrophotometric titration data. The method is efficient, however the component spectra showed intensive overlapping. The calculated acidity constants of fluorescein in water at ionic strength 0.1 are p K a1 = 2.20, p K a2 = 4.30 and p K a3 = 6.43. The acidity constants of the dye in ethanol–water solution were studied by the same procedure. Effect of surfactants and ethanol on acidity constants and pure spectrum of each component are also discussed.

Effect of Biocides on Biofilm Bacteria from Dental Unit Water Lines

Microbial biofilm formation in dental unit water lines (DUWL) is a phenomenon that has been recognized for nearly four decades. Water delivered by DUWL can harbor high numbers of bacteria, including opportunistic pathogens. Biofilms on tubing within DUWL may serve as a reservoir for these microorganisms and should therefore be controlled. In this study, the effects of eight biocides were monitored on DUWL biofilms individually and in combination by epifluorescence microscopy and total viable counts (TVC). The effects of sodium dodecyl sulphate (SDS), hydrogen peroxide (H2O2), sodium hypochlorite (NaOCl), phenol (Phe), Tween 20 (Tw 20), ethylenediaminetetraacetic acid (EDTA), chlorohexidine gluconate (CHX), and povidine iodine (PI) were tested on DUWL biofilms alone and in combination. PI was found to have negligible effects on biofilm removal either applied alone or in combined form with CHX. Applying all biocides simultaneously did not completely eliminate viable bacteria nor did they remove biofilm. Overall, when combined, the biocides performed better than singly applied products. The most effective biocides were NaOCl and Phe (both alone and in combination).

The Anesthetic-Like Effects of Diverse Compounds on Wild-Type and Mutant γ-Aminobutyric Acid Type A and Glycine Receptors

No theory of inhaled anesthetic action requires volatility of the anesthetic to accomplish the biophysical interaction of anesthetic with biological target. The identification of mutations that attenuate the effect of inhaled anesthetics on various receptors raises the possibility that nonvolatile compounds with anesthetic effects can be identified with the aid of these receptors. In previous studies, we identified compounds that were either charged or had an exceptionally low vapor pressure and which modulated anesthetic-sensitive receptors in a manner similar to inhaled anesthetics. We tested whether these, and another charged compound, shared a common mechanism with volatile anesthetics, by comparing their effect on wild-type gamma-aminobutyric acid type A (GABA(A)) or glycine receptors and mutant receptors that were engineered to be relatively resistant to inhaled anesthetics. The effect of beta-hydroxybutyric acid, ammonium chloride, diethylhexyl phthalate, and GABA were tested on homomeric alpha1 and mutant alpha1 (S267I) glycine receptors. The effect of sodium dodecyl sulfate and glycine were tested on alpha1 b2 gamma2s and mutant alpha1(S270I) beta2 gamma2s GABA(A) receptors. Receptors were expressed in Xenopus laevis oocytes and studied using two-electrode voltage clamping. For both GABA(A) and glycine receptors, isoflurane and ethanol were used as positive controls and propofol as a negative control (i.e., unaffected by the mutation). Beta-hydroxybutyric acid, ammonium chloride, diethylhexyl phthalate, and GABA all enhanced glycine receptor function. This effect was reduced by the S267I mutations. Sodium dodecyl sulfate and glycine enhanced GABA(A) receptor function, and the S270I mutation attenuated this effect. These findings support the hypothesis that the compounds studied modulate GABA(A) or glycine receptors by a mechanism similar to that of isoflurane and ethanol. Comparing the effect of drugs on anesthetic-sensitive wild-type receptors with relatively less sensitive mutant receptors may help identify compounds with anesthetic effects.

Effect of Sodium Dodecyl Sulphate on the Physicochemical, Thermal and Pasting Properties of Cassava Starch

AbstractThe effect of different concentrations of sodium dodecyl sulphate (SDS) on cassava starch properties after complexation and in situ addition were studied. The swelling volume of the starch‐SDS complexes increased to a maximum of 100 mL/g with increase in concentration of SDS (even at 0.004 mol SDS) with a corresponding decrease in solubility. During in situ addition also, a similar but gradual behaviour was observed for swelling volume and solubility. The apparent and total amylose contents showed an irregular trend. The soluble amylose content decreased with increase in concentration of SDS. In vitro enzyme digestibility of starch‐SDS complexes was significantly lowered compared to that of native starch. The water‐binding capacity showed an initial decrease followed by a significant increase at higher concentrations of SDS. DSC studies showed that in addition to the gelatinisation endotherm, a peak corresponding to the melting of the starch‐SDS complex was obtained in the case of in situ addition of the surfactant. The peak viscosity of starch during in situ addition of SDS exhibited a rapid increase except at the highest concentration. The peak viscosity of starch‐SDS complexes underwent an initial reduction followed by a gradual increase at higher concentrations. The breakdown, setback and pasting temperature were also affected.

Low Cationic Proportion Ampholytic Polymer: Synthesis, Solution Properties and Interaction with Anionic Surfactant

Novel ampholytic terpolymer of N-vinylformamide (NVF), vinylamine (VAm) and sodium acrylate (NA) with low cationic proportion was obtained by hydrolyzing copolymer of NVF and NA (PNVFNA). Solution properties of the polymer were investigated by methods of turbidity and viscosity experiment. The effect of sodium dodecyl sulfate (SDS) on solution viscosity was also investigated. The results showed that the turbidity curves were bimodal, and pH 3.0 was determined as the isoelectric point (IEP). At high salt concentration, polyampholyte effect was noticeable at IEP in viscosity experiment. Although the proportion of VAm in polyampholyte was lower, the solution properties were influenced markedly in the presence of SDS. At IEP, the viscosity increased more rapidly as salt concentration increased when 10-3 mol/L SDS contained in solution. A mechanism of SDS bound to positive sites on the collapsed globule surface was suggested.

Micellar Effects on the Reaction between an Arenediazonium Ion and the Antioxidants Gallic Acid and Octyl Gallate

AbstractThe effect of sodium dodecyl sulfate (SDS) micelles on the reaction between the 3‐methylbenzenediazonium (3MBD) ion and either the hydrophilic antioxidant gallic acid (GA) or the hydrophobic analogue octyl gallate (OG) have been investigated as a function of pH. Titration of GA in the absence and presence of SDS micelles showed that the micelles do not alter the first ionization equilibrium of GA. Analysis of the dependence of the observed rate constant (kobs) with pH shows that the reactive species are GA2− and OG−. Kinetics results in the absence and presence of SDS micelles suggest that SDS aggregates do not alter the expected reaction pathway. SDS Micelles inhibit the spontaneous decomposition of 3MBD as well as the reaction between 3MBD and either GA or OG, and upon increasing the SDS concentration, with kobs approaching the value for the thermal decomposition of 3MBD in the presence of SDS. Our results are consistent with the prediction of the pseudophase model and show that the origin of the inhibition for the reaction with GA is different to that for the reaction with OG; in the former case, the observed inhibition can be rationalized in terms of the micelle‐induced electrostatic separation of reactants in the micellar Stern layer, whereas the observed inhibition in the reaction with OG is a consequence of the dilution effect caused by increasing SDS concentration, decreasing the local OG− concentration in the Stern layer.

Electrochemical Investigation of Bovine Hemoglobin at an Acetylene Black Paste Electrode in the Presence of Sodium Dodecyl Sulfate

Electrochemical behaviors of bovine hemoglobin (Hb) at an acetylene black paste electrode based on the enhancement effect of sodium dodecyl sulfate (SDS) were investigated. In the optimal conditions, a very weak reduction peak was observed at an acetylene black paste electrode for hemoglobin in the absence of SDS. However, the reduction peak current increased remarkably after the addition of 4.0 × 10?4 mol L?1 SDS, suggesting that SDS exhibits obvious enhancement effect to the determination of hemoglobin. All the experimental parameters, such as pH value, concentration of SDS, accumulation time and accumulation potential were optimized for hemoglobin analysis. The proposed method possesses high sensitivity (detection limit is 3.0 × 10?9 mol L?1), wide linearity (6.0 × 10?9 to 6.0 × 10?7 mol L?1), rapid response and low cost. Finally, the method was successfully employed to determine hemoglobin in a spiked sample.

Direct Observation of the Effect of Sodium Dodecyl Sulfate (SDS) on the HCFC-22 Hydrate Formation in a Static Mixer

Abstract Direct observation of the formation behavior of HCFC-22 hydrate in a Kenics type static mixer was conducted focusing on the effect of an addition of a surfactant, sodium dodecyl sulfate (SDS). The formation pattern of the hydrate was changed by the SDS addition from “slurry” to “plug,” and a continuous cycle of hydrate film formation and bubble escape was observed. The hydrate formation rate was increased about 10-fold by the addition of SDS (1000 ppm).