Amount Of Sodium Dodecyl Sulfate Research Articles

Conductive nanofilm/melamine foam hybrid thermoelectric as a thermal insulator generating electricity: theoretical analysis and development

Harvesting waste energy through thermoelectric has widely gained attention to aid green energy production. Current efforts are to take advantages of nanomaterials and nanosystems because of dramatic improvements in the performance. However, its cost-effectiveness in generating a 3D configuration for a large-area use is hindered by high production cost. To overcome the present challenges, we propose a flexible and lightweight thermoelectric developed on a melamine foam using a simple dip-dry technique to self-assemble conductive nanofilms in the scaffold. Different amounts of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) conductive nanofilms were variedly fabricated in the foam due to altered amounts of sodium dodecyl sulfate (SDS) surfactant from 0 to 5 wt%. Together with experimental results, a theoretical model was constructed to predict thermal and electrical conductivities, indicating the strong influence of SDS to the electrical conductivity. As a result, the highest nanofilm formation in the foam structure is achieved by adding SDS at 3 wt%. The figure of merit (ZT) of thermoelectric foam is about 0.006–0.007. Our first device was also demonstrated with output voltage of 1.1 mV (ΔT = 40 K). The present study could provide the design and optimization of a hybrid thermoelectric that can act as a simultaneous thermal insulator and power generator.

Photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization of acrylonitrile in miniemulsion

Photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization of acrylonitrile (AN) in miniemulsion was reported. PET-RAFT polymerization of acrylonitrile (AN) was successfully accomplished with 4-cyanopentanoic acid dithiobenzoate (CPADB) as chain transfer agent (CTA), sodium dodecyl sulfate (SDS) as emulsifier, hexadecane (HD) as co-stabilizer and TiO2 as photocatalyst at 25 °C. The linear first-order kinetic plots were observed in miniemulsion with different amounts of SDS. Excellent temporal control was demonstrated by switching between ON/OFF states multiple times, and the prepared PAN macro-CTA was used successfully to perform the chain extension experiments, indicating high retention of chain end functionality. Furthermore, the obtained PAN was amidoximated with NH2OH·HCl. The Cd2+ was extracted with amidoxime (–C(NH2)=NOH) from aqueous solutions. The maximum adsorption of 98.6% Cd2+ with 400 mg of the adsorbent was observed at pH 6.0 and an initial Cd2+concentration of 4 mmol/L.

Preparation of Zinc Powders by Acid Electrowinning

During the electrowinning of zinc in a mixture electrolyte of zinc sulfate and ammonium sulfate, the effects of current density, Zn2+ mass concentration and electrolytic additives on the morphology and current efficiency of Zn powders were evaluated. Finer Zn powders were obtained at high current density and low Zn2+ mass concentration. However, the current efficiency decreased. Adding a proper amount of sodium dodecyl sulfate generated spherical Zn powders, and adding ethanol produced dendritic ones.

Electrical conductivity of polyaniline (PANI) assisted by anionic surfactant through emulsion polymerization technique

In this work, Polyaniline (PANI) was synthesized through emulsion polymerization assisted by sodium dodecyl sulfate (SDS) surfactant to investigate effects of surfactant to the electrical conductivity. The amount of SDS used has mol to the total quantity ratio of respectively 0.25%, 0.67%, 1.00%, and 2%. The emulsion aniline polymer obtained from the reaction was confirmed by FTIR. The addition of SDS surfactant as an additional component in the reaction solution, led to the chemical reaction run with a relatively slow rate. It indicated by a relatively long reaction time for an increase in the temperature of reaction solution. The viscosity of the emulsion aniline polymer increased with the addition of SDS. The higher amount of SDS is added, the higher the initial viscosity value of the emulsion. Electrical conductivity value evaluated by Four Point Probe (FPP) showed that the emulsion polymers of aniline doped with 80 ml Perchloric Acid (HQO4) have an ohmic relationship between current and voltage from which the conductivity was derived. It was found that the electrical conductivity value of doped PANI assisted by surfactant reached two times higher than that of surfactant-free synthesized PANI. The highest electrical conductivity value obtained is 3.97 S/cm.

Removal of Cd(Ⅱ) by micellar enhanced ultrafiltration: Role of SDS behaviors on membrane with low concentration

Surfactant monomers tend to adsorb and aggregate on membrane, which plays a crucial role in removal of metal ions by micellar enhanced ultrafiltration (MEUF) at low concentration level. In this paper, MEUF of cadmium(Ⅱ) (Cd(Ⅱ)) with low sodium dodecyl sulfate (SDS) concentration was studied. Ultrafiltration performance was evaluated in terms of rejection ratios of Cd(Ⅱ) and SDS and relative flux of membranes. The results showed that almost 90% of Cd(Ⅱ) were removed by MEUF when SDS concentration was merely 4 mmol/L. This indicates that reducing the dosage of anionic surfactant in removal of metal ions by MEUF is possible. The retention rates of SDS ranged from 20% to 60%. Relative flux dramatically declined when SDS concentration increased from 0.4 mmol/L to 4 mmol/L. In addition, SDS behaviors on membrane during ultrafiltration were analyzed based on Zhu and Gu's adsorption model and Hermia's blocking models. When large amounts of monomeric SDS existed in the bulk solution, SDS monomers adsorbed on membrane and aggregated into hemimicelles. With SDS concentration gradually increasing, standard pore blocking and cake filtration occurred because SDS hemimicelles deposited on membrane. Cd(Ⅱ) rejection was related to the fouling layer formed by deposition of SDS on membrane.

Bottom-Up and Top-Down Approaches to Explore Sodium Dodecyl Sulfate and Soluplus on the Crystallization Inhibition and Dissolution of Felodipine Extrudates

The objectives of this study were to explore sodium dodecyl sulfate (SDS) and Soluplus on the crystallization inhibition and dissolution of felodipine (FLDP) extrudates by bottom-up and top-down approaches. FLDP extrudates with Soluplus and SDS were prepared by hot melt extrusion, and characterized by polarized light microscopy, differential scanning calorimetry, and fourier transform infrared spectroscopy. Results indicated that Soluplus inhibited FLDP crystallization, and the whole amorphous solid dispersions (ASDs) were binary FLDP-Soluplus (1:3) and ternary FLDP-Soluplus-SDS (1:2:0.15∼0.3 and 1:3:0.2∼0.4) extrudates. Internal SDS (5%-10%) decreased glass transition temperatures of FLDP-Soluplus-SDS ternary ASDs without presenting molecular interactions with FLDP or Soluplus. The enhanced dissolution rate of binary or ternary Soluplus-rich ASDs in the nonsink condition of 0.05% SDS was achieved. Bottom-up approach indicated that Soluplus was a much stronger crystal inhibitor to the supersaturated FLDP in solutions than SDS. Top-down approach demonstrated that SDS enhanced the dissolution of Soluplus-rich ASDs via wettability and complexation with Soluplus to accelerate the medium uptake and erosion kinetics of extrudates, but induced FLDP recrystallization and resulted in incomplete dissolution of FLDP-rich extrudates. In conclusion, top-down approach is a promising strategy to explore the mechanisms of ASDs' dissolution, and small amount of SDS enhances the dissolution rate of polymer-rich ASDs in the nonsink condition.

Thermal Stability and Flame Retardancy of Polypropylene/NiAl Layered Double Hydroxide Nanocomposites.

NiAl layered double hydroxide (NiAl-LDH) was synthesized by co-precipitation method. And sodium dodecyl sulphate (SDS) as modifier was utilized to enlarge the d-spacing of NiAl-LDH to obtain SDS-NiAl-LDH. PP/SDS-NiAl-LDH nanocomposites were prepared with different amount of SDS- NiAl-LDH and PP by melt intercalation method. The results of XRD and TEM confirmed that intercalated and exfoliated-intercalated structures were formed. Compared with pure PP, PP/SDS- NiAl-LDH nanocomposites exhibited high thermal stability and residual to the presence of barrier effect of NiAl-LDH layers. Cone calorimetry analysis indicated that incorporation of SDS-NiAl-LDH obviously improved flame retardancy and smoke suppression properties of PP. With the addition of 5 wt% SDS-NiAl-LDH, the peak heat release rate (PHRR), the total heat release (THR) and smoke production rate (SPR) peak values reduced 32.4%, 16.0%, and 61.5% compared with those of pure PP, which were attributed to the barrier effect and excellent charing performance of SDS-NiAl-LDH.

Sodium Dodecyl Sulfate‐Modified Fe2O3/Molecular Sieves for Removal of Rhodamine B Dyes

Studying the removal of rhodamine B (RB) dye by using zeolite 13X molecular sieves supported by Fe2O3 nanoparticles (denoted as Fe2O3‐13X) is the main objective of this study. Fe2O3‐13X was synthesized and modified by the addition of sodium dodecyl sulfate (SDS). The prepared Fe2O3‐13X was characterized by XRD, TEM, SEM, and zeta potential. The effects of the solution pH, SDS amount, contact time, initial dye concentration, and adsorbent dosage on the removal efficiency of RB were studied. A maximum removal efficiency of 99.3% was achieved. The adsorption equilibrium data of RB were fitted using the Freundlich model, yielding the maximum adsorption capacity of 89.3 mg/g. The findings revealed that the RB adsorption onto Fe2O3‐13X modified with SDS (Fe2O3‐13X‐Ms) was described by a pseudo‐second‐order kinetic equation. The results reported in this paper indicate that a high RB removal percentage was attained by adding SDS to Fe2O3‐13X.

A novel strategy for the synthesis of polyamide-6 microspheres

In this study, we develop a novel method to prepare polyamide-6 (PA6) microspheres with designed morphology. The diameter range of the PA6 microspheres is controlled at 200 nm ∼ 500 nm by adding a certain amount of sodium dodecyl sulfate (SDS) surfactant in the polyamide-6/polyethylene glycol (PA6/PEG) system. The key strategy for the method is to induce phase inversion by PEG in the synthesis process. PEG and SDS are removed with water and without any toxicity to environment. Scanning electron microscope (SEM) and transmission electron microscope (TEM) have confirmed that the PA6 spherical morphologies. The crystallization behaviour of PA6 microspheres is investigated using X-ray diffraction (XRD) and Differential scanning calorimeter (DSC). We believe this strategy can be applied to prepare a variety of microspheres materials.

Determination of trace amounts of nystatin in water and vaccine samples using sodium dodecyl sulfate-coated iron oxide magnetic nanoparticles followed by high-performance liquid chromatography–ultraviolet detection

In this work, magnetic solid-phase extraction based on sodium dodecyl sulfate-coated Fe3O4 nanoparticles has been successfully applied for extraction and preconcentration of trace amounts of nystatin from water and vaccine samples prior to high-performance liquid chromatography–ultraviolet detection. Various experimental parameters affecting extraction and recovery of the analyte, such as the amount of sodium dodecyl sulfate, pH of the sample solution, salt concentration, extraction time, sample volume and desorption conditions, were systematically studied and optimized. Under optimized conditions, nystatin was quantitatively extracted. Proper linear range with good coefficient of determination, (R 2 > 0.99) and limit of detection and quantification (based on signal-to-noise ratios of 3 and 10) of 2.0 and 5.0 µg L−1, over the investigated concentration range (5–700 µg L−1), were obtained, respectively. The intra-day and inter-day relative standard deviations at 50 µg L−1 level of NYS were 1.4 and 4.5% based on six replicate determinations. The accuracy of the method was evaluated by recovery measurements on spiked samples. Suitable recoveries of 96–102 and 26–44% were achieved (at spiked levels of 50, 300 and 500 µg L−1) for water and vaccine samples, respectively.

Preparation of polymeric/inorganic nanocomposite particles in miniemulsions: II. Narrowly size-distributed polymer/SiO2 nanocomposite particles

Narrowly size-distributed poly(styrene-co-methyl methacrylate) (poly(St-co-MMA))/SiO2 nanocomposite particles (NCPs) were efficiently prepared through miniemulsion polymerization by using a special use strategy of surfactants. A trace amount of sodium dodecyl sulfate (SDS) was post-added to monomer miniemulsions stabilized with polyoxyethylene (20) sorbitan monolaurate (Tween-20). The number fraction of the poly(St-co-MMA)/SiO2 NCPs reached 97% in the as-synthesized emulsion stabilized with 0.15g of Tween-20 and 2.5mg of the post-added SDS. The highly efficient formation of poly(St-co-MMA)/SiO2 NCPs was realized through controlled mergence between the monomer droplets and latex particles during polymerization. The influence of the amount of post-added SDS, surface hydrophobic modification degree of SiO2 nanoparticles, and SiO2 content on the particle properties of latex particles was systematically investigated. The amount of post-added SDS and surface hydrophobic modification degree of SiO2 nanoparticles are two determining factors for the efficiency of polymer/SiO2 NCP formation.

The role of the surfactant sodium dodecyl sulfate to dynamically reduce mass transfer resistance of SPEEK coated membrane for oil-in-water emulsion treatment

Membrane fouling during the treatment of produced water containing oil emulsions remains a major technical challenge for the oil and gas industry. Here, we demonstrate the preparation and performance of a fouling resistant hollow fiber membrane using a synthetic saline oil-in-water emulsion. The membrane was prepared by coating commercial polyethersulfone (PES) hollow fibers with a layer of sulfonated polyether ether ketone (SPEEK). The SPEEK coated membrane was significantly more oleophobic than the support PES membrane, possibly due to a non-porous surface, higher hydrophilicity, and more negatively charged SPEEK surface. The SPEEK coated membrane could achieve complete oil rejection without any observable membrane fouling and considerably higher salt, turbidity, and sodium dodecyl sulfate (SDS) rejection than the support PES membrane. An initial increase in water flux was observed with the SPEEK coated membrane. The flux increase observed here could be attributed to the incorporation of SDS molecules into SPEEK polymeric network and subsequent electrostatic interaction amongst charged functional groups leading to conformational changes of the SPEEK layer. Dynamic adsorption and desorption experiments illustrated the interaction between SDS and SPEEK. A strong correlation between the amount of SDS entrapped in the SPEEK polymeric network and water flux was observed. Results from this study illustrated the potential of SPEEK coated membrane as a major breakthrough for oil recovery and wastewater reuse in the oil and gas industry.

Rapid removal of tetracycline antibiotics from water by coagulation-flotation of sodium dodecyl sulfate and poly(allylamine hydrochloride) in the presence of Al(III) ions

Abstract A coagulation-flotation method using an anionic surfactant, sodium dodecyl sulfate (SDS), and a cationic polyelectrolyte, poly(allylamine hydrochloride) [PAH], was designed for rapid removal of tetracycline antibiotics from water. The method was conducted by adding electrically equivalent amounts of SDS and PAH followed by feeding air bubbles. The air bubbles vigorously mixed water and induced the coagulation of SDS-PAH complex to from agglutinative coagulum on water surfaces. In the presence of Al(III) ions, tetracycline in water was collected to the coagulum as an hydrophobic ion-pair of the Al(III)-chelate with a dodecyl sulfate ion ( m / z = 736). Fluorometric study using a molecular probe, N -phenyl-1-naphthylamine, suggested the formation of hydrophobic region in SDS-PAH complex as well as air/water interfaces for the sorption of the hydrophobic ion-pair. Combined use of 20 mg L −1 SDS, 6.5 mg L −1 PAH, and 1 mg L −1 Al(III) ions allowed nearly complete ( > 99%) removal of tetracycline from water within 5 min. SDS concentration remaining in the treated water was 0.12 ± 0.05 mg L −1 , being lower than Japanese water regulation (0.2 mg L −1 ) of total anionic surfactants. Other tetracyclines and fluoroquinolone antibiotics as well as different acidic and basic pharmaceuticals were nearly completely (>96%) removed from water. Applicability to wastewater treatment was examined by using secondary effluents and synthesized hospital wastewaters.

Micellization of pH‐sensitive poly(butadiene)‐block‐poly(2 vinylpyridine)‐block‐poly(ethylene oxide) triblock copolymers: Complex formation with anionic surfactants

ABSTRACTThe micellization of three tailor‐made triblock copolymers, such as PB100–P2VP100–PEO104, PB185–P2VP108–PEO154, and PB37–P2VP115–PEO241, having similar total molecular weights and constant poly(2‐vinylpyridine) (P2VP) sequence lengths, was investigated as a function of pH and sodium dodecyl sulfate (SDS) concentration. At pH 7 the formation of intermicellar aggregates was observed, especially for copolymers of low poly(ethylene oxide) (PEO) content. A pH decrease from 7 to 3 leads to a particle size increase due to the electrostatic repulsion of the protonated P2VP chains. The influence of the PEO sequence length was also observed for zeta potential values. At pH 3, in the absence of SDS, core–shell–corona micelles are formed whereas in the presence of small amount of SDS (degree of neutralization DN = 0%–50%), a complex is formed between SDS and the protonated P2VP which leads to the shrinkage of the shell and thus to a decrease of the micellar sizes. For higher DN values, the micellar sizes increase due to the formation of large agglomerates and a transition occurs from a monomodal to a bimodal size distribution. Furthermore, it turned out that secondary aggregation, such as intermicellar aggregation, can completely be avoided if the degree of polymerization (DPn) of the water‐soluble block is significantly higher than the DPn of the water‐insoluble sequence. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45313.

Novelty aqueous two-phase extraction system based on ionic liquid for determination of sulfonamides in blood coupled with high-performance liquid chromatography

Ionic liquid/anionic surfactant aqueous two-phase system was developed and applied for the extraction of sulfonamides in blood. High-performance liquid chromatography was applied to the determination of the analytes. The blood sample was centrifuged and added to sodium dodecyl sulfate (SDS), ionic liquid 1-Hexyl-3-MethylImidazolium Chloride([C6MIM] Cl), K2HPO4. After the resulting mixture was ultrasonically shaken and centrifuged, the aqueous two phase system was formed and analytes were extracted into the upper phase. The parameters affecting the extraction efficiency, such as volume of ionic liquid, amount of sodium dodecyl sulfate, ionic strength, pH value of system, extraction time and temperature were investigated. The limits of detection of Sulfamethyldiazine (SMZ), Sulfamethizole (STZ), sulfachlorpyridazine (SCP), sulfamethoxazole (SMX) and Sulfisoxazole (SSZ) were 3.29, 4.13, 3.74, 2.45 and 3.60μgL−1, respectively. When the present method was applied to the analysis of real blood samples, the recoveries of analytes ranged from 85.5 to 110.9% and relative standard deviations were lower than 6.9%.

Separation/Analysis Safranine T in Food Samples Using Surfactant/Ionic Liquid Aqueous Two-Phase Systems

Sodium dodecyl sulfate (SDS)/room temperature ionic liquids (RTILs) 1-hexyl-3-methylimidazolium bromide aqueous two-phase systems (ATPSs) are presented as separation/enrichment coupled with ultraviolet spectrometry for separation/analysis safranine T in food samples. The main factors affecting the ATPSs, such as amount of SDS, RTILs, pH, and time, have been investigated in detail. Under the optimal conditions, the linear calibration curves for safranine T was obtained over the concentration ranges of 0.05–4.0 μg mL−1 with the correlation coefficient (R) 0.9984 and the detection limits of safranine T was 3.8 ng mL−1. The mechanism of ATPS phase separation for safranine T has been discussed. The method was successfully applied to the determination of safranine T in food samples.

Acetic acid urea-polyacrylamide gel electrophoresis: a rapid method for testing the genetic purity of sunflower seeds

Genetic purity testing is an important component of seed quality control. The objective of this study was to develop a rapid method for testing the genetic purity of sunflower seeds. We used six sunflower hybrids and their parental lines to study and improve a method based on the acetic acid urea-polyacrylamide gel electrophoresis (AU-PAGE) approach for testing the genetic purity of maize seeds. The results showed that the most abundant proteins in sunflower seeds were water-soluble proteins, followed by salt-soluble proteins, while there were relatively few other proteins. The AU-PAGE method was improved to increase the clarity of lanes backgrounds by adding an appropriate amount of sodium dodecyl sulfate to the protein extracting solution. The reduced background staining of the lanes improved the bands identification and increased the evidence of protein polymorphism. The method was validated as an efficient method for genetic purity testing of sunflower seeds. The improvements in this method could potentially be applied to other plants and other protein electrophoresis.

Secondary Structural Changes of Intact and Disulfide Bridges-Cleaved Human Serum Albumins in Thermal Denaturation up to 130°C - Additive Effects of Sodium Dodecyl Sulfate on the Changes.

The secondary structural changes of human serum albumin with the intact 17 disulfide bridges (HSA) and the disulfide bridges-cleaved human serum albumin (RCM-HSA) in thermal denaturation were examined. Most of the helical structures of HSA, whose original helicity was 66%, were sharply disrupted between 50 and 100°C. However, 14% helicity remained even at 130°C. The temperature dependence of the degree of disrupted helical structures of HSA was discussed in connection with questions about a general protein denaturation model. When HSA lost the disulfide bridges, about two-thirds of the original helices were disrupted. Although the helices of RCM-HSA remaining after the cleavage of the disulfide bridges were relatively resistant against the heat treatment, the helicity changed from 22% at 25°C to 14% at 130℃. The helicity of RCM-HSA at 130°C agreed with the helicity of HSA at the same temperature, indicating that the same helical moieties of the polypeptides remained unaffected at this high temperature. The additive effects of sodium dodecyl sulfate (SDS) on the structural changes of HSA and RCM-HSA in thermal denaturation were also examined. A slight amount of SDS protected the helical structures of HSA from thermal denaturation below 80°C. Upon cooling to 25°C after heat treatment at temperatures below 70°C with the coexistence of SDS of low concentrations, the helical structures of HSA were reformed to the original level at 25°C before heating. A similar tendency was also observed after heat treatment at 80°C. In contrast, the helical structures of the RCM-HSA complexes with SDS are completely recovered upon cooling to 25°C even after heat treatment up to 100°C. Similar investigations were also carried out on bovine serum albumins which had the intact 17 disulfide bridges and lost all of the bridges.

Synthesis and application of the drilling mud additive in the presence of surfactants

Drilling fluid is the most important lifeline of the drilling operation, that main task is facilitate the cuttings removal of the drilling. There are varieties of drilling fluids such as sodium bentonite based-drilling fluid is called “mud” and drilling foam or surfactant based-drilling fluid is called “soap”. The present work aims are study on the modified drilling mud properties by using the TiO2/ Polyacrylamide (PAM) as a nanocomposite additive. This additive was obtained through the aqueous solution polymerization of acrylamide monomer in the presence of TiO2 nanoparticles and high hydrophilic-lipophilic balance (HLB) surfactants such as sodium dodecyl sulfate (SDS) and polyoxyethylene sorbitan mono-oleate (Tween 80). At first, the TiO2/PAM nanocomposite was characterized by XRD, UV-Vis, FTIR, DLS and SEM. Then the viscosity, density -specific gravity- and filtration properties of the modified drilling mud were investigated in different amount of nanocomposite compounds. The results indicated that the density, fluid loss and filter cake thickness of the modified drilling mud were decreased with the increase of the surfactant concentration, whereas the viscosity was increased. With the increasing amount of SDS from 0.1 to 1.2 g in the synthesis process, the viscosity was increased approximately 4 cP and the density was decreased about 0.1 specific gravity. The nanoparticle and HLB value were affected in the filtration properties, but in general, that improved the fluid loss and filter cake thickness about 28 and 38% compared the based drilling mud, respectively.

Rapid formation of dry natural gas hydrate with high capacity and low decomposition rate using a new effective promoter

In this research, the effects of sulfonated Lignin (SL) on formation rate, capacity and stability of natural gas hydrate have been investigated and the results compared with those of hydrate formation in pure water and Sodium dodecyl sulfate (SDS) aqueous solution. Experimental results verified that the reactor pressure is reduced by 63.8% after 15h when hydrate is formed in 500ppm SL aqueous solution, while when using the same amount of SDS it is reduced no more than 57.8% after the same duration of time. It was also noticed that the formed hydrate when using SL had a lower decomposition rate than that of SDS aqueous solution. The reactor pressure increased 0.66MPa during dissociation of SL natural gas hydrate after 70h while in the case of SDS solution, at similar conditions this amount was 0.94MPa. On the other hand, SL solution does not spume and so the formed hydrate is quite dense, brittle and dry which can be easily converted to powder while the hydrate formed in the SDS solution is foamy.