Surfactant Water Research Articles

Spontaneous Imbibition of Capillaries under the End Effect and Wetting Hysteresis.

The phenomenon of spontaneous imbibition is widely present in the development process of tight oil/gas reservoirs. To further explore the spontaneous imbibition behavior of capillary tubes to provide theoretical and methodological references for the study of microscopic porous media imbibition phenomena, the capillaries that can be observed with the naked eye on the order of 10–100 μm were selected as research objects. Based on the theory of interface chemistry, the capillary end effect, and wetting hysteresis, the influence of the additional pressures generated by the two-phase interface on the spontaneous absorption of the horizontal capillary was studied. Some of the capillaries were processed for wettability, and then the water wettability of different capillaries was measured by the introduced concept, which is the conversion height of the self-absorption phase in the capillary. The capillaries were horizontally placed in the liquid for a spontaneous imbibition experiment, and the air–liquid two-phase menisci behavior was observed at the same time, and then the influence of water wettability, surfactant, and capillary diameter on spontaneous imbibition was discussed. It was found that in the equal diameter capillaries, the spontaneous air–liquid imbibition behavior of capillary tubes with different water wetting properties is different in sensitivity to surfactants and tube diameters; when surfactants are used to improve capillary water wettability to increase spontaneous imbibition efficiency, the initial water wettability of the capillary and the comprehensive changes in the capillary pressure caused by interfacial tension should be considered.

Arthrospira sp. mediated bioremediation of gray water in ceramic membrane based photobioreactor: process optimization by response surface methodology

Direct discharge of raw domestic sewage enriched with nitrogenous and phosphorous compounds into the water bodies causes eutrophication and other environmental hazards with detrimental impacts on public and ecosystem health. The present study focuses on phycoremediation of gray water with Arthrospira sp. using an innovative hydrophobic ceramic membrane-based photobioreactor system integrated with CO2 biofixation and biodiesel production, aiming for green technology development. Surfactant and oil-rich gray water collected from the domestic kitchen was used wherein, chloride, sulfate, and surfactant concentrations were statistically optimized using response surface methodology (RSM), considering maximum microalgal growth rate as a response for the design. Ideal concentrations (mg/L) of working parameters were found to be 7.91 (sulfate), 880.49 (chloride), and 144.02 (surfactant), respectively to achieve optimum growth rate of 0.43 gdwt/L/day. Enhancement of growth rate of targeted microalgae by 150% with suitable CO2 (19.5%) supply and illumination in the photobioreactor affirms its efficient operation. Additionally, harvested microalgal biomass obtained from the process showed a biodiesel content of around 5.33% (dry weight). The microalgal treatment enabled about 96.82, 87.5, and 99.8% reductions in BOD, COD, and TOC, respectively, indicating the potential of the process in pollutant assimilation and recycling of such wastewater along with value-added product generation.

A new strategy to dissolve long-chain surfactants in water at low temperatures

Choline alkoxylates were synthesised and used to solubilise long-chain surfactants under ambient conditions. In this way, so far underutilised natural feedstocks could be leveraged for the design of sustainable and efficient cleaning formulations.

Micellization and thermodynamics study of ester functionalized picoline-based ionic liquid surfactants in water.

A novel series of picoline-based ionic liquid surfactants, N-alkyoxycarbonyl-3-picoline bromides [CnEmpy][Br] (n = 10, 12, 14), have been synthesized. The thermal stability, aggregation behavior and surface activity of the synthetic ionic liquid surfactants were investigated systematically though a series of methods, such as thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tensiometry and conductivity. The thermodynamics of micellization of the ionic liquid surfactants solution were studied by using the conductivity method in the temperature range 278.15–318.15 K. The surface activity parameters and thermodynamics parameters were derived, respectively. The enthalpy–entropy compensation effect was further discussed by using relative thermodynamics parameters. It was found that the [CnEmpy][Br] have moderate surface activity, and their critical micelle concentration (CMC) decreased with the ester-functionalized chain length and exhibited a U-shape with temperature. The calculation results of the thermodynamic parameters showed that the micellization processes of [CnEmpy][Br] were spontaneous, endothermic at low temperature and exothermic at higher temperature.

Highly Efficient Degradation of Pfas and Other Surfactants in Water with Atmospheric Radial Plasma (Rap) Discharge

Highly Efficient Degradation of Pfas and Other Surfactants in Water with Atmospheric Radial Plasma (Rap) Discharge

Method Validation for Simultaneous Analysis of Surfactants in Tap Water Using Solid-phase Extraction-LC/MS

Method Validation for Simultaneous Analysis of Surfactants in Tap Water Using Solid-phase Extraction-LC/MS

Rheological study of CO2 foamed chelating stimulation fluids under harsh reservoir conditions

Foamed acid is usually an HCl acid-based stimulation fluid applied to carbonate reservoirs. However, this study investigates the rheology of a CO2 foamed chelating agent, L-glutamic acid-N, N-diacetic acid (GLDA), that acts as less corrosive, environmentally friendly, and more stable foamed acid. Foam rheometer and analyzer were used to study the foam rheology, quality, size and structure, and half-life. Five different commercial surfactants with different chemical structures were investigated. The study was conducted at 100 °C, 1000 psi, 3.5 pH level, and various water salinity, resembling harsh reservoir conditions. The general trend showed that the higher the water salinity, the higher the effective viscosity. It also showed that the chelating agent improved the effective viscosity of the high total dissolved solids (TDS) water samples. The highest viscosity (76 mPa⋅s) was attained by mixing GLDA with a cationic alkyl diamine derivative surfactant in formation water at a 100 1/s shear rate. The prolonged constant shear rate experiments revealed that some formulations are stable for more than 8 h. The study revealed that higher surfactant concentrations did not result in improved performance. For the first time, the study reveals that chelating agents could be used as a stable stimulation foamed fluid at harsh reservoir conditions.

Separation performance of ultrafiltration during the treatment of algae-laden water in the presence of an anionic surfactant

Ultrafiltration was demonstrated to be an effective and efficient method to treat algae-laden water. However, the presence of compounds such as surfactants can act as a stimulus for algae outbreak and change the characteristics of algae cells and derived organics. Therefore, it is necessary to investigate the filtration and separation performance of ultrafiltration during the treatment of algae-laden water in the presence of anionic surfactants (the most widely used surfactant type). In this study, sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (LAS) were employed respectively to simulate the presence of a low concentration of an anionic surfactant in eutrophicated water. It was found that surfactants present in natural waters could enhance the hydrophilicity of the algae interface and the stability of the algae-laden water system with mitigated algae aggregation. During the initial filtration process, membrane fouling was aggravated related to the more serious pore blocking induced by the present SDS or LAS; however, during the next stage, membrane fouling was alleviated due to the formation of a looser cake layer in the presence of SDS or LAS. The pore blocking at the earlier stage contributes more to the decrease of total flux when surfactants are involved. Furthermore, the disinfection byproduct formation potential was reduced with SDS or LAS mainly due to the degradation of free available chlorine by the surfactants. While the concentration of algal toxins was ascended in the ultrafiltration effluent, which indicates that the separation performance was highly impacted by the presence of anionic surfactant.

Analysis on the Formation of Water/Oil Emulsion System of High Water-cut Crude Oil and Its Profile and Flooding Effect

In view of the limitations of modulated flooding technology in low permeability high temperature reservoirs, the water/oil emulsion with the effect of expanding sweep volume and its influence on the effect of modulated flooding were studied. Under the condition of high water content (80% water content), the dispersion system formed by emulsifier 55# and crude oil is mainly water/oil emulsion. At the same time, the influence of surfactant type, water content, temperature and other factors on the formation of water/oil emulsion system was investigated, and the influence of emulsion properties on the effect of displacement was analyzed. The low permeability core experiment shows that the emulsifier with the effect of expanding sweep volume can improve the oil recovery by 17.93% on the basis of water flooding, which is obviously higher than that of polymer flooding. At the same time, emulsifier has good temperature resistance, which is of great significance for enhancing oil recovery in high temperature and low permeability water drive reservoirs.

EFFECT OF THE TYPE AND CONCENTRATION OF MIXTURE SURFACTANT AND PROTEIN ON THE STABILITY OF NUTMEG OIL NANOEMULSION

The application of essential oil is limited due to its low solubility, especially in water-based products. Using a nanoemulsion as a carrier is one way to overcome this disadvantage. Nanoemulsion is composed of the water phase, oil phase, surfactant, and cosurfactant. The use of a mixture of surfactants can affect the stability of the nanoemulsion. The aim of this research, therefore, is to find out the effect of the type and concentration of the mixture of surfactant and protein on the stability of nutmeg oil nanoemulsion. A Randomized Block Design (RBD) Factorial with 2 variables, which included the type (gelatin-span 60, gelatin-tween 80, span 60-tween 80) and concentration (20, 25, and 30 percent) of mixed surfactants and protein counts from the total oil was used with 1:1 comparison. The result showed there was a span of 60-tween 80 produced a nanoemulsion with the finest stability considering its creaming index value of 0%, the small droplet size of 95.88 nm, zeta potential value higher than -30 mV, and good uniformity less than 0.1 in polydispersity index. Gelatin-span 60 failed to produce an emulsion with nano-size due to its 2300.55 nm droplet size, zeta potential value less than 30 mV, and its uniformity in polydispersity index of more than 0.1.

Development of shoe insert for Diabetic Foot Ulcer Patients in case of Ethiopia

Foot ulcer is mainly developing due to diabetic disease. It is an open sore on the foot. The aim of this research is to develop polyurethane memory foam in sock/shoe insert in Ethiopia by replacing costly material silicon surfactant by locally available and affordable input materials castor oil as surfactant and tap water instead of distilled water for the diabetic foot ulcer patients. Under this research, it was able to prove the severity of foot ulcer in Ethiopia and enhance the high demand of orthotic appliance. Three memory foams in sock with different surfactant ratios were manufacture at AMAGA P.L.C foam factory, Bahir Dar Ethiopia using standard Polyols and diisocynates. The shoe insert /in sock was prepared by using materials used in the factory to prepare polyurethane (PU) memory foam mattress with 5g, 9.5 g and 10.36g of castor oil surfactant amount as a new replaced material instead of costly silicon surfactant from the three the first (castor oil 5g is not form a foam and hence no further investigation is conducted on it). Physical properties such as thickness, density, hardness, compression set, water absorption and abrasion resistance of developed in sock were tested. Further the new developed in sock was compared with that of existed commercial polyurethane in sock and the SATRA standards. The new developed in sock has showed an equivalent mechanical property with the standard.

Unraveling the Kinetics and Mechanism of Surfactant-Induced Wetting in Membrane Distillation: An In Situ Observation with Optical Coherence Tomography.

In this study, we performed a direct contact membrane distillation and successfully demonstrated the non-invasive imaging of surfactant-induced wetting using optical coherence tomography. This method enabled us to investigate the wetting kinetics, which was found to follow a "three-region" relationship between the wetting rate and surfactant concentration: the (i) nonwetted region, (ii) concentration-dependent region, and (iii) concentration-independent region at low, intermediate, and high surfactant concentrations, respectively. This wetting behavior was explained by the "autophilic effect", i.e., the wetting was caused by the transfer of surfactants from the water-vapor interface to the unwetted membrane and rendered this membrane hydrophilic, and then the wetting frontier moved forward under capillary forces. At region-(i), the surfactant concentration in the water-vapor interface (Clv) was too low to make the unwetted membrane sufficiently hydrophilic; thereby, the membrane could not be wetted. At region-(ii), due to the fast adsorption of the surfactant on the newly wetted membrane, the wetting rate was determined by the advection/diffusion of surfactants from the feed stream. Consequently, the wetting rate increased with the increases in the water flux and surfactant concentration. At region-(iii), the advection/diffusion provided excess surfactants for adsorption, and thus Clv reached its upper limit (maximum surface excess) and the wetting rate leveled off.

Influence of nanoparticles on rheological properties and foam properties of mixed solutions of fluorocarbon and hydrocarbon surfactants

Mixed dispersions of silica nanoparticles (NPs), nonionic hydrocarbon surfactant (APG0810), and fluorocarbon surfactant (FS-50) in water were prepared. The molecular interactions, rheological properties, and foam properties of the mixed dispersions were experimentally investigated. The enhancement mechanism of the NPs on the foam stability of the mixture of APG0810/FS-50 was analyzed. Results showed that the NPs strongly influenced the rheological and foam properties of the mixed solutions. The viscosity of the APG0810/FS-50/NPs dispersions varied linearly with the shear rate, and the viscoelastic modulus of the dispersions increased with increasing NP concentration. With the increase of NP concentration, the foam stability was enhanced but the foaming properties was weakened. Foam drainage, foam coarsening, and foam mechanical strength were apparently enhanced because of the aggregation of a large amount of NPs in the plateau borders. This research gives theoretical guidance for the application of NPs in fire extinguishing agent.

Ligno Sulphonate [SLS] Laboratory Testing For the Recovery of Residual Oil at Ledok Oil Field

Fossil energy much still needed and exhalated in demand every year on industrial sector, household, and transportation in Indonesia. In the other hand, oil gas production has decreases as many of oil and gas reservoirs have saturated with water breakthrough. Therefore, Enhance Oil Recovery [EOR] as one of proposed solution is adopted to optimize the remaining reserves of oil wells exploitation, especially from mature field that has lesser production capacity towards production problems. Ledok field Cepu district, Central Java Indonesia has many mature wells that produce liquids with its water cut higher than 90 %. The objective of study is to determine which variables that are involve on black liquor or Sodium Ligno Sulphonate [SLS] application as surfactant for EOR on laboratory measurements. Core flooding measurements had been developed and measured. Crude, formation water, and SLS surfactant were injected into the artificial cores. FTIR test show appearance of Sulphonate and Ether alkyl in its composition. Preliminary results show the surfactant has optimum performance to recover oil up to 79% with IFT value 10-1 dyne/cm.

Experimental study of foam propagation and stability in highly permeable porous media under lateral water flow: Diverting groundwater for application to soil remediation

Foam propagation and stability in highly permeable porous media, encountered in soil pollution applications, are still challenging. Here, we investigated the application of foam for blocking the aquifer to divert the flow from a contaminated zone and, therefore, ease the remediation treatments. The main aim was to better understand the critical parameters when the foam is injected into a highly permeable aquifer with high groundwater flow velocity (up to 10 m/day). A decimetric-scale 2D tank experimental setup filled with 1 mm glass beads was used. The front part of the 2D tank was made of transparent glass to photograph the foam flow using the light-reflected method. The water flow was generated horizontally through injection and pumping points on the sides of the tank. The pre-generated foam was injected at the bottom center of the tank. Water streamlines (using dye tracing) and water saturation were investigated using image interpretation. Results show that 100% of the water flow was diverted during the injection of the foam. Foam stability in porous media depends significantly on the horizontal water flow rate. Recirculating water containing the surfactant increases foam stability. The main mechanism of destruction was identified as the dilution of the surfactant in water. However, the head-loss measurements showed that despite foam destruction, the relative permeability of the water phase in the media remained quite low. Injection of foam increases the radius of gas propagation, thanks to foam's high viscosity, compared to a pure gas injection case. These results are new highlights on the efficiency of foam as a blocking agent, showing that it can also serve as a means for gas transport more efficiently in porous media, especially for soil remediation applications.

PH-responsive worm-based viscoelastic fluid formed by a dynamic covalent gemini surfactant

Responsive viscoelastic fluids based on wormlike micelles have attracted significant interest both in laboratory research and industrial applications due to their intelligent rheological response. However, pH-responsive worm-based viscoelastic fluids based on a dynamic imine surfactant remain a significant challenge. Herein, a novel worm-based viscoelastic fluid that can response to pH was fabricated utilizing a dynamic covalent gemini surfactant featuring a imine-type spacer. This unique gemini imine surfactant could be expediently obtained in situ by simply mixing an aldehyde-containing cationic surfactant (HOBAB) and hexyldiamine (C6DA) in water at a stoichiometric ratio of 2:1. Rheology and cryo-TEM experiments both demonstrated the formation of elongated wormlike micelles, responsible for the viscoelastic fluid. Because of its pH-sensitivity, the gemini imine surfactant could be damaged under acidic conditions and reformed under alkali conditions. Consequently, the solution of HOBAB and C6DA can be switched between a water-like fluid and worm-based viscoelastic fluid. Changing the precursors, such as the alkyldiamine or length of the hydrophobic chain, can also tailor the worm-based viscoelastic fluid based on a dynamic imine surfactant. For the C2-C6 spacer precursors, the viscoelastic fluid mainly resulted from the WLMs-based network, but for the C8 spacer precursor, it mainly originated from the densely packed of vesicles.

Structure and composition of mixed micelles formed by nonionic block copolymers and ionic surfactants in water determined by small-angle neutron scattering with contrast variation

HypothesisComplex fluids comprising polymers and surfactants exhibit interesting properties which depend on the overall composition and solvent quality. The ultimate determinants of the macroscopic properties are the nano-scale association domains. Hence it is important to ascertain the structure and composition of the domains, and how they respond to the overall composition. ExperimentsThe structure and composition of mixed micelles formed in aqueous solution between poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers (Pluronics or Poloxamers) and the ionic surfactant sodium dodecylsulfate (SDS) are determined from an analysis of small-angle neutron scattering (SANS) intensity data obtained at different contrasts. Different polymers and concentrations have been probed. FindingsThe SDS + Pluronic mixed micelles include polymer and some water in the micelle core that is formed primarily by alkyl chains. This is different than what was previously reported, but is consistent with a variety of experimental observations. This is the first report on the structure of SDS + Pluronic P123 (EO19PO69EO19) assemblies. The effects on the mixed micelle structure and composition of the surfactant concentration and the polymer hydrophobicity are discussed here in the context of interactions between the different components.

Role of chain length and electrolyte on the micellization of anionic fluorinated surfactants in water

The micellization of ionic surfactants in aqueous media reflects a balance between the hydrophobic attraction of surfactant tails and the electrostatic repulsion of surfactant headgroups. We investigate here the effect on surfactant micellization of the hydrophobic chain length and electrolyte composition, by focusing on the fluorinated surfactants sodium perfluorohexanoate (NaPFHx) and sodium perfluorooctanoate (NaPFO) in aqueous solution without/with NaCl, and analyzing experimental data from surface tension, pyrene fluorescence, small-angle neutron scattering (SANS), and viscosity techniques. The CMC of NaPFHx in water was 200 mM, much higher than that of NaPFO, 30 mM, due to the additional two -CF2- groups of the latter. Upon addition of 0.25 M NaCl to the aqueous solution, the CMC of NaPFHx and NaPFO decreased by about 50% and 80%, respectively. The NaPFHx and NaPFO micelles are both ellipsoid in shape. NaPFHx forms smaller micelles compared to NaPFO: the association number for NaPFHx in D2O was 15 compared to 25 for NaPFO. Upon NaCl addition, the micelle shape became more elongated. This is the first report on the NaPFHx micelle structure. The information presented here supports the re-formulation and replacement of long-chain fluorinated surfactants with relatively safer long-chain surfactants.

One‐step synthesis of polymer dispersions with large narrow‐size‐distribution particles via heterophase polymerization in the presence of surface‐active water‐insoluble organosilicon macromers

AbstractPolymerizable water‐insoluble surface‐active macromers (SAMs), namely α,ω‐divinylpolydimethylsiloxane (DVPDMS), α,ω‐dipropylmethacrylatepolydimethylsiloxane (DPMPDMS) and α,ω‐pair(vinylbenzyl)polydimethylsiloxane (PVBPDMS), were synthesized and characterized using NMR. The colloidal‐chemical properties of the synthesized compounds were studied in comparison with non‐polymerizable polydimethylsiloxane. Using DVPDMS, DPMPDMS and PVBPDMS as copolymerizable emulsifiers, polystyrene and poly(methyl methacrylate) suspensions with large particles, narrow particle size distribution and with the absence of the residual surfactant in the waste water were obtained. It is shown that in the presence of DPMPDMS it is possible to obtain polymer suspensions with an average particle diameter of 1.6 μm. The proposed mechanism of the effects of the SAMs on the polymerization is based on the copolymerization with the main monomers in the monomer–polymer particle interphases which results in stabilization of the particle protective layers from early stages of the reaction. © 2021 Society of Chemical Industry

Micellar Catalysis: Visible‐Light Mediated Imidazo[1,2‐a]pyridine C—H Amination with N‐Aminopyridinium Salt Accelerated by Surfactant in Water

Main observation and conclusionA light‐promoted metal‐free protocol for the amination of imidazo[1,2‐a]pyridines with N‐aminopyridinium salt by the assistance of surfactants in water was reported, charactering mild and environmentally benign conditions, as well as great functional group tolerance. Micelles with negatively charged polar surface and hydrophobic core formed from sodium dodecyl sulfate serve as an ideal medium for visible‐light mediated radical reaction of cationic pyridine salt and imidazo[1,2‐a]pyridine in aqueous phase. The electrostatic interaction between positively charged N‐aminopyridinium and negatively charged surface of micelles is of great significance in this method.