Sodium Dodecyl Sulfate Research Articles

Spherulite formation in green nonaqueous media: The impact of urea on gelation in glycerol

HypothesisLarge macroscopic assemblies formed by a surfactant, sodium dodecylsulfate (SDS), and glycerol, can be directed to assemble in a hierarchical manner by the addition of a strong hydrogen-bond donor/acceptor, such as urea. ContextSelf-assembly in complex media is important to a range of applications, for instance in biological media, which are multi-component, to industrial formulations, where additives are present for flavour, texture, and preservation. Here, the gelation and self-assembly of sodium dodecylsulfate (SDS) in glycerol is explored in the presence of an additive, urea. Urea was chosen due to its importance both fundamentally and industrially, but also because of its ability to form strong H-bonds and interact with both glycerol and SDS. ExperimentalTo cover the variety of length scales present in the gel-like phase, a combination of optical microscopy and small-angle X-ray scattering techniques were used to probe the micro- to nanoscale. FindingsOn the microscale, the formation of a spectacular spherulite phase, even at low urea contents - 0.1 wt%, upon cooling was observed, a stark difference to the microfibrillar phase observed in the absence of urea. Interestingly, the nanostructure of the two crystalline phases were similar and showed negligible differences. This suggests that urea is not involved in the SDS/glycerol microfibril formation but instead directs the assembly of spherulites by bundling the microfibrils. These ternary systems are also probed as a function of urea content, SDS concentration, and temperature. The observations in this work highlight the importance of small molecules in the self-assembly process, which is relevant both fundamentally but also industrially, where small molecules are often added to formulations.

Effect of Surfactants on the Permeation Rate and Selectivity of Polyamide Composite Membranes for Organic Solvent Nanofiltration

Solvent-resistant membranes are pivotal in industrial separations. This study aims to develop thin-film composite polyamide (TFC-PA) membranes with enhanced organic solvent nanofiltration (OSN) capabilities. Polyallylamine hydrochloride (PAAH) was used as the aqueous amine and isophthaloyl chloride (IPC) as the crosslinker to form the polyamide active layer by interfacial polymerization (IP) on a polyacrylonitrile (PAN) support. The impact of using anionic sodium dodecyl sulfate (SDS) and cationic cetyltrimethylammonium bromide (CTAB) to act as phase transfer agents during IP was investigated to understand their potential for facilitating the transfer of PAAH to the organic phase for reaction with IPC. The SDS and CTAB were separately dissolved into the PAAH solutions before IP to evaluate their effects on membrane properties. Extensive characterization including SEM, EDX, AFM, Water Contact Angle, ATR-FTIR, and Solid (CP-MAS) 13C-NMR revealed various chemical and structural features of the membrane. The membrane M2 (PAAH-IPC) (exhibited >98% rejection for various anionic and cationic dyes. The inclusion of SDS during interfacial polymerization led to a substantial 3-fold increase in methanol permeate flux from 31Lm-2 h-1 to 119Lm-2 h-1, at a pressure of 15bar. Conversely, the addition of CTAB resulted in membranes with higher flux but insufficient dye rejection. Moreover, after a three-week period of static aging no significant changes were detected in either permeability or solute rejection, substantiating their stability.

A Double Compatibilization Strategy To Boost the Performance of p-i-n Solar Cells Based on Perovskite Deposited in Humid Ambient Air.

Formamidinium lead iodide (FAPI) represents the most promising perovskite for single junction solar cells, exhibiting an impressive performance when deposited in a controlled nitrogen environment. In order to foster the real-world application of this technology, the deposition of FAPI in ambient air is a highly desirable prospect, as it would reduce fabrication costs. This study demonstrates that the wettability of FAPI precursors on the hole transporting layers (HTL) used to fabricate inverted p-i-n solar cells is extremely poor in ambient air, hampering the realization of a perovskite active layer with good optoelectronic quality. To address this issue, herein, a double compatibilization method is developed, which results in the attainment of remarkable performance, exceeding 21%, representing one of the highest reported efficiencies for FAPI solar cells fabricated in humid ambient air. The incorporation of a small quantity of anionic surfactant, comprising a hydrocarbon tail and a polar headgroup, sodium dodecyl sulfate (SDS), in the perovskite solution and an ultrathin layer of alumina nanoparticles on the HTL, results in a significant improvement in the wettability of the FAPI solution. This enables the reproducible deposition of highly homogeneous perovskite films with complete coverage and excellent optical and optoelectronic quality. Furthermore, devices based on FAPI with SDS exhibit enhanced stability, retaining 98% of their initial efficiency after 40 h of continuous illumination.

Pyranine Interaction with Amines in Micelles.

The fluorescence behavior of pyranine in anionic micellar system of sodium dodecyl sulphate was studied in the presence of selected amines. The amines included cyclopropylamine (CPA), ethylenediamine (EDA), benzylamine (BA), dibutylamine (DBA), cyclohexylamine (CHA), and polyethylenediamine (PEDA). All the studied amines quenched the intensity of pyranine. Study was performed in 0.05M and 0.1M SDS. The thermodynamic parameters were determined in order to understand the quenching of pyranine by the studied amines. Change in Gibbs free energy and quenching was found higher in 0.05M SDS concentration and was found lower when SDS concentration was increased to 0.1M SDS. Pyranine quenching by the amines studied were treated with an extended Stern-Volmer equation that produced the Stern-Volmer constant ([Formula: see text]). Binding constant (Kb), number of binding stoichiometry (n) and Gibbs free energy change (ΔGbinding) were found higher for lower surfactant concentration as compare to higher surfactant concentration. More negative (-ve) the Gibbs free energies more will be the quenching, higher will be the sensitivity and vice versa. The Gibbs free energies for all the studied amines were found in the order as cyclopropylamine > ethylenediamine > benzylamine > dibutylamine > cyclohexylamine > polyethylenediamine. Fluorescence quenching of pyranine by amines in aqueous SDS is reproducible and is useful for the determination of amines in environmental samples.

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

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

Effect of complex ionic liquid additives on the formation kinetics and separation efficiency of binary gas mixture hydrates

Rising carbon emissions worldwide have necessitated the discovery of efficient CO2 separation and capture technologies. Owing to their good CO2 selectivity, imidazolium-based ionic liquids (ILs) have been used as additives in hydrate-based gas separation (HBGS) technologies. Sodium dodecyl sulfate (SDS) can notably improve the rate of hydrate formation when used as a surfactant. However, the synergistic effect of imidazolium-based ILs and SDS remains unknown. This study aimed at investigating the synergistic effect of imidazolium-based ILs and SDS on the hydrate formation kinetics of binary gas mixtures of CO2/N2 at different temperatures. The carbon capture and storage capacity was determined, and HBGS was evaluated using pure imidazolium-based IL 1-butyl-3-methylimidazolium octyl sulfate ([BMIM] [OS]) and composites of IL and SDS as additives. Compared with pure water, [BMIM] [OS] effectively promoted gas hydrate formation and increased CO2 consumption by 107.9 %. The maximum CO2 separation factor was obtained at 273.15 K, and the mixed additive significantly enhanced gas consumption by 11.1 %. X-ray diffraction and Raman spectroscopy analysis indicated that the hydrate samples were type I structural hydrates and that [BMIM] [OS] improved the mass transfer process. The results of this study provide a theoretical basis for CO2 gas separation and capture.

Polymer and micellar catalysis in d-fructose oxidation by imidazolium fluorochromate: A kinetic and mechanistic study

This work investigated the oxidation of d-fructose using imidazolium fluorochromate (IFC) as an oxidant and analyzed how sodium dodecyl sulfate (SDS) and polyethylene glycol (PEG-400) affected the reaction kinetics. The process exhibited a unit-order dependence on IFC, d-fructose, and perchloric acid concentration. Perchloric acid was the primary source of hydrogen ions in the reaction mixture. The stoichiometry of the reaction indicated that 3 mol of d-fructose requires 4 mol of IFC. Acrylonitrile, a radical-generating species, did not impact the reaction rate, indicating the absence of a free radical intermediate. The reaction rate decreases as the Mn (II) ions concentration increases, suggesting the involvement of Cr (IV) species in the reaction. The dielectric value of the reaction medium (D) had an inverse effect on the rate, and the outcomes were consistent with the Amis (log k1 and 1/D) and Kirkwood plots (log k1 and (D-1/2D+1)), indicating the presence of dipole-dipole interactions in the process. SDS and PEG-400 catalyzed the reaction. The reaction showed significant catalysis before reaching the critical micelle concentration (CMC). However, the observed rate constants stabilized at higher SDS concentrations exceeding the CMC. Piszkiewicz's cooperativity model was employed to describe the surfactant catalysis, while the Benesi-Hildebrand equation was utilized to explain polymer catalysis. The activation parameters are ΔH† = 44.3 ± 1.3 kJ mol−1, and ΔS† = −133.4 ± 4.3 J K−1 mol−1. The products of the reaction have been identified by spectral analysis as d-arabinoniclactone and formic acid. The formation of an ester complex followed by its decomposition was proposed as the rate-limiting step in the proposed mechanistic reaction pathway.

What are the main proteins in the hemolymph of Haemaphysalis flava ticks?

BackgroundHaemaphysalis flava is a notorious parasite for humans and animals worldwide. The organs of H. flava are bathed in hemolymph, which is a freely circulating fluid. Nutrients, immune factors, and waste can be transported to any part of the body via hemolymph. The main soluble components in hemolymph are proteins. However, knowledge of the H. flava proteome is limited.MethodsThe hemolymph was collected from fully engorged H. flava ticks by leg amputation. Hemolymph proteins were examined by both blue native polyacrylamide gel electrophoresis (BN-PAGE) and sodium dodecyl sulfate PAGE (SDS-PAGE). Proteins extracted from the gels were further identified by liquid chromatography–tandem mass spectrometry (LC–MS/MS).ResultsTwo bands (380 and 520 kDa) were separated from tick hemolymph by BN-PAGE and were further separated into four bands (105, 120, 130, and 360 kDa) by SDS-PAGE. LC–MS/MS revealed that seven tick proteins and 13 host proteins were present in the four bands. These tick proteins mainly belonged to the vitellogenin (Vg) family and the α-macroglobulin family members. In silico structural analysis showed that these Vg family members all had common conserved domains, including the N-terminus lipid binding domain (LPD-N), the C-terminus von Willebrand type D domain (vWD), and the domain of unknown function (DUF). Additionally, two of the Vg family proteins were determined to belong to the carrier protein (CP) by analyzing the unique N-terminal amino acid sequences and the cleaving sites.ConclusionThese findings suggest that the Vg family proteins and α-macroglobulin are the primary constituents of the hemolymph in the form of protein complexes. Our results provide a valuable resource for further functional investigations of H. flava hemolymph effectors and may be useful in tick management.

Surfactant-Mediated Microalgal Flocculation: Process Efficiency and Kinetic Modelling

Microalgae are a valuable source of lipids, proteins, and pigments, but there are challenges in large-scale production, especially in harvesting. Existing methods lack proven efficacy and cost-effectiveness. However, flocculation, an energy-efficient technique, is emerging as a promising solution. Integrating surfactants enhances microalgal harvesting and disruption simultaneously, reducing processing costs. This study investigated cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), and sodium dodecyl sulphate (SDS) for harvesting Tetraselmis sp. strains (75LG and 46NLG). CTAB exhibits superior results, with 88% harvesting efficiency at 1500 and 2000 mg L−1 for 75LG and 46NLG, respectively, for 60 min of sedimentation—thus being able to reduce the operating time. Beyond evaluating harvesting efficiency, our study explored the kinetics of the process; the modified Gompertz model led to the best fit. Furthermore, the largest kinetic constants were observed with CTAB, thus highlighting its efficacy in optimising the microalgal harvesting process. With the incorporation of the suggested enhancements, which should be addressed in future work, CTAB could hold the potential to optimise microalgal harvesting for cost-effective and sustainable large-scale production, eventually unlocking the commercial potential of microalgae for biodiesel production.

Ecofriendly micellar mediated spectrofluorimetric method for ultrasensitive quantification of the antiparkinsonian drug safinamide in pharmaceutical formulation and spiked human plasma

A novel, highly sensitive and eco-friendly micellar-mediated spectrofluorimetric method was developed and validated for the determination of the novel antiparkinsonian drug safinamide mesylate in the presence of its related precursor impurity, 4-hydroxybenzaldehyde. The proposed approach relies on increasing the inherent fluorescence emission at 296 nm of safinamide, by forming hydrogen bonds between the mentioned drug and sodium dodecyl sulfate in the micellar system using 0.1 N HCl as a solvent, following excitation at 226 nm. A thorough investigation was conducted into the experimental factors affecting spectrofluorimetric behavior of the studied drug. A linearity plot of safinamide over the concentration range of 10.0–1000.0 ng/mL against the relative fluorescence intensities was established. The proposed method demonstrated excellent sensitivity down to the nano-gram level with detection and quantitation limits of 1.91 and 5.79 ng/mL, respectively. The studied drug was effectively determined in Parkimedine® Tablets. Furthermore, the proposed method allows for ultrasensitive quantification of safinamide in spiked human plasma, with satisfactory percentage recovery (98.97–102.28%). Additionally, the greenness assessment using the advanced green certificate classification approach, the complementary green analytical procedure index (Complex-GAPI), and the analytical GREEness metric approach (AGREE), along with the practicality check using the Blue Applicability Grade Index in addition to the all-inclusive overall whiteness evaluation using the RGB-12 model were carried out. The outcomes demonstrated the effectiveness and whiteness of the proposed technique. Clearly, the suggested approach has the advantages of being simple, requiring no pretreatment steps, and relying solely on direct measuring procedures.

GLUTENIN DIVERSITY OF FLOUR WHEAT (Triticum aestivum L.) FOR COOKIE QUALITY IN MEXICO

Glutenins are high- and low-molecular-weight proteins (HMW-G and LMW-G). They play a determining role in genetic improvement to define industrial quality in flour wheat, so understanding their variability is necessary for directing selection toward a specific quality. The objective of this research was to determine the diversity of HMW-G and LMW-G alleles of genotypes from the flour wheat breeding program of the National Institute of Forestry, Agricultural, and Livestock Research (INIFAP) useful for cookie quality. Twenty-five genotypes were used, including six Mexican cookie varieties, as well as 21 genotypes introduced from an international collection of accessions from the International Maize and Wheat Improvement Center (CIMMYT). HMW-G and LMW-G were identified based on their separation on polyacrylamide gels in the presence of sodium dodecyl sulfate. For HMW-G, the 2* variant in Glu-A1 was the most frequent variant for the trial and introduction nursery, with more than 80 %. At the Glu-B1 locus, the 7+9 and 7 variants were the most frequent, with 60 and 38.1 % in trial and nursery, respectively. For Glu-D1, the 2+12 variant was the most frequent in the trial with 64 %, and 5+10 with 85.7 % in nursery. The latter allele favors baking quality. For the Glu-A1 and Glu-D1 loci, it is necessary to introduce genotypes with null alleles or with the 2+121 variant in Glu-D1 associated with cookie quality. For the highest-frequency variants of LMW-G, c in Glu-A3, h in Glu-B3, and b in Glu-D3 are associated with baking quality. With the aforementioned, it is concluded that there is a low frequency and little variation in useful alleles of HMW-G and LMW-G for cookie quality in the introduced accessions analyzed, implying that new genetic sources that favor it should be explored.

Effect of macromolecular sodium polyacrylate on the molecular structure and properties of polyvinyl butyral synthesized deep eutectic solvent

AbstractSodium polyacrylate (PAAS), a macromolecule surfactant, was employed in the synthesis of polyvinyl butyral (PVB) using a deep eutectic solvent (DES) as the catalyst. Contrasting with traditional low molecular weight surfactants, scanning electron microscopy (SEM) analysis has confirmed that PAAS enhanced the uniformity of PVB granules while minimizing PAAS residuals, facilitating the production of films with superior transparency and resistance to yellowing. Investigations into the effects of varying molecular weights, dosages of PAAS, and aging times on the properties of PVB revealed that an increase in PAAS molecular weight correspondingly raised the acetal degree (AD) of PVB without affecting the molecular weight of PVB itself. Furthermore, yhe dosage of PAAS significantly impacted the properties of PVB, whereas aging time exhibits minimal influence on the AD of PVB. 1H‐NMR analysis indicated that the structural stability of PVB is due to the dominance of meso acetal isomers, which improved its mechanical properties when synthesized with PAAS3 (molecular weight 60,000 g/mol), containing 91.5% hexamethylene cycloacetal. Notably, compared to PVB synthesized using sodium dodecyl sulphate (SDS), PVB synthesized with PAAS3 exhibits superior mechanical properties, with significantly improved tensile strength and elongation. This phenomenon is further elucidated by SEM images. A comparison between the optimized self‐made PVB and commercial PVB shows that the self‐made PVB performs better, highlighting the critical role of macromolecular PAAS in enhancing the structure and mechanical properties of PVB.

Phenanthridium‐based conjugated probe for selective detection of anionic surfactant

AbstractThe quaternary ammonium complex of (2‐(methylthio)indeno[1,2,3‐gh]phenanthridin‐1‐yl)(phenyl)methanone (QAC) has been employed as a new and simple fluorescence sensor for detection of the anionic surfactant; sodium dodecyl sulphate (SDS), through fluorescence light‐up. The generation of electrostatic interaction and associated intermolecular arrangement between the probe and anionic surfactant is responsible for the fluorescence enhancement and subsequent selectivity towards the anionic surfactant. Concurrently, the probe was unaltered by the presence of cationic and non‐ionic systems. Utilizing this property, we were able to construct a facile and efficient method for the detection of anionic surfactants, featuring LOD values up to 1.1 μM concentrations in dimethylsulfoxide solvent. The light‐up detection was also confirmed via lifetime studies, with superior increments in average lifetime decay values (0.33–2.7 ns). The practical/real‐time applications of probe QAC as a sensor have also been investigated and successfully demonstrated via its ability to detect anionic surfactants from commercially available home usage products.

Characterization of a thermostable protease from Bacillus subtilis BSP strain

This study used conservative one variable-at-a-time study and statistical surface response methods to increase the yields of an extracellular thermostable protease secreted by a newly identified thermophilic Bacillus subtilis BSP strain. Using conventional optimization techniques, physical parameters in submerged fermentation were adjusted at the shake flask level to reach 184 U/mL. These physicochemical parameters were further optimized by statistical surface response methodology using Box Behnken design, and the protease yield increased to 295 U/mL. The protease was purified and characterized biochemically. Both Ca2+ and Fe2+ increased the activity of the 36 kDa protease enzyme. Based on its strong inhibition by ethylenediaminetetracetate (EDTA), the enzyme was confirmed to be a metalloprotease. The protease was also resistant to various organic solvents (benzene, ethanol, methanol), surfactants (Triton X-100), sodium dodecyl sulfate (SDS), Tween 20, Tween-80 and oxidants hydrogen per oxide (H2O2). Characteristics, such as tolerance to high SDS and H2O2 concentrations, indicate that this protease has potential applications in the pharmaceutical and detergent industries.

The impact of sodium lauryl sulfate on hydrogen evolution reaction in water electrolysis

This study confirms the sodium lauryl sulfate (SLS) surfactant is effective to enhance water electrolysis performance especially when combined with NaCl. The water electrolysis experiment on different concentrations of SLS and SLS-NaCl mixture electrolyte were performed. The results indicate the presence of NaCl is more effective to enhance the SLS containing electrolyte performance instead of adding more SLS concentration. More SLS concentration is effective to enhance hydrogen evolution reaction (HER) when NaCl is added. The effectiveness of NaCl is shown by the order of final HER SLS 0.5 M + NaCl 3.9212 × 10−7 Mol. L−1, SLS 0.3 M + NaCl 3.8789 × 10−7 Mol. L−1, and, SLS 0.5 M 3.6758 × 10−7 Mol. L−1. The SLS creates positively charged micelles which increases ion mobility and HER. The NaCl accelerates the HER due to the formation of smaller ion clusters that react more quickly with the cathode. Therefore, this study reveals the mechanism of electrolysis enhancement by surfactant mixed electrolyte.

Itch and Pain Behaviors in Irritant Contact Dermatitis Produced by Sodium Lauryl Sulfate in Mice

Irritant contact dermatitis (ICD) is a nonspecific skin inflammation caused by irritants, leading to itch and pain. We tested whether differential responses to histamine-dependent and -independent pruritogens can be evoked in ICD induced by sodium lauryl sulfate (SLS). An ICD mouse model was established with 5% SLS in acetone versus a vehicle topically applied for 24 h to the cheek. Site-directed itch- and pain-like behaviors, occurring spontaneously and in response to mechanical, thermal, and chemical stimuli (histamine, ß-alanine, BAM8-22, and bradykinin) applied to the cheek, were recorded before (day 0) and after irritant removal (days 1, 2, 3, and 4). Skin inflammation was assessed through visual scoring, ultrasound, and measurements of skin thickness. SLS-treated mice exhibited hyperalgesia-like behavior in response to mechanical and heat stimuli on day 1 compared to the controls. SLS mice exhibited more spontaneous wipes (pain) but not scratching bouts (itch) on day 1. Pruritogen injections caused more scratching but not wiping in SLS-treated mice compared to the controls. Only bradykinin increased wiping behavior compared to saline. SLS-treated mice developed noticeable erythema, scaling, and increased skin thickness on days 1 and 2. SLS induced cutaneous inflammation and behavioral signs of spontaneous pain and itching, hyperalgesia to mechanical and heat stimuli and a chemical algogen, and enhanced itch response to pruritogens. These sensory reactions preceded the inflammation peak and lasted up to two days.

Influence of supramolecular self-assembly of oppositely charged Co- and Sn-porphyrins on the their spectral-luminescent properties in aqueous and aqueous micellar media of ionic surfactants

The processes of supramolecular self-assembly of Co(III)-meso-tetra-(4-trimethylammoniophenyl)porphyrin (CoP) and bis-(4-(1-imidazolyl)-phenol)-Sn(IV)-meso-tetra(4-sulfophenyl)porphyrin (SnP) were studied using electronic, steady-state and time-resolved fluorescence, one- and two-dimensional NMR spectroscopy in aqueous media. The main product of such interaction at a 2:1 M ratio of Co and Sn porphyrinates was found to be supramolecular porphyrin trimer CoP–SnP–CoP formed due to donor-acceptor, hydrogen and electrostatic interactions. The distinctive features of the resulting trimer are: significant distortion of the spatial structure of the Co-porphyrin fragments and strong quenching of the Sn-porphyrin macrocycles fluorescence (by 70 %). The distortion of the spatial structure of Co porphyrinates is in good agreement with the quantum chemical calculations as well as with the electronic and NMR spectroscopy data. Adding surfactants – both anionic (Cetyltrimethylammonium bromide - CTAB) and cationic (Sodium dodecyl sulfate - SDS) – even at concentrations below the critical micelle concentration (CMC) leads to the supramolecular trimer destruction. In solutions of ionic surfactants, supramolecular trimer destruction is caused by the interaction of either the peripheral macrocycles of the trimer (CoP) with SDS micelles (premicellar aggregates) or the central macrocycle (SnP) with CTAB micelles (premicellar aggregates). This process is prolonged and the rate of trimer destruction depends on the surfactant concentration. The sizes of the CTAB and SDS micelles solubilized with porphyrin molecules were established by dynamic light scattering. In general, surfactant additions lead to an increase in the SnP fluorescence at least due to the destruction of the supramolecular self-assembly, as well as due to the changes in the state of its microenvironment.

Adsorptive flotation of cesium radionuclides from aqueous solutions using rice straw agriculture waste as a low-cost and eco-friendly adsorbent

ABSTRACT The removal of caesium radionuclides from an aqueous solution by flotation using rice straw (RS) agricultural waste as a low-cost and eco-friendly adsorbent in the presence of potassium ferrocyanide (KFC) was investigated. The influence of many adsorption parameters and flotation was evaluated on the removal efficiency of 137Cs. The adsorption results demonstrated that the concerned radionuclide was efficiently removed in the presence of 2 × 10−4 mol/L KFC using 10 g/L RS at pH ≥ 7. The double exponential kinetic model and the Freundlich model were the best models for fitting the adsorption kinetic and isotherm data, respectively. The maximum adsorption capacity of RS, calculated from the Langmuir model, was 280.405 mg/g. after being transferred to the flotation cell, 137Cs loaded onto ferrocyanide-modified rice straw (FMRS) was successfully floated at pH 7 using 3 × 10−4 mol/L cetyltrimethylammonium bromide (CTAB) surfactant in the presence of 4% ethanol. Removal percentages of 56% and > 99.5% were achieved for 137Cs-loaded FMRS within 5 min using sodium dodecyl sulphate (SDS) and CTAB, respectively. The results obtained in this investigation indicate the efficiency of the suggested strategy and hence its applicability for the removal of 137Cs+ from radioactive liquid wastes.

Effect of Surfactants on the Synthesis and Dissociation of Gas Hydrates

The synthesis and dissociation of methane hydrate and carbon dioxide hydrate were studied. Nonflammable gas hydrates can be used to extinguish flames in confined spaces. To increase the extinguishing efficiency, it is necessary to increase the dissociation rate (gas release rate) by using surfactant. The work investigates gas hydrates synthesized using sodium dodecyl sulfate (SDS). Experimental studies were carried out in wide ranges of surfactant concentration, the number of the stirrer revolutions and the initial water volume. To achieve the maximum rate of synthesis and dissociation, optimization of the specified parameters was performed. The influence of the key parameters on the dissociation rate was investigated experimentally and theoretically. The novelty of the work lies in solving a complex of interrelated tasks on the synthesis and dissociation of gas hydrate. It is shown that in order to achieve the maximum dissociation rate of carbon dioxide hydrate, it is necessary to optimize the following parameters: the diameter of the particles and their porosity, the porosity of the layer and the external heat flux.

Effect of Surfactants on the Synthesis and Dissociation of Gas Hydrates

The synthesis and dissociation of methane hydrate and carbon dioxide hydrate were studied. Nonflammable gas hydrates can be used to extinguish flames in confined spaces. To increase the extinguishing efficiency, it is necessary to increase the dissociation rate (gas release rate) by using surfactant. The work investigates gas hydrates synthesized using sodium dodecyl sulfate (SDS). Experimental studies were carried out in wide ranges of surfactant concentration, the number of the stirrer revolutions and the initial water volume. To achieve the maximum rate of synthesis and dissociation, optimization of the specified parameters was performed. The influence of the key parameters on the dissociation rate was investigated experimentally and theoretically. The novelty of the work lies in solving a complex of interrelated tasks on the synthesis and dissociation of gas hydrate. It is shown that in order to achieve the maximum dissociation rate of carbon dioxide hydrate, it is necessary to optimize the following parameters: the diameter of the particles and their porosity, the porosity of the layer and the external heat flux.