Dodecyl Sulfate Surfactant Research Articles

The Role of Surfactant on the Nanoparticle-Modifiers in Facilitating Scale Inhibition

Nanotechnology has been the prime approach over the last several decades including in scaling prevention. There has been a flurry of activity in incorporating nanoparticles (NPs) with scale inhibitors (SI) to help mitigate the scales’ growth at the early stage before it worsens. However, despite the increasing use of nanoparticles in industry, reservoir complexity such as salinity and heterogeneity have significantly impacted the nanoparticles' performance in the medium. The nanoparticles' repulsive forces are reduced when brine salinity is present, resulting in flocculation and coagulation of nanoparticles in suspension and phase separation. However, the stability and dispersion of nanoparticles may be improved by altering their characteristics by coating them with a surfactant for a particular application. This can be done by introducing a surfactant in the nanoparticle suspension. Herein, this paper aims to study the dispersion and stability of different types of NPs and their performance in Sodium Dodecyl Sulfate (SDS) surfactant solution. Results obtained proved that carbon-based NPs (graphene oxide (GO) and multi-walled carbon nanotube (MWCNT)) showed an excellent zeta potential measurement up to -116 mV when these NPs were dispersed in SDS solution. This surfactant has significantly improved the NPs stability by increasing electrostatic repulsion between the NPs while reducing the average size of agglomeration.

Hybrid Huff-n-Puff Process for Enhanced Oil Recovery: Integration of Surfactant Flooding with CO2 Oil Swelling

With increasing energy demands and depleting oil accessibility in reservoirs, the investigation of more effective enhanced oil recovery (EOR) methods for deep and tight reservoirs is imminent. This study investigates a novel hybrid EOR method, a synergistic approach of nonionic surfactant flooding with intermediate CO2-based oil swelling. This study is focused on the efficiency of surfactant flooding and low-pressure oil swelling in oil recovery. We conducted a fluorescence-based microscopic analysis in a microchannel to explore the effect of sodium dodecyl sulfate (SDS) surfactant on CO2 diffusion in Texas crude oil. Based on the change in emission intensity of oil, the results revealed that SDS enhanced CO2 diffusion at low pressure in oil, primarily due to SDS aggregation and reduced interfacial tension at the CO2 gas–oil interface. To validate the feasibility of our proposed EOR method, we adopted a ‘reservoir-on-a-chip’ approach, incorporating flooding tests in a polymethylmethacrylate (PMMA)-based micromodel. We estimated the cumulative oil recovery by comparing the results of two-stage surfactant flooding with intermediate CO2 swelling at different pressures. This novel hybrid approach test consisted of a three-stage sequence: an initial flooding stage, followed by intermediate CO2 swelling, and a second flooding stage. The results revealed an increase in cumulative oil recovery by nearly 10% upon a 2% (w/v) solution of SDS and water flooding compared to just water flooding. The results showed the visual phenomenon of oil imbibition during the surfactant flooding process. This innovative approach holds immense potential for future EOR processes, characterized by its unique combination of surfactant flooding and CO2 swelling, yielding higher oil recovery.

Unlocking the Catalytic Potential of Anionic Micelles: Insights into the Ce(IV)-Directed Phenylalanine Oxidation Kinetics in Asymmetric Hydrophobic Environments.

The oxidation kinetics of phenylalanine (Phe) by Ce(IV) have been examined in both the absence and presence of aqueous micellar media with asymmetric tails, specifically using sodium dodecyl sulfate (SDS) and sodium tetradecyl sulfate (STS) surfactants. The reaction progress was monitored by observing a decrease in absorbance using UV-vis spectroscopy. Interestingly, the kinetic profile revealed a consistent increase in the observed rate constant values as the concentration of the surfactant increased. The kinetic results have been analyzed by using numerous experimental studies, such as dynamic light scattering (DLS), zeta potential, 1H NMR analysis, FT-IR spectroscopy, conductometry, scanning electron microscopy (SEM), fluorometry, time-correlated single-photon counting (TCSPC), and transmission electron microscopy (TEM). Micellar aggregates maintain their spherical shape in the presence of the substrate, even at higher surfactant concentrations, as revealed by microstructural analysis. The substrate molecules are encapsulated to a greater extent in the inner micellar core of STS micelles on account of the more hydrophobic nature of STS surfactants. Therefore, in STS micellar media, fewer substrate molecules diffuse to the Stern layer compared to the SDS micellar medium, resulting in fewer molecules participating in the oxidative transformation reaction. As a result, the rate enhancement of oxidation kinetics is less pronounced in STS micelles than in SDS micelles. A plausible mechanism that aligns with the kinetic results has been highlighted, along with the interpretation of the Piszkiewicz model, to explain the observed catalytic effect of both micellar mediums.

Pengaplikasian Gelombang Elektromagnetik dan Nanopartikel Dielectric dalam Peningkatan Pemulihan Minyak

Enhanced oil recovery (EOR) is the recovery of oil remaining in a reservoir after primary and secondary recovery methods because it has been exhausted or is no longer economical, using thermal, chemical or mixed gas processes. Most conventional methods are not suitable for extracting oil from high temperature and high pressure (HTHP) reservoirs due to chemical degradation in the environment. Alternatively, electromagnetic (EM) energy is used as a thermal method to reduce oil viscosity in reservoirs, thereby increasing oil production. The application of nanotechnology in EOR is also investigated. In this study, we investigate a non-invasive method by injecting dielectric nanofluids into an oil reservoir simultaneously with electromagnetic irradiation, with the aim of increasing oil production by causing disruption at the oil-water interface. During core displacement tests, ZnO and Al2O3 nanofluids were shown to obtain higher amounts of residual oil than commercial sodium dodecyl sulfate (SDS) surfactant without EM irradiation. With EM irradiation, more residual oil is obtained compared to without irradiation. It has also been shown that changing the viscosity of dielectric nanofluids during electromagnetic irradiation increases sweep efficiency, resulting in higher oil recovery.

Optical properties, thermal conductivity, and viscosity of graphene-based nanofluids for solar collectors

Nanofluids based on graphene and water are promising working fluids for use in solar collectors. In this study, the optical properties, thermal conductivity, and viscosity of nanofluids based on water and graphene material, with the addition of sodium dodecyl sulfate (SDS) surfactant, were experimentally investigated. To obtain these nanofluids, graphene nanoparticles were synthesized using a plasma-chemical method and were later characterized by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The relationships between the concentrations of graphene in the nanofluids and the geometric parameters of vessels for effective absorption of solar energy were determined. The spectral dependences of the extinction coefficient for the nanofluids and for aqueous solutions with black aniline dye were compared. It was found that the application of graphene-based nanofluids is more effective than aqueous solutions based on aniline dye in photothermal energy conversion. Additionally, it was noted that the addition of graphene and the SDS surfactant does not lead to an increase in viscosity or a significant change in the thermal conductivity of the nanofluids for concentrations up to 0.02 wt%. The results showed that the studied nanofluids are effective absorbers of solar energy and, at the same time, do not require additional energy consumption to move through the solar harvesting circuit.

Upgrading Mixed Plastic Waste through Industrial Symbiosis: Pseudoductile Regenerated Cellulose Fiber-Reinforced Shredder Residue Composites.

The mechanical performance of mixed plastic waste from shredder residue is hindered by brittleness and catastrophic failure, limiting its potential applications. In this study, the mechanical properties of mixed plastic is enhanced by reinforcement with rayon fibers through a wet powder impregnation process to leverage the fiber's ductility and entanglement. However, mixed plastic remains poorly dispersed in water during the composite manufacturing, resulting in poorly consolidated composite, which further deteriorates the mechanical properties of mixed plastic from 1.5% strain-at-break to 0.7%. To address this issue, the addition of sodium dodecyl sulfate (SDS) surfactant is explored, where the optimal concentration is found beyond the critical micelle concentration at 10 mM. Lowering the surface tension of water and the adsorption of the SDS on the mixed plastic powder surface facilitated homogeneous dispersion of mixed plastic particles, resulting in well-consolidated rayon fiber-reinforced composites. The 30 wt % rayon fiber-reinforced mixed plastic composite prepared with SDS demonstrated a progressive failure behavior, exhibiting a strain-at-break of 8% and a remarkable 350% increase in impact strength compared to unreinforced mixed plastic. This approach provides a platform to overcome the inherent limitations of mixed plastic waste, offering waste-derived plastic alternatives and reducing the need for fossil-derived virgin materials for a wide range of noncritical applications.

Theoretical and experimental insights of two surfactants’ effects on SnIn electrodeposited coatings from ethaline

This work uses computational methodologies to investigate the behavior of Sn2+ and In3+ ions in deep eutectic solvent (DES) based on choline chloride and ethylene glycol (1ChCl:2EG, ethaline), under different conditions, such as different temperatures, ion ratios, and in the presence and absence of hexadecyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) surfactants. Furthermore, SnIn alloys were electrodeposited on Cu surfaces to analyze the effect of the investigated different conditions on the surface morphology and chemical composition of the electrodeposited coatings. Morphology and composition were analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDS). For computational approach, twelve Molecular Dynamics (MD) simulations were conducted using the GROMACS software. After MD simulations, Quantum Theory of Atoms in Molecules (QTAIM) properties were obtained. The results presented that In3+ showed a stronger affinity for Cl− than Sn2+ but it presents weaker and less stable interactions with OA (OA = oxygen of ethylene glycol-EG), particularly at higher temperatures. Electron Density and Electron Localization Function analysis indicated that In-Cl interactions are stronger and more polarized than other interactions. The Laplacian of Electron Density suggested an intermolecular nature for all interactions. The surfactant addition altered these interactions slightly, with CTAB reducing the density of Cl− around In3+ and SDS positively interacting with In3+ at 297 K and in a Sn2+:In3+ 1:1. As SDS interacted more with In3+ ions, the electrodeposition times varied between 4965 s and 75,541 s. SEM images revealed temperature- and potential-dependent changes in film morphology, changing from globular to smooth. CTAB and SDS additions led to uniform coating in Sn2+: In3+ solutions. For the 1:1 ratio at −1.4 V, there were no significant changes (between 75 and 77 %) in the percentage of Sn deposited with the use of surfactants at 297 K. At 343 K, the surfactant-free coating exhibited 69 % Sn, CTAB facilitated the Sn deposition, increasing the percentage to 92 %. At the same time, the presence of the SDS resulted in 79 % Sn. Similar behavior was obtained for −1.0 V. For 1:4 at −1.0 V at 297 K, 35 % of Sn was observed without surfactant, 29 % with CTAB, and 33 % with SDS. At 343 K, there was an increase in Sn content for 42 %, 49 % and 60 %, indicating the positive influence of the temperature, respectively. At −1.4 V, however, there was no observed influence on the Sn percentages without surfactant. With CTAB (between 29 and 34 %) at 297 and 343 K. At these temperatures, the addition of SDS promoted a higher content of Sn, increasing to 56 % and 43 %, respectively.

Impact of sodium dodecyl sulfate, cetyltrimethylammonium chloride and octyl glucoside surfactants on Aβ dimer conformations: A multiscale approach with MD simulations

This research investigates the effects of an anionic surfactant, sodium dodecyl sulfate (SDS), a cationic surfactant, cetyltrimethylammonium chloride (CTAC), and a nonionic surfactant, octyl glucoside (OG), on the conformation of beta-amyloid peptide dimer using molecular dynamics simulations to decipher the molecular mechanisms underlying these interactions and their effects on Aβ aggregation and toxicity in Alzheimer’s disease. Four simulation models were crafted, each housing a beta-amyloid peptide dimer, with three models incorporating 60 CTAC, 80 SDS, and 50 OG molecules to surpass the critical micelle concentration. Key findings include significant impacts of SDS, CTAC, and OG on the conformational dynamics of Aβ peptides as evidenced by RMSD and RMSF analyses. SDS notably increased the RMSF of residues 1–10 and had a pronounced effect on the C-termini, disrupting the critical salt bridge between aspartic acid 23 and lysine 28, associated with reduced peptide toxicity. Additionally, SDS disrupted more hydrogen bonds and hydrophobic interactions between the monomers of the Aβ dimer, predominantly in the C-termini region. Free Energy Landscape analysis revealed significant structural changes in the Aβ dimer in the presence of surfactants, with varying distributions of surfactant aggregates. Binding free energy calculations using MM-PBSA demonstrated that SDS exhibited the strongest binding affinity to the Aβ dimer, followed by CTAC and OG, with electrostatic forces playing a pivotal role. These outcomes align with experimental data, suggesting that SDS and CTAC, at concentrations above the CMC, diminish Aβ peptide aggregation and toxicity, whereas OG marginally increases toxicity.

Investigation of the synergistic effects of SiO2 and Al2O3 nanoparticles with SDS and CTAB surfactants on the stability and improving phase behavior of water-oil emulsions

The stability of emulsions is a significant challenge across various industries, including food, pharmaceutical, and petroleum. Surface-active agents utilized for enhanced oil recovery often exhibit inadequate performance under reservoir conditions with high salinity, presenting a critical barrier to effective emulsion stabilization. Furthermore, due to the extreme hydrophilic or hydrophobic nature of nanoparticles (NPs), they are not effective in stabilizing emulsions on their own. To address this limitation, a minimal quantity of surfactant was introduced into the NPs to improve their wettability and achieve dual wettability. This research has examined the synergistic effects of SiO₂ and Al₂O₃ NPs combined with sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) surfactants on water-oil emulsion stability. This approach enhances emulsion stability by combining the stabilizing effects of both the NPs and the surfactants, an aspect that has not been previously addressed in phase behavior studies through the examination of the interactions and surface behavior of surfactant-nanoparticle complexes at the oil-water interface. Several experiments, including phase behavior, FT-IR, zeta potential, contact angle, and interfacial tension (IFT) tests, were performed to evaluate the interaction of surfactants with NPs. The results demonstrate that combining NPs with surfactants, especially those with opposite charges, significantly reduces IFT to the order of 10−6 mN/m, which can overcome capillary pressure, and enhances optimal salinity levels even up to 75000 ppm. Interactions between CTAB-SiO₂ and SDS-Al₂O₃ notably improve the hydrophobicity of NPs, resulting in IFT reductions of 11.4 and 7 mN/m, respectively, compared to NPs alone.

Effect of ultrasonication time on the performance of carbon black water nanofluid in solar absorption

This research reveals an innovative way of finding the ultimate time of ultrasonication that offers photothermal capability across carbon black (CB) water nanofluids, a great contribution to the field of solar energy absorption and nanofluid technology. The samples were generated using a two-step procedure with varying ultrasonication periods employed, ranging from 15 to 120 minutes, in concentrations of 0.005 wt% CB nanoparticles and 0.005 wt% sodium dodecyl sulfate (SDS) surfactant. Thirty days after preparation visible observation and UV spectroscopy, scanning electron microscopy (SEM) images, and particle size distribution were used to confirm the samples’ stability. The stability properties results demonstrated the beneficial effects of ultrasonication on the dispersion properties of nanofluids. Ultrasonication of less than 30 minutes resulted in the early sedimentation of nanoparticles. According to the results, the investigated nanofluids have high photothermal conversion capability with ultrasonication time. According to the findings, 30 minutes is the “optimal” ultrasonic duration to maximize photothermal conversion efficiency.

Synergistic enhancement of oil recovery: Integrating anionic-nonionic surfactant mixtures, SiO2 nanoparticles, and polymer solutions for optimized crude oil extraction

Enhanced oil recovery (EOR) methods are essential for optimizing oil extraction from modern reservoirs. This research delved into the synergistic impact of combining anionic and nonionic surfactant mixtures with silica (SiO2) nanoparticles (NPs) in sodium chloride (NaCl) solutions, alongside the added enhancement of polymers, to improve crude oil recovery. The study comprehensively evaluated stability, rheological characteristics, interfacial tension (IFT) behavior, wettability alterations, and EOR experiments using mixtures of sodium dodecyl sulfate (SDS) and triton X-100 (TX-100) surfactants. Scenarios both with and without SiO2 NPs in a base solution containing 3000 ppm NaCl and 2000 ppm xanthan gum (XG) polymer were examined. Core flooding tests were carried out on San-Saba sandstone core specimens with low permeability. The stability tests and dynamic light scattering (DLS) analysis were performed to assess the stability of NPs in low saline-surfactant-polymer solution. It was observed that NPs significantly reduced the IFT between the test solutions and crude oil, with nanofluids exhibiting satisfactory stability at a 0.4 wt% SiO2 NPs concentration. Core flooding studies demonstrated a synergistic interaction between NPs and the binary surfactant-polymer mixture, resulting in substantially greater incremental recovery of oil in comparison with the case of using binary surfactant-polymer combination alone. The mechanisms contributing to EOR with nanofluids, such as IFT reduction and wettability alteration, were explored. Incorporating NPs at concentrations of 0.1, 0.2, and 0.4 wt% led to incremental oil recoveries of 4.01 %, 12.35 %, and 12.73 % of the original oil in place (OOIP), respectively, as opposed to the recovery achieved using only SDS + TX-100 + XG. Consequently, these findings advance the understanding of the potential application of SiO2 NPs in combination with the binary surfactant-polymer mixture as effective chemical EOR agents. Additionally, these insights aid in identifying suitable sandstone reservoirs for nanofluid application, contributing to the optimization of oil recovery strategies.

Performance evaluation of hybrid electrochemical oxidation and ultraviolet light-based persulfate process for the abatement of sodium dodecyl sulfate from wastewater.

The application of hybrid advanced oxidation processes (AOPs) is an efficacious way to remediate emerging contaminants from wastewater. In the present research work, a hybrid electrochemical oxidation and ultraviolet light-based persulfate activation processes (EO-UV/PS) were used to efficiently degrade sodium dodecyl sulfate (SDS) surfactant from synthetic and municipal wastewater. By operating the EO-UV/PS at optimum operating conditions at pH of 7.0, NaCl of 0.02M, current density of 6.4mA/cm2, persulfate dose of 2.5mM, and operating period of 180min, about 94.5 ± 2.8% of SDS (20mg/L) removal was achieved from synthetic wastewater. The abetment of SDS in both EO and UV/PS obeyed pseudo-first-order kinetics with a rate constant of 0.012 and 0.019min-1, respectively. Moreover, the economic analysis revealed 0.23 $ m-3order-1 as the operating cost for degrading SDS in EO-UV/PS. The degradation pathway experimentation suggested the generation of lauric acid by-product during SDS abatement. Besides, nearly 89.3 ± 2.9% of SDS and 58.7 ± 2.4% of total organic carbon reduction was also achieved from real municipal wastewater. Phytotoxicity test on Vigna radiata affirms the non-toxic nature of the EO-UV/PS effluent.

Temperature dependence of the near infrared absorption spectrum of single-wall carbon nanotubes dispersed by sodium dodecyl sulfate in aqueous solution: experiments and molecular dynamics study.

Single-wall carbon nanotubes (SWCNT) dispersed in water with the help of sodium dodecyl sulfate (SDS) surfactants exhibit a temperature dependent near infrared (NIR) exciton spectrum. Due to their biocompatibility and NIR spectrum falling within the transparent window for biological tissue, SWCNTs hold potential for sensing temperature inside cells. Here, we seek to elucidate the mechanism responsible for this temperature dependence, focusing on changes in the water coverage of the SWCNT as the surfactant structure changes with temperature. We compare optical absorption spectra in the UV-Vis-IR range and fully atomistic molecular dynamics (MD) simulations. The observed temperature dependence of the spectra for various SWCNTs may be attributed to changes in the dielectric environment and its impact on excitons. MD simulations reveal that the adsorbed SDS molecules effectively shield the SWCNT, with ~ 70% of water molecules removed from the first two adlayers; this coverage shows a modest temperature dependence. Although we are not able to directly demonstrate how this influences the NIR spectrum, this represents a potential pathway given the strong influence of the water environment on the excitons in SWCNTs. Optical absorption measurements were carried out in the UV-Vis-NIR range using a Varian Cary 5000 spectrophotometer in a temperature-controlled environment. PeakFit™ v. 4.06 was used as peak-fitting program in the spectral range 900-1400nm (890-1380meV) as a function of the temperature. Fully atomistic molecular dynamics simulations were conducted using the NAMD2 package. The CHARMM force field comprising two-body bond stretching, three-body angle deformation, four-body dihedral angle deformation, and nonbonded interactions (electrostatic and Lennard-Jones 6-16 potentials) was employed.

Green and sensitive detection of olopatadine in aqueous humor using a signal-on fluorimetric approach: GREEnness assessment.

Olopatadine (OLP) is widely utilized as an effective antihistaminic drug for alleviating ocular itching associated with allergic conjunctivitis. With its frequent usage in pharmacies, there arises a pressing need for a cost-effective, easily implementable, environmentally sustainable detection method with high sensitivity. This study presents a novel signal-on fluorimetric method for detecting OLP in both its pure form and aqueous humor. The proposed approach depends on enhancing the weak intrinsic fluorescence emission of OLP, achieving a remarkable increase of up to 680% compared to its intrinsic fluorescence. This enhancement is achieved by forming micelles around protonated OLP using an acetate buffer (pH 3.6) and incorporating a solution of sodium dodecyl sulfate (SDS) surfactant. A strong correlation (R = 0.9996) is observed between the concentration of OLP and fluorescence intensities ranging from 1.0 to 100.0 ng mL-1 with a limit of detection of 0.22 ng mL-1. This described method is successfully employed for quantifying OLP in both its powder form and pharmaceutical eye drops. Furthermore, it demonstrates robust performance in determining OLP in artificial aqueous humor with a percentage recovery of 99.05 ± 1.51, with minimal interference from matrix interferents. Moreover, the greenness of the described method was evaluated.

Mesoporous pineapple crown-derived activated carbon modified matrix for the detection of carbendazim in the presence of anionic surfactant

Carbon paste electrodes (CPEs) are commonly employed in electroanalysis because of their chemical stability, broad electrochemical window, low capacitive current, ease of fabrication, and surface renewability. Electrocatalysts can easily be embedded into CPEs to make them suitable for a variety of applications. Poor biowaste management presents a significant challenge in the agro-industry and agriculture due to the rapid decomposition of biowaste, driven by its high water content and limited biological stability, which leads to pest attraction and greenhouse gas emissions. Consequently, this green waste can be utilized for the development of electrocatalysts. Activated carbon (AC) has been utilized in progressive electrochemical applications as it exhibits high conductivity and porosity that help to enhance electrocatalytic activity. Herein, pineapple fruit crown (PC) peel-derived AC (PCAC) is utilized as the sensing material for the determination of fungicide, carbendazim (CBM). The synthesized material was characterized using SEM, FT-IR, XRD, EDX, AFM, CV and EIS. Besides, to enhance the surface properties, Sodium dodecyl sulfate (SDS) surfactant is used as a mediator in detecting CBM. The CV and SWV approaches were employed to assess the electrochemical response of the developed electrodes for the CBM determination. Under optimum experimental conditions, the SDS/PCAC/CPE exhibits low DLim and QLim values of 32.0 nM and 128.0 nM with considerable selectivity. Furthermore, the SDS/PCAC/CPE was employed in real-time analysis of CBM in spiked environmental samples, which showed satisfying recovery results. Moreover, the electrode showed good stability over multiple measurements, and these results demonstrate that SDS/PCAC/CPE is a promising sensor for CBM detection.

GO and surfactant assisted regulation of polyamide nanofiltration membranes for improved separation performance

Fabricating nanofiltration membranes with high water permeance and selectivity by tailoring the structure and morphology is crucial to efficient water purification. In this work, the fabrication of thin film nanocomposite (TFN) nanofiltration membranes by combining two methods, the surfactant-assembly interfacial polymerization (SARIP) and the addition of graphene oxide (GO) or ionic liquid functionalized graphene oxide (GO-IL) for the preparation of the selective PA layer on a novel porous substrate is reported. For the preparation of the porous substrate, mechanically robust, aromatic polyethers containing polar pyridine units (PDSPP) were chosen targeting to improved hydrophilicity and thus enhanced water permeability. The anionic sodium dodecyl sulfate (SDS) surfactant was used to regulate the interfacial polymerization thereby enabling the formation of dense PA layers with high cross-linking degree and consequently high salt rejections. On the other hand, the addition of GO/GO-IL nanosheets could impart hydrophilicity and antifouling properties. The novel porous PDSPP substrate was selected for the fabrication of TFN membranes due to its improved water permeability and superior salt rejection and increased hydrophilicity compared to commercial PSf substrate. The detailed study of the fabricated TFN membranes by ATR-FT-IR, SEM, AFM, XPS, contact angle measurements revealed the formation of polyamide selective layers with rougher surfaces, increased hydrophilicity and high cross-linking degrees (from 44 % to 94 %), resulted from the synergistic effect of SDS and GO incorporation. Moreover, the prepared TFN membranes exhibited high salt rejections while maintaining a moderate water permeability. In particular, the membrane containing the neat GO (TFNGO50) displayed excellent Na2SO4 and MgSO4 rejections (98.8 % and 99.5 %, respectively) while the NaCl rejection was 47.0 % and a water permeability value of 4.2 L m-2h−1 bar−1. The divalent salt rejections were among the highest values reported in the literature in comparison with commercial NF membranes and TFN membranes containing GO/functionalized GO. When GO-IL nanosheets were embedded in the PA layer, the water permeability was slightly improved while the salt rejections were significantly reduced compared to TFNGO50. Lastly, the incorporation of GO enhanced the anti-fouling properties of the prepared membranes due to increased hydrophilicity of the PA surface.

Surface modification for enhanced Anti‐Wetting properties of electrospun omniphobic membranes in membrane distillation

AbstractMembrane wetting caused by substances in the feed solution with low surface tension has posed serious issues for membrane distillation (MD). Omniphobic membranes could be helpful when dealing with this problem because they strongly repel liquids with a wide range of surface tensions. We fabricated electrospun omniphobic membranes containing PVDF‐TEOS‐PFDTMS, PVDF‐HFP‐TMOS‐PFDTMS, and PVDF‐HFP‐TEOS‐PFDTMS. All electrospun membranes have shown contact angles >90°, but the electrospun membrane containing PVDF‐HFP‐TEOS‐PFDTMS has shown super repellence with a contact angle >150° and maintains stable salt rejection and water flux in direct contact MD processes in the presence of sodium dodecyl sulfate surfactant (up to 0.3 mM). Furthermore, the morphology and crystallinity of the electrospun membranes were studied by scanning electron microscopy and Fourier‐transform infrared spectroscopy, and the percentage composition of elements was analyzed by x‐ray photoelectron spectroscopy. liquid entry pressure, mechanical strength, and the porosity of the electrospun omniphobic membranes were also studied.

A Janus membrane with silica nanoparticles interlayer for treating coal mine water via membrane distillation

The use of membrane distillation (MD) technology to treat coal mine water content has great potential, and the Janus membrane is very resistant to scaling and wetting during MD. In this work, SiO2 nanoparticles were electrostatically adsorbed onto the surface of a polyvinylidene fluoride (PVDF) membrane, followed by the construction of a polyamide (PA) layer through interfacial polymerization (IP). The intermediate layer of SiO2 nanoparticles can promote the enrichment of amine monomers during the subsequent IP process as well as slow its entry into the organic phase to regulate the PA layer. The addition of SiO2 nanoparticles was increased from 0 to 0.10 %, and the thickness of the polyamide layer was also reduced from 225.1 nm to 102.3 nm. Compared with the original membrane vapor flux of 40.9 ± 1.0LMH, the modified membrane vapor flux slightly increased to 46.2 ± 0.9LMH, but excessive SiO2 nanoparticles blocked the membrane pore, resulting in a decrease in flux. MD experiments show that the Janus membrane is wettability and scaling resistance when passing through the salt solution containing sodium dodecyl sulfate (SDS) surfactant or simulated wastewater as feed. At the same time, the interface thermodynamics of the simulated wastewater and the membrane are calculated to understand the anti-scaling mechanism of the membrane, offering a theoretical foundation for the application of real mine water.

Energy storage density enhancement in paraffin phase change material emulsions: A comparative study with two different base fluids

This investigation examined the thermophysical properties of emulsions comprising paraffin 56/58 phase change material (PCM) dispersed in water and ethylene glycol (60 wt%) aqueous solution to optimize energy storage density for low-temperature thermal applications. Dynamic Light Scattering analysis revealed a uniform dispersion of paraffin 56/58 PCM droplets in the basefluids, with an average diameter of approximately 150 nm achieved by incorporating sodium dodecyl sulfate surfactant. The latent heat of fusion for emulsions containing paraffin 56/58 PCM in ethylene glycol (60 wt%) exhibited values of 37.5/41.7, 58.5/63.9, 73.8/75.43, and 93/90.25 J/g for concentrations of 20, 30, 40, and 50 wt%, respectively, during melting/solidification phases. Furthermore, the highest energy storage densities of 306.95 and 361.3 kJ/kg were attained at a PCM concentration of 50 wt% in ethylene glycol (60 wt%) and water-based emulsions, respectively, surpassing those of similar working fluids. It is also indicated that water-based paraffin 56/58 PCMs offer superior energy storage density. However, under severe operating conditions such as extreme temperatures, ethylene glycol (60 wt%) based paraffin 56/58 emulsions demonstrate greater suitability, as the evaporation and freezing points of the basefluid can be adjusted by modulating the ethylene glycol concentration ratio.

Waste to fuel: A detailed combustion, performance, and emission characteristics of a CI engine fuelled with sustainable fish waste management augmentation with alcohols and nanoparticles

All over the world, 130 million tonnes of fish waste have been generated per annum. Improper disposal of such waste leads to environmental pollution, habitat degradation, oxygen depletion, spread of pathogens, parasites, and diseases. From this point of view, this research motivated to benefit from such fish waste by converting an alternative fuel along with various additives for diesel engines. Fish wastes gathered from the fish market are used as feedstock for producing fish waste biodiesel (FWBD) through the transesterification process. The derived fish waste biodiesel (FWBD) 60 %, 20 % diesel, and 20 % n-butanol (C4H9OH) by volume were blended (60FWBD+20Bu+20D) to form the test fuels. Then the fuel blends were used to convert two nano fuels by separately adding zinc oxide and graphene nanoparticles of 100 ppm along with sodium dodecyl sulphate surfactant, and the nanoparticles-added test fuels were exposed to sound waves of 50 kHz in an ultrasonicator for 1 h. These fuels were characterized to derive and ensure the fuel properties for diesel engines and tested such fuels in a 5.2 kW CI engine to do a comparative study. The experiments were conducted at the constant engine speed of 1500 rpm, and varying engine loads from 25 % to 100 % with intervals of 25 %. When the fish waste biodiesel was added to diesel fuel, the engine performance worsened in a given engine load, but it started to improve with the existence of nanoparticles. Compared to 60FWBD+20Bu+20D, graphene-based nano fuel blend recorded 1.99 % higher BTE, but 15.03 % higher NOx. Similarly, compared to 60FWBD+20Bu+20D, zinc oxide-based nano fuel blends recorded 6.75 % higher BTE and reduced NOx, CO, HC, and smoke emissions by 29.97 %, 15.98 %, 22.0 %, and 16.03 % respectively. In conclusion, the present research reveals that fish wastes can be used in diesel engines without any modification on the vehicular system, and this may contribute to both slowing down the rate of depletion of fossil reserves and the waste management of the fish wastes from nature in a useful way.