Addition Of SDS Research Articles

Effect of sodium dodecyl sulfate and different SiC quantities on electrodeposited Ni-Co alloy coatings

Ni-Co nanocomposites Prepared by electrodeposition in a modified Watts bath containing various quantities of silicon carbide SiC and the organic additive sodium dodecyl sulfate SDS as a surfactant. The influence of nanoparticle incorporation on the electrodeposit microstructure, mechanical characteristics, and deformation process was studied. Vickers micro-hardness and weight loss tests were used to study the mechanical properties and morphology. The microstructure has also been analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Co-deposition of uniformly dispersed SiC particles, on the other hand, was found to improve the extreme tensile strength of the deposits significantly; SDS lowered the surface tension, allowing the SiC particles to fill in all remaining gaps to achieve a homogeneous surface. A process involving atoms that can dramatically improve flexibility. The incorporation of SiC particles and raising the strain rate encouraged a ductile fracture mode in a nano-crystalline Ni-Co matrix, which demonstrated a mixed mod behavior of flexible and brittle fracture; it was evident that the addition of SDS increases the concentration of SiC particles in general on Ni-Co samples. Moreover, compare Ni-Co with various amounts of SiC and Ni-Co/SiC with adding SDS. Furthermore, to achieve the highest possible electroplating efficiency.

Fibrillar assembly of whey protein isolate and gum Arabic as iron carrier for food fortification

In this study, fibrous aggregates of whey protein isolate (WPI) and gum arabic (GA) containing ferric ions were fabricated, and its fibrillation process, morphology, secondary structure, driving force, iron release in simulated gastrointestinal phase as well as its sensory properties have been investigated. The results indicated that WPI/GAFe3+ fibrils could be well formed at the mass ratio of 15: 1, concentration of 2.0 wt%, pH 3.0, heated at 90 °C for 5 h. It was observed by scanning electron microscopy and found that the nanospheric GAFe3+ was regularly entangled at the end or junction of WPI fibrils. Both circular dichroism and FTIR confirmed that secondary conformations of protein have been transformed into specific forms during the fibrilization, along with an increase of β-sheet and a decrease of α-helix. The addition of SDS disintegrating the WPI/GAFe3+ fibrils revealed the significant contribution of intermolecular hydrophobic interaction as the dominant driving forces for the formation of WPI/GAFe3+ fibrils. The iron ions release showed a significant delay in the gastric phase and followed by a rapid increase in the intestinal phase, profitable for the orally administered products with high absorption in duodenum. Moreover, the WPI/GAFe3+ fibrils exhibited higher sensory scores compared with WPI/GAFe3+ nanoparticles on the attributes of texture, color, odor and acceptance. Thus, the proposed fabrication of WPI/GAFe3+ fibrils complexes is expected to be promising for iron fortification in food industry.

Ultrasound homogenization of milk cream at low temperature

Ultrasonication has been identified as a particularly promising technology for homogenization of dairy products. Homogenization of cream, by reducing fat globule size, can be utilized to inhibit creaming. The homogenization of cream usually leads to increased viscosity. Cream with fat level greater than 17% cannot be homogenized with satisfactory results since conventional homogenization methods cause coalescence and mostly agglomeration. The aim of this study was to investigate the influence of ultrasonication on milk cream (5-30% fat) and to study the phenomenon of formation of fat clusters during sonication (0.5-15 mins) at low temperature (2°C). The results showed that ultrasonication can reduce the fat globule size, although it resulted in the formation of fat clusters at short time (<1min), but at longer time, fat clusters can be broken. On the other hand, ultrasound homogenization tends to increase the viscosity of cream at various fat contents. Microstructure of solid phase showed that there was formation of double emulsions and partial fat coalescence. Ultrasound homogenization with the addition of SDS as small-molecule surfactant can prevent the formation of fat clusters. Fatty acid composition in solid phase shows that it consists of long-chain fatty acids in higher amount compared to that present in the liquid fraction. Whereas the concentration of short and medium chain fatty acids in the liquid phase was higher compared to that in solid phase. The utilization and optimization of ultrasound for cream homogenization has a potency to solve the limitation of conventional method (pressure homogenizer) which commonly used in dairy industry.

Enhancing the rheology and leachability of fly ash slurry using natural – synthetic mixed surfactant systemfor hydraulic stowing in underground mines

ABSTRACT The present investigation is intended to develop the stabilization and transportation behavior of fly ash slurry (FAS) using the mixture of the surfactants, namely, Sapindus laurifolia (S. laurifolia, natural) and sodium dodecyl sulfate (SDS, synthetic). In addition to the rheological study, an attempt has been made to remove the toxic and other trace metals through the leaching method to address the safe disposal of FAS for mining backfilling applications. The data obtained from the different rheological studies of ash concentrations in the range of 45–65.8% were fitted to the Bingham plastic model. Addition of synthetic surfactant SDS to natural surfactant S. Laurifolia does enhance the wettability of fly ash (FA) particles by decreasing the surface tension and increasing the zeta potential of the slurry. The effect of other parameters like temperature, mixed surfactant concentration, and FA concentration on the formulation, stability, and leachability of FAS was investigated and reported. The results from the present investigation revealed that the optimum dosages of surfactants for both leaching and transportation of FAS is 0.009 g/cc of saponin and 0.008 g/cc of SDS. The stabilization interaction and leaching mechanism were proposed considering the hydrophobic/hydrophilic property of FA, S. laurifolia, and SDS. Abbreviations CMC: Critical micellar concentration; S. laurifolia: Sapindus laurifolia; SDS: Sodium dodecyl sulfate; FA: Fly ash; FAS: Fly ash slurry; η: Dynamic viscosity; τ0: Yield stress; γ: Applied shear rate; ζ: Zeta potential; τ: Shear stress

SDS triggered transformation of highly hydrophobic Pluronics® nanoaggregate into polymer-rich and surfactant-rich mixed micelles

This work reveals the role of sodium dodecylsulphate (SDS, anionic surfactant) in altering the phase behaviour and aggregation characteristics of five very hydrophobic polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) triblock copolymers containing 10% PEO but with different molecular weight. These copolymers are molecularly dissolved in water at ≤15–20 °C and exist as unstable vesicular structure at temperature close to cloud point (CP) >20 °C. SDS enhanced the aqueous solubility and CP of copolymers in water; progressive addition of SDS triggered the transformation of unstable vesicles into spherical mixed micelles. A correlation between the molecular orbital energy levels of Pluronics® and SDS is well comprehended using computational simulation approach where the perception of SDS stabilized Pluronics® micelles is predicted and correlated with optimized parameters. The size/ shape of copolymer-surfactant mixed nanoscale aggregates was evaluated using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). The scattering studies showed the presence of spherical mixed aggregates, whose size expanded with increase in hydrophobicity of Pluronics®. In high SDS concentration regime, SANS analysis uncovered the diminishing size of vesicles into spherical mixed aggregates. The nanoscale Pluronics®-SDS mixed micelles remained stable in water where this investigation discloses the conceivable ability of orange-OT solubilization using UV–vis spectroscopy.

Plant-dairy protein blends: gelation behaviour in a filled particle matrix

• All emulsion droplets showed extensive bridging flocculation. • Viscosity of the emulsions varied depending on the type of protein added. • During heating, structure formation of the mixed systems showed three different stages. • Lupin or pea protein isolates with whey protein caused an earlier onset of aggregation. The objective of this work was to study the structure formation in mixed protein systems containing oil droplets. A model system was prepared with skim milk, whey proteins and plant proteins to a final concentration of 8% (w/w) and homogenized with 20% (w/w) coconut fat. Three plant-derived protein sources (namely, pea isolate, oat concentrate, and lupin isolate) were added to skim milk at two different ratios of plant/dairy proteins. A blend containing only dairy protein was also used as reference, prepared with skim milk and whey protein isolate. The formation of structure in the emulsion filled gels after homogenization and heating were evaluated, using SDS-PAGE, light scattering, rheology and confocal microscopy. All emulsions showed a high viscosity due to the high extent of bridging flocculation amongst the oil droplets confirmed by a decrease in the particle size of emulsions upon the addition of SDS. After heating and cooling, the emulsions showed no macroscopic phase separation. The results demonstrated that structuring of complex gels can be modulated by controlling the composition at the oil-water interface, as well as by modulating processing conditions, capitalizing on the gelling properties of the single components in the matrix.

Effect of sodium dodecyl sulfate on thermal properties of polyvinyl alcohol (PVA)/modified single-walled carbon nanotube (SWCNT) nanocomposites

This work was first started by modifying the single-walled carbon nanotube (SWCNT) with hydroxylation and silane reactions. Then, poly(vinyl alcohol) (PVA)/p-SWCNT, PVA/modified p-SWCNT, PVA/SDS/p-SWCNT and PVA/SDS/modified p-SWCNT nanocomposites were produced using the solution casting method. The effects of filling ratio, surfactant and functional group types on thermal properties of these nanocomposites were investigated by differential thermal analysis/thermogravimetry and differential scanning calorimetry. Structural and morphological properties of the samples were also examined using Brunauer–Emmett–Teller device, Fourier transform infrared-Attenuated total reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy and atomic force microscopy. It has been determined that the surface area of p-SWCNT decreases with the modification. Thermogravimetric analysis showed that the thermal stability of the composite depends on the loading fraction, the type of functional group and especially SDS. PVA and its nanocomposites degraded in two steps. The addition of SDS to PVA matrix increased thermal stabilities and glass transition temperatures of nanocomposites. PVA/SDS/p-SWCNT-OH nanocomposite was found to have the highest Tg temperature.

Characterization of undegraded and degraded silk fibroin and its significant impact on the properties of the resulting silk biomaterials

The silk fibroin (SF) regeneration process significantly affects the resulting biomaterials, unfortunately, there has been insufficient study regarding the most suitable regeneration method for SF. In this study, we prepared undegraded SF (uSF) and degraded SF (dSF) by common regeneration methods and studied their difference in detail. The results demonstrated that the degradation degree of SF peptide chain had little influence on the secondary structure and thermal stability of SF materials. While, uSF solution showed higher viscosity and surface tension than dSF solution. The uSF membrane (uSFM) could be elongated approximately 134%, 1.6 times the degraded SF membrane (dSFM). SEM implied that both uSF and dSF existed in aqueous solution as micelles with a diameter of approximately 30 nm. dSF could directly form SF nanoparticles (dSFNPs) when poured into acetone while uSF could only form nanoparticles (uSFNP) with the addition of SDS. Glucose oxidase embedded into dSFM and dSFNP showed high catalytic activities, but uSFNP demonstrated nearly no activity. In addition, the dSFM was more appropriate for L929 cell culture. Considering the obvious difference between the two SF proteins, our results are significant in guiding the application of appropriate SF proteins in tissue engineering materials, bioactive materials, bioink, etc.

The role of vinyl terminated silanes for producing highly concentrated polystyrene slurries in a single step process

Slurries with low viscosity and polystyrene (PS) nanoparticle concentration up to 52 wt.% have been synthesized in one-step process with no waste generation, by suspension polymerization and optimizing the concentration of dispersants (sodium dodecyl sulfate, SDS, and the cosurfactant, CS). The CS was manufactured in situ from tetraethyl orthosilicate (TEOS) and vinyltriethoxysilane (VTES). The incorporation of the CS on the PS polymer was confirmed by FT-IR, EDS, and TGA, observing the functionalization of PS nanoparticles with SiOH. Morphology and particle size of the dispersed solid, together with viscosity and stability of the polystyrene slurries (PSSs), were analyzed, finding an abrupt reduction of the viscosity for PSSs by combining SDS and CS. Addition of SDS and CS (3.0 and 1.5 wt.%, respectively) allowed to produce PSSs with improved stability (ζ = − 48.5 mV after 1 year), low viscosity (20.5 mPa·s at 25 °C), and Newtonian behavior, containing up to 40.0 wt.% of single-spherical PS nanoparticles (< 100 nm).

Estimation of the parameters of the Smoluchowski equation describing the occurrence of pores in a bilayer lipid membrane under soft poration.

The conductive lipid pores occurring in planar bilayer membranes are known to manifest themselves experimentally as current fluctuations. Reliable recording of such fluctuations during phase transitions, as well as in membranes with various additives (for example, SDS), allows one to determine the characteristics of hypothetical hydrophilic pores, namely, their number, sizes, lifetimes, and duration of time intervals between pores. Because, in contrast with electroporation, the emergence of pores in a membrane does not require high voltages, this process is called soft poration. Studying the characteristics of pores under soft poration allows us to estimate the parameters of the Smoluchowski equation and compare them with the corresponding parameters used to describe electroporation. In this work, the experimental characteristics of current fluctuations in the membrane with the addition of SDS to the bulk solution were used to estimate the parameters of the Smoluchowski equation: the pore edge tension, the energy of the hydrophobic pore/hydrophilic pore barrier, the coefficient of pore diffusion in the radius space, the initial distribution density of the number of pores, and the attempt rate density of the lipids in a membrane. The obtained estimates are close to the parameter values used in studies of electroporation.

Evaluation of gels formulated with whey proteins and sodium dodecyl sulfate as a fat replacer in low-fat sausage

Consumers are increasingly interested in low-fat meat products. Therefore, there is demand for new fat replacers that improve the quality of low-fat meat products. Whey protein isolate (WPI; 10% (w/v)) and sodium dodecyl sulfate (SDS; 0–0.09% (w/v)) were used to produce WPI-SDS gel as a fat replacer of low-fat meat products. Characteristics of WPI-SDS gel were evaluated using SDS-PAGE, FT-IR, viscometer, and texture analyzer. Addition of SDS to WPI increased gelation while reducing aggregation. Addition of 0.06% SDS to WPI-SDS gel has the highest viscosity and hardness, while 0.09% SDS decreased the heat stability of WPI. Quality characteristics including cooking loss, emulsion stability, hardness, and chewiness were significantly improved in WPI-SDS gel-supplemented low-fat sausages. Particularly, the highest hardness and chewiness were obtained in the low-fat sausage added with WPI-SDS gel containing 0.06% SDS. Our results suggest that WPI-SDS gel can be used as a fat replacer in low-fat meat products.

Formation and dissociation behaviors of SF6 hydrates in the presence of a surfactant and an antifoaming agent for hydrate-based greenhouse gas (SF6) separation

Sulfur hexafluoride (SF6), the most potent greenhouse gas, should be separated from gas mixtures for recycling and for mitigation of global warming. In this study, the formation and dissociation behaviors of SF6 hydrates in the presence of a surfactant (sodium dodecyl sulfate, SDS) and an antifoaming agent (antifoam A concentrate, AAC) were investigated, with a primary focus on kinetic, spectroscopic, and morphological analyses for hydrate-based SF6 separation. The optimum concentrations of SDS and AAC for SF6 hydrates were found to be 250 ppm and 1,500 ppm, respectively. The structure of SF6 hydrates in the presence of SDS and AAC was identified as structure II, indicating that SDS and AAC had no impact on hydrate structure. The formation behaviors of SF6 hydrates were thoroughly examined through gas uptake measurements, visual observation, and in-situ Raman spectroscopy. The addition of SDS 250 ppm significantly accelerated the formation rate of SF6 hydrate and the additional injection of AAC did not inhibit the promoting effect of SDS. Visual observation, temperature profiles, and volume of retrieved gas during the dissociation of SF6 hydrates clearly demonstrated that SDS also had a promoting effect on SF6 hydrate dissociation and its effect was slightly diminished with the addition of AAC, although AAC showed a powerful defoaming effect during the dissociation of SF6 hydrates. The experimental results obtained in this study will be very useful for accelerating the formation rate of SF6 hydrates using SDS and for solving the foaming problem using AAC in the design and operation of the gas hydrate-based SF6 separation process.

Surfactant‐assisted hydrothermal synthesis of NaTaO 3 nanotubes with enhanced photodegradation activity

The morphology of photocatalysts plays an important role in their photocatalytic activity. Here, a novel sodium tantalum trioxide (NaTaO3) nanotube photocatalyst was hydrothermally synthesised with the assistant of Na dodecyl sulphate (SDS) surfactant. The as-synthesised NaTaO3 nanotubes presented an enhanced light absorption, compared with NaTaO3 nanocubes prepared without the addition of SDS. By using rhodamine B (RhB) as organic pollutants model, the NaTaO3 nanotubes exhibited a 96.2% of photodegradation ratio after 80 min ultraviolet light irradiation, which was much higher than NaTaO3 nanocubes and commercial P25. The cycle degradation results revealed that NaTaO3 nanotubes had an excellent photochemical stability. The active species trapping experiment suggested that the dominating active species were hydroxyl radicals and superoxide radicals, rather than holes.

Effect of TBAB and SDS surfactants on the interfacial tension of CO2 Hydrate in water

The interfacial tension rate is an important factor in the kinetic study of gas hydrate formation. In this study, the interfacial tension between CO2 hydrate and water was calculated at various temperatures, pressures and solution concentrations a through measurement of the induction time according to the Classical Nucleation Theory (CNT). Experimental data for pure water showed that, at constant temperature, with increasing pressure, the interfacial tension decreases from 2.92 to 1.67 mN/m, and at constant pressure with increasing temperature, interfacial tension increases from 3.92 to 4.7 mN/m. At constant temperature, with increasing TBAB concentration from 1% to 3% by weight, the induction time decreases from 60 to 36 seconds. At higher temperatures, addition of SDS 500 ppm decreased the induction time and interfacial tension from 4.61 to 2.32 m N/m. Finally, the relationship of nucleation intensity and with the super saturation was obtained by fitting the experimental data. According to equations and graphs, the nucleation intensity is a function of temperature.

Interfacial instabilities due to immiscible fluid displacement in circular and non-circular microchannels

Interfacial instabilities caused by the displacement of one fluid by another were studied experimentally in three horizontal channels of different shape of cross section with hydraulic diameters ranging from 100 to 200 µm. Flow instabilities were induced by the displacement of a more viscous fluid (silicone oil) by an immiscible, less viscous fluid (aqueous solutions of glycerol) with viscosity ratios between the two fluids ranging from 20 to 100. In addition, the effect of surfactant was studied by the addition of Sodium Dodecyl Sulfate to the displacing fluid. Flow regime maps were developed for the different types of instability observed, with more complex 3-D instabilities shown to occur as the capillary number increases. Whilst fluid viscosities, channel shape and wall wettability were shown to affect the threshold capillary numbers for instabilities, the addition of SDS did not have a significant impact, which is believed to be a consequence of the long contact time between the two fluids during the whole displacement process. It was found that higher flow rates of the displacing fluid (resulting in more complex interfacial instabilities) did not cause a proportionally faster removal of the displaced fluid, which is an important finding for practitioners.

Метод экстракции ДНК из широкого спектра объектов с помощью обработки солями аммония

Currently, simple, rapid, and efficient techniques for DNA isolation from a wide range of organisms are in demand in biotechnology and bioinformatics. A key (and often limiting) step is the cell wall disruption and subsequent DNA extraction from the disintegrated cells. We have developed a new approach to DNA isolation from organisms with robust cell walls. The protocol includes the following steps: treatment of cells or tissue samples with ammonium acetate followed by cell lysis in low-salt buffer with the addition of SDS. Further DNA extraction is carried out according to standard methods. This approach is efficient for high-molecular native DNA isolation from bacteria, ascomycetes, yeast, and mammalian blood; it is also useful for express analysis of environmental microbial isolates and for plasmid extraction for two-hybrid library screening. express method for DNA isolation; ammonium salt treatment (в русских ключевых такой порядок), osmotic breakage of cells This study was financially supported by the NRC "Kurchatov Institute"-GOSNIIGENETIKA Kurchatov Genomic Center.

Composition Tuning of Single Step Electrodeposited CuInSe2 Thin Films Using Sodium Dodecyl Sulfate as Additive

CuInSe2 (CISe) thin films were electrodeposited on FTO substrates by single step deposition technique from an aqueous solution containing CuCl2, InCl3, HSeO3− ions and citric acid-sodium dodecyl sulfate (SDS) as the pH adjuster and additive, respectively. The effect of SDS concentration on the structural, composition, morphology and photo-electrochemical properties was characterized by SEM/EDAX, XRD, Raman and electrochemical (PEC) studies. The linear sweep voltammetry (LSV) and electrochemical impedance (EIS) results revealed that the addition of SDS limits the Cu-Se incubation time and enhances the diffusion controlled process which is considered to be the origin of the compositional and morphological tuning nature of the SDS in CISe deposition. The structural, compositional and PEC analysis revealed that for SDS concentration less the critical micelle concentration has almost no effect in controlling the Cu2Se secondary phase. The samples deposited in the presence of SDS (> 8 mM) exhibited better PEC properties due to the reduced Cu2Se phase. Further, the Mott–Schottky analysis of all the as-deposited thin films exhibited p-type conductivity.

Unfolding and partial refolding of a cellulase from the SDS-denatured state: From β-sheet to α-helix and back

Globular proteins are typically unfolded by SDS to form protein-decorated micelle-like structures. Several proteins have been shown subsequently to refold by addition of the nonionic surfactant octaethylene glycol monododecyl ether (C12E8). Thus SDS converts β-lactoglobulin, which has mainly β-sheet secondary structure, into a state rich in α-helicality, while addition of C12E8 leads to refolding and recovery of the original β-sheet structure. Here we extend these studies to the large β-sheet-rich cellulase Cel7b from Humicola insolens whose enzymatic activity provides a very sensitive refolding parameter. The enzymes widespread usage in the detergent industry makes it an obvious model system for protein-surfactant interactions. SDS-unfolding and subsequent refolding using C12E8 were investigated at pH 4.2 using near- and far-UV circular dichroism (CD), small-angle X-ray scattering (SAXS), isothermal titration calorimetry (ITC), size-exclusion chromatography (SEC) and activity measurements. The Cel7b:SDS complex can be described as a random configuration of 3–4 connected core-shell structures in which the protein is converted to a mainly α-helical secondary structure. Addition of C12E8 recovers almost all the secondary structure, part of the tertiary structure, about 50% of the activity and dissociates part of the protein population completely from detergent micelles. The lack of complete refolding may be due to charge neutralisation of Cel7b by SDS, kinetically trapping the enzyme into aggregated structures. In support of this, aggregates did not form when C12E8 was first mixed with Cel7b followed by addition of SDS. Formation of such aggregates may be a general phenomenon hampering quantitative refolding from the SDS-denatured state.

The effect of adding surfactant to the treating acid on the chemical properties of an acid-treated coal

In order to enhance the effect of acidizing coal seam with the compound solution, in this paper, the chemical characteristics of treated coal samples were analyzed, including proximate analysis, functional groups, mineral components and microcrystalline structures. The results show that acidification synergism of SDS reduces the ash content in the coal, and significantly increases the volatile component, fixed carbon content and low calorific value. The addition of SDS increases the content of hydrogen groups and hydroxyl groups. Acidification synergism of SDS reduces the degree of fatty chain length and the degree of branching (dfc-b) in the coal samples. Besides, in terms of microcrystalline structure, addition of the SDS has a large influence on the parameters the average diameter of the aromatic layer(La) and the stacking height of the aromatic layer (Lc). The results of this paper are great significance for studying the mechanism of chemical properties of acidified coal.

An attempt to co-deposit photovoltaic quality CuInSe2 thin films: effect of surfactant and deposition potential

CuInSe2 (CISe) thin films were prepared by single step electrodeposition technique using citrate-SDS electrolyte. Preliminary studies revealed that the initial deposition conditions have significant influence over the composition, film quality and the addition of SDS in the citrate electrolyte enhances adhesion, smoothness and eliminates multinuclear growth. To explore the capability of the citrate-sodium dodecyl sulfate (SDS) electrolyte, the CISe thin films deposited at various potentials were annealed at 300 °C in nitrogen atmosphere. The structural, morphological and compositional properties of the annealed CISe thin films were compared. Finally, CISe thin film deposited at − 0.65 V/SCE exhibiting the p-type electrical conductivity was confirmed by Mott–Schottky (M–S) and photoelectrochemical (PEC) studies.