Including Sodium Dodecyl Sulfate Research Articles

Delicate Analysis of Interacting Proteins and Their Assemblies by Flow Field-Flow Fractionation Techniques.

We study the efficiency of several asymmetrical flow field-flow fractionation (AF4) techniques to investigate self-associating wheat gluten proteins. We compare the use of a denaturing buffer including sodium dodecyl sulfate (SDS) and a mild chaotropic solvent, water/ethanol, as the eluent, on a model gluten sample. Through a thorough analysis of the data obtained from coupled light scattering detectors and with the identification of molecular composition of the eluted protein, we evidence coelution events in several conditions. We show that the focus step used in conventional AF4 with the SDS buffer leads to the formation of aggregates that coelute with monomeric proteins. By contrast, a frit-inlet device enables the fractionation of individual wheat proteins in the SDS buffer. Interestingly conventional AF4, using water/ethanol as eluent, is an effective method for fractionating gluten proteins and their complex dynamic assemblies, which involve weak forces and are composed of both monomeric and polymeric proteins.

Allergenicity Modulation of Casein with the Modifications of Linearization, Cross-Linking, and Glycation via the Regulation of Th1/Th2 Homeostasis.

Casein (CN) is the primary allergenic protein in cow's milk, contributing to the worldwide escalating prevalence of food allergies. However, there remains limited knowledge regarding the effect of structural modifications on CN allergenicity. Herein, we prepared three modified CNs (mCN), including sodium dodecyl sulfate and dithiothreitol-induced linear CN (LCN), transglutaminase-cross-linked CN (TCN), and glucose-glycated CN (GCN). The electrophoresis results indicated widespread protein aggregation among mCN, causing variations in their molecular weights. The unique internal and external structural characteristics of mCN were substantiated by disparities in surface microstructure, alterations in the secondary structure, variations in free amino acid contents, and modifications in functional molecular groups. Despite the lower digestibility of TCN and GCN compared to LCN, they significantly suppressed IL-8 production in Caco-2 cells without significantly promoting their proliferation. Moreover, GCN showed the weakest capacity to induce LAD2 cell degranulation. Despite the therapeutic effect of TCN, GCN-treated mice displayed the most prominent attenuation of allergic reactions and a remarkably restored Th1/Th2 imbalance, while LCN administration resulted in severe allergic phenotypes and endotypes in both cellular and murine models. This study highlighted the detrimental effect of linear modifications and underscored the significance of glycation in relation to CN allergenicity.

Electrostatic self-assembly effect of Fe3O4 nanoparticles on performance of carbon nanotubes in cement-based materials

Abstract The beneficial effect of carbon nanotubes (CNTs) to enhance the electrical conductivity and piezoresistivity of cement-based materials was highly contingent upon its dispersion. To achieve an appropriate dispersion of CNTs, ultrasonication, high-speed stirring, and chemical dispersion were commonly used, which raises the risk of structural damage of CNTs caused by the excessive energy. In this study, electrostatic self-assembly of Fe3O4 nanoparticles on CNTs was employed to efficiently disperse CNTs. To optimize the dispersion effect of conductive fillers in cement paste, the mix proportions including sodium dodecyl sulfate (SDS) concentration, CNTs concentration, and Fe3O4/CNTs ratios were adjusted. The dispersion degree and electrical property were evaluated by UV–vis absorption and zeta potential. In addition, the effect of self-assembled conductive filler dosage on the electrically conductive property of cement pastes was examined. The results show that the occurrence of electrostatic self-assembly was proved by the change of zeta potential, and the grape-bunch structure was observed by transmission electron microscopy. Further, the optimal proportions of self-assembled conductive fillers were 0.20 wt% SDS concentration, 0.05 wt% CNTs concentration, and 1:1 Fe3O4/CNTs ratio. The self-assembled conductive filler dosage between 0.02 and 0.10 wt% can effectively improve the electrical conductivity of cement paste with up to 68% reduction of resistivity.

Electrophoretic Methods for Identifying the Species of Seafood and Its Derivatives

The identification of the species of seafood and their products, whether they are fresh or cooked, is one of the key concerns of food regulations in many countries that have a significant intake of seafood. In point of fact, a commercial fraud happens when a species that is less value is intentionally substituted for a species that is more valuable, and a sanitary fraud takes place when a product that is potentially harmful is introduced into the market. A primary responsibility of veterinary inspection of seafood products is the detection of harmful species with the aim of removing them from the retail trade (Council Directive 91/493/ECC). Two efficient methods for seafood species identification are molecular biology methods and protein electrophoresis. Classic electrophoretic methods have been used for a long time to authenticate seafood; they are simple, accurate, and inexpensive compared to molecular biological methods, which are the wave of the future in food safety labs. The purpose of this article is to offer an overview of the electrophoretic methods commonly used to identify different species of seafood, including sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE), native or urea-isoelectric focusing electrophoresis (IEF), two-dimensional electrophoresis (2-DE), and capillary electrophoresis (CE).

A Plasmid-Borne Gene Cluster Flanked by Two Restriction-Modification Systems Enables an Arctic Strain of Psychrobacter sp. to Decompose SDS.

The cold-adapted Psychrobacter sp. strain DAB_AL62B, isolated from ornithogenic deposits on the Arctic island of Spitsbergen, harbors a 34.5 kb plasmid, pP62BP1, which carries a genetic SLF module predicted to enable the host bacterium to metabolize alkyl sulfates including sodium dodecyl sulfate (SDS), a common anionic surfactant. In this work, we experimentally confirmed that the pP62BP1-harboring strain is capable of SDS degradation. The slfCHSL genes were shown to form an operon whose main promoter, PslfC, is negatively regulated by the product of the slfR gene in the absence of potential substrates. We showed that lauryl aldehyde acts as an inducer of the operon. The analysis of the draft genome sequence of the DAB_AL62B strain revealed that the crucial enzyme of the SDS degradation pathway-an alkyl sulfatase-is encoded only within the plasmid. The SLF module is flanked by two restriction-modification systems, which were shown to exhibit the same sequence specificity. We hypothesize that the maintenance of pP62BP1 may be dependent on this unique genetic organization.

Influencing effects of different types of dispersants on the permeability levels of Coal-Bearing propped fractures in coalbed methane reservoirs

This study investigated how to effectively discharge deposited pulverized coal particles in coal-bearing propped fractures and improve the permeability levels of the propped fractures in order to enhance coalbed methane production. Four types of dispersants were selected to carry out wettability and permeability tests, including sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), dodecyl dimethyl betaine (BS-12), and alkyl poly glycoside dodecyl glucoside (APG). The results showed reductions in surface tension of 63.71 to 69.75 %, and reductions in contact angles of 40.08 to 60.46 %, when compared with water injections alone. In addition, under the same closure pressure conditions, the dispersant solutions had increased the permeability of the propped fractures by 76.67 to 123.34 % when compared with that of the water injections, and the pulverized coal discharge rates were increased by 1.44 to 2.41 times. The decreases in closure stress also contributed to the enhancement of the permeability of the propped fractures, with increases of between 11.24 and 29.18 % observed. This study found that for the four tested dispersants, the order of the effective wetting of the pulverized coal particles and enhancement of the permeability of the propped fractures were (from strong to weak) as follows: SDS > BS-12 > APG > SDBS. Among the tested dispersants, the 6 mmol/L SDS dispersant solution was found to be the most effective for improving the wettability of the pulverized coal particle surfaces and achieved the highest permeability improvement of the propped fractures.

Pipette-Free and Fully Integrated Paper Device Employing DNA Extraction, Isothermal Amplification, and Carmoisine-Based Colorimetric Detection for Determining Infectious Pathogens.

A pipette-free and fully integrated device that can be used to accurately recognize the presence of infectious pathogens is an important and useful tool in point-of-care testing, particularly when aiming to decrease the unpredictable threats posed by disease outbreak. In this study, a paper device is developed to integrate the three main processes required for detecting infectious pathogens, including DNA extraction, loop-mediated isothermal amplification (LAMP), and detection. All key reagents, including sodium dodecyl sulfate (SDS), NaOH, LAMP reagents, and carmoisine, are placed on the paper device. The paper device is operated simply via sliding and folding without using any bulky equipment, and the results can be directly observed by the naked eye. The optimized concentrations of sodium dodecyl sulfate (SDS), sodium hydroxide (NaOH), and carmoisine were found to be 0.1%, 0.1 M, and 0.5 mg/mL, respectively. The paper device was used to detect Enterococcus faecium at concentrations as low as 102 CFU/mL within 60 min. Also, E. faecium spiked in milk was successfully detected using the paper device, demonstrating the feasible application in real sample analysis.

Photonic Crystal Reflectors with Ultrahigh Sensitivity and Discriminability for Detecting Extremely Low-Concentration Surfactants.

Developing a facile, intuitive, ultrahigh-sensitive sensor to detect harmful substances in water is critical. Here, an ultrahigh-sensitive sensor is fabricated using a quaternized lamellae-structured polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) block copolymer (BCP), capable of detecting the heavily used surfactants including sodium dodecyl sulfate (SDS) and sodium methyl sulfate (SMS) through direct visualization of the structural color change. Two distinct detecting mechanisms, including unexpected blue-shifting and red-shifting reflectance wavelengths, are found for low and high concentrations of the SDS surfactant, respectively, due to concentration-dependent compatibility between the quaternized P2VP (QP2VP) block chains and SDS molecules. As the SDS concentration is low (0-1 mM), the QP2VP chains undergo the counter anionic exchange with the hydrophobic alkyl chains of the SDS, resulting in a blue shift toward colorlessness. In contrast, as the SDS concentration is high (>1 mM), the nanoaggregation of the SDS molecules in the layered QP2VP microdomain leads to enhanced hydration nature and increased lamellar periodicity with the red-shifting reflectance wavelength. In contrast, SMS with weaker hydrophobicity results in unchanged and red-shifting reflectance wavelengths at low and high concentrations. Inspired by this, detecting the extremely low-concentration SDS surfactant (0.01 mM) by direct visualization is achieved. The structural color change for surfactant detection also exhibits excellent reversibility and discriminability, providing a straightforward method of detecting anionic surfactants.

Effect of graphite on the self-sensing properties of cement and alkali-activated fly ash/slag based composite cementitious materials

This study investigated the self-sensing performances of cement and alkali-activated fly ash/slag (AAFS) systems with graphite powders as a conductive filler. Graphite powders must be evenly dispersed through the cement-based and AAFS matrices to obtain an adequate electrical response. The effects of graphite fineness on the fluidity, mechanical, rheological behavior, and cement hydration of cement paste were investigated. The finer graphite was found to have less effect on the mechanical property but seriously damaged the workability. Therefore, this research explored using four surfactants including sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), sodium salt of polynaphthalene sulphonic acid (NNO), and Triton X-100 (TX100) as dispersing agents for fine graphite in cement. The combination of NNO and TX100 was found to be the ideal admixture for improving the fluidity of graphite-containing cementitious materials. Furthermore, cement- and AAFS-based composites were produced with the graphite dispersions, and several tests such as electrical impedance spectroscopy (EIS), energy dispersive X-Ray (EDX) map analysis, mercury intrusion Porosimeter (MIP), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) were used to investigate their intrinsic characteristic. The results concluded that AAFS had a better conductivity than cement due to the higher porosity in the range of very small pores (<6 nm) and the higher ion concentration contribution. Finally, the self-sensing behavior of the mortars was investigated under cyclic loading, and the self-sensing mechanism was proposed. The sensing properties of graphite composite mortars under compression load can be attributed to the combination of ionic, contact, and tunneling conduction.

The Rheological Properties and Strength Characteristics of Cemented Paste Backfill with Air-Entraining Agent

Clogging pipelines is one of the most common and urgent problems in paste backfill mining. The aim of the present study was to solve the problem of pipe blockage in paste backfill mining. In this paper, paste mixed with coal gangue, fly ash, cement, and additives is used to investigate the influence of three air-entraining agents (AEAs) (including sodium dodecyl sulfate (SDS), triterpene saponin (SJ), and sodium abietate (SA)) on the flow characteristics and strength characteristics of the paste. A series of relevant tests was conducted on the paste, such as air content experiments, slump and expansion experiments, viscosity and yield stress tests, and the uniaxial compressive strength (UCS) test. The results show that the air content of the paste increases with increasing AEA content, but the increase is limited and reaches a maximum at 0.9 AEA. The slump of the paste increased by up to 10–13 mm, and expansion increased by up to 66–130 mm compared to the paste without AEA. The viscosity of the paste decreased by up to 0.13–0.20 Pa·s, and the yield stress decreased by 81.47%–93.7% of the original. The strength of the paste was also reduced, and after 28 days of curing, the strength was reduced by up to 1–1.2 MPa. Taking into account the strength requirement of 3 MPa for the paste from the Linxi mine, it was considered that the dosage of 0.9 B was a good choice, as it could better change the flowability of the paste and reduce the pipeline transportation resistance and transportation energy consumption. At the same time, the strength was also acceptable. The study in this paper can provide a reference for performance studies of pastes mixed with coal gangue, fly ash, cement, and additives as materials.

Amorphous S-doped NixCo3-xO4 for high-performance asymmetric supercapacitors

Amorphous S-doped NixCo3-xO4 materials were successfully synthesized using a facile co-precipitation method through changing additive in a mixed solution. As-prepared amorphous S-doped NixCo3-xO4 exhibit different Ni/Co ratio, O/S ratio, morphology and structure when a mixed solution including sodium dodecyl sulfate, without additive, or containing glycine. S-doped NixCo3-xO4 prepared with a mixed solution excluding additive (denoted as NixCo3-xO4-ySy-2) exhibits remarkable supercapacitive performance due to optimum Ni/Co ratio, minimum O/S ratio, proper morphology and structure. NixCo3-xO4-ySy-2 delivers a specific capacitance of 1335 F g−1 at 0.5 A g−1 and a ultra-high specific capacitance retention of 68.7% even at 16 A g−1, demonstrating high specific capacitance and good rate capability. Moreover, NixCo3-xO4-ySy-2 shows an initial specific capacitance retention of 80.8% after 2000 cycles, implying superior cycling stability. The assembled asymmetric supercapacitor (ASC) based on NixCo3-xO4-ySy-2 as the positive electrode and AC as the negative electrode achieves outstanding energy density of 31.87 Wh kg−1 at a power density of 900 W kg−1. The specific capacitance retention of the ASC is up to 90.2% after 2000 cycles, exhibiting excellent cycling stability. This study shows a promising electrode for supercapacitors device and provides an effective strategy for design of high-performance supercapacitor electrode materials.

Influences of different co-promoters on the mixed methane hydrate formation with salt water at moderate conditions

Effects of co-promoters on the mixed methane-THF hydrate formation in the presence of 3.5 wt% NaCl and 5.56 mol% THF solution were investigated at 8 MPa and 288.2 K in an unstirred reactor. The addition of NaCl resulted in the two-step hydrate formation, and it is the first stage that adversely affected the hydrate formation rate. However, the final gas uptake in this system was similar to that without NaCl. The synergistic effects on the kinetic promotion by adding a co-promoter including sodium dodecyl sulfate (SDS) and amino acids (valine, leucine, and methionine) were then studied. The results showed that the addition of the co-promoters reduced the induction time, minimized the length of the first stage formation, and increased the hydrate formation rate. Moreover, the induction time and the length of the first stage formation decreased along with the increase in the co-promoter concentration. However, the addition of SDS had the adverse effects by decreasing about half of the final gas uptake and the water to hydrate conversion for the system without SDS. Moreover, the addition of methionine resulted in the best performance as a kinetic promoter on the hydrate formation in the system with THF and NaCl. Up to 95 % of methane gas can be recovered from the hydrates formed with and without the co-promoters. The hydrate formation morphology illustrated the same pattern in all cases.

Using surfactants as matrix for the matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) of amino acids: Sodium dodecyl sulfate (SDS) and sodium octyl sulfate (SOS)

In the present study, the applicability of two surfactants including sodium dodecyl sulfate (SDS) and sodium octyl sulfate (SOS) as the matrix for the Matrix-Assisted Laser Desorption/Ionization (MALDI) of several amino acids (phenylalanine (Phe), valine (Val), proline (Pro), alanine (Ala), and tyrosine (Tyr)) is investigated. Also, the effect of the material of the repeller plate of the ionization part of the used time of flight (TOF) mass spectrometer on the spectral patterns of the amino acids is studied. Furthermore, the recorded MALDI spectra of amino acids are compared with their corresponding direct laser desorption/ionization (direct-LDI) TOF mass spectra. It is observed that the SDS is an appropriate matrix for the Na+ transfer to the Phe and Val amino acids, especially, when the Ag metal is selected as the material of the repeller plate. In this case, the peaks of the [M + Na]+ and [M-H + 2Na]+ species are considerably more intense compared to when the NaF salt is used as a Na+ source in the LDI of these amino acids. Unlike Phe and Val, the SDS is not a good matrix for the other selected amino acids. The decrease of the carbonic chain length of the surfactant on the MALDI spectrum of Phe is investigated and it is seen that the mentioned important peaks disappeared in the presence of SOS as the matrix. The density functional theory (DFT) calculation is employed to characterize the structure of [M + Na]+ and [M-H + 2Na]+ species and determine the interaction sites of amino acids for the Na+ attachment. Also, the change in standard Gibbs free energy (∆G°) of the M + Na+ → [M + Na]+ and [M + Na]+ + Na+ → [M-H + 2Na]+ + H+ reactions are calculated. Based on the values of ∆G°, the attachment of the first Na+ to the amino acid takes place in the gas phase while the attachment of the second one to [M + Na]+ is not a favorable process in the gas phase.

Dispersion of Carbon Nanotubes with "Green" Detergents.

Solubilization of carbon nanotubes (CNTs) is a fundamental technique for the use of CNTs and their conjugates as nanodevices and nanobiodevices. In this work, we demonstrate the preparation of CNT suspensions with “green” detergents made from coconuts and bamboo as fundamental research in CNT nanotechnology. Single-walled CNTs (SWNTs) with a few carboxylic acid groups (3–5%) and pristine multi-walled CNTs (MWNTs) were mixed in each detergent solution and sonicated with a bath-type sonicator. The prepared suspensions were characterized using absorbance spectroscopy, scanning electron microscopy, and Raman spectroscopy. Among the eight combinations of CNTs and detergents (two types of CNTs and four detergents, including sodium dodecyl sulfate (SDS) as the standard), SWNTs/MWNTs were well dispersed in all combinations except the combination of the MWNTs and the bamboo detergent. The stability of the suspensions prepared with coconut detergents was better than that prepared with SDS. Because the efficiency of the bamboo detergents against the MWNTs differed significantly from that against the SWNTs, the natural detergent might be useful for separating CNTs. Our results revealed that the use of the “green” detergents had the advantage of dispersing CNTs as well as SDS.

Characterization of a thermostable and solvent-tolerant laccase produced by Streptomyces sp. LAO.

Decaying wood samples were collected, and actinomycetes were isolated and screened for laccase production. The identity of the efficient laccase-producing isolate was confirmed by using a molecular approach. Fermentation conditions for laccase production were optimized, and laccase biochemical properties were studied. Based on the 16S rRNA gene sequencing and phylogenetic analysis, the isolate coded as HWP3 was identified as Streptomyces sp. LAO. The time-course study showed that the isolate optimally produced laccase at 84h with 40.58 ± 2.35 U/mL activity. The optimized physicochemical conditions consisted of pH 5.0, ferulic acid (0.04%; v/v), pine back (0.2g/L), urea (1.0g/L), and lactose (1g/L). Streptomyces sp. LAO laccase was optimally active at pH and temperature of 8.0 and 90°C, respectively, with remarkable pH and thermal stability. Furthermore, the enzyme had a sufficient tolerance for organic solvents after 16h of preincubation, with laccase activity > 70%. Additionally, the laccase maintained considerable residual activity after pretreatment with 100mM of chemical agents, including sodium dodecyl sulphate (69.93 ± 0.89%), ethylenediaminetetraacetic acid (93.1 ± 7.85%), NaN3 (96.28 ± 3.34%) and urea (106.03 ± 10.72%). The laccase's pH and thermal stability; and robust catalytic efficiency in the presence of organic solvents suggest its industrial and biotechnological application potentials for the sustainable development of green chemistry.

Effect of detergent type on the performance of liver decellularized extracellular matrix-based bio-inks

Decellularized extracellular matrix-based bio-inks (dECM bio-inks) for bioprinting technology have recently gained attention owing to their excellent ability to confer tissue-specific functions and 3D-printing capability. Although decellularization has led to a major advancement in bio-ink development, the effects of detergent type, the most important factor in decellularization, are still unclear. In this study, the effects of various detergent types on bio-ink performance were investigated. Porcine liver-derived dECM bio-inks prepared using widely used detergents, including sodium dodecyl sulfate (SDS), sodium deoxycholate (SDC), Triton X-100 (TX), and TX with ammonium hydroxide (TXA), were characterized in detail. SDS and SDC severely damaged glycosaminoglycan and elastin proteins, TX showed the lowest rate of decellularization, and TXA-based dECM bio-ink possessed the highest ECM content among all bio-inks. Differences in biochemical composition directly affected bio-ink performance, with TXA-dECM bio-ink showing the best performance with respect to gelation kinetics, intermolecular bonding, mechanical properties, and 2D/3D printability. More importantly, cytocompatibility tests using primary mouse hepatocytes also showed that the TXA-dECM bio-ink improved albumin secretion and cytochrome P450 activity by approximately 2.12- and 1.67-fold, respectively, compared with the observed values for other bio-inks. Our results indicate that the detergent type has a great influence on dECM damage and that the higher the dECM content, the better the performance of the bio-ink for 3D bioprinting.

Fabrication of Decellularized Engineered Extracellular Matrix through Bioreactor-Based Environment for Bone Tissue Engineering

Extracellular matrix (ECM)-contained grafts can be achieved by decellularization of native bones or synthetic scaffolds. Limitations associated with harvesting the native bone has raised interest in preparing in vitro ECM bioscaffold for bone tissue engineering. Here, we intend to develop an ECM-contained construct via decellularizing an engineered gelatin-coated β-tricalcium phosphate (gTCP) scaffold. In order to find an optimal protocol for decellularization of cell-loaded gTCP scaffolds, they were seeded with buccal fat pad-derived stem cells. Then, four decellularization protocols including sodium dodecyl sulfate, trypsin, Triton X-100, and combined solution methods were compared for the amounts of residual cells and remnant collagen and alteration of scaffold structure. Then, the efficacy of the selected protocol in removing cells from gTCP scaffolds incubated in a rotating and perfusion bioreactor for 24 days was evaluated and compared with static condition using histological analysis. Finally, decellularized scaffolds, reloaded with cells, and their cytotoxicity and osteoinductive capability were evaluated. Complete removal of cells from gTCP scaffolds was achieved from all protocols. However, treatment with Triton X-100 showed significantly higher amount of remnant ECM. Bioreactor-incubated scaffolds possessed greater magnitude of ECM proteins including collagen and glycosaminoglycans. Reseeding the decellularized scaffolds also represented higher osteoinductivity of bioreactor-based scaffolds. Application of Triton X-100 as decellularization protocol and usage of bioreactors are suggested as a suitable technique for designing ECM-contained grafts for bone tissue engineering.

Improved antifouling performance of a polyamide composite reverse osmosis membrane by surface grafting of dialdehyde carboxymethyl cellulose (DACMC)

Antifouling properties are considered to be essential to polyamide (PA) composite reverse osmosis (RO) membranes for their industrial applications. In this work, an antifouling material, dialdehyde carboxymethyl cellulose (DACMC), was prepared by the oxidation of carboxymethyl cellulose (CMC) and then grafted onto the surface of a nascent PA RO membrane to improve its antifouling properties. The results showed that DACMC grafting could endow the membrane with improved hydrophilicity, surface smoothness and NaCl retention, while the permeability was decreased slightly after DACMC grafting. The zeta potentials of the membrane could be adjusted by changing the DACMC concentration. In addition, three typical surfactants with various charge properties, including sodium dodecyl sulfate (SDS), polyoxyethylene octylphenol ether (OP-10) and cetyltrimethylammonium bromide (CTAB), were used as feed foulants to evaluate the antifouling property of membranes. The results showed that, for the anionic SDS and nonionic OP-10 surfactants, the modified membranes with more DACMC had better antifouling performance because the membrane hydrophilicity dominated the interaction between foulants and the membrane surface. For the cationic CTAB, however, the pristine membrane showed better antifouling performance than the modified membrane with low DACMC grafting concentrations (5 and 10 g/L). This difference was attributed to the stronger electrostatic adsorption between the cationic CTAB and the modified membranes with more negative charges. The modified membrane with high DACMC grafting concentrations (20 g/L) exhibited the best antifouling performance for all the surfactants thanks to its high hydrophilicity and low negative charge. Therefore, the charge and hydrophilic properties of the RO membrane must be designed rationally to enhance the antifouling performance of the RO membrane when treating surfactant-containing wastewater.

Study on Preparation and Performance of Calcium Carbide Slag Foam for Coal Mine Disaster Reduction and CO2 Storage

In the process of coal mining, coal spontaneous combustion in the gob area poses serious threats to the safety of mine production. Besides, coal combustion also produces a large amount of greenhouse gas CO2, which triggers a series of ecological environment problems. In order to solve these two problems, the idea of mineralizing CO2 with the alkaline industrial waste calcium carbide slag and then sending the foams to the gob area for coal spontaneous combustion prevention was proposed in this study. First, the effects of calcium carbide slag foaming under the action of different types of foaming agents, including sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), polyoxyethylene fatty alcohol sodium sulfate (AES), and octyl decyl glucoside (APG0810), were tested and analyzed. Furthermore, the effects of water glass (WG), sodium alginate (SA), polyvinyl alcohol 1799 (PVA), cement, and silica micro-powder on the foam stability were analyzed by investigating the stability coefficient and drainage volume of calcium carbide slag foam. On this basis, the configuration scheme of calcium carbide slag foam with high efficiency and good stability was determined. The experimental results on CO2 mineralization and coal spontaneous combustion inhibition reveal that the prepared calcium carbide slag foam can rapidly absorb CO2. Moreover, after calcium carbide slag foam treatment, the spontaneous combustion tendency of the coal sample is significantly reduced.

Stability appraisement of the alumina-brine nanofluid in the presence of ionic and non-ionic disparents on the alumina nanoparticles surface as heat transfer fluids: Quantum mechanical study and Taguchi-optimized experimental analysis

Nanofluids stability is a key factor that influences the properties of nanofluids, and it is necessary to study and analyze the influential factors affecting the dispersion stability of nanofluids. Although numerous methods have been developed to evaluate the stability of nanofluids, stability assessment through quantum mechanical study has been largely overlooked and theoretical behaviors behind this enhancement remain to be elucidated. The present work focuses on achieving stabilization of Al2O3/brine nanofluids by adding three surfactants, including Sodium Dodecyl Sulfate (SDS), Triton X-100(TRI), and Cetyl pyridinium chloride (CPC) into the suspension of alumina nanoparticles, which surrounds nanoparticles through the particle surface. Quantum mechanical calculations performed to understand the stability conferred by the surfactants on the surface and heat transfer capability studied using Taguchi-optimized experimental analysis. An experimental investigation to quantify the combined effect of pH, volume fraction, sodium chloride concentration, and temperature, on the dispersion and thermal conductivity of Al2O3/brine nanofluid, revealed that the optimum value for the thermal conductivity is obtained mainly by controlling all parameters as well as surfactant type. The SDS and TRI surfactants on the surface of the alumina nanoparticles (NP) increased the particle dispersion and heat transfer as chain-like nanofluids, while the CPC enhanced the particle aggregation and formed flake-like nanofluids to form nanofluids with lower thermal conductivity. The DFT calculations revealed that the interaction energy between NP and SDS molecules was stronger over other surfactants. Further, NP/SDS system was the most stable configuration and had the most negative binding energy. The QTAIM analysis indicated that hydrogen bridge interactions favor the stability of the fluid-surfactant mixture as NP/SDS > NP/TRI > NP/CPC.